{"paper_id":"3a74a5e0-b1ee-41a3-83eb-af288b09faaa","body_text":"Deciphering the Water Supply of a Polje by using Gravimetry | 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 Deciphering the Water Supply of a Polje by using Gravimetry Victor Klaba, Hélène Celle, Sajad Tabibi, Benjamin Fores, Julie Albaric, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8317008/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Among aquifers, karsts are known to present a heterogeneous structure leading to a specific hydrodynamic behavior mixing slow and fast circulations, which makes their study a real challenge. In addition to the specific nature of these structures, there is a need to improve the study methods that can be used to gain a better understanding of these systems. This study is the first to propose continuous gravimetric coupled with hydrodynamic measurements to understand the functioning of a polje whose intermittent flash floods can have disastrous socio-economic consequences. These flooding can be due either by surface water that can no longer infiltrate underground because its infiltration capacity has been exceeded or by overflow of the aquifer, both of which depend on the porosity of the karstic aquifer. The results allow deciphering the origin of water that cause the flooding and determining the storage of karstic aquifer that plays a decisive role. gravimetry hydrodynamic karst polje monitoring Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1. Introduction A polje is an endoreic basin with a flat bottom, often slightly tilted towards a drainage point, and surrounded by steep walls. Hydrogeologically, this karstic feature is characterized by a surface water, usually a watercourse, which runs off its surface and disappears into the limestone massif, through a preferential infiltration area called a ponor. These areas are prone to intermittent flooding (Gams, 1978 ; Prohic et al., 1998 ; Lopez-Chicanos et al. 2002; Ford and Williams, 2007 ; Mayaud et al., 2022 ). The development of poljes is influenced by two key factors: 1) the contact between a low-permeability zone, marked by surface run-off, and a high-permeability zone, where the ponor is located; 2) a strong hydraulic gradient that favours the sinking of the hydrographic network or the proximity of the karstic water table, allowing it to overflow. Together, these factors create a unique hydrological system. During periods of heavy rainfall, the river flowrate can increase sharply and surpass the absorption capacity of the ponors and lead to flooding. This latter can also result from the overflow of the aquifer, which normally drains infiltrated water. In such cases, the ponors reverse their function and become emissive turning into what is known as an “estavelle” (Gilli, 2008), which can form a lake that permanently submerge the ponor. In extreme cases, the water level may rise by several tens of meters, covering hundreds of square kilometres (Lučić, 2014 ) and potentially causing economic impacts. Depending on the geological or climatic context, flooding may occur as an exceptional event, om a multi-annual scale, or even permanently. The first step to decipher this mitigating flooding which may result from an unusually high supply of surface water and/or groundwater (Lopez-Chicano et al., 2002) is to understand its dynamics and causes. A water balance, including inflows and outflows, can be used to determine the origin of the waters supplying the ponors during high-water periods (Bonacci, 1987 ; López-Chicano et al., 2002 ; Milanović, 2004 ; Kovačič, 2010 ; Kovačič and Ravbar, 2010 ). However, as Kovačič ( 2010 ) notes, rigorously quantifying both inflows and outflows over time is highly challenging due to several factors: 1) numerous springs and ponors may go unreported due to their temporary nature or because they activate while submerged; 2) estavelles can act as both springs and ponors; 3) collecting a complete dataset is a labor-intensive and technically difficult task. Mayaud et al. ( 2022 ) present an alternative method based on the postulate that lake stage variation is directly linked to the water surplus causing the flood, combining water level fluctuations and digital elevation models. Among non-invasive geophysical methods, gravimetry can directly quantify water-mass fluctuations at the catchment scale (Kroner et al., 2006 ; Hasan et al., 2008 ; Jacob et al., 2010 ; Hector et al., 2013 ; Hemmings et al., 2016 ; Imanishi et al., 2006 ; Jacob et al., 2009 ; Pool and Eychaner, 1995; Van Camp et al., 2006 ; Wilson et al., 2011 ) or in localized areas (Naujoks et al., 2008 ; Kennedy et al. 2014 ). This study is the first to apply gravimetry to estimate the origin of the water supplying the karstic polje of Creux-sous-Roche in the Arcier karstic hydrosystem, a region where flooding has been a significant concern since the late 18th century. 2. Site setting The study site is located near the Saône swamp, south of Besancon. This area is characterized by the presence of several preferential infiltration areas, swallow holes and two ponors, whose lack sufficient capacity to absorb the flow during periods of heavy and prolonged rainfall. As a result, temporary lakes form multiple times per year, notably filling and emptying very quickly. This study concentrates on the Creux-sous-Roche large ponor because located near a private residence which could host a relative spring gravimeter. The Creux-sous-Roche is a classic ponor, resembling a flat-bottomed funnel with moderate to gentle slopes to the north, west, and southwest, and bordered by vertical rocky walls elsewhere. It serves as the final drainage point for an 800-heactare section of the Saône swamp and is closely connected to the upper Jurassic aquifer, reflecting its saturation levels. Water levels at the Creux-sous-Roche range from 368.42 m at the bedrock to 381.91 m when a temporary lake forms. Sometimes, the flow direction at Creux-sous-Roche reverses, exacerbating flooding. In a first effort to improve drainage at Creux-sous-Roche during flooding periods, two boreholes, each 10 m deep, were drilled close to the sinkhole. Both boreholes intersected joints, likely connecting the Upper and Middle Jurassic aquifers. Once the rains stop, the lake drains quickly due to the intense fracturing in the Creux-sous-Roche area, which lies along a deformation corridor (Klaba et al., 2023). The gravity station is located at 82 m horizontally from the Creux-sous-Roche ponor, at a higher altitude 22 m. The gravimeter, a gPhoneX-100, is housed in the garage of a private residence. 3. Observations This section provides an overview of the datasets used in this study. 3.1 Meteorological data Rainfall data were calculated using the RS_Minerve software (Foehn et al., 2020) for the barycenter of the six meteorological stations closest to the Creux-sous-Roche. The data, provided by Météo-Francey Météo-France ( https://donneespubliques.meteofrance.fr/ ), were available at an hourly time step for the period from September 15, 2020, to September 14, 2023. 3.2 Water level in the polje The Creux-sous-Roche is equipped with instruments to monitor water height at two locations: 1) at the surface, using a CTD Diver (vanEssen, precision ± 0,05% full scale); 2) at a depth of 15 meters, using an AQUATROLL 600 (± 0.01% full scale), positioned in a joint intersected by one of the boreholes. This latter sensor collected data from dec-2020 to oct-2021 and was eventually relocated next to the first sensor. 3.4 Instruments positioning The exact positions of the gravimeter and water level sensors were precisely measured using a Leica Geosystems GNSS with single-baseline real-time kinematic (RTK) corrections, achieving a precision of better than 15 mm. The zero level of the water level sensors was set at the altitude of the outside sensor (368.4747 m). Table 1 Coordinates of the gravimeter and the water gauge in the French Lambert 93 projected coordinate system. Instruments X (m) Y (m) Z (m) Gravimeter 935200.7274 6683987.5058 389.6824 Water gauge (surface) 935166.3612 6684049.0543 368.4747 Water gauge (deep) 935166.3612 6684049.0543 355.4747 3.5 Gravity measurements Continuous gravity observations were recorded using the relative spring gravimeter gPhoneX (SN:100), manufactured by Micro-g LaCoste Inc. This gravimeter is an improved model based on the Lacoste-Romberg principle. It is equipped with a metallic zero-length spring suspension, a well-controlled temperature sensor, and a modern acquisition system. The gravimeter is mounted on a tilt-controlled tripod to continuously maintain its verticality, making it suitable for long-term operation. Gravity measurements, which record variations along the vertical axis, began in late October 2020 (Figures S1 ). All pre-processing was performed using Tsoft (Van Camp and Vauterin, 2005 ), following high-standard procedures. First, a gravity tides prediction was removed from the raw data using a theoretical model. Additionally, the atmospheric pressure effect was corrected using an admittance factor of -3 nm s − 2 /mbar. The residuals were then carefully edited by: 1) correcting the raw 1-minute data for spikes, offsets, and other non-tidal perturbations such as accidental tilts during visits or earthquakes; 2) interpolating small data gaps; and 3) applying the tidal prediction model and atmospheric pressure correction to the residuals to create a clean time series. Finally, the data were decimated to hourly observations by applying a symmetric low-pass filter with a 2-hour cutoff period. Hourly gravity and atmospheric data were processed using tidal analysis software (Wenzel, 1996 ). This resulted in the best tidal prediction, which was used to remove tidal and atmospheric pressure effects from the edited data. Additionally, the time series was corrected for centrifugal acceleration due to polar motion. These geophysical corrections removed the predominant gravity effects while preserving signals from hydrological masses. The first month of data was discarded due to the significant exponential drift caused by the initial relaxation of the gravimeter's spring. Instrumental drift, which varies between instruments, needs to be estimated using absolute gravity measurements for long-term gravity changes. However, this study focuses on weekly gravity changes associated with rainfall. To remove the long-term signal (drift + annual variations), a low-degree polynomial was fitted to the data. Figure 2 clearly demonstrates a strong correlation between the rainfall rate and observed gravity variations. This suggests that the observed gravity signal is primarily influenced by the water content in both the polje and the surrounding soil. The water level observations in the polje and the well at its bottom are shown in Fig. 3 . As expected, these observations indicate that rainfall is the primary driver of both water level fluctuations and the observed gravity changes. 4. Estimating the direct Newtonian attraction of the water in the sinkhole The gravity station is installed on a concrete floor in the garage of a house adjacent to the polje. The station and polje are separated by a horizontal distance of 82 m and an altitude difference of 22 m. To evaluate the direct Newtonian gravitational attraction ( \\(\\:dg\\) ) of the water in the polje as a function of its water level, we use a digital terrain model and apply Newton’s law of gravitation: $$\\:dg=G\\:{\\rho\\:}_{water}\\frac{dV}{{d}^{2}}\\:\\frac{dh}{d}$$ 1 where \\(\\:G\\) is the universal gravitational constant, \\(\\:{\\rho\\:}_{water}\\) is the water density, \\(\\:dV\\) is a small volume of water, \\(\\:d\\) is the distance between the mass element dm= \\(\\:{\\rho\\:}_{water}dV\\) and the gravity station, and \\(\\:dh\\) is the altitude difference. The term \\(\\:\\frac{dh}{d}\\) projects the gravity vector along the vertical. This means that if the disturbing mass is at the same altitude as the gravimeter, it will not contribute to the detected signal. To compute the direct Newtonian attraction of the water in the polje, the volume is divided into small cubes, each with 1 m sides. We use the exact analytical formula for the direct gravitational attraction of a cube. The total effect, as a function of the water level, is then obtained by summing the contributions of each cube. Figure S2 shows the position of the gravimeter relative to the sinkhole, along with the lake configuration at three different water levels. Near the Creux-sous-Roche, the Fosses de Saône sinkhole, located approximately 200 m away, can host another temporary lake during high waters We also modeled its gravitational attraction using the digital terrain model. Although we do not have water level data for this sinkhole, we assume that the water levels are the same in both sinkholes due to their interconnected nature. The calculated direct Newtonian attraction from this second sinkhole is 10 times smaller. Two factors contribute to this reduced influence: first, gravity decreases according to the inverse-square law ( \\(\\:\\frac{1}{{r}^{2}}\\) ), and second, due to the distance, the vertical component of gravity decreases. We first calculate the direct Newtonian attraction for both Creux-sous-Roche and Fosses de Saône as a function of their respective water levels at 1 m intervals (Fig. 4 ). Then, a second- or third-degree polynomial is fitted, depending on the sites. The resulting analytical expressions are used to correct the observed gravity variations caused by the water content in them. 5. Estimating the porosity coefficient The remaining temporal changes in the gravity observations are primarily caused by variations in the water table level. If we assume that the water is uniformly distributed over an infinite horizontal layer with thickness \\(\\:h\\) , the direct mass attraction can be expressed using the Bouguer plate model: $$\\:dg=2\\pi\\:G\\:{\\rho\\:}_{water\\:}\\phi\\:\\:h\\:$$ 2 where \\(\\:{\\rho\\:}_{water}\\) is the density of the water and j is the porosity of the medium. The gravity variation depends on two parameters: \\(\\:h\\) and j . However, it is not possible to determine both parameters simultaneously from gravity data alone. To address this, we first assume that the water table \\(\\:h\\) is equivalent to the water level in the sinkhole and the well beneath the polje. The porosity j is then estimated by fitting a straight line to the plot of gravity residuals versus the water level above or below the polje (Fig. 5 ). The porosity can be expressed as: $$\\:\\phi\\:\\:=\\:\\frac{1}{2\\:\\pi\\:\\:{\\rho\\:}_{water}G\\:}\\:\\frac{dg}{dh}$$ 3 where dg/dh represents the slop of the curves in Fig. 6 . We obtained porosity values of 0.3% and 2.0% when considering the data below and above the sinkhole, respectively. These values differ by a factor of 10, which is too low for a karstic region. This discrepancy arises because the water levels in the polje and well are not accurate proxies for the water table level. Both tend to overestimate the water table level. The difference in porosity values clearly indicates distinct dynamic responses between the ponor area and the rest of the polje. The literature provides total porosity values for karstic systems ranging from 2% to 30%, depending on the degree of fracturing. These values can be classified into three types of porosity that coexist in karstic systems (Delbart, 2014 ; Goldscheider and Drew, 2007; Carrière, 2014 ). The first type is matrix porosity, which is related to lithology and typically presents low values, often only a few percent (Gilli, 2011 ). The second type, fracture porosity, is associated with the karst’s tectonic history and varies according to the size and opening of discontinuities, such as fractures and faults. The third type is duct porosity, which results from karstification and can reach effective values of up to 15%, influencing the movement of the water table. 6. Estimating the water table level Assuming a porosity value of 15%, we can estimate the water table level change ( dh ) by inverting Eq. ( 3 ) as follows: $$\\:dh=\\:\\frac{1}{2\\:\\pi\\:\\:{\\rho\\:}_{water}G\\:}\\:\\frac{dg}{\\phi\\:}$$ 4 Using this approach, we obtain the estimated water table level, which is shown in Fig. 6 . The water level variations are in phase with the water level in the polje, which is controlled by the rainfall regime. During sustained rainfall, the water table rises quickly. The rate of filling and the water level height depend on both the intensity and duration of the rainfall. Any variation in rainfall supply leads to similar variations in the water table and polje water levels. Once the rain stops, both the water level in the polje and water table levels in the aquifer drop rapidly. While Fig. 6 may suggest that the water table level returns to its pre-rain level, this is not entirely accurate. The seasonal variations have been smoothed out to remove the gravimeter's instrumental drift. This component could be further assessed if the relative gravity observations were complemented by episodic absolute gravity measurements. Data from the Gennes borehole, drilled into the upper Jurassic limestones ( https://infoterre.brgm.fr/ ), show that the water level varies between a minimum of 400.48 m and a maximum of 404.97 m from October 24, 2020, to June 30, 2023. The amplitude of these variations is approximately double that of the changes observed in the polje's water levels. The annual signal in the gravity observations has been filtered to remove the instrumental drift, so this component is missing from the gravity time series. The annual signal could account for up to half of the total amplitude in the water table level. In terms of variations, the water table level obtained by Gennes borehole and that simulated from gravimetric data are substantially similar, expected for the 03/2022-09/2022 period during which data quality is questioned (Fig. 7 ). Finally, a regression was performed between the water level in the polje and the estimated water table level derived from the gravimetric observations (Fig. 3 ). A simple admittance factor was obtained, allowing us to estimate the water table level based on the polje water level. The two levels are highly correlated, exhibiting similar phase behavior but differing in amplitude response to rainfall events. Conclusion The study explores the hydrological dynamics of a polje, specifically, the Creux-sous-Roche in the Arcier Karst hydrosystem, by using gravimetry. Water levels in the Creux-sous-Roche fluctuate primarily due to rainfall showed by consistent responses in water levels above and below the surface during rain events. A strong correlation was observed between rainfall rates and gravity variations, indicating that these gravity changes are mainly influenced by water content in the polje and surrounding soil. The gravitational attraction of water in the polje was modeled using Newton's law of gravitation. The study accounted for the distance and altitude difference between the gravimeter and the polje, allowing for accurate calculations of gravity changes based on water levels. After correcting gravity data for the influence of water in the sinkholes, the residual signals mainly reflect the water content in the soil beneath the gravimeter. Porosity values derived from the analysis were notably low (0.3% and 2%), indicating potential discrepancies in the reliability of using polje water levels as proxies for the actual water table levels in the karst system. The findings align anyway with literature, which indicates that total porosity in karstic systems ranges from 2% to 30%. Three types of porosity (matrix, fracture, and duct) were discussed, with duct porosity potentially reaching 15%, influencing groundwater dynamics. By assuming a porosity of 15%, estimated water table levels were calculated, showing consistency with data from a nearby borehole, which recorded significant fluctuations over the study period. Overall, the results underscore the complex hydrological dynamics of the Creux-sous-Roche area, highlighting the relationships between rainfall, water levels, gravitational measurements, and karstic porosity. In this way, the study demonstrates the potential of gravimetry to explore these dynamics and determine the storage and circulation potential of karst aquifers. Declarations Open Research Data: https://data.oreme.org/observation/snokarst Funding This work was supported by the Bourgogne-Franche-Comté region and AERMC (Agence de l’Eau Rhône, Méditerranée, Corse) through the TRANSKARST (TRANSdisciplinary research on KARSTic waters) project (grant number: CRBFC: 2019-Y-09074). Author Contribution A-Hélène Celle < [email protected] >B-Victor Klaba < [email protected] >C-Sajad Tabibi < [email protected] >D-Benjamin Fores < [email protected] >E-Julie Albaric < [email protected] >F-Flavien Choulet < [email protected] >G-Olivier Francis < [email protected] >All authors wrote the main manuscript textA, B, C and D prepare the figuresA and G found the fundings for the studyA, B, C, D, G participated to the field work and data analysis Acknowledgement The Arcier spring is a part of the Jurassic Karst observatory, affiliated to SNO Karst (Service National d’Observation du Karst). The authors would like to warmly thank Mr. and Mrs. Manevy, without whom the study would not have been possible, for giving access to their garage and electrical network to position the gravimeter. Data Availability Data: https://data.oreme.org/observation/snokarst References Bonacci, O. (1987), Karst hydrology: with special reference to the Dinaric karst. 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Supplementary Files Supplementarydata.pdf Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 03 Mar, 2026 Reviews received at journal 01 Mar, 2026 Reviews received at journal 19 Feb, 2026 Reviewers agreed at journal 03 Feb, 2026 Reviewers agreed at journal 28 Jan, 2026 Reviewers invited by journal 28 Jan, 2026 Editor assigned by journal 10 Dec, 2025 Submission checks completed at journal 09 Dec, 2025 First submitted to journal 09 Dec, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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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-8317008\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":581947435,\"identity\":\"983e9f24-a32e-444b-bcfd-6003732da49c\",\"order_by\":0,\"name\":\"Victor Klaba\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Université Marie et Louis Pasteur, CNRS UMR 6249 Chrono-Environnement\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Victor\",\"middleName\":\"\",\"lastName\":\"Klaba\",\"suffix\":\"\"},{\"id\":581947436,\"identity\":\"e7086d6f-9b87-4558-a670-be1737ac69c3\",\"order_by\":1,\"name\":\"Hélène Celle\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABE0lEQVRIie3QPUvDQBjA8efhgcuSkLUh0nyFCxmkoPSrJLsFJ3EQvHBwWfoB0slvkbnhoC7FuYNgpeBqxEWoiHnpmMTV4f7Twx0/7gXAZPqHcSDRTVY9VAA2AO67FVoPEDwRQoF5S4i3G8DivwnZ3TROzq00PVzfQuASpodL9XzG14TVx9X3FJiz7yOzZSmjfAvhSqKMFurNrgl5q4JHwCzee7FdonxHQcw1Kn+htO09vG/IKXgiAtX/lpfX7Oj8QDzXmB1nDRHEGnIvGOsnO1TkiPoUqgesiQsdiWGIbBPp25tJmGuU3vKpJc1bolANkUddftp3F4GbybL6utFzBs2PFdPAHSCnJj1ro8BkMplMo/0CrxBR51Gl4VcAAAAASUVORK5CYII=\",\"orcid\":\"\",\"institution\":\"Université Marie et Louis Pasteur, CNRS UMR 6249 Chrono-Environnement\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Hélène\",\"middleName\":\"\",\"lastName\":\"Celle\",\"suffix\":\"\"},{\"id\":581947437,\"identity\":\"745f26ea-115d-4113-9a19-e53c1b74bb96\",\"order_by\":2,\"name\":\"Sajad Tabibi\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Université du Luxembourg\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Sajad\",\"middleName\":\"\",\"lastName\":\"Tabibi\",\"suffix\":\"\"},{\"id\":581947438,\"identity\":\"fcba7abd-86bd-46e6-90fb-36fdd0b4fbcb\",\"order_by\":3,\"name\":\"Benjamin Fores\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Institut national de Recherches Archéologiques Préventives\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Benjamin\",\"middleName\":\"\",\"lastName\":\"Fores\",\"suffix\":\"\"},{\"id\":581947439,\"identity\":\"e120fc62-01d6-4bc6-ad85-a0ecdcf5a7a5\",\"order_by\":4,\"name\":\"Julie Albaric\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Université Marie et Louis Pasteur, CNRS UMR 6249 Chrono-Environnement\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Julie\",\"middleName\":\"\",\"lastName\":\"Albaric\",\"suffix\":\"\"},{\"id\":581947440,\"identity\":\"fd160d81-b496-4bf8-9ce0-bf8cdf7e8748\",\"order_by\":5,\"name\":\"Flavien Choulet\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Université Marie et Louis Pasteur, CNRS UMR 6249 Chrono-Environnement\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Flavien\",\"middleName\":\"\",\"lastName\":\"Choulet\",\"suffix\":\"\"},{\"id\":581947441,\"identity\":\"65f828b8-e865-485b-8803-549a95a8abd3\",\"order_by\":6,\"name\":\"Olivier Francis\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Université du Luxembourg\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Olivier\",\"middleName\":\"\",\"lastName\":\"Francis\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2025-12-09 11:23:13\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-8317008/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-8317008/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":101490650,\"identity\":\"df57467d-de32-46d1-aef1-bc575c116258\",\"added_by\":\"auto\",\"created_at\":\"2026-01-30 10:00:07\",\"extension\":\"png\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1277724,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eLocation of the polje of Creux-sous-Roche supplying Arcier’s spring.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage1.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/fbf2eea1bbfeb2f7f41c43e1.png\"},{\"id\":101751961,\"identity\":\"3f77476a-cabe-4d90-b513-0fb45622c513\",\"added_by\":\"auto\",\"created_at\":\"2026-02-03 10:24:33\",\"extension\":\"png\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":253726,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eFinal gravity residuals (nm/s²) after removing the instrumental drift plus the long-term gravity variations (top panel); rain gauge data (mm) corresponding to the same period (bottom panel).\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/5ab166fee7a524014a28350a.png\"},{\"id\":101751717,\"identity\":\"10e33731-787e-40c6-95d4-e753fe8c96e4\",\"added_by\":\"auto\",\"created_at\":\"2026-02-03 10:22:53\",\"extension\":\"png\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":101484,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eWater levels in the Creux-sous-Roche polje: blue represents the data collected at the surface; red represents data collected at a depth of 15 meters from dec-2020 to oct-2021, the sensor was relocated close to the surface sensor for the Sept-2022/June-2023 period.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage3.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/8dbb88829e8148ef9898543a.png\"},{\"id\":101490652,\"identity\":\"46806e89-f046-4a0c-9f0b-b650d272ad11\",\"added_by\":\"auto\",\"created_at\":\"2026-01-30 10:00:07\",\"extension\":\"jpeg\",\"order_by\":4,\"title\":\"Figure 4\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":546666,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eDirect Newtonian attraction of the water in Creux sous Roche and Fosses de Saone as a function of water level. The dots represent the results of the calculations at 1 m intervals, while the lines show the fitted low-degree polynomials used to estimate the gravity attraction for any given water level\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage4.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/325e8d891330dcabab4ec9a9.jpeg\"},{\"id\":101490655,\"identity\":\"7f9000e9-3afa-428b-a6b9-d30d2a8f6834\",\"added_by\":\"auto\",\"created_at\":\"2026-01-30 10:00:08\",\"extension\":\"jpeg\",\"order_by\":5,\"title\":\"Figure 5\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":489197,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eGravity residuals as a function of water level, showing the data for both the water level below (left panel) and above (right panel) the bottom of the sinkhole.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage5.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/ad818655bd9727f5f8112e20.jpeg\"},{\"id\":101752163,\"identity\":\"b1a780b2-436c-433c-9be5-4d30301d518f\",\"added_by\":\"auto\",\"created_at\":\"2026-02-03 10:25:49\",\"extension\":\"png\",\"order_by\":6,\"title\":\"Figure 6\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":130460,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eWater table level obtained from the gravity variations at the surface after correcting for the gravity attraction of the water in the polje.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage6.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/d8be2414b70ad1916d48434f.png\"},{\"id\":101751623,\"identity\":\"d096839d-2d51-4a9c-bf44-85665beaa2d5\",\"added_by\":\"auto\",\"created_at\":\"2026-02-03 10:21:52\",\"extension\":\"png\",\"order_by\":7,\"title\":\"Figure 7\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":51434,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eWater table level of the Gennes borehole from October 24, 2020, to June 30, 2023\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage7.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/45ddea2164e3359c371c14da.png\"},{\"id\":101880965,\"identity\":\"802ef46d-a7b0-46fa-8ff0-4c0243bca8ab\",\"added_by\":\"auto\",\"created_at\":\"2026-02-04 15:08:26\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":3386576,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/1ea310ef-c862-4578-958f-00f16d2f60bf.pdf\"},{\"id\":101752291,\"identity\":\"3c321c64-b791-41cb-96c9-20edad4e2316\",\"added_by\":\"auto\",\"created_at\":\"2026-02-03 10:26:37\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":667228,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Supplementarydata.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8317008/v1/24a7dc9878594ceba60d4fc1.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Deciphering the Water Supply of a Polje by using Gravimetry\",\"fulltext\":[{\"header\":\"1. Introduction\",\"content\":\"\\u003cp\\u003eA polje is an endoreic basin with a flat bottom, often slightly tilted towards a drainage point, and surrounded by steep walls. Hydrogeologically, this karstic feature is characterized by a surface water, usually a watercourse, which runs off its surface and disappears into the limestone massif, through a preferential infiltration area called a ponor. These areas are prone to intermittent flooding (Gams, \\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e1978\\u003c/span\\u003e; Prohic et al., \\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e1998\\u003c/span\\u003e; Lopez-Chicanos et al. 2002; Ford and Williams, \\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2007\\u003c/span\\u003e; Mayaud et al., \\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e). The development of poljes is influenced by two key factors: 1) the contact between a low-permeability zone, marked by surface run-off, and a high-permeability zone, where the ponor is located; 2) a strong hydraulic gradient that favours the sinking of the hydrographic network or the proximity of the karstic water table, allowing it to overflow. Together, these factors create a unique hydrological system.\\u003c/p\\u003e \\u003cp\\u003eDuring periods of heavy rainfall, the river flowrate can increase sharply and surpass the absorption capacity of the ponors and lead to flooding. This latter can also result from the overflow of the aquifer, which normally drains infiltrated water. In such cases, the ponors reverse their function and become emissive turning into what is known as an \\u0026ldquo;estavelle\\u0026rdquo; (Gilli, 2008), which can form a lake that permanently submerge the ponor. In extreme cases, the water level may rise by several tens of meters, covering hundreds of square kilometres (Lučić, \\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e2014\\u003c/span\\u003e) and potentially causing economic impacts. Depending on the geological or climatic context, flooding may occur as an exceptional event, om a multi-annual scale, or even permanently.\\u003c/p\\u003e \\u003cp\\u003eThe first step to decipher this mitigating flooding which may result from an unusually high supply of surface water and/or groundwater (Lopez-Chicano et al., 2002) is to understand its dynamics and causes. A water balance, including inflows and outflows, can be used to determine the origin of the waters supplying the ponors during high-water periods (Bonacci, \\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1987\\u003c/span\\u003e; L\\u0026oacute;pez-Chicano et al., \\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e2002\\u003c/span\\u003e; Milanović, \\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e2004\\u003c/span\\u003e; Kovačič, \\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e2010\\u003c/span\\u003e; Kovačič and Ravbar, \\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e2010\\u003c/span\\u003e). However, as Kovačič (\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e2010\\u003c/span\\u003e) notes, rigorously quantifying both inflows and outflows over time is highly challenging due to several factors: 1) numerous springs and ponors may go unreported due to their temporary nature or because they activate while submerged; 2) estavelles can act as both springs and ponors; 3) collecting a complete dataset is a labor-intensive and technically difficult task. Mayaud et al. (\\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e) present an alternative method based on the postulate that lake stage variation is directly linked to the water surplus causing the flood, combining water level fluctuations and digital elevation models.\\u003c/p\\u003e \\u003cp\\u003eAmong non-invasive geophysical methods, gravimetry can directly quantify water-mass fluctuations at the catchment scale (Kroner et al., \\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e2006\\u003c/span\\u003e; Hasan et al., \\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e2008\\u003c/span\\u003e; Jacob et al., \\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e2010\\u003c/span\\u003e; Hector et al., \\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e2013\\u003c/span\\u003e; Hemmings et al., \\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e2016\\u003c/span\\u003e; Imanishi et al., \\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e2006\\u003c/span\\u003e; Jacob et al., \\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e2009\\u003c/span\\u003e; Pool and Eychaner, 1995; Van Camp et al., \\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e2006\\u003c/span\\u003e; Wilson et al., \\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e2011\\u003c/span\\u003e) or in localized areas (Naujoks et al., \\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e2008\\u003c/span\\u003e; Kennedy et al. \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e2014\\u003c/span\\u003e). This study is the first to apply gravimetry to estimate the origin of the water supplying the karstic polje of Creux-sous-Roche in the Arcier karstic hydrosystem, a region where flooding has been a significant concern since the late 18th century.\\u003c/p\\u003e\"},{\"header\":\"2. Site setting\",\"content\":\"\\u003cp\\u003eThe study site is located near the Sa\\u0026ocirc;ne swamp, south of Besancon. This area is characterized by the presence of several preferential infiltration areas, swallow holes and two ponors, whose lack sufficient capacity to absorb the flow during periods of heavy and prolonged rainfall. As a result, temporary lakes form multiple times per year, notably filling and emptying very quickly. This study concentrates on the Creux-sous-Roche large ponor because located near a private residence which could host a relative spring gravimeter.\\u003c/p\\u003e \\u003cp\\u003eThe Creux-sous-Roche is a classic ponor, resembling a flat-bottomed funnel with moderate to gentle slopes to the north, west, and southwest, and bordered by vertical rocky walls elsewhere. It serves as the final drainage point for an 800-heactare section of the Sa\\u0026ocirc;ne swamp and is closely connected to the upper Jurassic aquifer, reflecting its saturation levels. Water levels at the Creux-sous-Roche range from 368.42 m at the bedrock to 381.91 m when a temporary lake forms. Sometimes, the flow direction at Creux-sous-Roche reverses, exacerbating flooding. In a first effort to improve drainage at Creux-sous-Roche during flooding periods, two boreholes, each 10 m deep, were drilled close to the sinkhole. Both boreholes intersected joints, likely connecting the Upper and Middle Jurassic aquifers. Once the rains stop, the lake drains quickly due to the intense fracturing in the Creux-sous-Roche area, which lies along a deformation corridor (Klaba et al., 2023).\\u003c/p\\u003e \\u003cp\\u003eThe gravity station is located at 82 m horizontally from the Creux-sous-Roche ponor, at a higher altitude 22 m. The gravimeter, a gPhoneX-100, is housed in the garage of a private residence.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e\"},{\"header\":\"3. Observations\",\"content\":\"\\u003cp\\u003eThis section provides an overview of the datasets used in this study.\\u003c/p\\u003e \\u003cdiv id=\\\"Sec4\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.1 Meteorological data\\u003c/h2\\u003e \\u003cp\\u003eRainfall data were calculated using the RS_Minerve software (Foehn et al., 2020) for the barycenter of the six meteorological stations closest to the Creux-sous-Roche. The data, provided by M\\u0026eacute;t\\u0026eacute;o-Francey M\\u0026eacute;t\\u0026eacute;o-France (\\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://donneespubliques.meteofrance.fr/\\u003c/span\\u003e\\u003cspan address=\\\"https://donneespubliques.meteofrance.fr/\\\" targettype=\\\"URL\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e), were available at an hourly time step for the period from September 15, 2020, to September 14, 2023.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec5\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.2 Water level in the polje\\u003c/h2\\u003e \\u003cp\\u003eThe Creux-sous-Roche is equipped with instruments to monitor water height at two locations: 1) at the surface, using a CTD Diver (vanEssen, precision\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0,05% full scale); 2) at a depth of 15 meters, using an AQUATROLL 600 (\\u0026plusmn;\\u0026thinsp;0.01% full scale), positioned in a joint intersected by one of the boreholes. This latter sensor collected data from dec-2020 to oct-2021 and was eventually relocated next to the first sensor.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec6\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.4 Instruments positioning\\u003c/h2\\u003e \\u003cp\\u003eThe exact positions of the gravimeter and water level sensors were precisely measured using a Leica Geosystems GNSS with single-baseline real-time kinematic (RTK) corrections, achieving a precision of better than 15 mm. The zero level of the water level sensors was set at the altitude of the outside sensor (368.4747 m).\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eCoordinates of the gravimeter and the water gauge in the French Lambert 93 projected coordinate system.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eInstruments\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eX (m)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eY (m)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eZ (m)\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eGravimeter\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e935200.7274\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e6683987.5058\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e389.6824\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eWater gauge (surface)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e935166.3612\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e6684049.0543\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e368.4747\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eWater gauge (deep)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e935166.3612\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e6684049.0543\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e355.4747\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec7\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.5 Gravity measurements\\u003c/h2\\u003e \\u003cp\\u003eContinuous gravity observations were recorded using the relative spring gravimeter gPhoneX (SN:100), manufactured by Micro-g LaCoste Inc. This gravimeter is an improved model based on the Lacoste-Romberg principle. It is equipped with a metallic zero-length spring suspension, a well-controlled temperature sensor, and a modern acquisition system. The gravimeter is mounted on a tilt-controlled tripod to continuously maintain its verticality, making it suitable for long-term operation.\\u003c/p\\u003e \\u003cp\\u003eGravity measurements, which record variations along the vertical axis, began in late October 2020 (Figures \\u003cspan refid=\\\"MOESM1\\\" class=\\\"InternalRef\\\"\\u003eS1\\u003c/span\\u003e). All pre-processing was performed using Tsoft (Van Camp and Vauterin, \\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e2005\\u003c/span\\u003e), following high-standard procedures. First, a gravity tides prediction was removed from the raw data using a theoretical model. Additionally, the atmospheric pressure effect was corrected using an admittance factor of -3 nm s\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e/mbar. The residuals were then carefully edited by: 1) correcting the raw 1-minute data for spikes, offsets, and other non-tidal perturbations such as accidental tilts during visits or earthquakes; 2) interpolating small data gaps; and 3) applying the tidal prediction model and atmospheric pressure correction to the residuals to create a clean time series. Finally, the data were decimated to hourly observations by applying a symmetric low-pass filter with a 2-hour cutoff period.\\u003c/p\\u003e \\u003cp\\u003eHourly gravity and atmospheric data were processed using tidal analysis software (Wenzel, \\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e1996\\u003c/span\\u003e). This resulted in the best tidal prediction, which was used to remove tidal and atmospheric pressure effects from the edited data. Additionally, the time series was corrected for centrifugal acceleration due to polar motion. These geophysical corrections removed the predominant gravity effects while preserving signals from hydrological masses. The first month of data was discarded due to the significant exponential drift caused by the initial relaxation of the gravimeter's spring.\\u003c/p\\u003e \\u003cp\\u003eInstrumental drift, which varies between instruments, needs to be estimated using absolute gravity measurements for long-term gravity changes. However, this study focuses on weekly gravity changes associated with rainfall. To remove the long-term signal (drift\\u0026thinsp;+\\u0026thinsp;annual variations), a low-degree polynomial was fitted to the data.\\u003c/p\\u003e \\u003cp\\u003eFigure \\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e clearly demonstrates a strong correlation between the rainfall rate and observed gravity variations. This suggests that the observed gravity signal is primarily influenced by the water content in both the polje and the surrounding soil.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe water level observations in the polje and the well at its bottom are shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e. As expected, these observations indicate that rainfall is the primary driver of both water level fluctuations and the observed gravity changes.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"4. Estimating the direct Newtonian attraction of the water in the sinkhole\",\"content\":\"\\u003cp\\u003eThe gravity station is installed on a concrete floor in the garage of a house adjacent to the polje. The station and polje are separated by a horizontal distance of 82 m and an altitude difference of 22 m. To evaluate the direct Newtonian gravitational attraction (\\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:dg\\\\)\\u003c/span\\u003e\\u003c/span\\u003e) of the water in the polje as a function of its water level, we use a digital terrain model and apply Newton\\u0026rsquo;s law of gravitation:\\u003cdiv id=\\\"Equ1\\\" class=\\\"Equation\\\"\\u003e\\u003cdiv format=\\\"TEX\\\" class=\\\"mathdisplay\\\" id=\\\"FileID_Equ1\\\" name=\\\"EquationSource\\\"\\u003e\\n$$\\\\:dg=G\\\\:{\\\\rho\\\\:}_{water}\\\\frac{dV}{{d}^{2}}\\\\:\\\\frac{dh}{d}$$\\u003c/div\\u003e\\u003cdiv class=\\\"EquationNumber\\\"\\u003e1\\u003c/div\\u003e\\u003c/div\\u003e\\u003c/p\\u003e \\u003cp\\u003ewhere \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:G\\\\)\\u003c/span\\u003e\\u003c/span\\u003e is the universal gravitational constant, \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:{\\\\rho\\\\:}_{water}\\\\)\\u003c/span\\u003e\\u003c/span\\u003e is the water density, \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:dV\\\\)\\u003c/span\\u003e\\u003c/span\\u003e is a small volume of water, \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:d\\\\)\\u003c/span\\u003e\\u003c/span\\u003e is the distance between the mass element \\u003cem\\u003edm=\\u003c/em\\u003e\\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:{\\\\rho\\\\:}_{water}dV\\\\)\\u003c/span\\u003e\\u003c/span\\u003e and the gravity station, and \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:dh\\\\)\\u003c/span\\u003e\\u003c/span\\u003e is the altitude difference. The term \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:\\\\frac{dh}{d}\\\\)\\u003c/span\\u003e\\u003c/span\\u003e projects the gravity vector along the vertical. This means that if the disturbing mass is at the same altitude as the gravimeter, it will not contribute to the detected signal.\\u003c/p\\u003e \\u003cp\\u003eTo compute the direct Newtonian attraction of the water in the polje, the volume is divided into small cubes, each with 1 m sides. We use the exact analytical formula for the direct gravitational attraction of a cube. The total effect, as a function of the water level, is then obtained by summing the contributions of each cube. Figure S2 shows the position of the gravimeter relative to the sinkhole, along with the lake configuration at three different water levels.\\u003c/p\\u003e \\u003cp\\u003eNear the Creux-sous-Roche, the Fosses de Sa\\u0026ocirc;ne sinkhole, located approximately 200 m away, can host another temporary lake during high waters We also modeled its gravitational attraction using the digital terrain model. Although we do not have water level data for this sinkhole, we assume that the water levels are the same in both sinkholes due to their interconnected nature. The calculated direct Newtonian attraction from this second sinkhole is 10 times smaller. Two factors contribute to this reduced influence: first, gravity decreases according to the inverse-square law (\\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:\\\\frac{1}{{r}^{2}}\\\\)\\u003c/span\\u003e\\u003c/span\\u003e), and second, due to the distance, the vertical component of gravity decreases.\\u003c/p\\u003e \\u003cp\\u003eWe first calculate the direct Newtonian attraction for both Creux-sous-Roche and Fosses de Sa\\u0026ocirc;ne as a function of their respective water levels at 1 m intervals (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e). Then, a second- or third-degree polynomial is fitted, depending on the sites. The resulting analytical expressions are used to correct the observed gravity variations caused by the water content in them.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e\"},{\"header\":\"5. Estimating the porosity coefficient\",\"content\":\"\\u003cp\\u003eThe remaining temporal changes in the gravity observations are primarily caused by variations in the water table level. If we assume that the water is uniformly distributed over an infinite horizontal layer with thickness \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:h\\\\)\\u003c/span\\u003e\\u003c/span\\u003e, the direct mass attraction can be expressed using the Bouguer plate model:\\u003cdiv id=\\\"Equ2\\\" class=\\\"Equation\\\"\\u003e\\u003cdiv format=\\\"TEX\\\" class=\\\"mathdisplay\\\" id=\\\"FileID_Equ2\\\" name=\\\"EquationSource\\\"\\u003e\\n$$\\\\:dg=2\\\\pi\\\\:G\\\\:{\\\\rho\\\\:}_{water\\\\:}\\\\phi\\\\:\\\\:h\\\\:$$\\u003c/div\\u003e\\u003cdiv class=\\\"EquationNumber\\\"\\u003e2\\u003c/div\\u003e\\u003c/div\\u003e\\u003c/p\\u003e \\u003cp\\u003ewhere \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:{\\\\rho\\\\:}_{water}\\\\)\\u003c/span\\u003e\\u003c/span\\u003e is the density of the water and j is the porosity of the medium.\\u003c/p\\u003e \\u003cp\\u003eThe gravity variation depends on two parameters: \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:h\\\\)\\u003c/span\\u003e\\u003c/span\\u003e and \\u003cem\\u003ej\\u003c/em\\u003e. However, it is not possible to determine both parameters simultaneously from gravity data alone. To address this, we first assume that the water table \\u003cspan class=\\\"InlineEquation\\\"\\u003e\\u003cspan class=\\\"mathinline\\\"\\u003e\\\\(\\\\:h\\\\)\\u003c/span\\u003e\\u003c/span\\u003e is equivalent to the water level in the sinkhole and the well beneath the polje. The porosity \\u003cem\\u003ej\\u003c/em\\u003e is then estimated by fitting a straight line to the plot of gravity residuals versus the water level above or below the polje (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe porosity can be expressed as:\\u003cdiv id=\\\"Equ3\\\" class=\\\"Equation\\\"\\u003e\\u003cdiv format=\\\"TEX\\\" class=\\\"mathdisplay\\\" id=\\\"FileID_Equ3\\\" name=\\\"EquationSource\\\"\\u003e\\n$$\\\\:\\\\phi\\\\:\\\\:=\\\\:\\\\frac{1}{2\\\\:\\\\pi\\\\:\\\\:{\\\\rho\\\\:}_{water}G\\\\:}\\\\:\\\\frac{dg}{dh}$$\\u003c/div\\u003e\\u003cdiv class=\\\"EquationNumber\\\"\\u003e3\\u003c/div\\u003e\\u003c/div\\u003e\\u003c/p\\u003e \\u003cp\\u003ewhere \\u003cem\\u003edg/dh\\u003c/em\\u003e represents the slop of the curves in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e.\\u003c/p\\u003e \\u003cp\\u003eWe obtained porosity values of 0.3% and 2.0% when considering the data below and above the sinkhole, respectively. These values differ by a factor of 10, which is too low for a karstic region. This discrepancy arises because the water levels in the polje and well are not accurate proxies for the water table level. Both tend to overestimate the water table level. The difference in porosity values clearly indicates distinct dynamic responses between the ponor area and the rest of the polje.\\u003c/p\\u003e \\u003cp\\u003eThe literature provides total porosity values for karstic systems ranging from 2% to 30%, depending on the degree of fracturing. These values can be classified into three types of porosity that coexist in karstic systems (Delbart, \\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e2014\\u003c/span\\u003e; Goldscheider and Drew, 2007; Carri\\u0026egrave;re, \\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e2014\\u003c/span\\u003e). The first type is matrix porosity, which is related to lithology and typically presents low values, often only a few percent (Gilli, \\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e2011\\u003c/span\\u003e). The second type, fracture porosity, is associated with the karst\\u0026rsquo;s tectonic history and varies according to the size and opening of discontinuities, such as fractures and faults. The third type is duct porosity, which results from karstification and can reach effective values of up to 15%, influencing the movement of the water table.\\u003c/p\\u003e\"},{\"header\":\"6. Estimating the water table level\",\"content\":\"\\u003cp\\u003eAssuming a porosity value of 15%, we can estimate the water table level change (\\u003cem\\u003edh\\u003c/em\\u003e) by inverting Eq.\\u0026nbsp;(\\u003cspan refid=\\\"Equ3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e) as follows:\\u003cdiv id=\\\"Equ4\\\" class=\\\"Equation\\\"\\u003e\\u003cdiv format=\\\"TEX\\\" class=\\\"mathdisplay\\\" id=\\\"FileID_Equ4\\\" name=\\\"EquationSource\\\"\\u003e\\n$$\\\\:dh=\\\\:\\\\frac{1}{2\\\\:\\\\pi\\\\:\\\\:{\\\\rho\\\\:}_{water}G\\\\:}\\\\:\\\\frac{dg}{\\\\phi\\\\:}$$\\u003c/div\\u003e\\u003cdiv class=\\\"EquationNumber\\\"\\u003e4\\u003c/div\\u003e\\u003c/div\\u003e\\u003c/p\\u003e \\u003cp\\u003eUsing this approach, we obtain the estimated water table level, which is shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e. The water level variations are in phase with the water level in the polje, which is controlled by the rainfall regime.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eDuring sustained rainfall, the water table rises quickly. The rate of filling and the water level height depend on both the intensity and duration of the rainfall. Any variation in rainfall supply leads to similar variations in the water table and polje water levels. Once the rain stops, both the water level in the polje and water table levels in the aquifer drop rapidly. While Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e may suggest that the water table level returns to its pre-rain level, this is not entirely accurate. The seasonal variations have been smoothed out to remove the gravimeter's instrumental drift. This component could be further assessed if the relative gravity observations were complemented by episodic absolute gravity measurements.\\u003c/p\\u003e \\u003cp\\u003eData from the Gennes borehole, drilled into the upper Jurassic limestones (\\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://infoterre.brgm.fr/\\u003c/span\\u003e\\u003cspan address=\\\"https://infoterre.brgm.fr/\\\" targettype=\\\"URL\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e), show that the water level varies between a minimum of 400.48 m and a maximum of 404.97 m from October 24, 2020, to June 30, 2023. The amplitude of these variations is approximately double that of the changes observed in the polje's water levels. The annual signal in the gravity observations has been filtered to remove the instrumental drift, so this component is missing from the gravity time series. The annual signal could account for up to half of the total amplitude in the water table level. In terms of variations, the water table level obtained by Gennes borehole and that simulated from gravimetric data are substantially similar, expected for the 03/2022-09/2022 period during which data quality is questioned (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig7\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eFinally, a regression was performed between the water level in the polje and the estimated water table level derived from the gravimetric observations (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e). A simple admittance factor was obtained, allowing us to estimate the water table level based on the polje water level. The two levels are highly correlated, exhibiting similar phase behavior but differing in amplitude response to rainfall events.\\u003c/p\\u003e\"},{\"header\":\"Conclusion\",\"content\":\"\\u003cp\\u003eThe study explores the hydrological dynamics of a polje, specifically, the Creux-sous-Roche in the Arcier Karst hydrosystem, by using gravimetry. Water levels in the Creux-sous-Roche fluctuate primarily due to rainfall showed by consistent responses in water levels above and below the surface during rain events. A strong correlation was observed between rainfall rates and gravity variations, indicating that these gravity changes are mainly influenced by water content in the polje and surrounding soil.\\u003c/p\\u003e \\u003cp\\u003eThe gravitational attraction of water in the polje was modeled using Newton's law of gravitation. The study accounted for the distance and altitude difference between the gravimeter and the polje, allowing for accurate calculations of gravity changes based on water levels. After correcting gravity data for the influence of water in the sinkholes, the residual signals mainly reflect the water content in the soil beneath the gravimeter.\\u003c/p\\u003e \\u003cp\\u003ePorosity values derived from the analysis were notably low (0.3% and 2%), indicating potential discrepancies in the reliability of using polje water levels as proxies for the actual water table levels in the karst system. The findings align anyway with literature, which indicates that total porosity in karstic systems ranges from 2% to 30%. Three types of porosity (matrix, fracture, and duct) were discussed, with duct porosity potentially reaching 15%, influencing groundwater dynamics. By assuming a porosity of 15%, estimated water table levels were calculated, showing consistency with data from a nearby borehole, which recorded significant fluctuations over the study period.\\u003c/p\\u003e \\u003cp\\u003eOverall, the results underscore the complex hydrological dynamics of the Creux-sous-Roche area, highlighting the relationships between rainfall, water levels, gravitational measurements, and karstic porosity. In this way, the study demonstrates the potential of gravimetry to explore these dynamics and determine the storage and circulation potential of karst aquifers.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e \\u003ch2\\u003eOpen Research\\u003c/h2\\u003e \\u003cp\\u003eData: \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://data.oreme.org/observation/snokarst\\u003c/span\\u003e\\u003cspan address=\\\"https://data.oreme.org/observation/snokarst\\\" targettype=\\\"URL\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/p\\u003e \\u003c/p\\u003e\\u003ch2\\u003eFunding\\u003c/h2\\u003e \\u003cp\\u003eThis work was supported by the Bourgogne-Franche-Comt\\u0026eacute; region and AERMC (Agence de l\\u0026rsquo;Eau Rh\\u0026ocirc;ne, M\\u0026eacute;diterran\\u0026eacute;e, Corse) through the TRANSKARST (TRANSdisciplinary research on KARSTic waters) project (grant number: CRBFC: 2019-Y-09074).\\u003c/p\\u003e\\u003ch2\\u003eAuthor Contribution\\u003c/h2\\u003e\\u003cp\\u003eA-H\\u0026eacute;l\\u0026egrave;ne Celle \\u0026lt;helene.celle@univ-fcomte.fr\\u0026gt;B-Victor Klaba \\u0026lt;victor.klaba@gmail.com\\u0026gt;C-Sajad Tabibi \\u0026lt;sajad.tabibi@uni.lu\\u0026gt;D-Benjamin Fores \\u0026lt;benjamin.fores@outlook.com\\u0026gt;E-Julie Albaric \\u0026lt;julie.albaric@univ-fcomte.fr\\u0026gt;F-Flavien Choulet \\u0026lt;flavien.choulet@univ-fcomte.fr\\u0026gt;G-Olivier Francis \\u0026lt;olivier.francis64@gmail.com\\u0026gt;All authors wrote the main manuscript textA, B, C and D prepare the figuresA and G found the fundings for the studyA, B, C, D, G participated to the field work and data analysis\\u003c/p\\u003e\\u003ch2\\u003eAcknowledgement\\u003c/h2\\u003e\\u003cp\\u003eThe Arcier spring is a part of the Jurassic Karst observatory, affiliated to SNO Karst (Service National d\\u0026rsquo;Observation du Karst). The authors would like to warmly thank Mr. and Mrs. Manevy, without whom the study would not have been possible, for giving access to their garage and electrical network to position the gravimeter.\\u003c/p\\u003e\\u003ch2\\u003eData Availability\\u003c/h2\\u003e\\u003cp\\u003eData: https://data.oreme.org/observation/snokarst\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003cp\\u003eBonacci, O. (1987), Karst hydrology: with special reference to the Dinaric karst. \\u003cem\\u003eSpringer-Verlag, Berlin\\u003c/em\\u003e, 184 pp. doi:10.1007/978-3-642-83165-2.\\u003c/p\\u003e\\n\\u003cp\\u003eFord D., Williams P. (2007), Karst Hydrogeology and Geomorphology. \\u003cem\\u003eJohn Wiley \\u0026amp; Sons\\u003c/em\\u003e, 562 pp., doi:10.1002/9781118684986\\u003c/p\\u003e\\n\\u003cp\\u003eCarrière S. (2014), Etude hydrogéophysique de la structure et du fonctionnement de la zone non saturée du karst. \\u003cem\\u003eThèse, Université d’Avignon et des Pays de Vaucluse\\u003c/em\\u003e, 218pp.\\u003c/p\\u003e\\n\\u003cp\\u003eDelbart, C. (2014), Variabilité spatio-temporelle du fonctionnement d’un aquifère karstique du Dogger : suivis hydrodynamiques et géochimiques multifréquences ; traitement du signal des réponses physiques et géochimiques. \\u003cem\\u003eThèse, Université Paris Sud\\u003c/em\\u003e, 232pp.\\u003c/p\\u003e\\n\\u003cp\\u003eDeville, S. (2013), Caractérisation de la zone non saturée des karsts par la gravimétrie et l’hydrogéologie. \\u003cem\\u003eThèse, Université Montpellier\\u003c/em\\u003e \\u003cem\\u003eII\\u003c/em\\u003e, 239 pp.\\u003c/p\\u003e\\n\\u003cp\\u003eGams, J. (1978), The polje: the problem of definition, with special regard to the Dinaric karst. \\u003cem\\u003eZeitschrift für Geomorphologie,\\u003c/em\\u003e 55, 170-181.\\u003c/p\\u003e\\n\\u003cp\\u003eGilli, E. (2011), Karstologie, karst grottes et sources. \\u003cem\\u003eEd. Dunod\\u003c/em\\u003e, 244 pp.\\u003c/p\\u003e\\n\\u003cp\\u003eGolscheider, N., Drew, D. (2007), Methods in Karst Hydrogeology. \\u003cem\\u003eWiley \\u0026amp; Sons,\\u003c/em\\u003e 280pp, doi:10.1201/9781482266023\\u003c/p\\u003e\\n\\u003cp\\u003eHasan, S., Troch, P.A., Bogaart, P.W., Kroner, C. (2008), Evaluating catchment-scale hydrological modelling by means of terrestrial gravity observations, \\u003cem\\u003eWater Resource \\u003c/em\\u003e\\u003cem\\u003eResearch\\u003c/em\\u003e, 44, W08416, doi:10.1029/2007WR006321\\u003c/p\\u003e\\n\\u003cp\\u003eHector, B., Séguis, L., Hinderer, J., Descloitres, M., Vouillamoz, J.M., Wubda, M., Le Moigne, N. (2013), Gravity effect of water storage changes in a weathered hard-rock aquifer in West Africa: results from joint absolute gravity, hydrological monitoring and geophysical prospection, \\u003cem\\u003eGeophysical Journal International\\u003c/em\\u003e, 194 (2), 737-750, doi:10.1093/gji/ggt146\\u003c/p\\u003e\\n\\u003cp\\u003eHemmings, B., Gottsmann, J., Whitaker, F., Coco, A. (2016), Investigating hydrological contributions to volcano monitoring signals: A time-lapse gravity example, \\u003cem\\u003eGeophysical Journal International\\u003c/em\\u003e, 207, doi:10.1093/gji/ggw266\\u003c/p\\u003e\\n\\u003cp\\u003eImanishi, Y., Kokubo, K., Tatehata, H. (2006), Effect of underground water on gravity observation Matsushiro, Japan, \\u003cem\\u003eJournal of Geodynamics\\u003c/em\\u003e, 41 (1-3), 221-226, doi:10.1016/j.jog.2005.08.031\\u003c/p\\u003e\\n\\u003cp\\u003eJacob, T., Chery, J., Bayer, R., Moigne, N.L., Boy, J.P., Vernant, P., Boudin, F. (2009), Time lapse surface to depth gravity measurements on a karst system reveal the dominant role of the epikarst as a water storage entity, \\u003cem\\u003eGeophysical Journal International\\u003c/em\\u003e, 177, 347-360, doi:10.1111/j.1365-246X.2009.04118.x.\\u003c/p\\u003e\\n\\u003cp\\u003eJacob, T., Bayer, R., Chery, J. \\u0026amp; Le Moigne, N. (2010), Time-lapse microgravity surveys reveal water storage heterogeneity of a karst aquifer, \\u003cem\\u003eJournal of Geophysical Research\\u003c/em\\u003e, 115 (B6), doi:10.1029/2009JB006616\\u003c/p\\u003e\\n\\u003cp\\u003eKennedy, J., Ferre, T.P.A., Güntner, A., Abe, M., Creutzfeldt, B. (2014), Direct measurement of subsurface mass change using the variable baseline gravity gradient method, \\u003cem\\u003eGeophysical Research Letters\\u003c/em\\u003e, 41, 2827-2834, doi:10.1002/2014GL059673\\u003c/p\\u003e\\n\\u003cp\\u003eKovačič, G. (2010), An attempt towards an assessment of the Cerknica Polje water balance. \\u003cem\\u003eActa Carsologica,\\u003c/em\\u003e 39 (1), 39-50, doi:10.3986/ac.v39i1.111\\u003c/p\\u003e\\n\\u003cp\\u003eKovačič, G., Ravbar, N. (2010), Extreme hydrological events in karst areas of Slovenia, the case of the Uni-ca River basin. \\u003cem\\u003eGeodinamica Acta\\u003c/em\\u003e, 23 (1-3), 89-100. doi:10.3166/ga.23.89-100\\u003c/p\\u003e\\n\\u003cp\\u003eKroner, C., Jahr, T., Naujoks, M., Weise, A., 2006. Hydrological signals in gravity - foe or friend? \\u003cem\\u003eDynamic Planet, IAG Symposia Series 130, Springer, ISBN 978-3-540-49349-5\\u003c/em\\u003e, 504-510.\\u003c/p\\u003e\\n\\u003cp\\u003eLópez-Chicano, M., Calvache, M.L., Martín-Rosales, W., Gisbert. J., 2002. Conditioning factors in flooding of karstic poljes - the case of the Zafarraya polje (South Spain). Catena, 49, 331-352, doi:10.1016/S0341-8162(02)00053-X.\\u003c/p\\u003e\\n\\u003cp\\u003eLučić, I. (2014), General aspects of the Karst Poljes of the Dinaric Karst. In Sackl P., Durst R., Kotrošan, D., Stumberger, B. (eds), Dinaric Karst Poljes - Floods for Life. \\u003cem\\u003eEuroNatur, Radolfzell\\u003c/em\\u003e, 17-24.\\u003c/p\\u003e\\n\\u003cp\\u003eNaujoks, M., Weise, A., Kroner, C., Jahr T. (2008), Detection of small hydrological variations in gravity by repeated observations with relative gravimeters. \\u003cem\\u003eJournal of Geodesy\\u003c/em\\u003e, 82 (9), 543-553, doi:10.1007/s00190-007-0202-9.\\u003c/p\\u003e\\n\\u003cp\\u003ePool, D.R., Eyechaner, J.H. (1995), Measurements of Aquifer-Storage Change and Specific Yield Using Gravity Surveys, \\u003cem\\u003eGroundwater\\u003c/em\\u003e, 33, 425-432, doi:10.1111/j.1745-6584.1995.tb00299.x\\u003c/p\\u003e\\n\\u003cp\\u003eMayaud, C., Kogovsek, B., Gabrovsek, F., Blatnik, M., Petric, M., Ravbar, N. (2022), Deciphering the water balance of poljes: example of Planinsko Polje (Slovenia). \\u003cem\\u003eActa Carsologica,\\u003c/em\\u003e 51 (2), 155-177. doi:10.3986/ac.v51i2.11029CC \\u003c/p\\u003e\\n\\u003cp\\u003eMilanović, P. (2004), Water resources engineering in karst. CRC Press, Boca Raton, 328 pp, doi:10.1201/9780203499443\\u003c/p\\u003e\\n\\u003cp\\u003eProhic, E., Peh, Z., Miko, S. (1998), Geochemical characterization of a karst polje. An example from Sinjsko Polje, Croatia. \\u003cem\\u003eEnvironmental Geology\\u003c/em\\u003e, 33 (4), 263-273.\\u003c/p\\u003e\\n\\u003cp\\u003eVan Camp, M., and Vauterin, P. (2005), Tsoft: graphical and interactive software for the analysis of time series and Earth tides, \\u003cem\\u003eComputers and Geosciences\\u003c/em\\u003e, 31(5), 631-640 [software], doi:10.1016/j.cageo.2004.11.015\\u003c/p\\u003e\\n\\u003cp\\u003eVan Camp, M., Vanclooster, M., Crommen, O., Petermans, T., Verbeeck, K., Meurers, B., van Dam, T., Dassargues, A. (2006), Hydrogeological investigations at the Membach station, Belgium, and application to correct long periodic gravity variations, Journal of Geophysical Research, 111, B10403, doi:10.1029/2006JB004405.\\u003c/p\\u003e\\n\\u003cp\\u003eWenzel, H-G. (1996), Thenanogal Software: Earth tide data processing package: ETERNA 3.30, In: Melchio P. Eds, Marées Terrestres Bulletin d'Information, 124, 9425-9439 [software]\\u003c/p\\u003e\\n\\u003cp\\u003eWilson, C.R., Scanlon, B., Sharp J., Longuevergne, L., Wu, H. (2011), Field Test of the Superconducting Gravimeter as a Hydrologic Sensor, \\u003cem\\u003eGroundwater\\u003c/em\\u003e, 50, 442-449, doi:10.1111/j.1745-6584.2011.00864.x\\u003c/p\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":false,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"pure-and-applied-geophysics\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"paag\",\"sideBox\":\"Learn more about [Pure and Applied Geophysics](https://www.springer.com/journal/24)\",\"snPcode\":\"24\",\"submissionUrl\":\"https://submission.nature.com/new-submission/24/3\",\"title\":\"Pure and Applied Geophysics\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false},\"keywords\":\"gravimetry, hydrodynamic, karst, polje, monitoring\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-8317008/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-8317008/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eAmong aquifers, karsts are known to present a heterogeneous structure leading to a specific hydrodynamic behavior mixing slow and fast circulations, which makes their study a real challenge. In addition to the specific nature of these structures, there is a need to improve the study methods that can be used to gain a better understanding of these systems. This study is the first to propose continuous gravimetric coupled with hydrodynamic measurements to understand the functioning of a polje whose intermittent flash floods can have disastrous socio-economic consequences. These flooding can be due either by surface water that can no longer infiltrate underground because its infiltration capacity has been exceeded or by overflow of the aquifer, both of which depend on the porosity of the karstic aquifer. The results allow deciphering the origin of water that cause the flooding and determining the storage of karstic aquifer that plays a decisive role.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Deciphering the Water Supply of a Polje by using Gravimetry\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2026-01-30 10:00:00\",\"doi\":\"10.21203/rs.3.rs-8317008/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"decision\",\"content\":\"Revision requested\",\"date\":\"2026-03-03T19:58:23+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-03-01T16:59:35+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-02-19T18:20:12+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"118229753126198995817561044248476009668\",\"date\":\"2026-02-03T08:56:00+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"91634296219192356531193847503372047808\",\"date\":\"2026-01-28T16:23:05+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2026-01-28T12:03:16+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2025-12-10T10:01:30+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2025-12-09T14:42:19+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Pure and Applied Geophysics\",\"date\":\"2025-12-09T11:10:39+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"pure-and-applied-geophysics\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"paag\",\"sideBox\":\"Learn more about [Pure and Applied Geophysics](https://www.springer.com/journal/24)\",\"snPcode\":\"24\",\"submissionUrl\":\"https://submission.nature.com/new-submission/24/3\",\"title\":\"Pure and Applied Geophysics\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false}}],\"origin\":\"\",\"ownerIdentity\":\"a30bf51b-f58b-43be-a733-27d2af646a30\",\"owner\":[],\"postedDate\":\"January 30th, 2026\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"under-review\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2026-04-14T07:23:49+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2026-01-30 10:00:00\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-8317008\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-8317008\",\"identity\":\"rs-8317008\",\"version\":[\"v1\"]},\"buildId\":\"XKTyCvWXoU3ODBz1xrDgd\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}