The International Research Laboratory MINERWA (Responsible Mining, West-Africa) has for objective to contribute to the comprehension of the distribution of mineral resources in Ivory Coast, and to their responsible exploration and exploitation, which implies a thorough understanding of environmental and societal impacts. It is co-funded by the French National Research Institute for Sustainable Development (IRD) and by the African Center of Excellence “Mines and Mining Environment” hosted by the INP-HB (Institut National Polytechnique Félix Houphouët-Boigny) in Yamoussoukro, Ivory Coast. It also involves the University Felix Houphouët-Boigny (UFHB, Abidjan), and 4 laboratories in France (Geosciences Environment Toulouse, PRODIG, Hydrosciences Montpellier and Espace-DEV). MINERWA is also part of the world-wide network AMEDEE (Activity of Mining, Environment, Development, Economy, Ethics, https://amedee-network.science/en/), which is an international collaborative R&D platform whose goal is to promote responsible mining in subtropical and intertropical areas in partnership. The approach is interdisciplinary and the research team is composed of specialists in social and environmental sciences and geologists. The focus is placed on a multi-scale analysis, from atomic/mineral to the crustal scale through the scale of territories. It aims to reinforce the analytical capabilities in Ivory coast, with a focus on free remote sensing data and software and low-coast portable instruments for geochemical analysis of rocks and contaminants in the field, including portable XRF, portable LIBS, portable gamma-ray spectrometers and portable visible/NIR spectrometers. The research laboratory shall be funded for 5 years and was initiated in 2019. The activities are divided into 5 work packages, including (1) a platform for continuous exchanges between the different actors, (2) capacity building, (3) geology of mineral ressources, (4) mines, environment and societies, (5) scale transfer. Several preliminary research outcomes in the framework of this laboratory will be presented in the session, in particular in relation to the environmental impact of artisanal mining in West Africa [1,2,3]. [1] Abass Saley, A. et al. , this session. [2] Ngome, M. et al., this session. [3] DAÏ, B.S.M. et al., this session.

In 1988, the Center for Operational Oceanographic Products and Services (CO-OPS), an office of NOAA’s National Ocean Service, began to record continuous 6-minute water temperature data with thermistors at the coastal stations of the National Water Level Observation Network. Today, 140 of the stations have accumulated at least 15 years of archived data. We performed extensive quality control of the daily-averaged water temperatures by excluding periods of suspect data revealed through inter-station comparison. All quality-controlled series have 15-25 years of daily means that, when aggregated, produce an average seasonal cycle for 365 days of the year. Residual temperature series obtained after subtracting the average seasonal cycle from the daily mean temperature depict the inter-annual variations. A threshold for defining an extreme residual water temperature was selected to highlight periods of anomalously warm or cold coastal water conditions. This type of climate information should prove valuable to users in the fields of ecology and fisheries management for quantifying anomalous temperature effects on coastal ecosystems (such as fisheries, corals, sea grasses, harmful algal blooms, etc). Knowledge of average seasonal water temperature cycles are also useful for validating coastal hydrodynamic models. Extended periods from weeks to months of high or low coastal sea levels can be correlated with coastal water temperature anomalies.

Rn and CO2 in-depth, as a proxy for pre-seismic activity Hovav Zafrir1,4, Uri Malik1, Elad Levintal2, Noam Weisbrod2, Yochai Ben Horin3, Zeev Zalevsky4, Nimrod Inbar5 1Geological Survey of Israel, 32 Yesha’ayahu Leibowitz, Jerusalem 9371234, Israel, 2The Zuckerberg Institute for Water Research, Ben-Gurion University, 8499000 Sede Boqer, Israel, 3Soreq Nuclear Research Center, Yavne 81800, Israel, 4Faculty of Engineering, Bar Ilan University, Ramat-Gan 52900, Israel, 5Ariel University, Ariel 40700, Israel. (First author e-mail: hzafrir@gmail.com; zafrir@gsi.gov.il). Abstract The method of long-term monitoring of subsurface gases in shallow to deep boreholes assumes that the climatic influence on geo-physicochemical parameters is limited since its energy decreases with the increase in the thickness of the geological cover. Hence, the monitoring of radon (Rn), CO2 and other constituents above and below the water table in deep boreholes enables to eliminate the climatic-induced periodic contributions, from the residual portion of the signals that are associated with the regional geodynamic processes, as have been proved by us recently for radon(*). Monitoring of radon and CO2 at a depth of several tens of meters along the Dead Sea Fault Zone, between the Dead Sea and the Hula Valley has led to a clear discovery of the phenomenon that both gases are affected by an underground tectonic activity related to the pre-seismic processes of producing earthquakes, even if they are weak. The pre-seismic processes even if not all end with earthquakes, cause the movement of gases in the subsurface geologic media and creating non-periodic signals that are wider than 20 to 24 hours. Hence, monitoring of any other natural gas at depth may show a similar expansion signal and may serve as a precursor for earthquakes. The necessary conditions needed to explore anomalous signals of gases that induced by pre-seismic processes at the depth, as accumulation and relaxation of lithospheric stress and strain, are: a) setup of a monitoring system within boreholes airspace, drilled to active faults, b) verify that there is at least one gas with concentration level few times above the conventional background level of the regional subsurface content, c) utilizing high sensitive detectors to recover changes in the gas content, with detection limit of few percents of the local average (As an example: for radon, the required content is at least 1kBq/m3 and the required sensitivity is better than 5%). (*) Zafrir, H., Ben Horin Y., Malik, U., Chemo, C., and Zalevsky, Z., 2016, Novel determination of radon-222 velocity in deep subsurface rocks and the feasibility to using radon as an earthquake precursor, J. Geophys. Res. Solid Earth, 121, 6346–6364, doi: 10.1002/2016JB013033.

WindNinja is a high-resolution diagnostic wind model developed for use by operational wildland fire management. The original version of WindNinja employed a numerical solver to enforce conservation of mass (COM). Because the COM solver is fast-running, requires little technical experience to run, and predicts ridgetop speed up and channeling effects well, it is widely used by the operational fire community. The COM solver has limitations, however, in regions where momentum effects dominate the flow, such as in regions of flow separation, which can occur on the lee-side of terrain obstacles. Recently, a second solver has been incorporated into WindNinja which enforces conservation of mass and momentum using computational fluid dynamics (CFD) techniques based on the Reynolds-Averaged Navier-Stokes (RANS) equations. In this work we compare simulations from the CFD solver to measurements made during three field campaigns (Askervein Hill, Bolund Hill, and Big Southern Butte) as well as to simulations from the COM solver and an LES model. Evaluations focus on near-surface winds during high-wind periods, which are of particular interest to wildland fire managers.

The South Atlantic Dipole (SAD) is the main mode of coupled variability between ocean and atmosphere on interannual and interdecadal timescales on the South Atlantic Ocean. Its oceanic component is characterized by a dipole of sea surface temperature (SST) anomalies between tropics and extratropics, while the atmospheric part is linked with the South Atlantic Subtropical High (SASH) variability. Some other important factors can influence the SAD, for instance, variations in the Atlantic Meridional Overturning Circulation (AMOC), which may alter the distribution of physical properties of the ocean such as the SST. Given the current background of anthropogenic global warming, some features have contributed to alter AMOC, such as Greenland’s continental ice melting and also the increase in Agulhas Leakage. Therefore, this work aims to identify possible changes in the SAD pattern during the period after industrial revolution (1851-2010). The SAD is the first mode found through the Singular Value Decomposition (SVD) of SST and Mean Sea Level Pressure (MSLP). This analysis was performed at intervals of 30 and 10 years, in order to encompass the interannual and interdecadal cycles of the SAD oscillation, at the same time that it is possible to analyze possible changes in the SAD throughout the study period (1851-2010). Preliminary results show strong signs of changes in the SAD configuration, both in its oceanic and atmospheric components, which probably have impacts on the climate of the adjacent continents, which will be further studied later. The analysis performed with NOAA-CIRES 20th Century Reanalysis V2c indicate a clockwise rotation of the SST anomaly dipole pattern, while the associated MSLP anomalies show a northwestern shift over the study period.

Absorption muon imaging is a technique that can measure density variations underground down to a few hundred meters. Then, it can prove to be useful in a mining environment: to help assess the ore bodies volumes and/or to monitor the underground for natural hazards that can happen at the surface because of the mining exploitation. Here we report the result of an experiment designed to test the capabilities and resolution power of a cosmic muon measurement in a mining environment compared to other standard geophysics tools: gravimetry and seismic studies. It consists of three independent measurement of a subset of the decommissioned iron mine of May-sur-Orne (France). The first one was made using a 50x50cm² micromegas based muon telescope installed at the deepest non-submerged level (50m underground) during 3 months. The second one is a gravimetry survey of the surface area inside the muon telescope acceptance cone. And the third one is a study of refracted and reflected seismic waves along a single line above the muon telescope location. The investigation volume was chosen because of the presence of surface risks (neighborhood), the unknown of some uncharted volume and the presence of an ore storage volume of several meter cubed that was used during the mine exploitation and which filling state is unknown. The data analysis showed that while muon tomography is able to detect the negative density anomaly of the storage volume, the gravimetry measurement is not sensible to it. However, the seismic study was able to detect the volume as well and its location and extension is compatible with the muon measurement.

Mountain ranges in seismically active regions often present vast numbers of deep-seated and voluminous landslides. In general, the comprehension of factors contributing to such slope failures can help better understand the dynamic history of a region. Here, we present the outcomes of our studies in the Buzau-Vrancea seismic region in the Romanian Carpathian Mountains, where massive slides are marked by “softened” hummocky morphologies that result from weathering and aging. The latter factors make it more difficult to understand the circumstances of slope failure development and to trace the limits between in-situ and displaced material. In particular, the uncertain subsurface structure of those large mass movements suggests the application of geophysical methods. We used several geophysical techniques, which allowed us to overcome limitations in terms of investigation depth and lateral resolution of single methods. Electrical resistivity measurements can be used to obtain lithological information, and to characterise the water content of the landslide deposits and of in situ rocks. On most sites, we combined electrical surveys with seismic methods: actively triggered seismic energy used for seismic refraction surveys - analyzed as 2D P-wave tomography (SRT) and as 1D MASW – together with passive methods using ambient noise, i.e. small-aperture seismic array and single station HVNR measurements. In contrast to P-wave velocity prospections, surface and shear wave velocity measurements are able to reveal deeper and lateral contrasts that are independent of the soils water content and thus useful to define the mechanical properties of complex slope deformations. Ambient noise array methods, in addition, generally allow very deep sounding. With this approach, we are able to distinguish the basal shearing horizon of the studied landslide, their volume, geometry, and general geomechanical parameters. The main focus of this work is on the combination of these methods, and on the advantage of interpreting these results in a full 3D geomodel of study sites based on the collected surface (UAV flights, LiDAR-DEMs) and geophysical subsurface data. The 3D geomodel will further be used as a basis for numerical calculations aiming at a back-analysis of the landslide development (in a static and possibly dynamic domain).

The Magnetospheric Multiscale (MMS) Science Data Center (SDC) at the Laboratory for Atmospheric and Space Physics (LASP), at the University of Colorado, has managed MMS science and ancillary data processing and distribution since MMS launched in March 2015. The MMS SDC employs automation in nearly every part of its operations. Automation is used to start up processing “runners” that listen on queues for new processing jobs, which are triggered by configurable timing rules, including cron and operational events, or certain data/data files being available. A separate set of SDC code then automatically creates processing jobs and tracks its progress. The MMS SDC runs processing jobs for each instrument (47 different job types in total), ranging from levels l1a to l3, for “survey” and “burst” modes, plotting, and cdf creation. The SDC runs anywhere from a few hundred to over 2,000 jobs per day (on average, 1,000 jobs per day). Processing jobs are scheduled in a few different ways, from running based on a fixed schedule in cron, to being triggered by certain mission events, to being triggered by the appearance of new files. Several fail-safes have been added into the code over time to ensure failures are caught and handled, however, situations do arise where failures occur and are dealt with when something in the SDC does not work as expected. Added to these complexities is the fact that the MMS mission is incredibly time-sensitive, and requires the SDC to be available and ready to handle issues 24/7/365, which can be challenging due to the limited staffing on MMS a few years into the mission. The importance of automation in MMS SDC processing is clear. Not only does automated processing relieve some of the load from the software engineers working on the SDC, but it ensures continued smooth operation of the MMS SDC. This then allows scientists to continue their research efforts unhindered. As time has progressed, various areas for improvement, and extra automation, in this process have been implemented. This poster will focus on automation improvements to keep the system running smoothly with almost no human involvement.

Antecedent Soil moisture (ASM) is one of the most important factors affecting the rainfall-runoff modelling process. Its existence and influence in computing runoff using Soil Conservation Service Curve Number (SCS-CN) method have been a point of discussion for many decades. In this study, a novel procedure has been proposed to estimate the ASM by modifying the SCS-CN method and verify its applicability by comparing the ASM with the observed soil moisture. Natural rainfall, runoff and soil moisture data from eight small experimental farms with similar land use and varying slopes viz. 1%, 3% , 5% and 8%, located at Roorkee, India have been utilized. The ASM is computed by optimizing two parameters i.e., absolute maximum potential retention (Sabs) and initial abstraction coefficient (λ), and the optimization is carried out by minimizing Root mean square error (RMSE). Results show that there exists a good agreement between observed and computed ASM for slopes 1%, 3% and 5% (R2 > 0.5). A fair correlation for slope of 8% (R2 of 0.31) is observed, which may be due to the inadequacy of data. This study will be helpful in calculating ASM for ungauged catchments and will further broaden the applications of SCS-CN method.

As it was recently predicted, the kinetic ballooning/interchange instability (BICI) can provoke reconnection onsets that lead to detached azimuthally thin earthward intrusions (heads) of depleted plasma tubes when 𝛽eq ⩽ 100. Such detached BICI heads would be seen as localized earthward-propagating dipolarization fronts. Using Time History of Events and Macroscale Interactions during Substorms observations in the plasma sheet at XGSM ≈ −11 Re and conjugate All-Sky Imager and magnetometer networks observations on the ground, we show four examples when prominent dipolarization fronts with moderate earthward flows were observed amidst azimuthally drifting interchange heads and concurrently with the ionospheric current intensifications near Time History of Events and Macroscale Interactions during Substorms footprints and auroral bright spots originating from dimmer azimuthal beads/rays. These events support the idea that some of the BICI heads detach from the region with reversed radial gradient of Bz. The detached BICI heads propagate earthward-driving ionospheric pseudo-breakups.

The Mw 7.2 Sarez strike-slip earthquake occurred on Dec 7, 2015 in the Pamir region at the North-West of the Tibetan Plateau. We used Sentinel-1A/B Interferometric Synthetic Aperture Radar (InSAR) data to investigate postseismic deformation due to the Mw 7.2 Sarez earthquake. We analyzed 2.5 years of post-earthquake acquisitions from the ascending track 100 and the descending track 005. Despite challenging surface conditions (that include rugged topography and snow cover), we were able to derive time series of line of sight (LOS) displacements within 150 km from the earthquake rupture. We used stacks of interferograms covering snow-free months, as well as persistent scatterers to detect possible deformation transients. Preliminary results indicate no postseismic relaxation signals above the noise level (10-20 mm/yr for average LOS velocities). We do observe coseismic deformation due to two M>6 earthquakes that occurred ~100 km to the North-East from the epicenter of the Sarez earthquake. We use constraints on the maximum amplitude of surface displacements provided by the InSAR data to provide bounds on the effective rheologic structure of the lower crust and upper mantle beneath Pamir.

The loss of biodiversity and the associated decline of ecosystem services vital for sustaining human life demand a comprehensive monitoring of plant biodiversity. Measuring biodiversity in the field on large areas generates issues like the need of a robust sampling design, the high demand on human and monetary resources and different biases introduced by humans and environmental conditions. These circumstances have recently triggered an extended use of remote sensing data to quantify biodiversity in a cost- and time-efficient way. Remotely sensed datasets represent the Earth surface at a certain point in time. Yet, it is not well studied what the use of a single dataset in time implies for biodiversity estimates. The functional dimension of biodiversity, expressed through functional traits within or between species, varies according to the phenological cycle. Further in grasslands, mowing and grazing events lead to temporal variations in the remotely sensed diversity. We provide an approach in which we integrate the temporal dimension in the quantification of biodiversity from space. Functional diversity is partitioned into a spatial and a temporal component. In particular, Sentinel-2 satellite datasets are well suited for this purpose, providing a complete landscape picture with high revisit time. In our study case, the incorporation of the temporal dimension and the interaction between spatial and temporal diversity by employing multiple datasets improves the retrieval of functional diversity in differently managed alpine grasslands. In comparison to the use of a single dataset, our approach provides more reliable recommendations for conservation and restoration decision-making on a regional scale.

Estimations of the surface soil moisture and distributions play a key role in the ecological, environmental, and topographical investigations for intertidal mudflats that are characteristically wet and periodically submerged by sea water. However, existing techniques have limitations of measurement. Along with the three-dimensional (3D) point cloud, long-range terrestrial laser scanners (TLSs) can simultaneously record the co-located intensity value of each echo that internally contains physical reflectance characteristics of the scanned point. Most long-range TLSs emit near-infrared lasers that can be strongly absorbed by the water. Thus, the intensity values of the areas with high water moisture are theoretically smaller than those of the regions with low moisture. In this study, the intensity data of long-range TLSs are corrected for the incidence angle and distance effects and the corrected intensity data are utilized to quantitatively estimate the surface soil moisture of intertidal mudflats. A case study is conducted for a mudflat in Chongming Island, Shanghai, China, using a long-range TLS (Riegl VZ-4000) that can measure distance up to 4000 m with a near-infrared wavelength of 1550 nm. Results show that compared with traditional techniques (e.g., gravimetric measurements) the corrected intensity data of long-range TLSs are a very effective data source for a quick, accurate, and detailed estimation of surface soil moisture for large-area mudflats. The estimation accuracy is approximately 97%. Additionally, by combining the point cloud of the mudflats the 3D distribution of the moisture can be accurately mapped to potentially analyze the intrinsic association between moisture and topography, vegetation coverage, and habitation of creatures in mudflats.

The Sandur greenstone belt (SGB) is a distinctive greenstone belt as it is perched within the Closepet granitoid rocks (CG). The emplacement of the CG is attributed to intrusion in a crustal scale transcurrent shear zone towards the end of Archaean (Moyen et al., 2003). The Chitradurga shear zone that forms the eastern margin of the Chitradurga greenstone belt, located west of the Closepet granite, is considered as the boundary between WDC and EDC. As per the division of the Dharwar craton, the domination of volcano-sedimentary sequences in SGB with abundant BIF and considerable greywacke-argillite lithologies, attest their similarity to the greenstone belts of WDC. Closer to the SGB, the rocks of the CG are known to host excellent mafic microgranular enclaves (MME) which might indicate interaction between the granitic magma with the older greenstone belt lithologies during intrusion. It is interesting to note that there is a progressive increase in crustal thickness from north towards south in the Dharwar craton and the SGB is found associated with the CG in the shallow zones of the north (Moyen et al., 2003). The mafic volcanic rocks are predominantly basaltic in composition and are composed of amphibole, pyroxene, plagioclase and quartz with titanite and magnetite as accessory minerals. The rocks are classified as tholeiitic basalts that were metamorphosed to amphibolite grade. Preliminary geochemical studies on these rocks show significant differences in their trace element distribution. The chondrite-normalized REE patterns show moderate to high contents of REE and have unfractionated pattern. The basalts show a flat to slightly LREE enriched pattern. Some samples show slight negative Eu anomaly and some do not show any significant anomaly. Some associated rocks also have complementary enrichment-depletion of certain elements. All of these point to multiple petrogenetic processes involved in the generation of these magmatic precursor rocks.

In March 2019 cyclone Idai led to a compound flooding event in Mozambique combining high river runoff and storm induced water level extremes and causing damages up to 2 billion USD and more than 1200 fatalities. The co-occurrence of storm surges, wind waves, and flooding through heavy precipitation and runoff increases the risk of flooding and exacerbates the impacts along the vulnerable Southern African coasts. To mitigate the associated high-impacts, it is essential to know the probability of theses compound events (multivariate extreme event analysis) and understand the processes driving them (Wahl et al. 2015). In the project CASISAC*, we propose a regionalized multivariate assessment of extreme events to model extremes as combination of storm surge, waves, river discharge and high precipitation at southern African coasts (Namibia, South Africa, Mozambique). We develop a multivariate statistical model based on copulas to represent and analyze the physical mechanism underlying compound events and their return periods under present day climate conditions. The African regions are particularly poor sampled by tide gauges and available records include large gaps. To overcome the data scarcity, ancillary data from high-resolution ocean model hindcasts (Schwarzkopf et al. 2019) based on the NEMO model will complement the analysis. An integrated analysis of observational records from tide gauges in combination with ocean model hindcasts allows us to regionalize compound extreme events corresponding to certain return periods along the entire coastline. In this presentation, we will show preliminary results of the multivariate extreme value model analysis chain. *CASISAC (Changes in the Agulhas System and its Impact on Southern African Coasts: Sea level and coastal extremes) is funded by the German Federal Ministry of Education and Research (BMBF) under the grant number 03F0796C. Schwarzkopf et al. (2019): The INALT family – a set of high-resolution nests for the Agulhas Current system within global NEMO ocean/sea-ice configurations. In: Geoscientific Model Development, Vol. 12, 7, 3329-3355, doi: 10.5194/gmd-12-3329-2019. Wahl et al. (2015): Increasing risk of compound flooding from storm surge and rainfall for major US cities. In: Nature Climate Change, Vol. 5, 12, 1093-1097, doi: 10.1038/nclimate2736.

While waves propagating over a uniform current are simply subject to a Doppler shift of their phase, inhomogeneous flows can modify the wavenumber, direction, and amplitude of the waves, having the potential to largely modulate the surface wave field. Even though the theoretical basis for such interactions is well established, comprehensive observations and modeling of wave–current interactions are mostly limited to either tidal or large–scale currents and a lot remains unknown about how waves and currents interact when both fields are highly variable, such as near ocean fronts and eddies. In the present work, the extent to which the surface wave field off the California coast is modulated by the California Current System is investigated. Optimized currents and winds from a state estimate of the California Current System are used to force the wave model WaveWatch III in order to quantify the relative importance of local winds and currents in modulating the surface wave variability in this region. As satellite altimeters evolve towards resolving finer scales, knowing the wave field with precision may help the interpretation of sea surface height measurements at high wavenumbers and frequencies, which has particular relevance for the planning of the Surface Water and Ocean Topography (SWOT) mission.

Formed by Mississippi River sediments, south Louisiana is a flat, low-lying coastal region with high-clay content soils and heavy annual precipitation that is particularly susceptible to damage caused by extreme storms and flooding. In August 2016, a stationary storm system caused over 50 cm of rain to fall across much of southeast Louisiana. Largely rural, the major trends in the hard-hit Amite River Basin have been conversion of agricultural land to forest beginning in the mid-20th century and rapid urbanization and development spurred by economic and population growth in the Baton Rouge area following the oil boom of the 1970s, as well as later waves of migration following Hurricane Katrina and the 2016 floods. This analysis examines the effects of spatially and temporally changing land use on runoff and flooding within the watershed and is part of a larger research project which seeks to also quantify the relative impacts of changes in precipitation and planform geometry. To quantify the effects of land-use change on flooding, runoff curve number (CN) maps were created using NRCS soil type data and USGS land cover data. Areas with a higher CN experience less interception and infiltration of surface water and the flood risk is consequently greater. While CN for the Basin overall dropped from 86 to 79 between 1938 and 2018, CN dropped from 82 to 70 in rural areas due to reforestation and increased from 86 to 90 in the southern portion of the Basin due to urbanization. These data were then input into the HEC-HMS and coupled 1D/2D HEC-RAS components of a numerical model of the Amite River Basin. Flooding behavior under different design storms and land cover conditions was then observed and quantified. In examining the major contributing factors to flooding in south Louisiana, this research project aims to create a more comprehensive understanding of flooding and propose potential mitigation strategies and design interventions for alleviating the worst effects.

Coastal aquifers are prone to saltwater intrusion as increased demand for freshwater leads to heavy, unregulated pumping from these coastal aquifers. Under sustainable pumping conditions, the saltwater-freshwater interface is stable but rarely monitored. When saltwater intrusion is first detected, saltwater-freshwater interface is already disturbed and starts moving inland. Any numerical simulation-based methodology to manage saltwater intrusion requires the initial saltwater-freshwater interface to be known. Numerical models need to satisfy the boundary conditions and the initial conditions (Cauchy–Riemann equation) for the solution to exist. However, in the absence of any monitoring, the initial position of the saltwater-freshwater interface is unknown, which forms the initial condition for numerical models and thus fall in the category of initial value problem. Pool and Carrera’s correction factor for the sharp interface approach is used to estimate the initial saltwater-freshwater interface. Generally, groundwater head information is readily available, which can be used to locate the saltwater-freshwater interface. Ghyben-Herzberg relation is used for estimating the initial position of the interface, but the level of accuracy of the information derived from Ghyben-Herzberg relation is low. Hence, in this study Pool and Carrera’s correction factor for density ratio is used in Ghyben-Herzberg relation for accurate estimation initial interface location. The developed method is applied to a real coastal site in Puri, India, where the aquifer is encroached by saltwater intrusion. The performance evaluation results show the applicability of this methodology