Investigating the Influence of Salt Concentration in Drying Lake Urmia on Saline Water Intrusion in an Adjacent Aquifer

Investigating the Influence of Salt Concentration in Drying Lake Urmia on Saline Water Intrusion in an Adjacent Aquifer | 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 Investigating the Influence of Salt Concentration in Drying Lake Urmia on Saline Water Intrusion in an Adjacent Aquifer Hojjat Ahmadi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5249986/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 Drying of Lake Urmia due to less water entry and evaporation leads to a rise in salt concentration as well as the saline water density. The declining saline water level and rising of its density have the opposite effect on the saltwater intrusion dynamic. In this study, based on the groundwater and lake water level fluctuations and density variation of Lake Urmia over two decades, the saltwater interaction in one of the coastal aquifers has been studied numerically using SEAWAT. The findings of the research have been approved by comparing the model results with the recorded data collected from the observation wells in the studied aquifer. The achieved results showed that in the case of constant lake water density saltwater wedge progresses slightly by the middle of the studied period and then recedes to the lakeside while considering the increasing density of the lake over 27 years showed that the length of the saltwater wedge in the field scale surprisingly has been expanded more than 250% during the shrinking period of the lake with more than 6 m dropping of water level. Overall, considering the behavior of the saltwater intrusion around the coastal area based on our findings would be conducive to the realistic management of the saline lakes and the implementation of any restoration program for drying lakes. Groundwater Salinity Density Lake Urmia Intrusion Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Introduction Saline water is recognized as a prominent contributor to groundwater contamination globally, posing a significant threat to freshwater resources in coastal regions (Barlow and Reichard, 2010; Werner et al., 2013). The significance of groundwater as a crucial freshwater resource in arid and semi-arid regions cannot be overstated, as it plays a pivotal role in fostering sustainable development within the agricultural and industrial sectors. Consequently, researchers have primarily focused on analyzing the interplay between saltwater and groundwater in coastal areas characterized by a dry climate (Agoubi, 2021; Lin et al., 2008; Shi and Jiao, 2014; Strack et al., 2016). According to the literature, saltwater intrusion is a complicated phenomenon and depends on different factors such as the recharge/discharge of the aquifer, climatological/meteorological factors, geological properties, hydrodynamic parameters, groundwater, and saline water properties, and elevation. (Dhal and Swain, 2022; Ketabchi and Jahangir, 2021; Laabidi and Bouhlila, 2022; Morgan et al., 2013; Shi and Jiao, 2014; Werner et al., 2013). However, among the aforementioned parameters, the main reason for saltwater intrusion into the surrounding coastal aquifers is the density difference between saltwater and freshwater (Bear, 2013; Bobba, 1993; Cheng et al., 1998; Frind, 1982; Huyakorn et al., 1987; Simpson and Clement, 2003; Vacher, 1988; Verruijt, 1968; Younes and Fahs, 2014). Most of the conducted research in the experimental and field scale intrusion have considered constant density for saline water even in transient boundary condition (Badaruddin and Mehdizadeh, 2021; Crestani et al., 2022; da Silva et al., 2020; Dalai and Dhar, 2023; Ketabchi and Jahangir, 2021; Ketabchi et al., 2016; Ketabchi et al., 2014; Lin et al., 2008; Morgan et al., 2013; Shi and Jiao, 2014; Yang et al., 2015; Zhang, 2012), because the most studied aquifers located around open sea shore lines (Abd-Elaty and Zelenakova, 2022; Alberti et al., 2009; Dokou et al., 2017), therefore the primary rationale for employing a constant density assumption is attributed to the consistent temporal stability of seawater salinity (Adusumilli et al., 2020; Dokou et al., 2017; Li et al., 2020; Sparks et al., 1980; Yang et al., 2019). The drying of lakes worldwide is generally recognized as a significant consequence of long lasting droughts result in climate change (Abbaspour et al., 2012; Coppens et al., 2020; Senatore et al., 2019; Woolway et al., 2020; Wurtsbaugh et al., 2017), and anthropogenic activities (AghaKouchak et al., 2021; Alizade Govarchin Ghale et al., 2018; Chuai et al., 2012; Rad et al., 2022; Sheibani et al., 2020) have accompanied with rising of salinity and water density (Liu et al., 2022; Thorslund and van Vliet, 2020). Investigation of lake water salinity in Lake Urmia and the Dead Sea shows that the salt concentration has reached to saturated and even saturated level (Khlaifat et al., 2020; Parsinejad et al., 2022; Sheibani et al., 2023). The salt concentration in Aral Sea has initiated to rising after modern desiccation of the water level since the 1950s. During last decades the water level has droped continusly by more than 28 m, during this degradation the lake departed to different zones and the salinity raised up 100–200% in different departed parts (Aladin et al., 2019). Krupa and Grishaeva (2019) reported that the salt concentration in the Small Aral (the northern part of the lake) has decreased since 1990 by implementing the restoration program for the relevant part separated by using a levee from the origin. The salinity variation in shallow lakes is significantly higher than in deep lakes. Comparison of three lakes with different depth and surface area (Great Salt Lake, Mono Lake, and in the same basing in Utah shows that Pyramid Lake) revealed that the lakes with big surface area are more disposed to evaporation, so water table fluctuations make sever variation to the volume of the water as well as dissolved material concentration (Baxter and Butler, 2020). Monitoring of Great Salt Lakes shows that the salt concentration has varied between 60 g/l to 280 g/l in the southern part meanwhile it had raised up 350 g/l in the northern part during the last 45 years (White et al., 2015). Hence, based on the importance of the salt density difference with fresh water as the main reason for saltwater intrusion and dependency of density of lake waters with water volume as well as the water table, it is reasonable considering variable density in the saltwater intrusion analysis. However, a few studies regarding coastal groundwater dynamic around saline lakes were conducted by considering constant concentration and saline water density, (Ahmadi et al., 2022; Ahmed and Altunkaynak, 2019; Janardhana and Khairy, 2019; Motallebian et al., 2019; Sheibani et al., 2020; Shibuo et al., 2004, 2006; Yechieli et al., 2010) while the studied cases had temporal variable salt concentration during the studied period. An experimental study investigating the influence of seawater density on saltwater intrusion around the Bohai Sea in China revealed that even a slight variation in sea density can cause a shift from steady-state intrusion to transient behavior under the sea water level stable circumstances. The experimental tests demonstrated a significant advancement in the saline plume when the saltwater density increased from 1.019 to 1.025 g/ml (Na et al., 2019). A sensitivity analysis of saltwater density in the range of 1.020 to 1.030 g/ml showed that the performances of installed cutwall in an unconfined aquifer as a groundwater protecting structure from saltwater intrusion is reduced with increasing saltwater density (Abdoulhalik and Ahmed, 2017). Motallebian et al. (2022) conducted an experimental scale intrusion test at the fixed boundary condition with different salt concentrations for saline water. They reported that increasing saltwater concentrations 2 and 2.5 times from initial values led to the advancement of saltwater wedge more than 2 and 3 times of initial length, respectively. Shibuo et al. (2006) examined the effect density of seawater under different sea shore geometry and informed that the rising of density in steep shoreline make more progression of the saltwater wedge in comparison to the flat shore. Based on their findings 90% increase of saltwater density in flat geometry makes the expansion of saltwater wedge up to 200% while in steep cases it was more than 250%. In the presented review of literature, it is evident that there is limited research available on the influence of both density and salt concentration variation, particularly within a narrow range of density variation, on saltwater intrusion around coastal aquifers. However, when focusing on drying lakes such as Urmia Lake, which exhibit hypersaline conditions encompassing a wide range of salt concentrations ranging from 150 g/l up to 410 g/l, this research gap becomes even more pronounced. To address this significant research gap, our current study aims to conduct a comprehensive investigation of the groundwater dynamics associated with the drying of Urmia Lake under severe water level and salinity variations. In our analysis, we consider the real-time recorded lake water level and groundwater table, taking into account the actual salt concentration and its corresponding density. By incorporating these essential factors, we can obtain a more accurate understanding of the complex processes occurring within the coastal aquifer connected to drying lakes. In addition to the variable concentration scenarios, we also examine the problem under a constant concentration scenario to establish a basis for comparison. This comparative analysis allows us to better assess the impact of salt concentration on saline water intrusion. By considering both realistic variable cases and the constant concentration case, we can obtain valuable insights into the behavior and consequences of salt concentration variation. This research provides a deeper understanding of the processes influencing saline water intrusion in the coastal aquifer connected to Lake Urmia or other hypersaline lakes. Site description To study the effect of desiccation of a saltwater lake on the surrounding aquifers Lake Urmia has been considered in this study, which is the largest lake in the Middle East and one of the largest saltwater lakes in the world, with a maximum recorded area of more than 6100 km 2 (Léger et al., 1987) in the northwest of Iran. Additionally, it is located at a level of 1250 m above the elevation of the open seas (Van Stappen et al., 2001) between the West and East Azerbaijan provinces. The length of the lake along the north to the south reaches 140 km and expands to a maximum of 85 km along the east to the west. The average level of the lake bed was 1267 m above the open sea level (Vaheddoost and Aksoy, 2018). Moreover, the average depth of the lake was 6 m and its maximum depth was 16 m in the northern parts of the lake in normal conditions (Amiri et al., 2016). Despite the high altitude of the lake above sea level, most of the residential areas around the lake are about 30 m above the lake level (Noori and Aghaei, 2013). Figure 1 shows the position of Lake Urmia. The lake has undergone severe reductions in the water level and volume due to climate change, the construction of numerous dams on feeder rivers, excessive exploitation of basin water resources, and management problems. Thus, the lake area has reduced to less than 2100 km 2 and the water level dropped around 8 m during 1995-2015 (Danesh-Yazdi and Ataie-Ashtiani, 2019; Jalili et al., 2016; Pouladi et al., 2020; Soudi et al., 2017; Soudi et al., 2019). The variation of the lake water level for about 60 years is depicted in Figure 2 (A). Since 2013, due to the creation of the Urmia Lake Restoration National Committee and the implementation of some water management projects, a slight increase has occurred in water levels (Danesh-Yazdi and Ataie-Ashtiani, 2019). However, the reduction in the water level has significantly caused to increase in salinity concentration, and consequently, water density. Figure 2 (B) illustrates the changes in the salinity concentration and water density of the lake. Likewise, Figure 2 (C) displays changes in the density of Lake Urmia in recent years since the shrinking of the lake has dramatically begun and the water level has decreased beneath the ecological level (1274 m) as shown in Figure 2 (A). There are 17 aquifers around Lake Urmia, and the Rashakan aquifer, which is located in the western part of Lake Urmia, has special conditions for the implementation of our model. Owing to a long feeder area from the western mountains border of the aquifer recharge and discharge (abstraction and depletion to the lake), in this aquifer are approximately in balance (Javadzadeh et al., 2020). Figure 2 depicts the position of the aquifer relative to the lake and its basin. The aquifer is located in young terraces and alluvium, including Limestone, Marl, and Conglomerate in the south region. The average thickness of the Rashakan aquifer is estimated at 45 m and the bedrock elevation is approximately 1235.8 m throughout the aquifer. In addition, the topography of the area has a relatively mild slope, and the height difference between the highest and lowest parts of the plain is nearly 50 m. Most input parameters of the model are defined based on the measured data, except for diffusion and dispersion coefficients which are selected based on the filed and reported data (Motallebian et al., 2022).Table 1 presents the input parameters of the Rashakan aquifer. Table 1. Parameters used for the scenarios of numerical simulation on the experimental model and the Rashakan aquifer near Lake Urmia Parameters Value Rashakan Aquifer Porosity (n) 0.28 Longitudinal dispersivity (α L ) 7 m Transverse dispersivity (α T ) 2 m Molecular diffusion (D m ) 1e-7 Hydraulic conductivity (K) 2.5 m/day Time steps 1 day Grid size 5 m The initial density of saline water 1.10 gr/cm 3 Range of final density of saline water 1.1-1.30 gr/cm 3 The four installed piezometric wells have continuously recorded groundwater levels in the aquifer since 2004. The positions of the piezometric wells are shown in Figure 1, indicated by orange points located in the northern part of the aquifer. Three piezometers, namely A, B, and D, are situated near the lake, while piezometer C is approximately 850 m away from the shore. The water level observed at the present piezometer is used as the groundwater level at the boundary of the aquifer's geometry. The data collected from piezometers A and D have been utilized to assess the validity of the numerical modeling procedures. Since the water table in the piezometer closest to the lake is expected to correspond to the lake water level, the data collected from piezometer B was not considered in the current analysis. Based on the recorded data, the recharge and discharge of the Rashakan aquifer appear to be nearly balanced, which can be attributed to the implementation of a groundwater preservation program by the local water agency, however, some reports show the average rate of the level reduction in this aquifer was reported as 0.12 m/year, meanwhile, the rate of the dropping of the lake water level was 35 cm/year (Sheibani et al., 2020), It appears more likely that the reported decrease in the groundwater table is attributed to the dropping water level of the lake. Modeling procedure To investigate the impact of variations in lake water density over the 27-year drying period (from 1995-2022), the migration of saline water from the lake inland was studied under two different circumstances: a. Variable salt concentration (VSC) of lake water, using real-time recorded values of lake salinity. b. Constant salt concentration (CSC) based on the lake's normal condition before the drying period. The objective was to understand how the changing density of lake water influenced the movement of saline water into the surrounding inland areas. In the case of CSC, the salinity of the lake was determined to be 150 g/l, and the density was measured at 1.10 g/ml. For both conditions, the head-controlled method was used for the numerical modeling, however unlike to common fixed head method (Werner and Simmons, 2009) in which the inland head variation of groundwater is considered independent of saline water level fluctuations, real-time recorded groundwater head at the relevant boundary of the aquifer was imposed to the model. Meanwhile, the water level decreased from 1277.85 m in 1995 to 1270.09 m on September 21, 2022, was taken into account as the boundary condition for the lakeside. Creating the initial conditions for the interface position within the aquifer at the initiation of the studied period prior to the lake water decline has been one of the fundamental steps of this study. To this end, first, an initial steady state analysis was conducted to estimate the position of the saltwater-freshwater interface by acting boundary conditions for the inland groundwater level and saline water levels in the lakeside based on conditions in 1995 without considering saltwater density and concentration variation. Of course, the assessment of recorded data on lake water levels demonstrates the level of lake water had been approximately constant over a long period from 1955 to 1995 except in the normal seasonal oscillations however. Hence, to determine the amount of intrusion into the Rashakan aquifer a steady-state analysis was carried out based on the average water level in Lake Urmia equal to 1276.51 m,above open seas levels (ASL), over 40 years from 1955 to 1995. The groundwater at this period was considered 1285.1 m ASL which is one meter more than the highest recorded level in monitoring history of the relevant observation well. The value is extrapolated based on the descending slope of the groundwater level. Figure 3 shows the entered hydraulic boundary conditions for the model. As previously mentioned, during the wet period of the lake (between 1955 and 1995), the salinity and density of the lake water were approximately 150 g/l and 1.10 g/ml, respectively. Considering that the water level has been dramatically reduced in Lake Urmia, the effect of increasing the density should be considered when analyzing the intrusion behavior. As shown in Figure 2C, density variations in different years were nonlinear and continuous. The density changes at the boundary in the lakeside were applied to the numerical model by converting the nonlinear behavior of density relative to the time to a stepped quasi-linear state in different stress periods in the SEAWAT. The mean value of densities of saline water at the beginning and end of each stress period involved for the corresponding stress period in transient analysis. Hence beyond the steady state analysis of the initial condition for 40 years, the transient analysis of 27 years of lake water interaction with the Rashakan aquifer was discretized into 17 different stress periods. The shortest period was 3 months and the longest was 5 years for the last five years since lake water density remains constant owing to reaching saturated levels of dissolved salts. Specific Head type boundary condition was used for both sides of the model according to the recorded water level in the lake and piezometric well at the land side boundary of the aquifer. As shown in Figure 1, the skinny elongated aquifer of Rashakan is stretched along the shoreline. Therefore a section of the aquifer in 5 m thickness was modeled with the 3D grid approach in which acted as a 2D model. To comprehend the impact of salt concentration on saltwater intrusion and its consequent effect on rising density, the results from the VSC and SCS states were analyzed. Results and discussion Intrusion before drying lake Before the study of the saltwater interaction with adjacent groundwater for the drying period of Lake Urmia, a steady-state analysis was carried out based on the constant water level in Lake Urmia over 40 years from 1955 to 1995. Figure 4 depicts the saltwater intrusion length for the studied steady-state conditions. As seen in the figure the length of the intruded saltwater is less than 200 m and the needed time to reach a stable wedge lasts almost 20 years. The results on numerivcal model in this figure shows, similar to the results of Chang and Clement (2013), after 20 years of analysis vectors of saline and fresh water in the domain got parallel and so the saltwater wedge reached the final position. Drying Period Variable Density (VSC) Over overview of the lake water elevation history presented in Figure 1 demonstrates that , since 1995, after reaching to the highest recorded water level a decline of lake water level was initiated. The drop of water level in the past 27 years was divided in two parts. The first part was lasted from 1995 to 2006 and the second period was started from 2007 to 2022. The rate of dropping of water level in the first part was slightly faster than the second part because at this period the lake area was more vast and so more evaporation had been accrued while the discharge flow of rivers wasn’t able to compensate the huge volume of the lost water because of sever evaporation. In the second period due to shrinking the lake water body the same inlet flow could somewhat up the evaporated height of the lake water level more in comparison to the first period. Moreover, in recent years, due to the implementation of some restoration projects, a significant increase in the discharge of rivers into the lake has been reported. This increased inflow has led to a slight rise in water levels within the lake. The enhanced river discharge has helped to partially offset the effects of evaporation, contributing to the stabilization or even a slight increase in water levels (Parsinejad et al., 2022). However, the evidences confirm unsustainability of the restoration program. Generally, the water dropping is accompanied with a rising of salinity and density. Modeling of saltwater intrusion based on the density variation and water level at the both inland and lake sides is presented in Figure 5. The figure shows the advancing of the saltwater wedge in different years after starting of drying up the lake. Based on the achieved results, the rate of encroachment of wedge toe is slower in the first decline period than the second, nevertheless, the rating of lake water decline at the beginning times of the drying period between 1995 to 2006 was faster than the second period. After initiating of lake water dropping, the wedge length had remained constant for almost two years. It had started to continually expand under the aquifer since 2006. During the years 2006 and 2007, owing to a considerable wet season and high precipitation in those years a remarkable jump in groundwater elevation happened (Alizadeh‐Choobari et al., 2016; Mohebzadeh and Fallah, 2019). As a result, the decline in the lake water level was halted temporarily. However, numerical models confirm a very slightly advancement of the saltwater wedge during those years as shown in Figure 5. Comparison of flow vectors of the aforementioned two years (2006 and 2007) with others shows that a convection upward flow had developed in the upper part of the wedge, meanwhile the wedge in the bottom was moving to the landside. The upper upward convection flow had happened because of the rising up groundwater level in the boundary at the relevant years as shown in Figure 3. The configuration of convection flows is influenced by the presence of a stagnation area in which the plume struggles to move forward, resulting in the diversion of horizontal flow to upward. Typically, the stagnation point is located in front of the wedge tip, where the opposing vectors of freshwater and saltwater intersect. At this point, the hydraulic energy of both saltwater and freshwater becomes equal. During the receding state by rising groundwater level, the stagnation point penetrates into the saltwater wedge (Chang and Clement, 2013). Under such circumstances the fresh water forces saltwater to flash out from the occupied region. According to the stagnation points in the interface area of the wedge in the years 2006 and 2007, it can be concluded, The upper part of the aquifer is under the pressure of freshwater, while the lower part of the aquifer is under the pressure of saline water. Despite the movement of the stagnation points in the upper regions of the plume towards the saline water, intrusion is observed throughout the aquifer at all. This contradictory behavior is caused by the increased saline water density. In fact during this period, despite of constant lake water level, its rising density covers the effect of the temporary groundwater level rising on the inside. Of course, the advancement of the saltwater wedge during the discussed period was very low. In the following, from mid-2007 until 2022, the intrusion of saltwater has significantly increased inland, encroaching more than twice the length of the wedge compared to the years prior to the lake's drought period as shown in Figure 5b . The flow vectors presented by the model in 2022 confirm the elimination of developed convection flows within the plume. This can be attributed to either the decline in groundwater levels or the increased energy of saltwater due to rising density. Similar behavior reported by researchers who worked on the coastal aquifers around Lake Urmia (Ahmadi et al., 2022; Motallebian et al., 2022). Constant Density (CSC) To investigate the impact of density variations on saltwater intrusion, another model was developed to simulate the interaction between the saline water of Urmia Lake and the surrounding Rashakan aquifer. The modeling assumed not only a constant density at the beginning of the drying period, but also implying that the salt concentration of the lake water remained constant throughout the 27-year drought period. For the current analysis, the initial conditions were set to represent at VSC procedure, and a 40-year intrusion modeling study was conducted under fixed head boundary conditions. Figure 6 illustrates the results of the analysis at the same time intervals thet have been presented in VSC state . During the initial stage of drying, a slight upward movement was observed in the saltwater wedge. However, a significant rise in groundwater levels in 2006 led to the recession of the intruded saltwater wedge. As depicted in this figure, the flow vectors within the plume reversed direction, flowing back into the saltwater reservoir from the freshwater side. Notably, stagnation points, where vectors of opposite directions intersect, were found within the plume. Over time, these stagnation points in the form of a wave moved outside the plume and into the saline water chamber. Subsequently, the wedge continued to recede to a new position, eventually reaching almost an steady state condition by 2022. The flow vectors observed under the steady state condition align with the findings of Goswami and Clement (2007) and Chang and Clement (2013), where the saline water concentration was kept constant in their respective tests. Reviewing the presented information in Figure 6b illustrates the length of the wedge over the 27-year drying period. It is evident that the wedge length exhibited slight variations over time. Remarkably, the concentration of the saline water remained constant at 155 gr/l throughout the entire period. As previously mentioned, saltwater intrusion experienced modest advancement during the initial period from 1995 to 2006. However, during the second period of drying, the wedge receded back towards the lake. Based on the constant concentration assumption, the saltwater wedge shrank by approximately 10% of its original length in 1995. Motallebian et al. (2022) showed that receding of saltwater leads to dropping of surrounding groundwater level in case of fixed head boundary condition of groundwater in the landside, therefore, it is concluded that the a part of the dropping of groundwater head which is seen in Figure 3 might be because of the lake water dropping. However, realistic modeling of lake water interaction with Rashakan aquifer showed, as presented in Figure 5, that the saltwater wedge has advanced significantly under the freshwater. It causes to lifting of groundwater in a strip bound from lake shore, and consequently could compensates a part of the impact of lake water dropping into the groundwater level. Perhaps the groundwater table would have dropped more than the recorded values if the wedge had moved back to the lakeside. Validation of the Results of Modeling The interaction between the saltwater dynamics of Lake Urmia and the surrounding groundwater of the Rashakan aquifer exhibits distinct variations in both the Variable Salinity Condition (VSC) and Constant Salinity Condition (CSC) modeling scenarios. In the VSC state, the wedge length has expanded, whereas in the CSC state, not only has the wedge failed to advance in the aquifer, but it has also receded inland. Since the VSC employs more realistic hydraulic and concentration boundary conditions compared to the CSC modeling, it is reasonable to expect more accurate results in the VSC regarding the dynamics of the saltwater wedge and groundwater. However, it is important to note that there is a lack of recorded data regarding saltwater concentration and monitoring of ions to evaluate the computed saltwater plume beneath the aquifer. Motallebian et al. (2022) demonstrate that under similar hydraulic boundaries, higher concentrations of saline water result in an elevated groundwater table because of the more intruded saline water. The observed groundwater elevation data obtained from Piezometers A and D (Fig. 1) were compared with the results of both the VSC and CSC numerical models in terms of the computed groundwater level at the same location. The comparison results are presented in Figure 7. It is evident from the figure that the VSC model yields more consistent results compared to the CSC model. Both models share the same initial conditions before 1995, and the difference in the intruded saltwater wedge remains relatively consistent until 2007. Therefore, the observed data and computed results exhibit good agreement in the initial segments of the presented data. However, after 2007, the saltwater wedge in the VSC state significantly encroaches further inland, while in the CSC state, it recedes towards the lake. Consequently, the computed groundwater table in the VSC model aligns more closely with the real conditions, and the corresponding numerical model and observed data support the validity of the saltwater wedge's advancement around the drying Lake Urmia. Flow Budget The computed flux of freshwater into the lake and saltwater into the aquifer in both studied states is presented in Figure 8. It is evident from this figure that the flow rates of freshwater and saltwater exhibit distinct variations throughout the studied period. Unlike the two conventional techniques commonly used for setting boundary conditions, namely flux-controlled and head controlled, where either the groundwater flux or head is kept fixed (Badaruddin and Mehdizadeh, 2021; Chang et al., 2011; Robinson et al., 2016; Werner et al., 2013), both the head and flux were transient in the domain of our study. The pattern of groundwater flux variation follows the imposed groundwater head at the relevant boundary conditions, while the infiltration of saltwater in the VSC adheres to the saltwater density. The observed spikes in the results correspond to the incremental rise in salt concentration during the designated stress periods. To elucidate this, the average salt concentration at the beginning and end of each stress period was utilized as the representative saline water concentration for the corresponding time interval. A comparison between the computed groundwater discharge in the VSC and the CSC states reveals that the groundwater discharge into the lake is nearly half in the case of constant concentration, whereas the saltwater flux into the aquifer is more than twice as much in the VSC. Reviewing of the presented data in Fig 8 shows that the groundwater flux was around 4 m 3 /day/m at the beginning of the drying period then has been reduced to lower than 2 m 3 /day/m eventually. Meanwhile, analyzing the saltwater infiltration flux during the drying period indicated that the rate of saltwater intrusion in 2022 has increased nearly two-fold compared to the normal lake condition in 1995. Conclusion We studied groundwater interaction with drying Lake Urmia in the coastal Rashakan aquifer located at the west shore of Lake Urmia. Environmental crisis of Lake Urmia has been started in 1995, when the water level dropped dramatically due to anthropogenic issues and climate changing (Parsinejad et al., 2022). We considered recorded field data around the boundary of the studied aquifer to draw a precise perspective of intrusion of lake saline water into the neighboring aquifer. In this regard, the increasing of density and concentration of salt over 27 years, from 1995 to the initiation of the lake crisis, were entered in SEAWAT as a popular saltwater intrusion model. The model results demonstrated that in spite of dropping of water elevation in the lake by more than 6 m, the saltwater has been intruded in the Rashakan aquifer continuously throughout 27 years more than 2 times, approximately from 200 m to 530 m. The findings of this study mentioned that the ignorance of salt concentration increase in the modeling of saltwater intrusion problems would lead to lower estimate of the developed wedge. Additionally, analysis of groundwater flux to the lake showed that exacerbation of intrusion due to rising density create a huge saltwater plume that acts as an underground barrier in front of groundwater flow and makes a significant reduction in the discharge of groundwater into the lake. Although the infiltrating saltwater finally encounters freshwater, circuit, and moves back into the lake through the transition zone of the wedge after reaching the state state, the volume of saline water in the body of saltwater wedge must be considered in any water balance analysis of the lake because of its considerable volume. In fact, in transient conditions significant volume of lake water infiltrates into the surrounding lands and it may not last even in hundreds of years (Ahmadi et al., 2022). Hence, it seems a huge valume of water of drying Lake Urmia infiltrated into the surrounding aquifers, while it might miscalculated as evaporated water during the recent drying period. Consequently, in the case of entry of enough volume of water to the lake, concentration of salt could be reduced as well as its density. This likely leads to the receding of the saltwater wedge into the lake and emphasizes groundwater dishcharge into the lake which could expedite rising of water level in the lake. Declarations Conflict of interest The author declares no conflict of interest. Ethics Approval The author confirms this research follows the ethical standards. Consent to Participate Not applicable. Consent to Publication The author consents to publish this paper in Water Conservation Science and Engineering journal. Funding The author received no financial support for the research and publication of this paper. Author Contribution The whole of the manuscript including conceptualization, data collecting, data analysis, numerical modeling, and writing has been prepared by Hojjat Ahmadi. Acknowledgment Not applicable Data Availability The data are available upon request from the corresponding author. References Abbaspour, M., Javid, A.H., Mirbagheri, S.A., Ahmadi Givi, F., Moghimi, P., 2012. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5249986","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":371776357,"identity":"03005419-1023-4194-aafe-e22c477a28c4","order_by":0,"name":"Hojjat 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11:05:17","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":202291,"visible":true,"origin":"","legend":"\u003cp\u003eLocation of Lake Urmia in Iran and the Middle East and the studied aquifer within the installed piezometers\u003c/p\u003e","description":"","filename":"1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/c9ac4f4e030827d0c4a5483f.jpeg"},{"id":69437554,"identity":"fe286942-deae-4b42-8e30-92f4e65b31fa","added_by":"auto","created_at":"2024-11-20 10:49:17","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":237660,"visible":true,"origin":"","legend":"\u003cp\u003eA) Changes in the concentration and density of Lake Urmia water, B) Changes in the level and density of Lake Urmia Water in different years, C) Quasi-linear variations of Lake Urmia salinity compared to real salinity\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/1d042cf5e54e10ae7faea264.png"},{"id":69437547,"identity":"c75a9eb4-44e0-463c-a03a-4a5cb8295fa3","added_by":"auto","created_at":"2024-11-20 10:49:17","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":82053,"visible":true,"origin":"","legend":"\u003cp\u003eThe water level in groundwater and lake water level in the boundaries of the model\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/5ec4a9278e42fcfafbadc9d0.png"},{"id":69439370,"identity":"462be90c-eb5b-42f4-9933-30f5b8ec6fa5","added_by":"auto","created_at":"2024-11-20 11:05:17","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":228185,"visible":true,"origin":"","legend":"\u003cp\u003eFlow vectors, saltwater wedge, and progressing tip of the saline plume with time before drying of the lake\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/9b9851d96d0d4511571a83e9.png"},{"id":69438965,"identity":"e2ece6c1-1475-48d1-8953-0b9aa615a81b","added_by":"auto","created_at":"2024-11-20 10:57:17","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":295944,"visible":true,"origin":"","legend":"\u003cp\u003eSaltwater wedge length under Rashakan aquifer with density variable state.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/1be6a10f18479f90e24bed1c.png"},{"id":69438962,"identity":"f93c5b0a-0279-4332-8ea5-10d34e8fe7c4","added_by":"auto","created_at":"2024-11-20 10:57:17","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":262494,"visible":true,"origin":"","legend":"\u003cp\u003eSaltwater wedge length under Rashakan aquifer without density variable state.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/58fff5890d2fa75501c49725.png"},{"id":69437552,"identity":"18c103de-8876-4a1f-bb1c-35674c2ded7c","added_by":"auto","created_at":"2024-11-20 10:49:17","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":164133,"visible":true,"origin":"","legend":"\u003cp\u003eComparison observed and computed groundwater level under different modeling states of VSC (Variable density) and CSC (Constant density) in the Rashakan Aquifer\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/a62eaf367c1a0d93bfa3edac.png"},{"id":69438963,"identity":"e0168b84-2e71-43c9-9060-2747f7294908","added_by":"auto","created_at":"2024-11-20 10:57:17","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":185931,"visible":true,"origin":"","legend":"\u003cp\u003eGroundwater discharge into the lake and saltwater intrusion rate over the drying period of Lake Urmia in the Rashakan aquifer\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/ef5b07f40575b15b360522b4.png"},{"id":71038036,"identity":"11dc5cb2-a46d-48ec-8105-a15701fea3b7","added_by":"auto","created_at":"2024-12-10 13:18:02","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1855207,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5249986/v1/d1b1e7fc-958d-4326-9b15-d5461567e7ee.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Investigating the Influence of Salt Concentration in Drying Lake Urmia on Saline Water Intrusion in an Adjacent Aquifer","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSaline water is recognized as a prominent contributor to groundwater contamination globally, posing a significant threat to freshwater resources in coastal regions (Barlow and Reichard, 2010; Werner et al., 2013). The significance of groundwater as a crucial freshwater resource in arid and semi-arid regions cannot be overstated, as it plays a pivotal role in fostering sustainable development within the agricultural and industrial sectors. Consequently, researchers have primarily focused on analyzing the interplay between saltwater and groundwater in coastal areas characterized by a dry climate (Agoubi, 2021; Lin et al., 2008; Shi and Jiao, 2014; Strack et al., 2016).\u003c/p\u003e \u003cp\u003eAccording to the literature, saltwater intrusion is a complicated phenomenon and depends on different factors such as the recharge/discharge of the aquifer, climatological/meteorological factors, geological properties, hydrodynamic parameters, groundwater, and saline water properties, and elevation. (Dhal and Swain, 2022; Ketabchi and Jahangir, 2021; Laabidi and Bouhlila, 2022; Morgan et al., 2013; Shi and Jiao, 2014; Werner et al., 2013). However, among the aforementioned parameters, the main reason for saltwater intrusion into the surrounding coastal aquifers is the density difference between saltwater and freshwater (Bear, 2013; Bobba, 1993; Cheng et al., 1998; Frind, 1982; Huyakorn et al., 1987; Simpson and Clement, 2003; Vacher, 1988; Verruijt, 1968; Younes and Fahs, 2014). Most of the conducted research in the experimental and field scale intrusion have considered constant density for saline water even in transient boundary condition (Badaruddin and Mehdizadeh, 2021; Crestani et al., 2022; da Silva et al., 2020; Dalai and Dhar, 2023; Ketabchi and Jahangir, 2021; Ketabchi et al., 2016; Ketabchi et al., 2014; Lin et al., 2008; Morgan et al., 2013; Shi and Jiao, 2014; Yang et al., 2015; Zhang, 2012), because the most studied aquifers located around open sea shore lines (Abd-Elaty and Zelenakova, 2022; Alberti et al., 2009; Dokou et al., 2017), therefore the primary rationale for employing a constant density assumption is attributed to the consistent temporal stability of seawater salinity (Adusumilli et al., 2020; Dokou et al., 2017; Li et al., 2020; Sparks et al., 1980; Yang et al., 2019).\u003c/p\u003e \u003cp\u003eThe drying of lakes worldwide is generally recognized as a significant consequence of long lasting droughts result in climate change (Abbaspour et al., 2012; Coppens et al., 2020; Senatore et al., 2019; Woolway et al., 2020; Wurtsbaugh et al., 2017), and anthropogenic activities (AghaKouchak et al., 2021; Alizade Govarchin Ghale et al., 2018; Chuai et al., 2012; Rad et al., 2022; Sheibani et al., 2020) have accompanied with rising of salinity and water density (Liu et al., 2022; Thorslund and van Vliet, 2020). Investigation of lake water salinity in Lake Urmia and the Dead Sea shows that the salt concentration has reached to saturated and even saturated level (Khlaifat et al., 2020; Parsinejad et al., 2022; Sheibani et al., 2023). The salt concentration in Aral Sea has initiated to rising after modern desiccation of the water level since the 1950s. During last decades the water level has droped continusly by more than 28 m, during this degradation the lake departed to different zones and the salinity raised up 100\u0026ndash;200% in different departed parts (Aladin et al., 2019). Krupa and Grishaeva (2019) reported that the salt concentration in the Small Aral (the northern part of the lake) has decreased since 1990 by implementing the restoration program for the relevant part separated by using a levee from the origin.\u003c/p\u003e \u003cp\u003eThe salinity variation in shallow lakes is significantly higher than in deep lakes. Comparison of three lakes with different depth and surface area (Great Salt Lake, Mono Lake, and in the same basing in Utah shows that Pyramid Lake) revealed that the lakes with big surface area are more disposed to evaporation, so water table fluctuations make sever variation to the volume of the water as well as dissolved material concentration (Baxter and Butler, 2020). Monitoring of Great Salt Lakes shows that the salt concentration has varied between 60 g/l to 280 g/l in the southern part meanwhile it had raised up 350 g/l in the northern part during the last 45 years (White et al., 2015). Hence, based on the importance of the salt density difference with fresh water as the main reason for saltwater intrusion and dependency of density of lake waters with water volume as well as the water table, it is reasonable considering variable density in the saltwater intrusion analysis. However, a few studies regarding coastal groundwater dynamic around saline lakes were conducted by considering constant concentration and saline water density, (Ahmadi et al., 2022; Ahmed and Altunkaynak, 2019; Janardhana and Khairy, 2019; Motallebian et al., 2019; Sheibani et al., 2020; Shibuo et al., 2004, 2006; Yechieli et al., 2010) while the studied cases had temporal variable salt concentration during the studied period. An experimental study investigating the influence of seawater density on saltwater intrusion around the Bohai Sea in China revealed that even a slight variation in sea density can cause a shift from steady-state intrusion to transient behavior under the sea water level stable circumstances. The experimental tests demonstrated a significant advancement in the saline plume when the saltwater density increased from 1.019 to 1.025 g/ml (Na et al., 2019). A sensitivity analysis of saltwater density in the range of 1.020 to 1.030 g/ml showed that the performances of installed cutwall in an unconfined aquifer as a groundwater protecting structure from saltwater intrusion is reduced with increasing saltwater density (Abdoulhalik and Ahmed, 2017). Motallebian et al. (2022) conducted an experimental scale intrusion test at the fixed boundary condition with different salt concentrations for saline water. They reported that increasing saltwater concentrations 2 and 2.5 times from initial values led to the advancement of saltwater wedge more than 2 and 3 times of initial length, respectively. Shibuo et al. (2006) examined the effect density of seawater under different sea shore geometry and informed that the rising of density in steep shoreline make more progression of the saltwater wedge in comparison to the flat shore. Based on their findings 90% increase of saltwater density in flat geometry makes the expansion of saltwater wedge up to 200% while in steep cases it was more than 250%.\u003c/p\u003e \u003cp\u003eIn the presented review of literature, it is evident that there is limited research available on the influence of both density and salt concentration variation, particularly within a narrow range of density variation, on saltwater intrusion around coastal aquifers. However, when focusing on drying lakes such as Urmia Lake, which exhibit hypersaline conditions encompassing a wide range of salt concentrations ranging from 150 g/l up to 410 g/l, this research gap becomes even more pronounced. To address this significant research gap, our current study aims to conduct a comprehensive investigation of the groundwater dynamics associated with the drying of Urmia Lake under severe water level and salinity variations. In our analysis, we consider the real-time recorded lake water level and groundwater table, taking into account the actual salt concentration and its corresponding density. By incorporating these essential factors, we can obtain a more accurate understanding of the complex processes occurring within the coastal aquifer connected to drying lakes. In addition to the variable concentration scenarios, we also examine the problem under a constant concentration scenario to establish a basis for comparison. This comparative analysis allows us to better assess the impact of salt concentration on saline water intrusion. By considering both realistic variable cases and the constant concentration case, we can obtain valuable insights into the behavior and consequences of salt concentration variation. This research provides a deeper understanding of the processes influencing saline water intrusion in the coastal aquifer connected to Lake Urmia or other hypersaline lakes.\u003c/p\u003e"},{"header":"Site description","content":"\u003cp\u003eTo study the effect of desiccation of a saltwater lake on the surrounding aquifers Lake Urmia has been considered in this study, which is the largest lake in the Middle East and one of the largest saltwater lakes in the world, with a maximum recorded area of more than 6100 km\u003csup\u003e2\u003c/sup\u003e (L\u0026eacute;ger et al., 1987) in the northwest of Iran. Additionally, it is located at a level of 1250 m above the elevation of the open seas (Van Stappen et al., 2001) between the West and East Azerbaijan provinces. The length of the lake along the north to the south reaches 140 km and expands to a maximum of 85 km along the east to the west. The average level of the lake bed was 1267 m above the open sea level (Vaheddoost and Aksoy, 2018). Moreover, the average depth of the lake was 6 m and its maximum depth was 16 m in the northern parts of the lake in normal conditions (Amiri et al., 2016). Despite the high altitude of the lake above sea level, most of the residential areas around the lake are about 30 m above the lake level (Noori and Aghaei, 2013). Figure 1 shows the position of Lake Urmia. The lake has undergone severe reductions in the water level and volume due to climate change, the construction of numerous dams on feeder rivers, excessive exploitation of basin water resources, and management problems. Thus, the lake area has reduced to less than 2100 km\u003csup\u003e2\u003c/sup\u003e and the water level dropped around 8 m during 1995-2015 (Danesh-Yazdi and Ataie-Ashtiani, 2019; Jalili et al., 2016; Pouladi et al., 2020; Soudi et al., 2017; Soudi et al., 2019).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe variation of the lake water level for about 60 years is depicted in Figure 2 (A). Since 2013, due to the creation of the Urmia Lake Restoration National Committee and the implementation of some water management projects, a slight increase has occurred in water levels (Danesh-Yazdi and Ataie-Ashtiani, 2019). However, the reduction in the water level has significantly caused to increase in salinity concentration, and consequently, water density. Figure 2 (B) illustrates the changes in the salinity concentration and water density of the lake. Likewise, Figure 2 (C) displays changes in the density of Lake Urmia in recent years since the shrinking of the lake has dramatically begun and the water level has decreased beneath the ecological level (1274 m) as shown in Figure 2 (A).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThere are 17 aquifers around Lake Urmia, and the Rashakan aquifer, which is located in the western part of Lake Urmia, has special conditions for the implementation of our model. Owing to a long feeder area from the western mountains border of the aquifer recharge and discharge (abstraction and depletion to the lake), in this aquifer are approximately in balance (Javadzadeh et al., 2020). Figure 2 depicts the position of the aquifer relative to the lake and its basin. The aquifer is located in young terraces and alluvium, including Limestone, Marl, and Conglomerate in the south region. The average thickness of the Rashakan aquifer is estimated at 45 m and the bedrock elevation is approximately 1235.8 m throughout the aquifer. In addition, the topography of the area has a relatively mild slope, and the height difference between the highest and lowest parts of the plain is nearly 50 m. Most input parameters of the model are defined based on the measured data, except for diffusion and dispersion coefficients which are selected based on the filed and reported data (Motallebian et al., 2022).Table 1 presents the input parameters of the Rashakan aquifer.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e Parameters used for the scenarios of numerical simulation on the experimental model and the Rashakan aquifer near Lake Urmia\u0026nbsp;\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"541\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameters\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eValue\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRashakan Aquifer\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003ePorosity (n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003eLongitudinal dispersivity (\u0026alpha;\u003csub\u003eL\u003c/sub\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e7 m\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003eTransverse dispersivity (\u0026alpha;\u003csub\u003eT\u003c/sub\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e2 m\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003eMolecular diffusion (D\u003csub\u003em\u003c/sub\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e1e-7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003eHydraulic conductivity (K)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e2.5 m/day\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003eTime steps\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e1 day\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003eGrid size\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e5 m\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003eThe initial density of saline water\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e1.10 gr/cm\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 321px;\"\u003e\n \u003cp\u003eRange of final density of saline water\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 220px;\"\u003e\n \u003cp\u003e1.1-1.30 gr/cm\u003csup\u003e3\u003c/sup\u003e\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\u003eThe four installed piezometric wells have continuously recorded groundwater levels in the aquifer since 2004. The positions of the piezometric wells are shown in Figure 1, indicated by orange points located in the northern part of the aquifer. Three piezometers, namely A, B, and D, are situated near the lake, while piezometer C is approximately 850 m away from the shore. The water level observed at the present piezometer is used as the groundwater level at the boundary of the aquifer\u0026apos;s geometry. The data collected from piezometers A and D have been utilized to assess the validity of the numerical modeling procedures. Since the water table in the piezometer closest to the lake is expected to correspond to the lake water level, the data collected from piezometer B was not considered in the current analysis.\u003c/p\u003e\n\u003cp\u003eBased on the recorded data, the recharge and discharge of the Rashakan aquifer appear to be nearly balanced, which can be attributed to the implementation of a groundwater preservation program by the local water agency, however, some reports show the average rate of the level reduction in this aquifer was reported as 0.12 m/year, meanwhile, the rate of the dropping of the lake water level was 35 cm/year (Sheibani et al., 2020), It appears more likely that the reported decrease in the groundwater table is attributed to the dropping water level of the lake.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eModeling procedure\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo investigate the impact of variations in lake water density over the 27-year drying period (from 1995-2022), the migration of saline water from the lake inland was studied under two different circumstances:\u003c/p\u003e\n\u003cp\u003ea. Variable salt concentration (VSC) of lake water, using real-time recorded values of lake salinity.\u003c/p\u003e\n\u003cp\u003eb. Constant salt concentration (CSC) based on the lake\u0026apos;s normal condition before the drying period.\u003c/p\u003e\n\u003cp\u003eThe objective was to understand how the changing density of lake water influenced the movement of saline water into the surrounding inland areas. In the case of CSC, the salinity of the lake was determined to be 150 g/l, and the density was measured at 1.10 g/ml. For both conditions, the head-controlled method was used for the numerical modeling, however unlike to\u003cspan dir=\"RTL\"\u003e\u0026nbsp;\u003c/span\u003ecommon fixed head method\u0026nbsp;(Werner and Simmons, 2009)\u0026nbsp;in which the inland head variation of groundwater is considered independent of saline water level fluctuations, real-time recorded groundwater head at the relevant boundary of the aquifer was imposed to the model. Meanwhile, the water level decreased from 1277.85 m in 1995 to 1270.09 m on September 21, 2022, was taken into account as the boundary condition for the lakeside.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Creating the initial conditions for the interface position within the aquifer at the initiation of the studied period prior to the lake water decline has been one of the fundamental steps of this study. To this end, first, an initial steady state analysis was conducted to estimate the position of the saltwater-freshwater interface by acting boundary conditions for the inland groundwater level and saline water levels in the lakeside based on conditions in 1995 without considering saltwater density and concentration variation. Of course, the assessment of recorded data on lake water levels demonstrates the level of lake water had been approximately constant over a long period from 1955 to 1995 except in the normal seasonal oscillations however. Hence, to determine the amount of intrusion into the Rashakan aquifer a steady-state analysis was carried out based on the average water level in Lake Urmia equal to 1276.51 m,above open seas levels (ASL), over 40 years from 1955 to 1995. The groundwater at this period was considered 1285.1 m ASL which is one meter more than the highest recorded level in monitoring history of the relevant observation well. The value is extrapolated based on the descending slope of the groundwater level. Figure 3 shows the entered hydraulic boundary conditions for the model. As previously mentioned, during the wet period of the lake (between 1955 and 1995), the salinity and density of the lake water were approximately 150 g/l and 1.10 g/ml, respectively.\u003c/p\u003e\n\u003cp\u003eConsidering that the water level has been dramatically reduced in Lake Urmia, the effect of increasing the density should be considered when analyzing the intrusion behavior. As shown in Figure 2C, density variations in different years were nonlinear and continuous. The density changes at the boundary in the lakeside were applied to the numerical model by converting the nonlinear behavior of density relative to the time to a stepped quasi-linear state in different stress periods in the SEAWAT. The mean value of densities of saline water at the beginning and end of each stress period involved for the corresponding stress period in transient analysis. Hence beyond the steady state analysis of the initial condition for 40 years, the transient analysis of 27 years of lake water interaction with the Rashakan aquifer was discretized into 17 different stress periods. The shortest period was 3 months and the longest was 5 years for the last five years since lake water density remains constant owing to reaching saturated levels of dissolved salts. Specific Head type boundary condition was used for both sides of the model according to the recorded water level in the lake and piezometric well at the land side boundary of the aquifer. As shown in Figure 1, the skinny elongated aquifer of Rashakan is stretched along the shoreline. Therefore a section of the aquifer in 5 m thickness was modeled with the 3D grid approach in which acted as a 2D model. \u0026nbsp;To comprehend the impact of salt concentration on saltwater intrusion and its consequent effect on rising density, the results from the VSC and SCS states were analyzed.\u003c/p\u003e"},{"header":"Results and discussion","content":"\u003cp\u003e\u003cstrong\u003eIntrusion before drying lake\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBefore the study of the saltwater interaction with adjacent groundwater for the drying period of Lake Urmia, a steady-state analysis was carried out based on the constant water level in Lake Urmia over 40 years from 1955 to 1995. Figure 4 depicts the saltwater intrusion length for the studied steady-state conditions. As seen in the figure the length of the intruded saltwater is less than 200 m and the needed time to reach a stable wedge lasts almost 20 years. The results on numerivcal model in this figure shows, similar to the results of \u0026nbsp;Chang and Clement (2013), after 20 years of analysis vectors of saline and fresh water in the domain got parallel and so the saltwater wedge reached the final position.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDrying Period\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eVariable Density (VSC)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOver overview of the lake water elevation history presented in Figure 1 demonstrates that , since 1995, after reaching to the highest recorded water level a decline of lake water level was initiated. The drop of water level in the past 27 years was divided in two parts. The first part was lasted from 1995 to 2006 and the second period was started from 2007 to 2022. The rate of dropping of water level in the first part was slightly faster than the second part because at this period the lake area was more vast and so more evaporation had been accrued while the discharge flow of rivers wasn\u0026rsquo;t able to compensate the huge volume of the lost water because of sever evaporation. In the second period due to shrinking the lake water body the same inlet flow could somewhat up the evaporated height of the lake water level more in comparison to the first period. Moreover, in recent years, due to the implementation of some restoration projects, a significant increase in the discharge of rivers into the lake has been reported. This increased inflow has led to a slight rise in water levels within the lake. The enhanced river discharge has helped to partially offset the effects of evaporation, contributing to the stabilization or even a slight increase in water levels (Parsinejad et al., 2022). However, the evidences confirm unsustainability of the restoration program.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eGenerally, the water dropping is accompanied with a rising of salinity and density. Modeling of saltwater intrusion based on the density variation and water level at the both inland and lake sides is presented in Figure 5. The figure shows the advancing of the saltwater wedge in different years after starting of drying up the lake. Based on the achieved results, the rate of encroachment of wedge toe is slower in the first decline period than the second, nevertheless, the rating of lake water decline at the beginning times of the drying period between 1995 to 2006 was faster than the second period. After initiating of lake water dropping, the wedge length had remained constant for almost two years. It had started to continually expand under the aquifer since 2006. During the years 2006 and 2007, owing to a considerable wet season and high precipitation in those years a remarkable jump in groundwater elevation happened\u0026nbsp;(Alizadeh‐Choobari et al., 2016; Mohebzadeh and Fallah, 2019). As a result, the decline in the lake water level was halted temporarily. However, numerical models confirm a very slightly advancement of the saltwater wedge during those years as shown in Figure 5.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Comparison of flow vectors of the aforementioned two years (2006 and 2007) with others shows that a convection upward flow had developed in the upper part of the wedge, meanwhile the wedge in the bottom was moving to the landside. The upper upward convection flow had happened because of the rising up groundwater level in the boundary at the relevant years as shown in Figure 3. The configuration of convection flows is influenced by the presence of a stagnation area in which the plume struggles to move forward, resulting in the diversion of horizontal flow to upward. Typically, the stagnation point is located in front of the wedge tip, where the opposing vectors of freshwater and saltwater intersect. At this point, the hydraulic energy of both saltwater and freshwater becomes equal. During the receding state by rising groundwater level, the stagnation point penetrates into the saltwater wedge (Chang and Clement, 2013). Under such circumstances the fresh water forces saltwater to flash out from the occupied region. According to the stagnation points in the interface area of the wedge in the years 2006 and 2007, it can be concluded, The upper part of the aquifer is under the pressure of freshwater, while the lower part of the aquifer is under the pressure of saline water. Despite the movement of the stagnation points in the upper regions of the plume towards the saline water, intrusion is observed throughout the aquifer at all. This contradictory behavior is caused by the increased saline water density. In fact during this period, despite of constant lake water level, its rising density covers the effect of the temporary groundwater level rising on the inside. Of course, the advancement of the saltwater wedge during the discussed period was very low.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the following, from mid-2007 until 2022, the intrusion of saltwater has significantly increased inland, encroaching more than twice the length of the wedge compared to the years prior to the lake\u0026apos;s drought period as shown in Figure 5b . The flow vectors presented by the model in 2022 confirm the elimination of developed convection flows within the plume. This can be attributed to either the decline in groundwater levels or the increased energy of saltwater due to rising density. Similar behavior reported by researchers who worked on the coastal aquifers around Lake Urmia (Ahmadi et al., 2022; Motallebian et al., 2022). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConstant Density (CSC)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo investigate the impact of density variations on saltwater intrusion, another model was developed to simulate the interaction between the saline water of Urmia Lake and the surrounding Rashakan aquifer. The modeling assumed not only a constant density at the beginning of the drying period, but also implying that the salt concentration of the lake water remained constant throughout the 27-year drought period. For the current analysis, the initial conditions were set to represent at VSC procedure, and a 40-year intrusion modeling study was conducted under fixed head boundary conditions. Figure 6 illustrates the results of the analysis at the same time intervals thet have been presented in VSC state . During the initial stage of drying, a slight upward movement was observed in the saltwater wedge. However, a significant rise in groundwater levels in 2006 led to the recession of the intruded saltwater wedge. As depicted in this figure, the flow vectors within the plume reversed direction, flowing back into the saltwater reservoir from the freshwater side. Notably, stagnation points, where vectors of opposite directions intersect, were found within the plume. Over time, these stagnation points in the form of a wave moved outside the plume and into the saline water chamber. Subsequently, the wedge continued to recede to a new position, eventually reaching almost an steady state condition by 2022. The flow vectors observed under the steady state condition align with the findings of Goswami and Clement (2007) and Chang and Clement (2013), where the saline water concentration was kept constant in their respective tests.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eReviewing the presented information in Figure 6b illustrates the length of the wedge over the 27-year drying period. It is evident that the wedge length exhibited slight variations over time. Remarkably, the concentration of the saline water remained constant at 155 gr/l throughout the entire period.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAs previously mentioned, saltwater intrusion experienced modest advancement during the initial period from 1995 to 2006. However, during the second period of drying, the wedge receded back towards the lake. Based on the constant concentration assumption, the saltwater wedge shrank by approximately 10% of its original length in 1995.\u003c/p\u003e\n\u003cp\u003eMotallebian et al. (2022) showed that receding of saltwater leads to dropping of surrounding groundwater level in case of fixed head boundary condition of groundwater in the landside, therefore, it is concluded that the a part of the dropping of groundwater head which is seen in Figure 3 might be because of the lake water dropping. \u0026nbsp;However, realistic modeling of lake water interaction with Rashakan aquifer showed, as presented in Figure 5, that the saltwater wedge has advanced significantly under the freshwater. It causes to lifting of groundwater in a strip bound from lake shore, and consequently could compensates a part of the impact of lake water dropping into the groundwater level. Perhaps the groundwater table would have dropped more than the recorded values if the wedge had moved back to the lakeside.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eValidation of the Results of Modeling\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe interaction between the saltwater dynamics of Lake Urmia and the surrounding groundwater of the Rashakan aquifer exhibits distinct variations in both the Variable Salinity Condition (VSC) and Constant Salinity Condition (CSC) modeling scenarios. In the VSC state, the wedge length has expanded, whereas in the CSC state, not only has the wedge failed to advance in the aquifer, but it has also receded inland. Since the VSC employs more realistic hydraulic and concentration boundary conditions compared to the CSC modeling, it is reasonable to expect more accurate results in the VSC regarding the dynamics of the saltwater wedge and groundwater. However, it is important to note that there is a lack of recorded data regarding saltwater concentration and monitoring of ions to evaluate the computed saltwater plume beneath the aquifer. Motallebian et al. (2022) demonstrate that under similar hydraulic boundaries, higher concentrations of saline water result in an elevated groundwater table because of the more intruded saline water. The observed groundwater elevation data obtained from Piezometers A and D (Fig. 1) were compared with the results of both the VSC and CSC numerical models in terms of the computed groundwater level at the same location. The comparison results are presented in Figure 7. It is evident from the figure that the VSC model yields more consistent results compared to the CSC model. Both models share the same initial conditions before 1995, and the difference in the intruded saltwater wedge remains relatively consistent until 2007. Therefore, the observed data and computed results exhibit good agreement in the initial segments of the presented data. However, after 2007, the saltwater wedge in the VSC state significantly encroaches further inland, while in the CSC state, it recedes towards the lake. Consequently, the computed groundwater table in the VSC model aligns more closely with the real conditions, and the corresponding numerical model and observed data support the validity of the saltwater wedge\u0026apos;s advancement around the drying Lake Urmia.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFlow Budget\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe computed flux of freshwater into the lake and saltwater into the aquifer in both studied states is presented in Figure 8. It is evident from this figure that the flow rates of freshwater and saltwater exhibit distinct variations throughout the studied period. Unlike the two conventional techniques commonly used for setting boundary conditions, namely flux-controlled and head controlled, where either the groundwater flux or head is kept fixed (Badaruddin and Mehdizadeh, 2021; Chang et al., 2011; Robinson et al., 2016; Werner et al., 2013), both the head and flux were transient in the domain of our study. The pattern of groundwater flux variation follows the imposed groundwater head at the relevant boundary conditions, while the infiltration of saltwater in the VSC adheres to the saltwater density. The observed spikes in the results correspond to the incremental rise in salt concentration during the designated stress periods. To elucidate this, the average salt concentration at the beginning and end of each stress period was utilized as the representative saline water concentration for the corresponding time interval.\u003c/p\u003e\n\u003cp\u003eA comparison between the computed groundwater discharge in the VSC and the CSC states reveals that the groundwater discharge into the lake is nearly half in the case of constant concentration, whereas the saltwater flux into the aquifer is more than twice as much in the VSC. Reviewing of the presented data in Fig 8 shows that the groundwater flux was around 4 m\u003csup\u003e3\u003c/sup\u003e/day/m at the beginning of the drying period then has been reduced to lower than 2 m\u003csup\u003e3\u003c/sup\u003e/day/m eventually. \u0026nbsp;Meanwhile, analyzing the saltwater infiltration flux during the drying period indicated that the rate of saltwater intrusion in 2022 has increased nearly two-fold compared to the normal lake condition in 1995.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eWe studied groundwater interaction with drying Lake Urmia in the coastal Rashakan aquifer located at the west shore of Lake Urmia. Environmental crisis of Lake Urmia has been started in 1995, when the water level dropped dramatically due to anthropogenic issues and climate changing (Parsinejad et al., 2022). We considered recorded field data around the boundary of the studied aquifer to draw a precise perspective of intrusion of lake saline water into the neighboring aquifer. In this regard, the increasing of density and concentration of salt over 27 years, from 1995 to the initiation of the lake crisis, were entered in SEAWAT as a popular saltwater intrusion model.\u003c/p\u003e \u003cp\u003eThe model results demonstrated that in spite of dropping of water elevation in the lake by more than 6 m, the saltwater has been intruded in the Rashakan aquifer continuously throughout 27 years more than 2 times, approximately from 200 m to 530 m. The findings of this study mentioned that the ignorance of salt concentration increase in the modeling of saltwater intrusion problems would lead to lower estimate of the developed wedge. Additionally, analysis of groundwater flux to the lake showed that exacerbation of intrusion due to rising density create a huge saltwater plume that acts as an underground barrier in front of groundwater flow and makes a significant reduction in the discharge of groundwater into the lake. Although the infiltrating saltwater finally encounters freshwater, circuit, and moves back into the lake through the transition zone of the wedge after reaching the state state, the volume of saline water in the body of saltwater wedge must be considered in any water balance analysis of the lake because of its considerable volume. In fact, in transient conditions significant volume of lake water infiltrates into the surrounding lands and it may not last even in hundreds of years (Ahmadi et al., 2022). Hence, it seems a huge valume of water of drying Lake Urmia infiltrated into the surrounding aquifers, while it might miscalculated as evaporated water during the recent drying period. Consequently, in the case of entry of enough volume of water to the lake, concentration of salt could be reduced as well as its density. This likely leads to the receding of the saltwater wedge into the lake and emphasizes groundwater dishcharge into the lake which could expedite rising of water level in the lake.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eConflict of interest\u003c/h2\u003e\n\u003cp\u003eThe author declares no conflict of interest.\u003c/p\u003e\n\u003ch2\u003eEthics Approval\u003c/h2\u003e\n\u003cp\u003eThe author confirms this research follows the ethical standards.\u003c/p\u003e\n\u003ch2\u003eConsent to Participate\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch2\u003eConsent to Publication\u003c/h2\u003e\n\u003cp\u003eThe author consents to publish this paper in Water Conservation Science and Engineering journal.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eThe author received no financial support for the research and publication of this paper.\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003eThe whole of the manuscript including conceptualization, data collecting, data analysis, numerical modeling, and writing has been prepared by Hojjat Ahmadi.\u003c/p\u003e\n\u003ch2\u003eAcknowledgment\u003c/h2\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003ch2\u003eData Availability\u003c/h2\u003e\n\u003cp\u003eThe data are available upon request from the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAbbaspour, M., Javid, A.H., Mirbagheri, S.A., Ahmadi Givi, F., Moghimi, P., 2012. 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Journal of Coastal Research 29(2). https://doi.org/10.2112/jcoastres-d-12-00068.1.\u003c/li\u003e\n\u003c/ol\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":"Groundwater, Salinity, Density, Lake Urmia, Intrusion","lastPublishedDoi":"10.21203/rs.3.rs-5249986/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5249986/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eDrying of Lake Urmia due to less water entry and evaporation leads to a rise in salt concentration as well as the saline water density. The declining saline water level and rising of its density have the opposite effect on the saltwater intrusion dynamic. In this study, based on the groundwater and lake water level fluctuations and density variation of Lake Urmia over two decades, the saltwater interaction in one of the coastal aquifers has been studied numerically using SEAWAT. The findings of the research have been approved by comparing the model results with the recorded data collected from the observation wells in the studied aquifer. The achieved results showed that in the case of constant lake water density saltwater wedge progresses slightly by the middle of the studied period and then recedes to the lakeside while considering the increasing density of the lake over 27 years showed that the length of the saltwater wedge in the field scale surprisingly has been expanded more than 250% during the shrinking period of the lake with more than 6 m dropping of water level. Overall, considering the behavior of the saltwater intrusion around the coastal area based on our findings would be conducive to the realistic management of the saline lakes and the implementation of any restoration program for drying lakes.\u003c/p\u003e","manuscriptTitle":"Investigating the Influence of Salt Concentration in Drying Lake Urmia on Saline Water Intrusion in an Adjacent Aquifer","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-11-20 10:49:12","doi":"10.21203/rs.3.rs-5249986/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":"abf224e8-1f29-4144-a178-174e4f00fc43","owner":[],"postedDate":"November 20th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-12-10T13:09:43+00:00","versionOfRecord":[],"versionCreatedAt":"2024-11-20 10:49:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5249986","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5249986","identity":"rs-5249986","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}