Groundwater Level Changes Research Articles

Investigating the role of ENSO in groundwater temporal variability across Abu Dhabi Emirate, United Arab Emirates using machine learning algorithms

Accurate prediction of groundwater levels is crucial for managing groundwater resources efficiently. The complex aquifer heterogeneity and groundwater abstraction variation present challenges to have accurate groundwater level models over Abu Dhabi emirate, United Arab Emirates. In the present study, two data-driven models are employed, which are the Long Short-Term Memory (LSTM) and the Random Forest (RF) to develop a model for the prediction of monthly groundwater level in the Abu Dhabi Emirate. The incorporated data in the models are precipitation, terrestrial water storage, soil moisture, evapotranspiration, and the El Niño-Southern Oscillation (ENSO) 3.4 index. The groundwater monitoring wells data are obtained for 263 monitoring wells distributed over Abu Dhabi emirate for the period 2000-2023 in a monthly temporal scale. The models’ performance was assessed using the Nash-Sutcliffe efficiency (NSE), root mean square error (RMSE) the coefficient of determination (R2) and Percent bias (PBIAS). An optimization technique was also applied to address the impact of the lags on enhancing the groundwater level model. The LSTM model outperformed the RF model during the testing period, achieving R2 =0.79, NSE=0.70, RMSE=0.38 meters and PBIAS= 0.2% with a 3-month lag. The global sensitivity analysis was applied to understand the importance of each parameter and its influence on the models’ output. This study highlights the potential use of data-driven models for the prediction of groundwater level which could aid water managers to monitor the groundwater resources at a regional scale. The developed model can serve as an alternative approach for predicting groundwater level change over the Abu Dhabi Emirate.

Justification of Criteria and Assessment of Environmental Safety during the Operation of Metro Facilities

Introduction. In today's world, with the increasing pace of urbanization, environmental safety plays a crucial role in urban planning and management. Subway operations, as an important part of urban infrastructure, contribute to population mobility, but they can also cause significant environmental problems. Such scientists as Kulikova E.Yu., Konyukhov D.S., Potapova E.V., Balovtsev S.V., Chunyuk D.Yu., etc have studied these issues. However, their research mostly ignores the fact that one of the major threats to environmental safety is the degradation of tunnel linings due to hydrogeological processes. This not only increases the risk of accidents but also increases the likelihood of negative impacts on groundwater and the environment. Therefore, the study of the nature of the development of defects in tunnel linings and their dynamics over time is of both scientific and practical interest, and is the aim of this research. To achieve this objective, it is necessary to analyze the relationship between the condition of the tunnel lining and environmental safety based on data about defects in subway tunnel structures and their impact on the environment.Materials and Methods. For this study, we used defective sections of the subway tunnel linings from several lines of the Moscow Metro as materials. We conducted field studies of the lining's condition and geodetic surveys of the tunnels, which revealed significant changes in the indicators compared to the normative values as a result of the interaction between the human-made environment and the surrounding nature. Additionally, we employed seismoacoustic inspection methods to inspect the tunnel linings using shock excitation.Results. Data on the dependence of defect development on changes in groundwater level has been obtained. Defects in tunnel linings contribute to the leakage of chemically active substances into soil and groundwater, which threatens biodiversity and reduces water quality used by the population.Discussion and Conclusion. Field surveys have shown that defects in tunnel linings, such as cracks, concrete leaching, and waterproofing violations, have a direct impact on environmental safety. Therefore, maintaining the integrity of these structures is a key element in ensuring environmental safety in urban areas. The results of this research will form the basis for developing comprehensive proposals to improve monitoring techniques and ensure the structural integrity of tunnel structures.

Influence of Land Use and Land Cover Changes and Precipitation Patterns on Groundwater Storage in the Mississippi River Watershed: Insights from GRACE Satellite Data

Growing human demands are placing significant pressure on groundwater resources, causing declines in many regions. Identifying areas where groundwater levels are declining due to human activities is essential for effective resource management. This study investigates the influence of land use and land cover, crop types, and precipitation patterns on groundwater level trends across the Mississippi River Watershed (MRW), USA. Groundwater storage changes from 2003 to 2015 were estimated using data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. A spatiotemporal analysis was conducted at four scales: the entire MRW, groundwater regimes based on groundwater level change rates, 31 states within the MRW, and six USGS hydrologic unit code (HUC)-2 watersheds. The results indicate that the Lower Mississippi region experienced the fastest groundwater decline, with a Sen’s slope of −0.07 cm/year for the mean equivalent water thickness, which was attributed to intensive groundwater-based soybean farming. By comparing groundwater levels with changes in land use, crop types, and precipitation, trends driven by human activities were identified. This work underscores the ongoing relevance of GRACE data and the GRACE Follow-On mission, launched in 2018, which continues to provide vital data for monitoring groundwater storage. These insights are critical for managing groundwater resources and mitigating human impacts on the environment.

Analysis of landslide deformation mechanisms and coupling effects under rainfall and reservoir water level effects

Changes in rainfall, groundwater levels, and reservoir water levels exacerbate the deformation of water-involved landslides, accelerating the transition from landslide evolution to extinction. Extracting the destruction patterns of landslides from extensive monitoring data, and understanding their overall deformation mechanisms are crucial for geological hazard prevention and control. Herein, we took the Jiuxianping landslide in the Three Gorges Reservoir area as an example and proposed a deformation mechanism analysis model for water-related landslides based on monitoring data mining techniques. Using Granger causality testing, the study analyzes the spatiotemporal characteristics of GPS displacement data from three different profiles, which confirms that Jiuxianping exhibits a traction destruction mode. By comparing GPS displacement data and their Granger causality relationships across different profiles, we reveal that segmented sliding features of the landslide's front, middle, and trailing during its evolution. Furthermore, the impact intensity of triggering factors (rainfall and reservoir water level changes) on landslide displacement was identified. Based on GPS displacement data from profiles II–II′, an empirical mode decomposition–long short-term memory-regression model (EMD-LSTM-regression) is developed for multisource prediction of landslide displacements. The Shapley additive explanations algorithm is used to analyze the influence of rainfall and reservoir water level changes on periodic displacements at different positions of the landslide. Owing to the large area of the Jiuxianping landslide, the response to triggering factors varies across different locations. In the context of global warming and frequent extreme weather events, these findings offer important insights for preventing and mitigating water-related landslides in the Three Gorges Reservoir area, while also providing new perspectives for the analysis of global water-involved landslide deformation.

Past Groundwater Drought in the North American Cordillera

AbstractGroundwater level records in North America are relatively short (<60 years), preventing long‐term analysis of historical changes in groundwater levels associated with drought. In this study, tree ring widths are used to reconstruct groundwater levels in three regions in the North American Cordillera: Central British Columbia (BC), Canada, the Southern Interior Region of BC, and the San Luis Valley in Colorado, USA. Periods with severe drought conditions, identified using regime shift and threshold analyses were: 1890–1900 and 1950–1970 in Colorado, around 1920–1940 in the BC Interior, and 1935–1945 in Central BC. The groundwater level reconstructions are correlated with several climate indices and have similar regime shifts as identified in streamflow and drought records. The groundwater level reconstructions are strongly related to winter snowpack, suggesting that the observed trend of declining snowpack in recent years may lead to declining groundwater availability in these regions.

Long-Term Ground Deformation Monitoring and Quantitative Interpretation in Shanghai Using Multi-Platform TS-InSAR, PCA, and K-Means Clustering

Ground subsidence in urban areas is mainly due to natural or anthropogenic activities, and it seriously threatens the healthy and sustainable development of the city and the security of individuals’ lives and assets. Shanghai is a megacity of China, and it has a long history of ground subsidence due to the overexploitation of groundwater and urban expansion. Time Series Synthetic Aperture Radar Interferometry (TS-InSAR) is a highly effective and widely used approach for monitoring urban ground deformation. However, it is difficult to obtain long-term (such as over 10 years) deformation results using single-platform SAR satellite in general. To acquire long-term surface deformation monitoring results, it is necessary to integrate data from multi-platform SAR satellites. Furthermore, the deformations are the result of multiple factors that are superimposed, and relevant studies that quantitatively separate the contributions from different driving factors to subsidence are rare. Moreover, the time series cumulative deformation results of massive measurement points also bring difficulties to the deformation interpretation. In this study, we have proposed a long-term surface deformation monitoring and quantitative interpretation method that integrates multi-platform TS-InSAR, PCA, and K-means clustering. SAR images from three SAR datasets, i.e., 19 L-band ALOS-1 PALSAR, 22 C-band ENVISAT ASAR, and 20 C-band Sentinel-1A, were used to retrieve annual deformation rates and time series deformations in Shanghai from 2007 to 2018. The monitoring results indicate that there is serious uneven settlement in Shanghai, with a spatial pattern of stability in the northwest and settlement in the southeast of the study area. Then, we selected Pudong International Airport as the area of interest and quantitatively analyzed the driving factors of land subsidence in this area by using PCA results, combining groundwater exploitation and groundwater level change, precipitation, temperature, and engineering geological and human activities. Finally, the study area was divided into four sub-regions with similar time series deformation patterns using the K-means clustering. This study helps to understand the spatiotemporal evolution of surface deformation and its driving factors in Shanghai, and provides a scientific basis for the formulation and implementation of precise prevention and control strategies for land subsidence disasters, and it can also provide reference for monitoring in other urban areas.

A groundwater level spatiotemporal prediction model based on graph convolutional networks with a long short-term memory

ABSTRACT The performance of regional groundwater level (GWL) prediction model hinges on understanding intricate spatiotemporal correlations among monitoring wells. In this study, a graph convolutional network (GCN) with a long short-term memory (LSTM) (GCN–LSTM) model is introduced for GWL prediction utilizing data from 16 wells located in the northeastern Xiangtan City, China. This model is designed to account for both the hybrid temporal dependencies and spatial autocorrelations among wells. It consists of two parts: the spatial part employs GCNs to extract spatial characteristics from a spatial self-similarity weight matrix and an attribute self-similarity weight matrix among wells; the temporal part utilizes a LSTM module to capture the temporal patterns of GWL sequences, along with monthly precipitation and temperature data. This model dynamically predicts changes in groundwater levels, achieving higher accuracy on average compared to single-well predictions using LSTM. By incorporating both temporal dependencies and spatial autocorrelations, the GCN–LSTM model demonstrated an average improvement in goodness-of-fit of approximately 11.21% over the LSTM-based model for individual wells. Its application holds significant reference value for the sustainable utilization and development of groundwater resources in Xiangtan City.

Integration of multiple observations for validation of mechanisms of earthquake-triggered groundwater level Anomalies: 2016 Taiwan Meinong earthquake

This study analyzes multi-depth groundwater level data and integrated observation data to validate the previously proposed mechanisms of hydrological anomalies triggered by the 2016 M6.4 Meinong earthquake in Taiwan. The main influence area was northwest of the epicenter, which may be due to the blind fault rupture, intensity distribution, and hydrogeological properties. The step changes in groundwater level do not fit the concept of epicentral distance, static stress–strain theory, or the focal mechanism. The distribution of step changes in groundwater level have a pattern similar to that of horizontal peak ground velocity. The results imply that these changes may be driven by dynamic stress–strain, instead of static stress–strain. The minimum horizontal peak ground velocity and acceleration of the Meinong earthquake, which induced obvious step changes in groundwater level and soil liquefaction, are provided. The pressure dissipation ability of an aquifer (e.g., transmissivity) may affect the persistence of groundwater responses. Four wells located near the surface rupture area, which has cemented or partial cemented geological material, showed an obvious step decrease in the groundwater level at a deep depth and all wells showed an increase in the groundwater level at a shallow depth. These decreases and increases of the groundwater level at different depths have different mechanisms, which are discussed in this study. The integrated observations made during the Meinong earthquake show that ground motion and the hydraulic properties might be important factors in hydrological anomalies. The results of this study are an important reference for further studies on earthquake hydrology.

Monitoring seismic velocity changes at Campi Flegrei (Italy) using seismic noise interferometry

Campi Flegrei is a volcanic field located west of Naples (Italy) in a densely populated area. Since 2005, its ground has been rising steadily due to the accumulation of fluids at shallow depths. The inflation of volcanic edifices is a possible precursor of an impending eruption. The uplift is accompanied by increasing seismic activity. This raises concerns about the possibility that the volcano may be on the verge of an eruption. To track the fluid movement, it is possible to monitor subtle changes of velocities of seismic waves by exploring ambient seismic noise. By examining different frequency bands, we can observe velocity changes at different depths. We interpret these changes as a monitoring of depth-dependent deformation in addition to the standard monitoring of surface deformation. We observe a velocity decrease in the long-term trend, presumably due to the extension of the hydrothermal system at shallow depths. To explain the long-term changes, we model a spherical pressure source to simulate volumetric strain changes induced by recent fluid activity. The model explains both, surface and subsurface deformation which leads to the opening of microcracks and pores, resulting in the observed velocity decrease. The short-term velocity changes are mainly driven by temperature or groundwater level changes. Once velocity changes are corrected for seasonal effects, remaining short term velocity changes can be associated with volcanic activity and earthquake swarms.

Very‐Near‐Field Coseismic Fault Pressure Drop and Delayed Postseismic Cross‐Fault Flow Induced by Fault Damage From the 2018 M6.3 Hualien, Taiwan Earthquake

AbstractEarthquakes can produce rock damage, poroelastic deformation, and ground shaking that modify fault zone hydrogeologic properties. Coseismic and postseismic hydrologic response to the ruptured fault can serve as constraints on hydrogeologic property changes. Here, we document fluid pressure responses to the 2018 M6.3 Hualien, Taiwan earthquake and model the postseismic fault zone hydrology inferred from very‐near‐fault data. Two groundwater wells located ∼180–250 m from the fault damage zone experienced 10–15 m of groundwater level decline followed by a prolonged (>6 months) recovery. Poroelastic models indicate that strain dilation in the fault's hanging wall can produce water level reductions of several meters. However, the model cannot explain groundwater level change in the footwall nor the delayed postseismic recovery, suggesting fault zone damage played a primary role in both the coseismic and postseismic water level reductions. Fluid flow models incorporating the effects of coseismic fault damage on the temporal evolution of hydrologic fault properties show enhanced hydraulic anisotropy after the earthquake. The best‐fit models show that while both vertical hydraulic conductivity and specific storage likely increased within the fault zone, the horizontal hydraulic conductivity is low, suggesting the fault zone behaves as a hydraulic barrier to cross‐fault flow with modeled diffusivities as low as ∼10−3 m2/s. High‐fidelity hydrologic measurements in the very‐near‐field of fault zones (e.g., within a few hundred meters) may be a useful tool to constrain the spatial and temporal evolution of fault zone properties before, during, and after rupture.

Determining the Effective Meteorological Parameters on Potato Yield in Niğde Province and Yield Prediction with Machine Learning and Deep Learning Models

In this study, we explore the impact of meteorological parameters on potato yield in Nigde province, a key agricultural region in Turkey for potato production. Understanding the relationship between weather conditions and crop yield is crucial for optimizing agricultural practices and ensuring food security, especially in regions susceptible to climate variability. The study includes all meteorological parameters observed and recorded in Nigde Directorate of Meteorology, covering the period between 1990 and 2023. Through the analysis of historical weather data and potato yield records, we aim to identify the most influential meteorological factors affecting potato production. Then, artificial intelligence techniques such as Random Forest, Gradient Boost, Convolutional Neural Networks and Recurrent Neural Networks are utilized to predict the potato yield in order to provide valuable insights into how different weather patterns influence crop performance. The findings suggest that potato yield is correlated with meteorological parameters to some degree and AI techniques can predict the potato yield but lacks the precision. The reason is that potato production in Nigde is mostly done with irrigation. However, this further increases the risk that could result from the changes in groundwater levels and pollution in irrigation ponds for agricultural practices in Nigde.

Investigation of groundwater level change and its impact on slope stability in the Sector-E of Afsin-Elbistan Open-Pit Lignite Mine in Turkey

Investigation of groundwater level change and its impact on slope stability in the Sector-E of Afsin-Elbistan Open-Pit Lignite Mine in Turkey

Effects of groundwater level changes on soil characteristics and vegetation response in arid and semiarid coal mining areas.

Coal mining in arid and semiarid regions often leads to numerous ecological and environmental problems, such as aquifer depletion, lake shrinkage, vegetation degradation, and surface desertification. The drainage from coal mining activities is a major driving force in the evolution of the groundwater-soil-vegetation system. In order to explore the effect of groundwater level fluctuation on soil properties and the response mechanism of surface vegetation in coal mining areas, this study is based on hydrogeological and ecological vegetation investigations in the Bojianghaizi Basin, and soil and vegetation samples are collected in the areas with different groundwater levels, and soil and vegetation indexes are analyzed with the aid of methods such as numerical statistics, linear regression, and correlation analysis with the aid of the Origin software. The results show that there is a significant negative correlation between groundwater table (GWT) and soil water content (SWC), soil conductivity, soil organic matter (SOM), soil available nitrogen (SAN), and soil available potassium (SAK). Mining activities have led to the destruction of the soil structure, greatly reducing its ability to retain water and fertilizer. The contents of SWC, SOM, and SAN in the mining area are significantly reduced, which are at least 49.73%, 47.56% and 59.90% lower than those around the mining area. On the northern and southern sides of the lake, serious soil salinization exists in the lakeshore zone where the depth to the water table is <0.5m, and the water required for the growth of vegetation here mainly comes from the groundwater, so there are only a few water-loving and saline-resistant plants; when the depth to the water table is 0.5-7m, the growth of surface vegetation is influenced by the double impacts of the water table and atmospheric precipitation with a high degree of species richness; when the depth to the water table is >7m, the surface vegetation is only dependent on the limited atmospheric precipitation for water. When the depth of groundwater is >7m, the surface vegetation only relies on limited atmospheric precipitation for water, and drought-tolerant plants mainly grow in these areas. This study not only provides a scientific basis for the sustainable development and environmental protection of similar mines in the world, but also has important significance in guiding the ecological management and rational utilization of water resources in coal mine areas. What is more, This study provides valuable insights into sustainable water resource management in arid and semi-arid regions, crucial for mitigating the ecological impacts of coal mining activities.

Influence Mechanism of Water Level Variation on Deformation of Steep and Toppling Bedding Rock Slope

The construction of major hydropower projects globally is challenged by slope deformation in reservoir areas. The deformation and failure mechanisms of large rock slopes are complex and poorly understood, making prevention and management extremely challenging. In order to explore the influence mechanism of the water level variation on the deformation of steep toppling bedding rock slopes, this paper takes the right bank slope near the dam area of the Longtou Hydropower Station as an example, and field investigations, deformation monitoring, physical simulation tests and numerical analyses are carried out. It is found that the slope deformation response is obvious under the influence of the reservoir water level variation, which is mainly reflected in the change in the slope groundwater level, rock mechanical parameters and seepage field in the slope body. The toe of the slope produces plastic deformation and maximum displacement. With the increase in the reservoir water level, the plastic zone expands and the displacement increases, which leads to the intensification of the slope deformation. This paper puts forward that the deformation and failure modes of the steep and toppling bedding rock slope caused by water level variation are due to shear dislocation, bending deformation and toppling fracture. This study reveals the influence mechanism of the water level variation on the deformation of steep and toppling bedding rock slopes, which can provide theoretical support for the construction of major hydropower projects.

Response of dissolved organic carbon in streams draining peatbogs to extreme rainfall-runoff events: a case study from Šumava (Bohemian Forest) National Park, Czech Republic

The presented study investigates the dynamics of DOC concentrations in headwater peatbog areas with respect to the extreme rainfall-runoff (R-R) events hydrometeorological catchment preconditions (23 variables in total). The main data sources were automatic devices for monitoring of groundwater level, discharges and rainfalls providing data in 10 min steps installed in the Vydra River catchment and one automatic water sampler ISCO in sub-catchment of the Rokytka River basin in the Šumava (Bohemian Forest) National Park. The study period was 2018–2021, in which 18 R-R events were analysed. Data of DOC variability and catchment conditions were analysed using Spearman’s correlation coefficient, Principal Component Analysis and DOC/Q hysteresis loops. Changes in groundwater level and discharges had the greatest influence on DOC concentrations. Higher mean and maximum DOC were measured during events after a longer period without an extreme R-R event. The greater lag time of maximum DOC after peak flow and the higher mean DOC during the event were primarily due to hydrometeorological preconditions of the catchment. The highest DOC was in autumn after the previous summer period with low discharges and low groundwater levels. DOC was also positively correlated with air and water temperatures.

Rising damp in heritage sites under urban expansion: A comprehensive case study of the Jinsha Earthen Site

Rising damp poses a significant threat to cultural heritage, yet its dynamics within actual heritage sites remain inadequately understood, particularly regarding its evolution and the impact of urbanization. The Jinsha Site, an earthen site from the Shang periods, is primarily composed of silt, with a layer of sand beneath and pebbles at the bottom, making it susceptible to rising damp. This study investigates the Jinsha Site as a case, monitoring soil water content and electrical conductivity, tracking changes in groundwater, precipitation, and river water levels, and investigating the relationship between urbanization and rising damp. The study aims to understand the process, causes, and influencing factors of rising damp and evaluate previous preservation strategies. The findings indicate that groundwater level in the sand layer trigger dampness, whereas the pebble layer exhibits dryness. Urban construction from 2006 to 2013 and 2014–2017 caused fluctuating groundwater levels, leading to repeated transitions between dryness and dampness at the site. Rainfall and river levels have negligible effect; even rainfall exceeding 100 mm (frequency <0.0056) only raises groundwater levels by approximately 1 m and increases water content by less than 2 % for a brief duration, typically less than half a month. The 2022 groundwater pumping strategy effectively maintained levels beneath the pebble layer (506 m), decreasing moisture by 12.71 % and conductivity by 0.27 dS/m. This study reflects on previous protection effortsand offers evidence-based strategies for heritage conservation amidst urban expansion.

Chronostratigraphy of the Late Glacial Żabinko site (western Poland) and investigation of the dose rate variability

The Żabinko exposure (western Poland) reveals the classic fluvio-aeolian succession known from studies in the European Sand Belt. Previous chronostratigraphic studies were mainly based on uncalibrated radiocarbon dates from organic sediments and thermoluminescence dating. The picture visible from these studies indicated a number of discrepancies between these methods. The new research in this exposure was based on optically stimulated luminescence (OSL) dating and calibrated radiocarbon dates. The results obtained indicate a general discrepancy between the results achieved by these two methods. While the radiocarbon dates provide some meaningful picture and allow correlation with previous studies, the results of OSL dating do not allow for a chronological model of sedimentary processes. The OSL dates show large inversions of the results and are clearly younger than the other dating results. Detailed analysis of OSL measurements shows radioactive disequilibrium and variability linked to differential stratification of sediments, significantly impacting the assessment of environmental dose rates. We believe that this atypical variability is presumably the result of postdepositional processes, such as changes in groundwater levels, chemical weathering and radionuclide migration.

The Importance of seismic microzonation under the threat of an earthquake of the north anatolian fault in nilüfer, bursa, turkiye

The Nilüfer district experienced the most recent urbanization among the central districts of Bursa in South Marmara region with the completion of rapid construction. Since 358 BCE, many destructive earthquakes were reported on the branches of the North Anatolian Fault (NAF) which caused extensive damage to buildings and loss of life near Bursa city. Besides some studies conducted to define the soil behavior in the vicinity of Bursa, a seismic hazard study in Nilüfer is still lacking. We, therefore, carried out a microzonation study including the following steps. First, an earthquake hazard analysis was conducted and the peak ground acceleration (PGA) values were determined for an expected earthquake. In the next step, MASW (Multi-Channel Analysis of Surface Wave) measurements conducted at 54 points in 28 neighbourhoods of Nilüfer district were evaluated. Soil mechanical parameters were determined at 11 boreholes to assess the liquefaction potential. It was found that almost half of the study area suffers from low damage considering only the vulnerability index (Kg) index, which depends on the site effect. Therefore, in addition to the Kg values, we created a microzonation map using the results of soil liquefaction, settlement, changes in groundwater level, and the average values of spectral acceleration. The study area is classified by four damage levels changing from low to high. Using only the Kg index could not quantify the potential damage level in the study area, thus we showed that the districts of Altınşehir, Hippodrome, Ürünlü and Alaaddinbey, Ertuğrul, 29 Ekim, 23 Nisan, Ahmetyesevi and Minareliçavuş were identified at potentially high-risk damage zones. The results of this study clearly showed that considering the Kg index, which depends only on the local site effect, may lead to inadequate damage values.

Estimation of groundwater-level changes based on GRACE satellite and GLDAS assimilation data in the Songnen Plain, China

Estimation of groundwater-level changes based on GRACE satellite and GLDAS assimilation data in the Songnen Plain, China

Shallow water table rise and fluctuation between 1977 and 2010 in Madinah City, Saudi Arabia

Madinah City in Saudi Arabia is rapidly growing with high population growth, water demand, sewage generation, and agricultural activities. The hydrogeological layering sequence in Madinah City reveals that there are three main layers that extend within the areas between wadi systems. The shallow water table rise (SWTR) problem has risen in several areas of the city, and the fluctuations in the piezometric water observed from the shallow aquifer systems. The research aims to investigate the changes in shallow groundwater levels within the Madinah City. Sources of water table rise and fluctuations are investigated through an extensive field hydro-geological survey comprising wells drilling and water level monitoring, which indicated the following results between 1977 and 2010 including those of newly drilled wells: (i) water flow is partially blocked along wadi Alaqiq and this has caused an increased regional flow moving from west along wadi Alaqiq towards the central area; (ii) groundwater levels have changed in the agricultural areas as indicated by 15–26 m rise along wadi Alaqiq; (iii) groundwater level fluctuations as indicated by 590 m amsl (1977) against less than 575 m amsl (2010) in the east and southeast of the study area as a result of increased heavy pumping since past 37 years. The overall flow phenomenon is reflected in the groundwater gradients on an increasing trend with orientation from the western region along the wadi Alaqiq towards the central area and southeast which has invariably resulted in the overall declining of water levels throughout the affected area.