Erosion Rate Study of Yardang Landforms Downstream of the Peacock River

Erosion Rate Study of Yardang Landforms Downstream of the Peacock River | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Erosion Rate Study of Yardang Landforms Downstream of the Peacock River Bai Youliang, Bo Li, Jinhong Rong, Hui Chen, Jinming Zheng, Jianshe Liu, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4927891/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Yardang landforms are significant subjects for research concerning climate change, geomorphological evolution, aeolian sand management, and ecosystem stability. The Lop Nur area, as the origin of the term "Yardang," has seen limited in-depth studies of its Yardang landform development and evolution. This paper integrates field surveys of Yardang landforms downstream of the Peacock River, 14C dating, optical dating, large-scale topographic mapping, and 3D laser scanning to investigate the erosion rates of these landforms. The key findings are as follows: ( 1 ) The average erosion rate of the Yardang landforms downstream of the Peacock River since 565 ± 25a BP is between 1.54 and 0.00 cm/year, with 88.32% of the area experiencing rates between 1.37 and 0.55 cm/year; currently, 72% of the area is undergoing erosion at rates ranging from 3.0 to 0.0 cm/year, with 17.30% of that area experiencing rates between 1.2 and 0.6 cm/year, and 38.70% experiencing less than 0.6 cm/year. The current erosion rates are significantly lower than historical averages, with some low-lying areas currently accumulating sediment; ( 2 ) A comprehensive research method has been established, based on the developmental patterns of Yardang landforms for historical average erosion rates and on 3D laser scanning for current erosion rates. This method has enabled the determination of both historical average and current erosion rates in the Yardang area downstream of the Peacock River. The establishment of a permanent erosion monitoring network in this area will support long-term tracking and monitoring of Yardang landform development and provide a foundation for research on climate change, geomorphological evolution, aeolian sand management, and ecosystem stability in the region; ( 3 ) The study systematically determined the deposition time, exposure time, and erosion time related to Yardang development downstream of the Peacock River, which are 2.8 ± 0.3ka BP, 1900a BP, and 565 ± 25a BP, respectively. These findings are crucial for understanding the evolution of Yardang landforms in the area and will facilitate the advancement of numerical simulations towards long-term geomorphological evolution research. The study provides insights into the timing of Yardang landform development, historical and current erosion rates, and establishes a comprehensive research methodology, which is essential for quantitative research on the formation and development environment of Yardang landforms downstream of the Peacock River. Yardang Landforms Erosion Rate 3D Laser Scanning Chronology Peacock River Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Introduction The term "Yardang" was first proposed by the Swedish explorer Sven Hedin during his field investigation in the Lop Nur area of Eastern Xinjiang, and it has since become a hot topic of research. Hedin believed that the Yardangs in the Lop Nur area were formed around 1500 years ago, with a current height of 6 meters, thus deducing that the rate of wind erosion in this area is 4 mm/year（Hedin S A., 1904）.while investigating the Yardang landforms in the Loulan area, used the cultural layers inside and outside the ancient city as a standard for calculating the rate of wind erosion, suggesting that the maximum erosion rate in this area is 4.7 mm/year, the minimum is 2.4 mm/year, and the average is 3.6 mm/year（Xia Xuncheng.,1987）. Lin Guiquan et al. analyzed the morphological characteristics and genesis of the Baidun Yardang through Google Earth imagery data（Lin Guiquan et al.,2022 ）. Pan Dadong et al. used high-resolution remote sensing imagery from Google Earth to obtain the morphological characteristics of 1200 individual Yardangs in four areas of Lop Nur, and evaluated the main dynamics of Yardang development in Lop Nur. Lin Yongchong et al（Pan Dadong et al.,2022）. conducted studies on the differential erosion characteristics of Yardang landforms and the impact of surface weathering on the development of Yardang landforms in the Loulan area of Xinjiang, suggesting that the development of Yardang landforms in the Loulan area is mainly influenced by wind erosion, but the regional lithological characteristics and gravitational effects have a particularly significant impact on the erosion of Loulan Yardangs. In addition, weathering effects influenced by a small amount of precipitation, diurnal temperature difference, and strong solar radiation have an important impact on the development of Yardang landforms in the Loulan area（Lin Yongchong et al.,2017；Lin Yongchong et al.,2018；）. Xia Xuncheng proposed that the formation process of Yardang landforms in the Lop Nur area includes four stages: surface destruction, rudimentary Yardang, Yardang formation, and Yardang disappearance（Xia Xuncheng.,1987）. Research on the Yardang landforms in the northwestern part of China, the Lop Nur area, has found that there is a moderate positive correlation between the length and thickness of the collapsed blocks, and the ratio between the two is mostly between 1.2 and 2.5（Lin Yongchong et al.,2017；Lin, Y. et al.,2018 ）. Song Haoze et al. calculated the average wind erosion rate in the vicinity of the Loulan site after 0.5 ka BP to be 6.2 mm/year based on stratigraphic age and Yardang height data（Song Haoze et al.,2021）. Compared with the research progress of Yardang landforms in the Lop Nur area, the research results on Yardang in the Qaidam Basin have obvious advantages, such as a large number of statistical results in the quantitative analysis of Yardang morphological parameters（Lin, Y. et al.,2018；Li Jiyan et al.,2011；Li, J. et al,2016b ）, and the exploration of its evolutionary process（ Halimov, et al.,1989；Wang, J.et al., 2018a,）and influencing factors（Hu, C. et al.,2017）on the basis of morphological classification; in terms of Yardang wind erosion and regional evolution, methods such as geological profiles and 10 Be numerical simulation have been used to test the rate of wind erosion and analyze the process（Kapp, P.et al.,2011；Rohrmann et al.,2013； Wu, L.et al.,2019；Wang, Z.T.et al.,2013）and based on the study of wind erosion rate, the contribution of the Qaidam Basin to the sediment source of the Loess Plateau has been analyzed（Rohrmann et al.,2013；Heermance et al.,2013）. Yardang landforms, as an important research subject involving climate change, geomorphological evolution, wind and sand control, and ecosystem stability, in addition, the Lop Nur area with large-scale Yardang landforms is also a microcosm of environmental changes in the arid northwest region, therefore, in-depth research and system integration of Yardang landforms in the Lop Nur area is imperative. In terms of the study of the formation and development environment of Yardang landforms, foreign studies mainly reflect the wind erosion of sedimentary rocks through the observation of Yardang wind erosion rates（Ward A W et al.,1984； Goudie A S et al.,1999；Al-Dousari A M et al.,2009）. At the same time, the determination of wind erosion rates is the focus of quantitative research on wind erosion environmental characteristics, which is conducive to analyzing the migration of materials in the wind transport process（Ding Zhaojing.,2020）. Given the current progress in Yardang geomorphological chronology research（Vincent P et al.,2006；Al-Dousari A M et al.,2009；Niu Qinghe et al.,2013；Yanjie Wang et al.,2016； Kangkang Li et al.,2021）and the widespread application of three-dimensional laser scanning technology（ Xu Z J et al.,2021；O. P. Yermolaev et al.,2018；Jennifer Telling et al.,2017；Xijiang Chen et al.,2020；Stefano Fabbri et al.,2017）, it has laid the foundation for obtaining the historical average erosion rate and current erosion rate of Yardang landforms in the downstream of the Kune River. 1 Study Area Overview The study area is located in the Lop Nur area in the eastern part of the Tarim Basin in Xinjiang, Asia. The terrain of the area is flat and has long been the convergence center of the Tarim Basin. In ancient times, the area once reached 20,000 square kilometers, and even in 1958, it was still 3,000 square kilometers. There were rivers such as the Tarim River, the Kune River, and the Che'erqin River that flowed into the area, as well as the Milan River, Ruoqiang River, and Washijia River originating from the Altun Mountains, but the water volume was small. At present, there are no lakes in Lop Nur and the surrounding areas, and there are no perennial rivers flowing into Lop Nur. The area has a typical warm temperate continental arid desert climate, with little rainfall, large evaporation, large temperature difference, and strong wind force. The rainfall in the lake basin area is only 10-20 mm, and the evaporation reaches more than 3000 mm, with a dryness of 30-60, and the relative humidity in summer is almost zero. There are many strong winds in the area, with the wind direction mainly from the northeast and northeast-east, and frequent wind-sand activities. There are about 3,000 square kilometers of Yardang landforms distributed in the north, east, and west of Lop Nur, mainly including the downstream of the Kune River Yardang, Baidun Yardang, Yanshashan nearby Yardang, and sporadic distribution of Yardang in the Aqiq Valley. The research object of this study is the Yardang landforms downstream of the Kune River. The main rock type of this Yardang area is the early to middle Holocene river-lake sedimentary strata, mainly composed of coarse-grained silty sand layers and fine-grained silty clay layers interbedded. 2 Research Methods The age when Yardang landforms began to form is an important time scale for studying their erosion rate and erosion volume, and it is also a prerequisite for determining the formation and development process of Yardang landforms and their environment. The commonly used methods for obtaining the absolute age of Yardang landform formation can be summarized into four categories: indirect inference based on erosion rate, direct determination based on the age of the top strata, indirect inference based on the remains of ancient human activities, and indirect inference based on related sedimentation and climate change. Through extensive geological surveys, it was found that in the Loulan area, some Yardang top strata, due to the protection of vegetation and fallen leaves, are the original final sedimentary strata, and the top strata have not been eroded. The deposition time of Yardang landforms can be determined by the optically stimulated luminescence (OSL) test data of the top strata samples; the exposure time of Yardang landforms can be inferred by the well-preserved fallen leaves of tall trees at the top of some Yardangs, as well as the large number of withered trees around, combined with tree rings; some Yardang tops have withered shrubs or trees, and it is inferred that after the formation of the Yardang top strata, influenced by climate change, the area gradually separated from the water body and began to grow a large number of trees or shrubs. Later, with the climate deteriorating, the trees died in large areas, and the shrubs with stronger environmental adaptability continued to grow until all the shrubs also died. Under the harsh climatic conditions and the unprotected Yardang top strata, erosion began. Therefore, the erosion time of Yardang landforms can be determined by the 14 C dating test data of the shrub samples; the near-horizontal lake sedimentary strata in the study area, as well as the well-preserved withered shrubs or trees at the top of the Yardangs at the same level, can be inferred as the erosion benchmark of the Yardang landforms in the area. Based on the age when the Yardang landforms in the area began to form and the erosion benchmark, the erosion rate can be accurately obtained, that is, the historical average erosion rate based on the development law of Yardang landforms. The erosion rate of Yardang landforms obtained by the above methods is the average erosion rate from the beginning of its development to the present, which is greatly different and has a phased characteristic due to the differentiated characteristics of the strata lithology, climate change, and the inherent laws of each stage of the Yardang landform development process. Only the historical average erosion rate is difficult to accurately portray the development law of Yardang landforms. With the widespread application of three-dimensional laser scanning technology, the foundation for obtaining the current erosion rate has been laid. Representative monitoring points are selected in the study area, and at least three permanent control stakes are buried at each monitoring point to build an erosion monitoring network. The three-dimensional scanning total station is used to scan each monitoring point regularly to obtain point cloud data. By comparing the differences between the two phases of point cloud data, the erosion rate is obtained, that is, the current erosion rate based on three-dimensional laser scanning. At the same time, the establishment of the permanent erosion monitoring network will also provide support for the long-term tracking and monitoring of the development process of Yardang landforms in the future. 2.1 Sample Collection and Field Measurement Through extensive surveys of the Yardang landforms downstream of the Kune River, a 550m*450m area in the active area of the Yardang landforms was selected as the study area. A large-scale mapping technology with unmanned aerial vehicles was used, based on oblique photogrammetry, with a forward overlap rate of 80% and a side overlap rate of 75%. Images were obtained by a M300 drone equipped with a five-lens camera; three representative monitoring points were set up, control stakes were buried, and an erosion monitoring network was constructed. The three-dimensional laser scanning total station was used to complete three cycles of three-dimensional laser scanning measurement work to obtain the current erosion rate of the study area; two well-preserved Yardang landform tops with similar elevations were selected, and two samples of withered vegetation (shrubs) were collected, one sample of widely distributed withered vegetation (trees) with a larger diameter and well-preserved around the Yardang, and one sample of Yardang top sediment covered by shrub or tree leaves, forming a set of sediment deposition time, exposure time, and erosion time related to the development of Yardang landforms downstream of the Kune River. 2.2 Laboratory Experiments and Analysis 14 C Dating Test. Sample pretreatment was completed at the Experimental Testing Center of the China Seismological Bureau's Geological Research Institute. Wood samples were soaked in hydrochloric acid and alkali to remove impurities, then rinsed with deionized water until neutral and dried at low temperature; the dried samples and silver were placed into a quartz tube, vacuumed to 10-2 Pa, and heated in a muffle furnace at 900 degrees for more than 16 hours; the quartz tube was placed in a corrugated tube, vacuumed to 10-2 Pa, the quartz tube was broken, the pressure gauge reading was recorded, and CO 2 was collected with a gas collection bottle, and the vacuum reduction system was added according to the ratio of CO 2 :H 2 = 1:2. The graphite carbon was obtained by heating in a furnace with a catalytic iron powder and dehumidifying conditions. It was sent to the Institute of Heavy Ion Physics of Peking University for 14 C testing using an accelerator mass spectrometer, and the sample age was obtained, with an age calculated using the Libby half-life of 5568 years and an error of 1σ. Optical Dating Test. Sample pretreatment and testing were carried out on the Daybreak 2200 optical dating instrument at the Experimental Testing Center of the China Seismological Bureau's Geological Research Institute. Under the red light (640±10nm) in the laboratory, the sample was opened, and the surface layer of the sample was cut off 3~4cm to remove the exposed part of the sample surface. The remaining sample was treated with 40% hydrogen peroxide and 30% hydrochloric acid to remove organic matter and carbonates, and 30% hydrofluoric acid was added for 5 days to remove feldspar. After washing with distilled water until neutral, the particles of 4~11μm were separated according to the principle of static sedimentation and fixed on a stainless steel measuring disc. The measuring disc was irradiated in the 801 E irradiation instrument, and the content of uranium, thorium, and potassium was measured by the medium activation method. Large-scale Topographic Mapping. Based on the existing national benchmark points as the base control points, GNSS static measurement was used to measure the newly built control points in the survey area, and the survey benchmark control measurement was completed. According to the baseline length and network structure, a D-level GNSS control network was constructed; the reference station was set up on a known control point, and the RTK measurement method was used to collect satellite observation data through the mobile station, forming differential data for real-time processing to obtain the ground coordinates of the target point, and completing the photo control point measurement; a long-endurance drone mapping platform was used, equipped with LiDAR, to perform terrain-following flight over the survey area to obtain survey influence and point cloud data; after image matching and aerial triangulation, feature points were extracted to achieve three-dimensional model reconstruction of the actual scene, and large-scale topographic mapping was carried out based on the actual scene three-dimensional model using EPSW. Surface 3D Laser Scanning Data Processing. The 3Dreshaper software was used to register and merge the point cloud data based on key points, then manually selected appropriate areas for cutting to ensure that the two point clouds to be compared basically overlap in the same area, and finally the two point clouds were exported for subsequent processing; the point cloud denoising was carried out using the SOR (Statistical Outlier Removal) filtering algorithm based on PCL (Point Cloud Library), which mainly includes redundant points, isolated points, and drifting points; the processed point cloud data was analyzed for deformation monitoring using the M3C2 algorithm (Multiscale Model To Model Cloud Comparison) (the core of the algorithm includes selecting reference point cloud data to calculate Core points, calculating the surface normal of three-dimensional space, and calculating the distance between two point clouds), and the deformation monitoring analysis was realized using the CloudCompare software to obtain the surface erosion/deposition situation of the study area. 3 Results 3.1 Historical Average Erosion Rate Based on the Development Law of Yardang Landforms The top of the Yardang landforms downstream of the Kune River is extensively covered with withered shrubs or trees (see Figure 1), and some Yardang tops still well preserve the fallen leaves of shrubs or trees (see Figure 2), and the elevations of the aforementioned Yardang tops are very close to each other. Combined with the near-horizontal lake sedimentary sequence of the area where the Yardang landforms downstream of the Kune River are located, it can be judged that before the development of Yardang landforms, vegetation covered the entire distribution area of the Yardang landforms. As the climate environment of the area gradually deteriorated, vegetation died in large areas, losing its effective protective effect on the ground, and Yardang began to develop. Therefore, the 14C age of the withered vegetation (shrubs) at the top of the Yardang landforms can be used as the age when the Yardang landforms in this area began to form, and the Yardang tops with preserved shrubs or tree leaves can be used as the erosion benchmark, based on which, the erosion rate of the Yardang landforms downstream of the Kune River can be obtained. In addition, a large number of withered trees still remain around the Yardang landforms (see Figures 3-4), and the latest time when the Yardang landforms in this area separated from the water body can be judged through the 14C age of the withered trees. （1） 14 C Dating Test of Withered Vegetation on the Top and Around Yardang Landforms Two samples of withered vegetation (shrubs) were collected from two well-preserved Yardang landform tops with similar elevations (designated as Yardang 001 and Yardang 003). Additionally, one sample of withered vegetation (trees) with a larger diameter and well-preserved, which is widely distributed around the Yardang landforms (designated as Yardang 002), was also collected. The 14 C dating tests were conducted by the Carbon-14 Laboratory of the Geological Research Institute, China Seismological Bureau. The results of the tests are presented in Table 1. （2）Optical Dating Test of Sediments on the Top of Yardang Landforms Covered by Shrub or Tree Leaves A sample of sediment from the top of a Yardang landform covered by the fallen leaves of shrubs or trees was collected, designated as Sample 09. The optical dating test was conducted by the Optical Dating Laboratory of the Geological Research Institute, China Seismological Bureau. The results of the test are presented in Table 2. （3）Erosion Depth Distribution Mapping Utilizing the results from the large-scale topographic mapping, the erosion depth distribution map of the study area was completed using ArcGIS. The results can be seen in Figure 5. （4）Calculation of Historical Average Erosion Rate Taking into account the 14C dating test data of the target Yardang top and the surrounding withered vegetation, the formation time of the Yardang landforms in the study area is determined to be 565±25a BP. Combined with the topography and geomorphology of the study area (erosion depth), the erosion rate over the past 565±25a BP can be obtained. The results are presented in Figure 6. From Figure 2, it can be observed within the study area that the historical (565±25a BP) average erosion rates are distributed as follows: 1.54 to 1.38 cm/a accounting for 2.99%, 1.37 to 1.21 cm/a accounting for 11.50%, 1.20 to 1.05 cm/a accounting for 14.63%, 1.04 to 0.88 cm/a accounting for 23.91%, 0.87 to 0.72 cm/a accounting for 26.17%, 0.71 to 0.55 cm/a accounting for 12.11%, 0.54 to 0.39 cm/a accounting for 5.84%, 0.38 to 0.23 cm/a accounting for 1.97%, 0.22 to 0.06 cm/a accounting for 0.7%, and 0.05 to 0.00 cm/a accounting for 0.18%. Overall, based on the optical dating test data of the sediments on the top of Yardang landforms covered by shrub or tree leaves within the study area, it is inferred that the accumulation period of the lake and river strata in this region dates back to 2.8±0.3 ka BP. According to the preliminary estimation of the 14 C age of the well-preserved withered vegetation (trees) with larger diameters surrounding the Yardang and their tree ring data, it is judged that the Yardang landforms in this area became disconnected from the water body around 1900a BP. Considering the 14 C dating test data of the withered vegetation on the top and around the Yardang, the formation time of the Yardang landforms in this area is determined to be 565±25a BP. Since then, the deposition time, exposure time, and erosion time of the Yardang landforms downstream of the Kune River have been obtained, and overall, the erosion rate in the range of 1.37 to 0.55 cm/a accounts for 88.32%. 3.2 Current Erosion Rate Based on 3D Laser Scanning Three monitoring points with strong representativeness were established, control stakes were buried, and an erosion monitoring network was constructed. A three-dimensional laser scanning total station was used to complete three cycles (December 1, 2019, June 11, 2020, and April 12, 2021) of 3D laser scanning measurement work. Through data analysis, the current erosion rate of the Yardang landforms downstream of the Kune River was obtained. The specific analysis process can be seen in Figure 7. （1）Establishment of the Erosion Monitoring Network Casting cement pillars with a diameter of 20 cm and a length of 150 cm, a forced alignment device is placed on one end of the pillar at the top to create a control stake; through field geological surveys, three representative areas are selected for long-term monitoring and control stakes are buried (see Figure 8); the deformation monitoring reference points are set outside the deformation area, in a stable position, and easy to preserve for the long term, and are re-surveyed before each measurement; after the control stakes are laid out, the second-class leveling is carried out to set up the leveling, and the plane coordinates are calculated using a triangulation network; through the above work, a millimeter-level deformation monitoring network is established. （2）Data Collection The LeicaMS50 was utilized for scanning with a range of 20 meters, a sampling interval of 1 centimeter, and a scanning error of 0.6 millimeters. In each monitoring area, three clearly identifiable spherical targets introduced by FARO were set up for scanning. The on-site scanning can be seen in Figure 9. Three-dimensional laser scanning data from three monitoring areas over three periods were obtained. （3）Data Processing Surface erosion monitoring is primarily achieved through the collection of point cloud data for deformation detection. In practice, due to the non-repeatability of individual points in the point cloud data collected from two scans using 3D laser scanning technology, direct deformation detection is challenging. The 3Dreshaper software is employed to register and merge point cloud data based on keypoints, and to crop the data. The PCL (Point Cloud Library) SOR (Statistical Outlier Removal) filtering algorithm is utilized for denoising the point cloud, and the M3C2 (Multiscale Model To Model Cloud Comparison) algorithm is applied for calculating deformation detection of the point cloud to obtain the surface erosion changes in the study area. The erosion rate is presented in Figure 10. From Figure 10, it can be seen that within the study area, the areas currently subject to erosion account for approximately 72%. The current erosion rate in the erosion areas is 3.0 to 2.4 cm/a, accounting for 2.83%, 2.4 to 1.8 cm/a accounting for 4.82%, 1.8 to 1.2 cm/a accounting for 8.32%, 1.2 to 0.6 cm/a accounting for 17.30%, and 0.6 to 0 cm/a accounting for 38.70%. Overall, in the 72% of the study area that is eroding, the erosion rate of 1.2 to 0 cm/a accounts for 56.00%. In comparison, the current erosion rate is significantly lower than the historical average erosion rate. In contrast, 28% of the area shows varying degrees of sedimentation, and this area is generally in lower-lying regions. The historical average erosion rate in these areas is essentially at its maximum, leading to an even greater discrepancy between the current erosion rate and the historical average rate in these regions. (3) Error Analysis In the study of Yardang landform erosion rates, 3D scanning technology, as a new method, is crucial for accurately obtaining the erosion rate in the study area. The precision and reliability of this technology are vital, and error analysis is a key step in ensuring the effectiveness of the technology application and the credibility of the erosion data. The sources of error mainly include four items: equipment calibration error (m 1 ), control network measurement error (m 2 ), point cloud stitching error (m 3 ), and point cloud detection error (m 4 ). The equipment calibration error is obtained through indoor testing. A high-precision control network is established, and five black and white targets are set up on a wall. The center coordinates of the five black and white targets are extracted from the 3D laser scanner point cloud data, and the error range of the 3D scan is obtained by comparing the before and after data, as seen in Table 3. The m_instrument is ultimately determined to be 1 millimeter; m_stitching is determined to be 2.9 millimeters based on the point cloud stitching report; m_network is determined to be 0.3 millimeters according to the first-class plane control precision limit; m_detection is determined to be 1 millimeter based on the comparison of concurrent data. According to the law of error propagation, the total error (m_total) is determined to be: 4 Discussion Zheng Benxing et al., in their study of the Yardang landforms west of Yumen Pass, summarized the formation of Yardang landforms into three periods: the accumulation period of river and lake sediments, the period of sediments disconnecting from the water body, and the period of sediments being subjected to erosion. These three stages constitute the complete process of Yardang landform formation, making the corresponding deposition time, exposure time, and erosion time significant for the study of Yardang landform formation. They also allow for better extraction of the environmental background information contained within Yardangs, which can be applied to the analysis of the evolution process of Yardang landforms（Zheng Benxing et al.,2002）. According to the optical dating test data of the sediments on the top of Yardangs covered by shrub or tree leaves in the study area, it is inferred that the accumulation period of the river and lake sediments in this area dates back to 2.8±0.3 ka BP. Based on the 14 C age of the well-preserved dead vegetation (trees) around the Yardangs, combined with the traditional understanding that the lifespan of Populus euphratica (Euphrates Poplar) is generally 100-300 years, and the preliminary estimation of the tree rings of the fallen dead trees around the Yardangs, it is judged that the Yardang landforms in this area disconnected from the water body around 1900 years ago. The Loulan archaeological site features buildings with beams up to 15 meters long and column bases with a diameter of 60-70 centimeters, surrounded by Populus euphratica, with 14 C dating results of approximately 1856±80 years BP. Today, near Loulan, one can still see large areas of dead and fallen Populus euphratica along the ancient river course, with diameters of more than 50 centimeters being common. It is estimated that during the heyday of Loulan (1st to 4th century AD), the forest coverage in the area could reach 40%（Xia Xuncheng.,1987）. Research on the ancient tombs on the terraces downstream of the Kune River indicates that about 2000 years ago, there were large Populus euphratica forests growing along the banks of the downstream Kune River, with water in the river and a dry climate suitable for the growth of Populus euphratica（Xia Xuncheng.,1987）. Field investigations have confirmed that Loulan City was located at the lower part of the delta where the water network was interwoven and the forest was dense at that time. The building materials of the ancient city were mainly local Populus euphratica, and there are still a large number of Populus euphratica accumulated in the urban area, with 14 C dating results of 1730±90 years BP（Xia Xuncheng.,1987）. The results of previous studies further corroborate the inference of the disconnection time of Yardang landforms from the water body in this area in the current study. Considering the 14 C dating test data of the dead vegetation on the top and around Yardangs, the formation time of Yardang landforms in this area is determined to be 565±25 years BP. Lin Yongchong et al. found during field investigations in the Loulan area that Yardangs developed on the ancient oasis, and due to strong wind erosion, most of the ancient oasis surface has been eroded, and a few Yardang tops with ancient oasis surfaces often retain plant residues rooted in the soil, indicating that these residual tops are the ancient oasis surface（Lin Yongchong et al.,2020）. The 14 C dating test data of plant residues on the top of low Yardangs in the Loulan area by Li and Lin Yongchong（Lin Yongchong et al.,2020；Li K K et al.,2019） show that there was a widespread ancient oasis around 0.45 to 0.65 ka BP, and since then, there has been no extensive oasis development （Li Kangkang et al.,2018）, which is consistent with the results of this test. Lin Yongchong et al. believe that the Yardang landforms in the Loulan area are currently in an active development period. The strata consist of coarse-grained sandy silt layers and finer clay-bearing silt layers, and the geomorphological development is mainly influenced by wind erosion, with gravity also playing a special role, leading to obvious differential erosion characteristics of Yardang landforms in the Loulan area（Lin Yongchong et al.,2017）. This results in significant differences in the erosion rate of Yardang landforms in different stages of development, such as the historical average erosion rate of 1.37 to 0.55 cm/a accounting for 88.32% in the study area, the current erosion rate of 1.2 to 0.6 cm/a accounting for 17.30%, and 0.6 to 0 cm/a accounting for 38.70%. In comparison, the current erosion rate is much lower than the historical average rate, and it is preliminarily inferred that the bottom area of the current Yardang landforms may be close to the erosion benchmark of the area, resulting in a smaller current erosion rate than the historical average rate. Given the progress in Yardang geomorphological chronology research and the widespread development of plant residues on Yardang tops in the Loulan area, as well as the extensive application of 3D laser scanning technology in the field of erosion research, a new comprehensive research method for Yardang landform erosion rates has emerged, that is, a comprehensive research method based on the historical average erosion rate of Yardang landform development laws and the current erosion rate based on 3D laser scanning. This method not only obtains the historical average erosion rate and the current erosion rate simultaneously but also can carry out long-term tracking and monitoring of the development process of Yardang landforms, better depicting the specific process of erosion, such as the process analysis of local accumulation in a short time, the retrogressive erosion of gullies developed in low-lying areas, and the collapse phenomenon of hard clay-bearing silt layers with slow erosion due to differences in strata lithology. The acquisition and accuracy improvement of Yardang ages, in addition to the improvement and correct application of technical methods, require the integration of various methods, while also combining the natural geographical environmental background of the region, and comprehensively using the three times related to Yardang development - deposition time, exposure time, and erosion time（Ding Zhaojing.,2020）. A comprehensive comparison of previous studies on the erosion rate of the Lop Nur area（Hedin S A., 1904；Xia Xuncheng.,1987；Song Haoze et al.,2021）shows that at that time, due to the progress of Yardang geomorphological chronology research and the extensiveness of the survey area, there was a significant difference from the results of this study. The first is the formation time of Yardangs, 1500 years BP（Hedin S A., 1904）and nearly a thousand years（Xia Xuncheng.,1987） are obviously too old. The second is the height of Yardangs, with differences between less than 4 meters（Lin Yongchong et al.,2017）, 4-7 meters difference between mounds and gullies in the Loulan Yardang distribution area（Xia Xuncheng.,1987）, and an average height of 3.1 meter（Song Haoze et al.,2021）. The Loulan Yardang landforms are widely distributed, with an area of about 1300 square kilometers, and the height of Yardangs and the erosion time in some areas are difficult to fully reflect the development of Yardangs in the area. In terms of Yardang height, through nearly 10 years of field investigations crossing the downstream of the Kune River several times, the study area was selected as an area with relatively large Yardang height, and the specific height can be seen in Figure 1, where some places even have a relative height difference of up to 13 meters. In terms of Yardang erosion time, Lin Yongchong et al. （Lin Yongchong et al.,2020）and Li K K et al.（Li K K et al.,2018）collected reed ages on the ancient oasis surface in the Loulan area, and Li K K et al. （Li K K et al.,2018）collected the ages of Tamarix and Populus euphratica in the Loulan area, which are basically consistent with this study, combined with the deposition time and exposure time of the study area, it can be considered that the erosion time of Yardang landforms in the Loulan area is 565±25 years BP. Since then, the deposition time, exposure time, and erosion time related to the development of Yardang landforms downstream of the Kune River have been obtained, which is of decisive significance for determining the erosion rate in the area and is also of great significance for the analysis of the evolution process of Yardang landforms in the area, and will further promote the development of Yardang numerical simulation towards the direction of long-term scale geomorphological evolution research in the area. 5 Conclusion This study, integrating field investigations of Yardang landforms downstream of the Kune River, 14 C dating tests, optical dating tests, large-scale topographic mapping, and 3D laser scanning of the surface, has completed a study on the erosion rates of Yardang landforms downstream of the Kune River. The main conclusions are as follows: （1）The average erosion rate of Yardang landforms downstream of the Kune River since 565±25a BP is between 1.54 to 0.00 cm/a, with the range of 1.37 to 0.55 cm/a accounting for 88.32%. The area currently undergoing erosion is about 72%, with current erosion rates ranging from 3.0 to 0.0 cm/a, where the range of 1.2 to 0.6 cm/a accounts for 17.30%, and 0.6 to 0 cm/a accounts for 38.70%. Compared to historical averages, the current erosion rate is significantly lower, and some low-lying areas are currently in a state of accumulation. （2）A comprehensive research method based on the development laws of Yardang landforms for historical average erosion rates and current erosion rates based on 3D laser scanning has been established. This method has obtained both the historical average and current erosion rates of Yardang landforms downstream of the Kune River. The establishment of a permanent erosion monitoring network will provide support for long-term tracking and monitoring of the development process of Yardang landforms in the area in the future and lay a solid foundation for research on climate change, geomorphological evolution, wind and sand control, and ecosystem stability in the region. （3）The study systematically obtained the deposition time, exposure time, and erosion time related to the development of Yardang landforms downstream of the Kune River, which are 2.8±0.3 ka BP, 1900a BP, and 565±25a BP, respectively. These are of significant importance for the interpretation of the evolution process of Yardang landforms in the area and will undoubtedly promote the development of Yardang numerical simulation towards the direction of long-term scale geomorphological evolution research. Additionally, the determined times related to Yardang landform development provide important implications for the study of climate change in the Lop Nur area. In summary, this study, through extensive field geological investigations, has gained a deeper understanding of the morphology and development of the approximately 1300km² Yardang landforms downstream of the Kune River, especially the height differences between mounds and gullies and the heights of the Yardangs themselves. Combined with dating tests, the historical average erosion rate of Yardang landforms downstream of the Kune River was obtained, addressing the issue of inaccurate erosion rates in the area due to the lack of Yardang formation ages and incomplete understanding of Yardang heights. For the first time, the study systematically obtained the deposition time, exposure time, and erosion time related to the development of Yardang landforms downstream of the Kune River, breaking the traditional perception that "Determining the age of Yardang formation is quite difficult, and there is no direct method to date it, which is also a bottleneck in Yardang geomorphological research（Niu Qinghe et al.,2011）. The issue of Yardang formation age has become a bottleneck in Yardang geomorphological research, which has always troubled researchers（Niu Qinghe et al.,2013）." This is of significant importance for interpreting the evolution process of Yardang landforms in the area and can provide reference for other regions in obtaining the formation age of Yardang landforms and the rise and fall of Loulan civilization. Based on 3D laser scanning technology, the current erosion rate of Yardang landforms downstream of the Kune River was obtained, achieving the understanding that "During the active development period of Yardang landforms, some areas can exhibit accumulation within a certain period." The establishment of a permanent erosion monitoring network can not only monitor the collapse process of hard silt layers with clay and the retrogressive erosion of gullies developed in low-lying areas over the long term but also provide technical support for the development of Yardang numerical simulation towards the direction of long-term scale geomorphological evolution research. Declarations Funding Statement: The research presented in this manuscript was conducted with internal financial support, signifying a self-funded initiative by the authors and their affiliated institution. This approach underscores our dedication to the scientific endeavor, independent of external financial constraints, and reflects the robust support from our academic environment. Author Contribution Bai Youliang: Conceptualization, Methodology, Data curation, Writing – original draft, Writing – review & editing.Bo Li: Data curation, Software, Writing – review & editing.Jinhong Rong: Formal analysis, Writing – review & editing.Hui Chen: Data curation, Writing – review & editing.Jianshe Liu: Formal analysis, Writing – review & editing.Tan Bao: Formal analysis, Writing – review & editing.Jiangnan Jin: Formal analysis, Writing – review & editing.Chuan Wang: Formal analysis, Writing – review & editing.Jinming Zheng: Conceptualization, Methodology, Data curation, Software, Formal analysis, Writing – original draft, Writing – review & editing.All authors have read and agreed to the published version of the manuscript. References Hedin S A. Central Asia and Tibet[J]. 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Aeolian Res. 2018, 30: 41-47. Song Haoze, Yang Xiaoping, Mu Guijin et al. Geomorphology and origin of Yardangs in Lop Nur Lake region[J]. Acta Geographica Sinica, 2021, 76(9): 2187-2202. Li Jiyan, Dong Zhibao. Morphological Parameters of Yardangs in Southeastern Qaidam Basin[J]. Bulletin of Soil and Water Conservation, 2011, 31(4): 122-125. Li, J., Dong, Z., Qian, G. et al. Yardangs in the Qaidam Basin, northwestern China: Distribution and morphology[J]. Aeolian Res, 2016b, 20: 89-99. Halimov, M., Fezer, F. Eight yardang types in central Asia[J]. Zeitschrift Fur Geomorphologie, 1989, 33: 205-217. Wang, J., Xiao, L., Reiss, D. et al. Geological Features and Evolution of Yardangs in the Qaidam Basin, Tibetan Plateau (NW China): A Terrestrial Analogue for Mars[J]. J. Geophys. Res.-Planets, 2018a, 123: 2336-2364. Hu, C., Chen, N., Kapp, P. et al. Yardang geometries in the Qaidam Basin and their controlling factors[J], 2017, 299: 142-151. Kapp, P., Pelletier, J.D., Rohrmann, A. et al. 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Ward A W, Greeley R.E. Evolution of the yardangs at Rogers Lake, California[J]. Geological Society of America Bulletin, 1984, 95(7): 829-837. Goudie A S, Stokes S, Cook J, et al. Yardang landforms from Kharga Oasis, southwestern Egypt[J]. Zeitschrift Fur Geomorphologie, 1999, 116(S1): 97-112. Al-Dousari A M, Al-Elaj M, Al-Enezi E, et al. Origin and characteristics of yardangs in the Um Al-Rimam depressions (NKuwait)[J]. Geomorphology, 2009, 104: 93-104. Ding Zhaojing. Optically Stimulated Luminescence chronology and paleo-environmental implications of yardangs in the Qaidam Basin[D]. China University of Geosciences, 2020. Vincent P, Kattan F. Yardangs on the Cambro-Ordovician saq sandstones, North-West Saudi Arabia[J]. Zeitschrift Fur Geomorphologie, 2006, 50(3): 305-320. Al-Dousari A M, Al-Elaj M, Al-Enezi E, et al. Origin and characteristics of yardangs in the Um Al-Rimam depressions (N Kuwait)[J]. Geomorphology, 2009, 104(3-4): 93-104. Niu Qinghe, Qu Jianjun, Liu Benli, et al. Dating methods for chronological study of Yardang Landforms: A review and perspective in application[J]. Marine Geology & Quaternary Geology, 2013, 33(4): 201-208. Yanjie Wang, Fadong, Xujiao Zhang, et al. Formation and evolution of yardangs activated by Late Pleistocene tectonic movement in Dunhuang, Gansu Province of China[J]. Journal of Earth System Science, 2016, 125(8): 1603-1614. Kangkang Li, Xiaoguang Qin, Bing Xu, et al. Palaeofloods at ancient Loulan, northwest China: Geoarchaeological perspectives on burial practices[J]. Quaternary International, 2021, 577: 131-138. Xu Z J, Quan X, Shi H W, et al. Erosion process and spatial distribution characteristics of erosion-deposition on the loess slope[J]. Journal of Shanxi Normal University (Natural Science Edition), 2021, 49(6): 98-105. O. P. Yermolaev, A. M. Gafurov, and B. M. Usmanov. Evaluation of Erosion Intensity and Dynamics Using Terrestrial Laser Scanning[J]. Eurasian Soil Science, 2018, 51(7): 814-826. 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Tables Tab.1 the 14 C age of Withered vegetation on the top of yardangs Lab Code Field number Sample substance From now on 1) (a BP) Tree wheel correction 2) (Cal BP) siding-to-siding block m±s CG-2020-1272 Yardan 001 wood 565±25 626(36.2%)605cal BP 557(32.0%)539cal BP 585±36 CG-2020-1273 Yardan 002 wood 1780±25 1729(33.8%)1691cal BP 1671(34.4%)1625cal BP 1693±50 CG-2020-1274 Yardan 003 wood 525±30 550(68.2%)516cal BP 548±33 Tab.2 the OSL age of ediment on the top of yardangs Send sample number Experimental number depth of burial (m) α counting rate (Counts/ks) K (%) moisture content (%) Environmental dose rate (Gy/ka) dose （Gy ） age (ka BP ) No.9 LEDL09-330 0.3 10.9±0.2 1.9 1 4.32±0.18 12.1±1.0 2.8±0.3 Tab.3 A test on scanning accuracy of black-and-white target（Unit：mm） call the roll Coordinate of the control network measurement Scan point cloud data acquisition coordinates Spatial distance deviation X Y Z X Y Z T1 -4636.07 -1598.74 -203.28 -4637.52 -1599.40 -203.75 1.66 T2 -3600.30 1977.64 996.04 -3600.37 1978.57 996.35 0.98 T3 -1365.92 2545.90 -170.56 -1365.36 2546.14 -170.61 0.61 T4 5697.99 -3832.15 864.91 5699.53 -3832.18 864.90 1.54 T5 -1634.35 -3896.70 1247.71 -1634.94 -3897.16 1247.93 0.78 Additional Declarations No competing interests reported. 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10","display":"","copyAsset":false,"role":"figure","size":1111676,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of current erosion rate of the study region\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-4927891/v1/efbb3d9edde5f17a4c86460d.png"},{"id":66325122,"identity":"06ef99e2-c381-4863-a3e4-5bfc267000b0","added_by":"auto","created_at":"2024-10-10 12:47:12","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":9449096,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4927891/v1/a45ef698-8424-46fb-a69f-55ae85dc933f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Erosion Rate Study of Yardang Landforms Downstream of the Peacock River","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe term \u0026quot;Yardang\u0026quot; was first proposed by the Swedish explorer Sven Hedin during his field investigation in the Lop Nur area of Eastern Xinjiang, and it has since become a hot topic of research. Hedin believed that the Yardangs in the Lop Nur area were formed around 1500 years ago, with a current height of 6 meters, thus deducing that the rate of wind erosion in this area is 4 mm/year（Hedin S A., 1904）.while investigating the Yardang landforms in the Loulan area, used the cultural layers inside and outside the ancient city as a standard for calculating the rate of wind erosion, suggesting that the maximum erosion rate in this area is 4.7 mm/year, the minimum is 2.4 mm/year, and the average is 3.6 mm/year（Xia Xuncheng.,1987）. Lin Guiquan et al. analyzed the morphological characteristics and genesis of the Baidun Yardang through Google Earth imagery data（Lin Guiquan et al.,2022\u0026nbsp;）. Pan Dadong et al. used high-resolution remote sensing imagery from Google Earth to obtain the morphological characteristics of 1200 individual Yardangs in four areas of Lop Nur, and evaluated the main dynamics of Yardang development in Lop Nur. Lin Yongchong et al（Pan Dadong et al.,2022）. conducted studies on the differential erosion characteristics of Yardang landforms and the impact of surface weathering on the development of Yardang landforms in the Loulan area of Xinjiang, suggesting that the development of Yardang landforms in the Loulan area is mainly influenced by wind erosion, but the regional lithological characteristics and gravitational effects have a particularly significant impact on the erosion of Loulan Yardangs. In addition, weathering effects influenced by a small amount of precipitation, diurnal temperature difference, and strong solar radiation have an important impact on the development of Yardang landforms in the Loulan area（Lin Yongchong et al.,2017；Lin Yongchong et al.,2018；）. Xia Xuncheng proposed that the formation process of Yardang landforms in the Lop Nur area includes four stages: surface destruction, rudimentary Yardang, Yardang formation, and Yardang disappearance（Xia Xuncheng.,1987）. Research on the Yardang landforms in the northwestern part of China, the Lop Nur area, has found that there is a moderate positive correlation between the length and thickness of the collapsed blocks, and the ratio between the two is mostly between 1.2 and 2.5（Lin Yongchong et al.,2017；Lin, Y. et al.,2018\u0026nbsp;）. Song Haoze et al. calculated the average wind erosion rate in the vicinity of the Loulan site after 0.5 ka BP to be 6.2 mm/year based on stratigraphic age and Yardang height data（Song Haoze et al.,2021）.\u003c/p\u003e\n\u003cp\u003eCompared with the research progress of Yardang landforms in the Lop Nur area, the research results on Yardang in the Qaidam Basin have obvious advantages, such as a large number of statistical results in the quantitative analysis of Yardang morphological parameters（Lin, Y. et al.,2018；Li Jiyan et al.,2011；Li, J. et al,2016b\u0026nbsp;）, and the exploration of its evolutionary process（\u0026nbsp;Halimov, et al.,1989；Wang, J.et al., \u0026nbsp;2018a,）and influencing factors（Hu, C. et al.,2017）on the basis of morphological classification; in terms of Yardang wind erosion and regional evolution, methods such as geological profiles and \u003csup\u003e10\u003c/sup\u003eBe numerical simulation have been used to test the rate of wind erosion and analyze the process（Kapp, P.et al.,2011；Rohrmann et al.,2013；\u0026nbsp; Wu, L.et al.,2019；Wang, Z.T.et al.,2013）and based on the study of wind erosion rate, the contribution of the Qaidam Basin to the sediment source of the Loess Plateau has been analyzed（Rohrmann et al.,2013；Heermance et al.,2013）. Yardang landforms, as an important research subject involving climate change, geomorphological evolution, wind and sand control, and ecosystem stability, in addition, the Lop Nur area with large-scale Yardang landforms is also a microcosm of environmental changes in the arid northwest region, therefore, in-depth research and system integration of Yardang landforms in the Lop Nur area is imperative.\u003c/p\u003e\n\u003cp\u003eIn terms of the study of the formation and development environment of Yardang landforms, foreign studies mainly reflect the wind erosion of sedimentary rocks through the observation of Yardang wind erosion rates（Ward A W et al.,1984； \u0026nbsp; Goudie A S et al.,1999；Al-Dousari A M et al.,2009）. At the same time, the determination of wind erosion rates is the focus of quantitative research on wind erosion environmental characteristics, which is conducive to analyzing the migration of materials in the wind transport process（Ding Zhaojing.,2020）. Given the current progress in Yardang geomorphological chronology research（Vincent P et al.,2006；Al-Dousari A M et al.,2009；Niu Qinghe et al.,2013；Yanjie Wang et al.,2016； \u0026nbsp;Kangkang Li et al.,2021）and the widespread application of three-dimensional laser scanning technology（ Xu Z J et al.,2021；O. P. Yermolaev et al.,2018；Jennifer Telling et al.,2017；Xijiang Chen et al.,2020；Stefano Fabbri et al.,2017）, it has laid the foundation for obtaining the historical average erosion rate and current erosion rate of Yardang landforms in the downstream of the Kune River.\u003c/p\u003e"},{"header":"1 Study Area Overview ","content":"\u003cp\u003eThe study area is located in the Lop Nur area in the eastern part of the Tarim Basin in Xinjiang, Asia. The terrain of the area is flat and has long been the convergence center of the Tarim Basin. In ancient times, the area once reached 20,000 square kilometers, and even in 1958, it was still 3,000 square kilometers. There were rivers such as the Tarim River, the Kune River, and the Che\u0026apos;erqin River that flowed into the area, as well as the Milan River, Ruoqiang River, and Washijia River originating from the Altun Mountains, but the water volume was small. At present, there are no lakes in Lop Nur and the surrounding areas, and there are no perennial rivers flowing into Lop Nur. The area has a typical warm temperate continental arid desert climate, with little rainfall, large evaporation, large temperature difference, and strong wind force. The rainfall in the lake basin area is only 10-20 mm, and the evaporation reaches more than 3000 mm, with a dryness of 30-60, and the relative humidity in summer is almost zero. There are many strong winds in the area, with the wind direction mainly from the northeast and northeast-east, and frequent wind-sand activities. There are about 3,000 square kilometers of Yardang landforms distributed in the north, east, and west of Lop Nur, mainly including the downstream of the Kune River Yardang, Baidun Yardang, Yanshashan nearby Yardang, and sporadic distribution of Yardang in the Aqiq Valley. The research object of this study is the Yardang landforms downstream of the Kune River. The main rock type of this Yardang area is the early to middle Holocene river-lake sedimentary strata, mainly composed of coarse-grained silty sand layers and fine-grained silty clay layers interbedded.\u003c/p\u003e"},{"header":"2 Research Methods","content":"\u003cp\u003eThe age when Yardang landforms began to form is an important time scale for studying their erosion rate and erosion volume, and it is also a prerequisite for determining the formation and development process of Yardang landforms and their environment. The commonly used methods for obtaining the absolute age of Yardang landform formation can be summarized into four categories: indirect inference based on erosion rate, direct determination based on the age of the top strata, indirect inference based on the remains of ancient human activities, and indirect inference based on related sedimentation and climate change. Through extensive geological surveys, it was found that in the Loulan area, some Yardang top strata, due to the protection of vegetation and fallen leaves, are the original final sedimentary strata, and the top strata have not been eroded. The deposition time of Yardang landforms can be determined by the optically stimulated luminescence (OSL) test data of the top strata samples; the exposure time of Yardang landforms can be inferred by the well-preserved fallen leaves of tall trees at the top of some Yardangs, as well as the large number of withered trees around, combined with tree rings; some Yardang tops have withered shrubs or trees, and it is inferred that after the formation of the Yardang top strata, influenced by climate change, the area gradually separated from the water body and began to grow a large number of trees or shrubs. Later, with the climate deteriorating, the trees died in large areas, and the shrubs with stronger environmental adaptability continued to grow until all the shrubs also died. Under the harsh climatic conditions and the unprotected Yardang top strata, erosion began. Therefore, the erosion time of Yardang landforms can be determined by the \u003csup\u003e14\u003c/sup\u003eC dating test data of the shrub samples; the near-horizontal lake sedimentary strata in the study area, as well as the well-preserved withered shrubs or trees at the top of the Yardangs at the same level, can be inferred as the erosion benchmark of the Yardang landforms in the area. Based on the age when the Yardang landforms in the area began to form and the erosion benchmark, the erosion rate can be accurately obtained, that is, the historical average erosion rate based on the development law of Yardang landforms.\u003c/p\u003e\n\u003cp\u003eThe erosion rate of Yardang landforms obtained by the above methods is the average erosion rate from the beginning of its development to the present, which is greatly different and has a phased characteristic due to the differentiated characteristics of the strata lithology, climate change, and the inherent laws of each stage of the Yardang landform development process. Only the historical average erosion rate is difficult to accurately portray the development law of Yardang landforms. With the widespread application of three-dimensional laser scanning technology, the foundation for obtaining the current erosion rate has been laid. Representative monitoring points are selected in the study area, and at least three permanent control stakes are buried at each monitoring point to build an erosion monitoring network. The three-dimensional scanning total station is used to scan each monitoring point regularly to obtain point cloud data. By comparing the differences between the two phases of point cloud data, the erosion rate is obtained, that is, the current erosion rate based on three-dimensional laser scanning. At the same time, the establishment of the permanent erosion monitoring network will also provide support for the long-term tracking and monitoring of the development process of Yardang landforms in the future.\u003c/p\u003e\n\u003cp\u003e2.1 Sample Collection and Field Measurement Through extensive surveys of the Yardang landforms downstream of the Kune River, a 550m*450m area in the active area of the Yardang landforms was selected as the study area. A large-scale mapping technology with unmanned aerial vehicles was used, based on oblique photogrammetry, with a forward overlap rate of 80% and a side overlap rate of 75%. Images were obtained by a M300 drone equipped with a five-lens camera; three representative monitoring points were set up, control stakes were buried, and an erosion monitoring network was constructed. The three-dimensional laser scanning total station was used to complete three cycles of three-dimensional laser scanning measurement work to obtain the current erosion rate of the study area; two well-preserved Yardang landform tops with similar elevations were selected, and two samples of withered vegetation (shrubs) were collected, one sample of widely distributed withered vegetation (trees) with a larger diameter and well-preserved around the Yardang, and one sample of Yardang top sediment covered by shrub or tree leaves, forming a set of sediment deposition time, exposure time, and erosion time related to the development of Yardang landforms downstream of the Kune River.\u003c/p\u003e\n\u003cp\u003e2.2 Laboratory Experiments and Analysis \u003csup\u003e14\u003c/sup\u003eC Dating Test. Sample pretreatment was completed at the Experimental Testing Center of the China Seismological Bureau\u0026apos;s Geological Research Institute. Wood samples were soaked in hydrochloric acid and alkali to remove impurities, then rinsed with deionized water until neutral and dried at low temperature; the dried samples and silver were placed into a quartz tube, vacuumed to 10-2 Pa, and heated in a muffle furnace at 900 degrees for more than 16 hours; the quartz tube was placed in a corrugated tube, vacuumed to 10-2 Pa, the quartz tube was broken, the pressure gauge reading was recorded, and CO\u003csub\u003e2\u003c/sub\u003e was collected with a gas collection bottle, and the vacuum reduction system was added according to the ratio of CO\u003csub\u003e2\u003c/sub\u003e:H\u003csub\u003e2\u003c/sub\u003e = 1:2. The graphite carbon was obtained by heating in a furnace with a catalytic iron powder and dehumidifying conditions. It was sent to the Institute of Heavy Ion Physics of Peking University for \u003csup\u003e14\u003c/sup\u003eC testing using an accelerator mass spectrometer, and the sample age was obtained, with an age calculated using the Libby half-life of 5568 years and an error of 1\u0026sigma;.\u003c/p\u003e\n\u003cp\u003eOptical Dating Test. Sample pretreatment and testing were carried out on the Daybreak 2200 optical dating instrument at the Experimental Testing Center of the China Seismological Bureau\u0026apos;s Geological Research Institute. Under the red light (640\u0026plusmn;10nm) in the laboratory, the sample was opened, and the surface layer of the sample was cut off 3~4cm to remove the exposed part of the sample surface. The remaining sample was treated with 40% hydrogen peroxide and 30% hydrochloric acid to remove organic matter and carbonates, and 30% hydrofluoric acid was added for 5 days to remove feldspar. After washing with distilled water until neutral, the particles of 4~11\u0026mu;m were separated according to the principle of static sedimentation and fixed on a stainless steel measuring disc. The measuring disc was irradiated in the 801 E irradiation instrument, and the content of uranium, thorium, and potassium was measured by the medium activation method.\u003c/p\u003e\n\u003cp\u003eLarge-scale Topographic Mapping. Based on the existing national benchmark points as the base control points, GNSS static measurement was used to measure the newly built control points in the survey area, and the survey benchmark control measurement was completed. According to the baseline length and network structure, a D-level GNSS control network was constructed; the reference station was set up on a known control point, and the RTK measurement method was used to collect satellite observation data through the mobile station, forming differential data for real-time processing to obtain the ground coordinates of the target point, and completing the photo control point measurement; a long-endurance drone mapping platform was used, equipped with LiDAR, to perform terrain-following flight over the survey area to obtain survey influence and point cloud data; after image matching and aerial triangulation, feature points were extracted to achieve three-dimensional model reconstruction of the actual scene, and large-scale topographic mapping was carried out based on the actual scene three-dimensional model using EPSW.\u003c/p\u003e\n\u003cp\u003eSurface 3D Laser Scanning Data Processing. The 3Dreshaper software was used to register and merge the point cloud data based on key points, then manually selected appropriate areas for cutting to ensure that the two point clouds to be compared basically overlap in the same area, and finally the two point clouds were exported for subsequent processing; the point cloud denoising was carried out using the SOR (Statistical Outlier Removal) filtering algorithm based on PCL (Point Cloud Library), which mainly includes redundant points, isolated points, and drifting points; the processed point cloud data was analyzed for deformation monitoring using the M3C2 algorithm (Multiscale Model To Model Cloud Comparison) (the core of the algorithm includes selecting reference point cloud data to calculate Core points, calculating the surface normal of three-dimensional space, and calculating the distance between two point clouds), and the deformation monitoring analysis was realized using the CloudCompare software to obtain the surface erosion/deposition situation of the study area.\u003c/p\u003e"},{"header":"3 Results","content":"\u003cp\u003e\u003cstrong\u003e3.1 Historical Average Erosion Rate Based on the Development Law of Yardang Landforms\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe top of the Yardang landforms downstream of the Kune River is extensively covered with withered shrubs or trees (see Figure 1), and some Yardang tops still well preserve the fallen leaves of shrubs or trees (see Figure 2), and the elevations of the aforementioned Yardang tops are very close to each other. Combined with the near-horizontal lake sedimentary sequence of the area where the Yardang landforms downstream of the Kune River are located, it can be judged that before the development of Yardang landforms, vegetation covered the entire distribution area of the Yardang landforms. As the climate environment of the area gradually deteriorated, vegetation died in large areas, losing its effective protective effect on the ground, and Yardang began to develop. Therefore, the 14C age of the withered vegetation (shrubs) at the top of the Yardang landforms can be used as the age when the Yardang landforms in this area began to form, and the Yardang tops with preserved shrubs or tree leaves can be used as the erosion benchmark, based on which, the erosion rate of the Yardang landforms downstream of the Kune River can be obtained. In addition, a large number of withered trees still remain around the Yardang landforms (see Figures 3-4), and the latest time when the Yardang landforms in this area separated from the water body can be judged through the 14C age of the withered trees.\u003c/p\u003e\n\u003cp\u003e（1）\u003csup\u003e14\u003c/sup\u003eC Dating Test of Withered Vegetation on the Top and Around Yardang Landforms\u003c/p\u003e\n\u003cp\u003eTwo samples of withered vegetation (shrubs) were collected from two well-preserved Yardang landform tops with similar elevations (designated as Yardang 001 and Yardang 003). Additionally, one sample of withered vegetation (trees) with a larger diameter and well-preserved, which is widely distributed around the Yardang landforms (designated as Yardang 002), was also collected. The \u003csup\u003e14\u003c/sup\u003eC dating tests were conducted by the Carbon-14 Laboratory of the Geological Research Institute, China Seismological Bureau. The results of the tests are presented in Table 1.\u003c/p\u003e\n\u003cp\u003e（2）Optical Dating Test of Sediments on the Top of Yardang Landforms Covered by Shrub or Tree Leaves\u003c/p\u003e\n\u003cp\u003eA sample of sediment from the top of a Yardang landform covered by the fallen leaves of shrubs or trees was collected, designated as Sample 09. The optical dating test was conducted by the Optical Dating Laboratory of the Geological Research Institute, China Seismological Bureau. The results of the test are presented in Table 2.\u003c/p\u003e\n\u003cp\u003e（3）Erosion Depth Distribution Mapping\u003c/p\u003e\n\u003cp\u003eUtilizing the results from the large-scale topographic mapping, the erosion depth distribution map of the study area was completed using ArcGIS. The results can be seen in Figure 5.\u003c/p\u003e\n\u003cp\u003e（4）Calculation of Historical Average Erosion Rate\u003c/p\u003e\n\u003cp\u003eTaking into account the 14C dating test data of the target Yardang top and the surrounding withered vegetation, the formation time of the Yardang landforms in the study area is determined to be 565\u0026plusmn;25a BP. Combined with the topography and geomorphology of the study area (erosion depth), the erosion rate over the past 565\u0026plusmn;25a BP can be obtained. The results are presented in Figure 6.\u003c/p\u003e\n\u003cp\u003eFrom Figure 2, it can be observed within the study area that the historical (565\u0026plusmn;25a BP) average erosion rates are distributed as follows: 1.54 to 1.38 cm/a accounting for 2.99%, 1.37 to 1.21 cm/a accounting for 11.50%, 1.20 to 1.05 cm/a accounting for 14.63%, 1.04 to 0.88 cm/a accounting for 23.91%, 0.87 to 0.72 cm/a accounting for 26.17%, 0.71 to 0.55 cm/a accounting for 12.11%, 0.54 to 0.39 cm/a accounting for 5.84%, 0.38 to 0.23 cm/a accounting for 1.97%, 0.22 to 0.06 cm/a accounting for 0.7%, and 0.05 to 0.00 cm/a accounting for 0.18%.\u003c/p\u003e\n\u003cp\u003eOverall, based on the optical dating test data of the sediments on the top of Yardang landforms covered by shrub or tree leaves within the study area, it is inferred that the accumulation period of the lake and river strata in this region dates back to 2.8\u0026plusmn;0.3 ka BP. According to the preliminary estimation of the \u003csup\u003e14\u003c/sup\u003eC age of the well-preserved withered vegetation (trees) with larger diameters surrounding the Yardang and their tree ring data, it is judged that the Yardang landforms in this area became disconnected from the water body around 1900a BP. Considering the \u003csup\u003e14\u003c/sup\u003eC dating test data of the withered vegetation on the top and around the Yardang, the formation time of the Yardang landforms in this area is determined to be 565\u0026plusmn;25a BP. Since then, the deposition time, exposure time, and erosion time of the Yardang landforms downstream of the Kune River have been obtained, and overall, the erosion rate in the range of 1.37 to 0.55 cm/a accounts for 88.32%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Current Erosion Rate Based on 3D Laser Scanning\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThree monitoring points with strong representativeness were established, control stakes were buried, and an erosion monitoring network was constructed. A three-dimensional laser scanning total station was used to complete three cycles (December 1, 2019, June 11, 2020, and April 12, 2021) of 3D laser scanning measurement work. Through data analysis, the current erosion rate of the Yardang landforms downstream of the Kune River was obtained. The specific analysis process can be seen in Figure 7.\u003c/p\u003e\n\u003cp\u003e（1）Establishment of the Erosion Monitoring Network\u003c/p\u003e\n\u003cp\u003eCasting cement pillars with a diameter of 20 cm and a length of 150 cm, a forced alignment device is placed on one end of the pillar at the top to create a control stake; through field geological surveys, three representative areas are selected for long-term monitoring and control stakes are buried (see Figure 8); the deformation monitoring reference points are set outside the deformation area, in a stable position, and easy to preserve for the long term, and are re-surveyed before each measurement; after the control stakes are laid out, the second-class leveling is carried out to set up the leveling, and the plane coordinates are calculated using a triangulation network; through the above work, a millimeter-level deformation monitoring network is established.\u003c/p\u003e\n\u003cp\u003e（2）Data Collection\u003c/p\u003e\n\u003cp\u003eThe LeicaMS50 was utilized for scanning with a range of 20 meters, a sampling interval of 1 centimeter, and a scanning error of 0.6 millimeters. In each monitoring area, three clearly identifiable spherical targets introduced by FARO were set up for scanning. The on-site scanning can be seen in Figure 9. Three-dimensional laser scanning data from three monitoring areas over three periods were obtained.\u003c/p\u003e\n\u003cp\u003e（3）Data Processing\u003c/p\u003e\n\u003cp\u003eSurface erosion monitoring is primarily achieved through the collection of point cloud data for deformation detection. In practice, due to the non-repeatability of individual points in the point cloud data collected from two scans using 3D laser scanning technology, direct deformation detection is challenging. The 3Dreshaper software is employed to register and merge point cloud data based on keypoints, and to crop the data. The PCL (Point Cloud Library) SOR (Statistical Outlier Removal) filtering algorithm is utilized for denoising the point cloud, and the M3C2 (Multiscale Model To Model Cloud Comparison) algorithm is applied for calculating deformation detection of the point cloud to obtain the surface erosion changes in the study area. The erosion rate is presented in Figure 10.\u003c/p\u003e\n\u003cp\u003eFrom Figure 10, it can be seen that within the study area, the areas currently subject to erosion account for approximately 72%. The current erosion rate in the erosion areas is 3.0 to 2.4 cm/a, accounting for 2.83%, 2.4 to 1.8 cm/a accounting for 4.82%, 1.8 to 1.2 cm/a accounting for 8.32%, 1.2 to 0.6 cm/a accounting for 17.30%, and 0.6 to 0 cm/a accounting for 38.70%. Overall, in the 72% of the study area that is eroding, the erosion rate of 1.2 to 0 cm/a accounts for 56.00%. In comparison, the current erosion rate is significantly lower than the historical average erosion rate. In contrast, 28% of the area shows varying degrees of sedimentation, and this area is generally in lower-lying regions. The historical average erosion rate in these areas is essentially at its maximum, leading to an even greater discrepancy between the current erosion rate and the historical average rate in these regions.\u003c/p\u003e\n\u003cp\u003e(3) Error Analysis\u003c/p\u003e\n\u003cp\u003eIn the study of Yardang landform erosion rates, 3D scanning technology, as a new method, is crucial for accurately obtaining the erosion rate in the study area. The precision and reliability of this technology are vital, and error analysis is a key step in ensuring the effectiveness of the technology application and the credibility of the erosion data. The sources of error mainly include four items: equipment calibration error (m\u003csub\u003e1\u003c/sub\u003e), control network measurement error (m\u003csub\u003e2\u003c/sub\u003e), point cloud stitching error (m\u003csub\u003e3\u003c/sub\u003e), and point cloud detection error (m\u003csub\u003e4\u003c/sub\u003e). The equipment calibration error is obtained through indoor testing. A high-precision control network is established, and five black and white targets are set up on a wall. The center coordinates of the five black and white targets are extracted from the 3D laser scanner point cloud data, and the error range of the 3D scan is obtained by comparing the before and after data, as seen in Table 3. The m_instrument is ultimately determined to be 1 millimeter; m_stitching is determined to be 2.9 millimeters based on the point cloud stitching report; m_network is determined to be 0.3 millimeters according to the first-class plane control precision limit; m_detection is determined to be 1 millimeter based on the comparison of concurrent data. According to the law of error propagation, the total error (m_total) is determined to be:\u003c/p\u003e\n\u003cp\u003e\u003cimg 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width=\"565\" height=\"45\"\u003e\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"4 Discussion","content":"\u003cp\u003eZheng Benxing et al., in their study of the Yardang landforms west of Yumen Pass, summarized the formation of Yardang landforms into three periods: the accumulation period of river and lake sediments, the period of sediments disconnecting from the water body, and the period of sediments being subjected to erosion. These three stages constitute the complete process of Yardang landform formation, making the corresponding deposition time, exposure time, and erosion time significant for the study of Yardang landform formation. They also allow for better extraction of the environmental background information contained within Yardangs, which can be applied to the analysis of the evolution process of Yardang landforms（Zheng Benxing et al.,2002）. According to the optical dating test data of the sediments on the top of Yardangs covered by shrub or tree leaves in the study area, it is inferred that the accumulation period of the river and lake sediments in this area dates back to 2.8\u0026plusmn;0.3 ka BP. Based on the \u003csup\u003e14\u003c/sup\u003eC age of the well-preserved dead vegetation (trees) around the Yardangs, combined with the traditional understanding that the lifespan of Populus euphratica (Euphrates Poplar) is generally 100-300 years, and the preliminary estimation of the tree rings of the fallen dead trees around the Yardangs, it is judged that the Yardang landforms in this area disconnected from the water body around 1900 years ago. The Loulan archaeological site features buildings with beams up to 15 meters long and column bases with a diameter of 60-70 centimeters, surrounded by Populus euphratica, with \u003csup\u003e14\u003c/sup\u003eC dating results of approximately 1856\u0026plusmn;80 years BP. Today, near Loulan, one can still see large areas of dead and fallen Populus euphratica along the ancient river course, with diameters of more than 50 centimeters being common. It is estimated that during the heyday of Loulan (1st to 4th century AD), the forest coverage in the area could reach 40%（Xia Xuncheng.,1987）. Research on the ancient tombs on the terraces downstream of the Kune River indicates that about 2000 years ago, there were large Populus euphratica forests growing along the banks of the downstream Kune River, with water in the river and a dry climate suitable for the growth of Populus euphratica（Xia Xuncheng.,1987）. Field investigations have confirmed that Loulan City was located at the lower part of the delta where the water network was interwoven and the forest was dense at that time. The building materials of the ancient city were mainly local Populus euphratica, and there are still a large number of Populus euphratica accumulated in the urban area, with \u003csup\u003e14\u003c/sup\u003eC dating results of 1730\u0026plusmn;90 years BP（Xia Xuncheng.,1987）. The results of previous studies further corroborate the inference of the disconnection time of Yardang landforms from the water body in this area in the current study. Considering the \u003csup\u003e14\u003c/sup\u003eC dating test data of the dead vegetation on the top and around Yardangs, the formation time of Yardang landforms in this area is determined to be 565\u0026plusmn;25 years BP. Lin Yongchong et al. found during field investigations in the Loulan area that Yardangs developed on the ancient oasis, and due to strong wind erosion, most of the ancient oasis surface has been eroded, and a few Yardang tops with ancient oasis surfaces often retain plant residues rooted in the soil, indicating that these residual tops are the ancient oasis surface（Lin Yongchong et al.,2020）. The \u003csup\u003e14\u003c/sup\u003eC dating test data of plant residues on the top of low Yardangs in the Loulan area by Li and Lin Yongchong（Lin Yongchong et al.,2020；Li K K et al.,2019）\u0026nbsp;show that there was a widespread ancient oasis around 0.45 to 0.65 ka BP, and since then, there has been no extensive oasis development\u0026nbsp;（Li Kangkang et al.,2018）, which is consistent with the results of this test.\u003c/p\u003e\n\u003cp\u003eLin Yongchong et al. believe that the Yardang landforms in the Loulan area are currently in an active development period. The strata consist of coarse-grained sandy silt layers and finer clay-bearing silt layers, and the geomorphological development is mainly influenced by wind erosion, with gravity also playing a special role, leading to obvious differential erosion characteristics of Yardang landforms in the Loulan area（Lin Yongchong et al.,2017）. This results in significant differences in the erosion rate of Yardang landforms in different stages of development, such as the historical average erosion rate of 1.37 to 0.55 cm/a accounting for 88.32% in the study area, the current erosion rate of 1.2 to 0.6 cm/a accounting for 17.30%, and 0.6 to 0 cm/a accounting for 38.70%. In comparison, the current erosion rate is much lower than the historical average rate, and it is preliminarily inferred that the bottom area of the current Yardang landforms may be close to the erosion benchmark of the area, resulting in a smaller current erosion rate than the historical average rate. Given the progress in Yardang geomorphological chronology research and the widespread development of plant residues on Yardang tops in the Loulan area, as well as the extensive application of 3D laser scanning technology in the field of erosion research, a new comprehensive research method for Yardang landform erosion rates has emerged, that is, a comprehensive research method based on the historical average erosion rate of Yardang landform development laws and the current erosion rate based on 3D laser scanning. This method not only obtains the historical average erosion rate and the current erosion rate simultaneously but also can carry out long-term tracking and monitoring of the development process of Yardang landforms, better depicting the specific process of erosion, such as the process analysis of local accumulation in a short time, the retrogressive erosion of gullies developed in low-lying areas, and the collapse phenomenon of hard clay-bearing silt layers with slow erosion due to differences in strata lithology.\u003c/p\u003e\n\u003cp\u003eThe acquisition and accuracy improvement of Yardang ages, in addition to the improvement and correct application of technical methods, require the integration of various methods, while also combining the natural geographical environmental background of the region, and comprehensively using the three times related to Yardang development - deposition time, exposure time, and erosion time（Ding Zhaojing.,2020）. A comprehensive comparison of previous studies on the erosion rate of the Lop Nur area（Hedin S A., 1904；Xia Xuncheng.,1987；Song Haoze et al.,2021）shows that at that time, due to the progress of Yardang geomorphological chronology research and the extensiveness of the survey area, there was a significant difference from the results of this study. The first is the formation time of Yardangs, 1500 years BP（Hedin S A., 1904）and nearly a thousand years（Xia Xuncheng.,1987） are obviously too old. The second is the height of Yardangs, with differences between less than 4 meters（Lin Yongchong et al.,2017）, 4-7 meters difference between mounds and gullies in the Loulan Yardang distribution area（Xia Xuncheng.,1987）, and an average height of 3.1 meter（Song Haoze et al.,2021）. The Loulan Yardang landforms are widely distributed, with an area of about 1300 square kilometers, and the height of Yardangs and the erosion time in some areas are difficult to fully reflect the development of Yardangs in the area. In terms of Yardang height, through nearly 10 years of field investigations crossing the downstream of the Kune River several times, the study area was selected as an area with relatively large Yardang height, and the specific height can be seen in Figure 1, where some places even have a relative height difference of up to 13 meters. In terms of Yardang erosion time, Lin Yongchong et al. （Lin Yongchong et al.,2020）and Li K K et al.（Li K K et al.,2018）collected reed ages on the ancient oasis surface in the Loulan area, and Li K K et al. （Li K K et al.,2018）collected the ages of Tamarix and Populus euphratica in the Loulan area, which are basically consistent with this study, combined with the deposition time and exposure time of the study area, it can be considered that the erosion time of Yardang landforms in the Loulan area is 565\u0026plusmn;25 years BP. Since then, the deposition time, exposure time, and erosion time related to the development of Yardang landforms downstream of the Kune River have been obtained, which is of decisive significance for determining the erosion rate in the area and is also of great significance for the analysis of the evolution process of Yardang landforms in the area, and will further promote the development of Yardang numerical simulation towards the direction of long-term scale geomorphological evolution research in the area.\u003c/p\u003e"},{"header":"5 Conclusion","content":"\u003cp\u003eThis study, integrating field investigations of Yardang landforms downstream of the Kune River, \u003csup\u003e14\u003c/sup\u003eC dating tests, optical dating tests, large-scale topographic mapping, and 3D laser scanning of the surface, has completed a study on the erosion rates of Yardang landforms downstream of the Kune River. The main conclusions are as follows:\u003c/p\u003e\n\u003cp\u003e（1）The average erosion rate of Yardang landforms downstream of the Kune River since 565\u0026plusmn;25a BP is between 1.54 to 0.00 cm/a, with the range of 1.37 to 0.55 cm/a accounting for 88.32%. The area currently undergoing erosion is about 72%, with current erosion rates ranging from 3.0 to 0.0 cm/a, where the range of 1.2 to 0.6 cm/a accounts for 17.30%, and 0.6 to 0 cm/a accounts for 38.70%. Compared to historical averages, the current erosion rate is significantly lower, and some low-lying areas are currently in a state of accumulation.\u003c/p\u003e\n\u003cp\u003e（2）A comprehensive research method based on the development laws of Yardang landforms for historical average erosion rates and current erosion rates based on 3D laser scanning has been established. This method has obtained both the historical average and current erosion rates of Yardang landforms downstream of the Kune River. The establishment of a permanent erosion monitoring network will provide support for long-term tracking and monitoring of the development process of Yardang landforms in the area in the future and lay a solid foundation for research on climate change, geomorphological evolution, wind and sand control, and ecosystem stability in the region.\u003c/p\u003e\n\u003cp\u003e（3）The study systematically obtained the deposition time, exposure time, and erosion time related to the development of Yardang landforms downstream of the Kune River, which are 2.8\u0026plusmn;0.3 ka BP, 1900a BP, and 565\u0026plusmn;25a BP, respectively. These are of significant importance for the interpretation of the evolution process of Yardang landforms in the area and will undoubtedly promote the development of Yardang numerical simulation towards the direction of long-term scale geomorphological evolution research. Additionally, the determined times related to Yardang landform development provide important implications for the study of climate change in the Lop Nur area.\u003c/p\u003e\n\u003cp\u003eIn summary, this study, through extensive field geological investigations, has gained a deeper understanding of the morphology and development of the approximately 1300km\u0026sup2; Yardang landforms downstream of the Kune River, especially the height differences between mounds and gullies and the heights of the Yardangs themselves. Combined with dating tests, the historical average erosion rate of Yardang landforms downstream of the Kune River was obtained, addressing the issue of inaccurate erosion rates in the area due to the lack of Yardang formation ages and incomplete understanding of Yardang heights. For the first time, the study systematically obtained the deposition time, exposure time, and erosion time related to the development of Yardang landforms downstream of the Kune River, breaking the traditional perception that \u0026quot;Determining the age of Yardang formation is quite difficult, and there is no direct method to date it, which is also a bottleneck in Yardang geomorphological research（Niu Qinghe et al.,2011）. The issue of Yardang formation age has become a bottleneck in Yardang geomorphological research, which has always troubled researchers（Niu Qinghe et al.,2013）.\u0026quot; This is of significant importance for interpreting the evolution process of Yardang landforms in the area and can provide reference for other regions in obtaining the formation age of Yardang landforms and the rise and fall of Loulan civilization. Based on 3D laser scanning technology, the current erosion rate of Yardang landforms downstream of the Kune River was obtained, achieving the understanding that \u0026quot;During the active development period of Yardang landforms, some areas can exhibit accumulation within a certain period.\u0026quot; The establishment of a permanent erosion monitoring network can not only monitor the collapse process of hard silt layers with clay and the retrogressive erosion of gullies developed in low-lying areas over the long term but also provide technical support for the development of Yardang numerical simulation towards the direction of long-term scale geomorphological evolution research.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding Statement:\u003c/h2\u003e \u003cp\u003eThe research presented in this manuscript was conducted with internal financial support, signifying a self-funded initiative by the authors and their affiliated institution. This approach underscores our dedication to the scientific endeavor, independent of external financial constraints, and reflects the robust support from our academic environment.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eBai Youliang: Conceptualization, Methodology, Data curation, Writing \u0026ndash; original draft, Writing \u0026ndash; review \u0026amp; editing.Bo Li: Data curation, Software, Writing \u0026ndash; review \u0026amp; editing.Jinhong Rong: Formal analysis, Writing \u0026ndash; review \u0026amp; editing.Hui Chen: Data curation, Writing \u0026ndash; review \u0026amp; editing.Jianshe Liu: Formal analysis, Writing \u0026ndash; review \u0026amp; editing.Tan Bao: Formal analysis, Writing \u0026ndash; review \u0026amp; editing.Jiangnan Jin: Formal analysis, Writing \u0026ndash; review \u0026amp; editing.Chuan Wang: Formal analysis, Writing \u0026ndash; review \u0026amp; editing.Jinming Zheng: Conceptualization, Methodology, Data curation, Software, Formal analysis, Writing \u0026ndash; original draft, Writing \u0026ndash; review \u0026amp; editing.All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHedin S A. Central Asia and Tibet[J]. Scottish Geographical Magazine, 1904: 202-212. \u003c/li\u003e\n\u003cli\u003eXia Xuncheng. Scientific Exploration and Research in Lop Nur[M]. Science Press, 1987: 52-59, 100-109, 298. \u003c/li\u003e\n\u003cli\u003eLin Guiquan, Lin Yongchong, Wang Xueping. Morphological characteristics and genesis of Bailongdui Yardang landforms in Lop Nur, Xinjiang[J]. Arid Land Geography, 2021, 44(5): 1309-1316. \u003c/li\u003e\n\u003cli\u003ePan Dadong, Lin Yongchong. Morphological characteristics of Yardangs in Lop Nur, Xinjiang Province[J]. Journal of Arid Land Resources and Environment, 2022, 36(6): 157-163. \u003c/li\u003e\n\u003cli\u003eLin Yongchong, Mu Guijin, Qin Xiongguang et al. Erosion Characteristics of Yardangs at Loulan Area, Xinjiang, China[J]. Journal of Desert Research, 2017, 37(1): 33-39.\u003c/li\u003e\n\u003cli\u003eLin Yongchong, Mu Guijin, Qin Xiongguang et al. Weathering impact on the development of Yardang landforms in Loulan region[J]. Arid Land Geography, 2018, 41(6): 1278-1284. \u003c/li\u003e\n\u003cli\u003eLin, Y., Xu, L., Mu, G. Differential erosion and the formation of layered yardangs in the Loulan region (Lop Nur), eastern Tarim Basin. Aeolian Res. 2018, 30: 41-47. \u003c/li\u003e\n\u003cli\u003eSong Haoze, Yang Xiaoping, Mu Guijin et al. Geomorphology and origin of Yardangs in Lop Nur Lake region[J]. Acta Geographica Sinica, 2021, 76(9): 2187-2202. \u003c/li\u003e\n\u003cli\u003eLi Jiyan, Dong Zhibao. Morphological Parameters of Yardangs in Southeastern Qaidam Basin[J]. Bulletin of Soil and Water Conservation, 2011, 31(4): 122-125.\u003c/li\u003e\n\u003cli\u003eLi, J., Dong, Z., Qian, G. et al. Yardangs in the Qaidam Basin, northwestern China: Distribution and morphology[J]. Aeolian Res, 2016b, 20: 89-99. \u003c/li\u003e\n\u003cli\u003eHalimov, M., Fezer, F. Eight yardang types in central Asia[J]. Zeitschrift Fur Geomorphologie, 1989, 33: 205-217. \u003c/li\u003e\n\u003cli\u003eWang, J., Xiao, L., Reiss, D. et al. Geological Features and Evolution of Yardangs in the Qaidam Basin, Tibetan Plateau (NW China): A Terrestrial Analogue for Mars[J]. J. Geophys. Res.-Planets, 2018a, 123: 2336-2364.\u003c/li\u003e\n\u003cli\u003eHu, C., Chen, N., Kapp, P. et al. Yardang geometries in the Qaidam Basin and their controlling factors[J], 2017, 299: 142-151. \u003c/li\u003e\n\u003cli\u003eKapp, P., Pelletier, J.D., Rohrmann, A. et al. Wind erosion in the Qaidam basin, central Asia: Implications for tectonics, paleoclimate, and the source of the Loess Plateau[J]. GSA Today, 2011, 21: 4-10. \u003c/li\u003e\n\u003cli\u003eRohrmann, A., Heermance, R., Kapp, P. et al. Wind as the primary driver of erosion in the Qaidam Basin, China[J]. Earth Planet. Sci. Lett, 2013, 374: 1-10. \u003c/li\u003e\n\u003cli\u003eWu, L., Prush, V., Lin, X.B. et al. Quantifying Wind Erosion During the Late Quaternary in the Qaidam Basin, Central Asia[J]. Geophys. Res. Lett., 2019, 46: 6378-6387. \u003c/li\u003e\n\u003cli\u003eWang, Z.T., Wang, H.T., Niu, Q.H. et al. Abrasion of yardangs[J]. Phys. Rev. E, 2011, 84: 031304. [18] Heermance, R.V., Pullen, A., Kapp, P. et al. Climatic and tectonic controls on sedimentation and erosion during the Pliocene-Quaternary in the Qaidam Basin (China)[J]. Geol. Soc. Am. Bull., 2013, 125: 833-856. \u003c/li\u003e\n\u003cli\u003eHeermance,R.V.,Pullen,A.,Kapp,P.et al.Climatic and tectonic controls on sedimentation and erosion during the Pliocene-Quaternary in the Qaidam Basin (China)[J]. Geol. Soc. Am. Bull.,2013,125:833-856. \u003c/li\u003e\n\u003cli\u003eWard A W, Greeley R.E. Evolution of the yardangs at Rogers Lake, California[J]. Geological Society of America Bulletin, 1984, 95(7): 829-837.\u003c/li\u003e\n\u003cli\u003eGoudie A S, Stokes S, Cook J, et al. Yardang landforms from Kharga Oasis, southwestern Egypt[J]. Zeitschrift Fur Geomorphologie, 1999, 116(S1): 97-112. \u003c/li\u003e\n\u003cli\u003eAl-Dousari A M, Al-Elaj M, Al-Enezi E, et al. Origin and characteristics of yardangs in the Um Al-Rimam depressions (NKuwait)[J]. Geomorphology, 2009, 104: 93-104. \u003c/li\u003e\n\u003cli\u003eDing Zhaojing. Optically Stimulated Luminescence chronology and paleo-environmental implications of yardangs in the Qaidam Basin[D]. China University of Geosciences, 2020. \u003c/li\u003e\n\u003cli\u003eVincent P, Kattan F. Yardangs on the Cambro-Ordovician saq sandstones, North-West Saudi Arabia[J]. Zeitschrift Fur Geomorphologie, 2006, 50(3): 305-320. \u003c/li\u003e\n\u003cli\u003eAl-Dousari A M, Al-Elaj M, Al-Enezi E, et al. Origin and characteristics of yardangs in the Um Al-Rimam depressions (N Kuwait)[J]. Geomorphology, 2009, 104(3-4): 93-104. \u003c/li\u003e\n\u003cli\u003eNiu Qinghe, Qu Jianjun, Liu Benli, et al. Dating methods for chronological study of Yardang Landforms: A review and perspective in application[J]. Marine Geology \u0026amp; Quaternary Geology, 2013, 33(4): 201-208.\u003c/li\u003e\n\u003cli\u003eYanjie Wang, Fadong, Xujiao Zhang, et al. Formation and evolution of yardangs activated by Late Pleistocene tectonic movement in Dunhuang, Gansu Province of China[J]. Journal of Earth System Science, 2016, 125(8): 1603-1614. \u003c/li\u003e\n\u003cli\u003eKangkang Li, Xiaoguang Qin, Bing Xu, et al. Palaeofloods at ancient Loulan, northwest China: Geoarchaeological perspectives on burial practices[J]. Quaternary International, 2021, 577: 131-138.\u003c/li\u003e\n\u003cli\u003eXu Z J, Quan X, Shi H W, et al. Erosion process and spatial distribution characteristics of erosion-deposition on the loess slope[J]. Journal of Shanxi Normal University (Natural Science Edition), 2021, 49(6): 98-105. \u003c/li\u003e\n\u003cli\u003eO. P. Yermolaev, A. M. Gafurov, and B. M. Usmanov. Evaluation of Erosion Intensity and Dynamics Using Terrestrial Laser Scanning[J]. Eurasian Soil Science, 2018, 51(7): 814-826. \u003c/li\u003e\n\u003cli\u003eJennifer Telling, Andrew Lyda, Preston Hartzell, et al. Review of Earth science research using terrestrial laser scanning[J]. Earth-Science Reviews, 2017, 169: 35-68. \u003c/li\u003e\n\u003cli\u003eXijiang Chen, Ya Ban, Xianghong Hua, et al. A method for the calculation of Detectable Landslide using Terrestrial Laser Scanning data[J]. Measurement, 2020, 160: 107852. \u003c/li\u003e\n\u003cli\u003eStefano Fabbri, Beatrice M.S. Giambastiani, Flavia Sistilli, et al. Geomorphological analysis and classification of foredune ridges based on Terrestrial Laser Scanning (TLS) technology[J]. Geomorphology, 2017, 295: 436-451.\u003c/li\u003e\n\u003cli\u003eZheng Benxing, Zhang Linyuan, Hu Xiaohong. Distribution and Characteristics of Yardang Landform and Its Formation Period, West to Yumenguan, Gansu[J]. Journal of Desert Research, 2002, 22(1): 40-46.\u003c/li\u003e\n\u003cli\u003eLin Yongchong, Mu Guijin, Li Wen et al. Environmental change of the ancient oasis in Loulan, Xinjiang during the Little Ice Age[J]. Journal of Arid Land Resources and Environment, 2020, 34(7): 125-132.\u003c/li\u003e\n\u003cli\u003eLi K K, Qin X G, Zhang L. et al. Oasis landscape of the ancient Loulan on the west bank of Lop Nur, northwest China, inferred from vegetation utilization for architecture[J]. The Holocene, 2019, 29(6): 1030-1044.\u003c/li\u003e\n\u003cli\u003eLi Kangkang, Qin Xiaoguang, Zhang Lei, et al. The ancient oasis and human activity in Lop Nur (Loulan) region during 1260-1450 AD[J]. Quaternary Sciences, 2018, 38(3): 720-731.\u003c/li\u003e\n\u003cli\u003eLi K K, Qin X G, Zhang L. et al. Hydrological change and human activity during Yuan\u0026ndash;Ming Dynasties in the Loulan area, northwestern China[J]. The Holocene, 2018, 28(8): 1-10.\u003c/li\u003e\n\u003cli\u003eNiu Qinghe, Qu Jianjun, Li Xiaoze, et al. Review and prospect of yardang landforms research[J]. ADVANCES IN EARTH SCIENCE, 2011, 26(5): 516-527.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTab.1 the\u0026nbsp;\u003csup\u003e14\u003c/sup\u003eC\u0026nbsp;age of\u0026nbsp;Withered vegetation\u0026nbsp;on the top of yardangs\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"540\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.11111111111111%\" rowspan=\"2\"\u003e\n \u003cp\u003eLab Code\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.777777777777779%\" rowspan=\"2\"\u003e\n \u003cp\u003eField number\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.777777777777779%\" rowspan=\"2\"\u003e\n \u003cp\u003eSample substance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.925925925925926%\" rowspan=\"2\"\u003e\n \u003cp\u003eFrom now on\u003csup\u003e1)\u003c/sup\u003e\u003c/p\u003e\n \u003cp\u003e(a BP)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"42.407407407407405%\" colspan=\"2\"\u003e\n \u003cp\u003eTree wheel correction\u003csup\u003e2)\u003c/sup\u003e(Cal BP)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"62.280701754385966%\"\u003e\n \u003cp\u003esiding-to-siding block\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"37.719298245614034%\"\u003e\n \u003cp\u003em\u0026plusmn;s\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.14100185528757%\"\u003e\n \u003cp\u003eCG-2020-1272\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.801484230055658%\"\u003e\n \u003cp\u003eYardan 001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.801484230055658%\"\u003e\n \u003cp\u003ewood\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.955473098330241%\"\u003e\n \u003cp\u003e565\u0026plusmn;25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.34508348794063%\"\u003e\n \u003cp\u003e626(36.2%)605cal BP\u003c/p\u003e\n \u003cp\u003e557(32.0%)539cal BP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.955473098330241%\"\u003e\n \u003cp\u003e585\u0026plusmn;36\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.14100185528757%\"\u003e\n \u003cp\u003eCG-2020-1273\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.801484230055658%\"\u003e\n \u003cp\u003eYardan 002\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.801484230055658%\"\u003e\n \u003cp\u003ewood\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.955473098330241%\"\u003e\n \u003cp\u003e1780\u0026plusmn;25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.34508348794063%\"\u003e\n \u003cp\u003e1729(33.8%)1691cal BP\u003c/p\u003e\n \u003cp\u003e1671(34.4%)1625cal BP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.955473098330241%\"\u003e\n \u003cp\u003e1693\u0026plusmn;50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.14100185528757%\"\u003e\n \u003cp\u003eCG-2020-1274\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.801484230055658%\"\u003e\n \u003cp\u003eYardan 003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.801484230055658%\"\u003e\n \u003cp\u003ewood\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.955473098330241%\"\u003e\n \u003cp\u003e525\u0026plusmn;30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.34508348794063%\"\u003e\n \u003cp\u003e550(68.2%)516cal BP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.955473098330241%\"\u003e\n \u003cp\u003e548\u0026plusmn;33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTab.2 the OSL age of ediment\u0026nbsp;on the top of yardangs\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"547\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.689213893967093%\"\u003e\n \u003cp\u003eSend sample number\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.990859232175502%\"\u003e\n \u003cp\u003eExperimental number\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.140767824497258%\"\u003e\n \u003cp\u003edepth of burial (m)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.248628884826326%\"\u003e\n \u003cp\u003e\u0026alpha;\u0026nbsp;counting rate\u003c/p\u003e\n \u003cp\u003e(Counts/ks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.581352833638026%\"\u003e\n \u003cp\u003eK\u003c/p\u003e\n \u003cp\u003e(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.689213893967093%\"\u003e\n \u003cp\u003emoisture content\u003c/p\u003e\n \u003cp\u003e(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.893967093235831%\"\u003e\n \u003cp\u003eEnvironmental dose rate\u003c/p\u003e\n \u003cp\u003e(Gy/ka)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.614259597806216%\"\u003e\n \u003cp\u003edose\u003c/p\u003e\n \u003cp\u003e（Gy\u0026nbsp;）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.151736745886655%\"\u003e\n \u003cp\u003eage\u003c/p\u003e\n \u003cp\u003e(ka \u0026nbsp;BP )\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.689213893967093%\"\u003e\n \u003cp\u003eNo.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.990859232175502%\"\u003e\n \u003cp\u003eLEDL09-330\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.140767824497258%\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.248628884826326%\"\u003e\n \u003cp\u003e10.9\u0026plusmn;0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.581352833638026%\"\u003e\n \u003cp\u003e1.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.689213893967093%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.893967093235831%\"\u003e\n \u003cp\u003e4.32\u0026plusmn;0.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.614259597806216%\"\u003e\n \u003cp\u003e12.1\u0026plusmn;1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.151736745886655%\"\u003e\n \u003cp\u003e2.8\u0026plusmn;0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTab.3 A test on scanning accuracy of black-and-white target（Unit：mm）\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"508\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.464566929133857%\" rowspan=\"2\"\u003e\n \u003cp\u003ecall the roll\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.023622047244096%\" colspan=\"3\"\u003e\n \u003cp\u003eCoordinate of the control network measurement\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"37.99212598425197%\" colspan=\"3\"\u003e\n \u003cp\u003eScan point cloud data acquisition coordinates\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.519685039370078%\" rowspan=\"2\"\u003e\n \u003cp\u003eSpatial distance deviation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.71087533156499%\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.71087533156499%\"\u003e\n \u003cp\u003eY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\"\u003e\n \u003cp\u003eZ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.24137931034483%\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.50663129973475%\"\u003e\n \u003cp\u003eY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.445623342175065%\"\u003e\n \u003cp\u003eZ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.447937131630649%\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.37721021611002%\"\u003e\n \u003cp\u003e-4636.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.37721021611002%\"\u003e\n \u003cp\u003e-1598.74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.394891944990176%\"\u003e\n \u003cp\u003e-203.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.770137524557956%\"\u003e\n \u003cp\u003e-4637.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.966601178781925%\"\u003e\n \u003cp\u003e-1599.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.180746561886052%\"\u003e\n \u003cp\u003e-203.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.4852652259332%\"\u003e\n \u003cp\u003e1.66\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.447937131630649%\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.37721021611002%\"\u003e\n \u003cp\u003e-3600.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.37721021611002%\"\u003e\n \u003cp\u003e1977.64\u003c/p\u003e\n \u003c/td\u003e\n 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\u003cp\u003e0.78\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Yardang Landforms, Erosion Rate, 3D Laser Scanning, Chronology, Peacock River","lastPublishedDoi":"10.21203/rs.3.rs-4927891/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4927891/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eYardang landforms are significant subjects for research concerning climate change, geomorphological evolution, aeolian sand management, and ecosystem stability. The Lop Nur area, as the origin of the term \"Yardang,\" has seen limited in-depth studies of its Yardang landform development and evolution. This paper integrates field surveys of Yardang landforms downstream of the Peacock River, 14C dating, optical dating, large-scale topographic mapping, and 3D laser scanning to investigate the erosion rates of these landforms. The key findings are as follows: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) The average erosion rate of the Yardang landforms downstream of the Peacock River since 565\u0026thinsp;\u0026plusmn;\u0026thinsp;25a BP is between 1.54 and 0.00 cm/year, with 88.32% of the area experiencing rates between 1.37 and 0.55 cm/year; currently, 72% of the area is undergoing erosion at rates ranging from 3.0 to 0.0 cm/year, with 17.30% of that area experiencing rates between 1.2 and 0.6 cm/year, and 38.70% experiencing less than 0.6 cm/year. The current erosion rates are significantly lower than historical averages, with some low-lying areas currently accumulating sediment; (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) A comprehensive research method has been established, based on the developmental patterns of Yardang landforms for historical average erosion rates and on 3D laser scanning for current erosion rates. This method has enabled the determination of both historical average and current erosion rates in the Yardang area downstream of the Peacock River. The establishment of a permanent erosion monitoring network in this area will support long-term tracking and monitoring of Yardang landform development and provide a foundation for research on climate change, geomorphological evolution, aeolian sand management, and ecosystem stability in the region; (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) The study systematically determined the deposition time, exposure time, and erosion time related to Yardang development downstream of the Peacock River, which are 2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.3ka BP, 1900a BP, and 565\u0026thinsp;\u0026plusmn;\u0026thinsp;25a BP, respectively. These findings are crucial for understanding the evolution of Yardang landforms in the area and will facilitate the advancement of numerical simulations towards long-term geomorphological evolution research. The study provides insights into the timing of Yardang landform development, historical and current erosion rates, and establishes a comprehensive research methodology, which is essential for quantitative research on the formation and development environment of Yardang landforms downstream of the Peacock River.\u003c/p\u003e","manuscriptTitle":"Erosion Rate Study of Yardang Landforms Downstream of the Peacock River","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-09-20 02:29:31","doi":"10.21203/rs.3.rs-4927891/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0a7fbc50-c94b-4735-a8cc-a4444440e641","owner":[],"postedDate":"September 20th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-10-10T12:38:57+00:00","versionOfRecord":[],"versionCreatedAt":"2024-09-20 02:29:31","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4927891","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4927891","identity":"rs-4927891","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}