Alluvial Aquifer Research Articles

Strategies for water salinity management in alluvial aquifer in a multilevel crop planning

Strategies for water salinity management in alluvial aquifer in a multilevel crop planning

Spatiotemporal Variability of Groundwater Quality for Irrigation: A Case Study in Mimoso Alluvial Valley, Semiarid Region of Brazil

Alluvial aquifers are vital for agricultural communities in semiarid regions, where groundwater quality is often constrained by seasonal and spatial salinity variations. This study employed geostatistical methods to analyze the spatial and temporal variability of electrical conductivity (EC) and the sodium adsorption ratio (SAR) and elaborate an indicative quality map in the Mimoso Alluvial Aquifer, Pernambuco, Brazil. Groundwater samples were collected and analyzed for cations, total hardness (TH), and the percentage of sodium (PS). Moreover, the relation between EC and the SAR was used to determine the groundwater quality for irrigation. Cation concentrations followed the order Ca2+ > Mg2+ > Na+ > K+. EC and the SAR exhibited medium to high variability, with spatial dependence ranging from moderate to strong, and presented a strong cross-spatial dependence. Results showed that sequential Gaussian simulation (SGS) provided a more reliable groundwater classification for agricultural purposes compared to kriging methods, enabling a more rigorous evaluation. Based on the strong geostatistical cross correlation between EC and RAS, a novel water quality index was proposed, properly identifying regions with lower groundwater quality. The resulting spatial indicator maps classified groundwater as suitable (64.7%), restricted use (2.08%) and unsuitable (2.38%) for irrigation. The groundwater quality maps indicated that groundwater was mostly suitable for agriculture, except in silty areas, also corresponding to regions with low hydraulic conductivity at the saturated zone. Soil texture, rainfall, and water extraction significantly influenced spatial and temporal patterns of groundwater quality. Such correlations allow a better understanding of the groundwater quality in alluvial valleys, being highly relevant for water resources management in semiarid areas.

Spatial and depth distribution of salinity and nitrate in a depleted alluvial aquifer (Haouz plain, Morocco)

Spatial and depth distribution of salinity and nitrate in a depleted alluvial aquifer (Haouz plain, Morocco)

“Leaky Weirs” capture alluvial deposition and enhance seasonal mountain-front recharge in dryland streams

“Leaky weirs” are rock structures installed in dryland streams, which are anchored into exposed bedrock, loosely cemented, and designed to allow water to slowly pass through. They are being tested at a ranch in southeastern Arizona, USA, to restore and conserve the historic range and desert wetlands. Data are collected to assess how leaky weirs impact surface water, subsurface water, and groundwater recharge—including stream discharge, timing, and depth of infiltration, and groundwater elevations. Three adjacent watersheds, two with outlets just below leaky weirs and one with leaky weirs farther upstream, were instrumented with water-level loggers, wildlife cameras, and crest stage instruments with temperature sensors in the soil. As most groundwater recharge is assumed to be focused along the mountain fronts in this region, mountain-block recharge is also evaluated to differentiate between the two using isotope analyses. Finally, a single, late-season flood event is scrutinized to consider the leaky weir effect on all monitored components in the water budget. Results indicated groundwater flow is primarily from the mountains to the east via older, regional mountain-block recharge. However, the development of shallow alluvial aquifers is supported by the leaky weirs, that slow flows, capture permeable sediments, and allow infiltration, thus enhancing mountain-front recharge. In turn, these new pockets of water help support the restoration of historic wetlands. Sediment accumulates where leaky weirs are installed, reducing flashy peak flows, and resulting in a series of infiltration ponds along the channel that support vegetation during growing seasons and recharge the shallow aquifer during non-growing seasons.

Land use land cover dynamics and its impact on SWL fluctuation in shallow alluvial aquifers of the Purba Bardhaman plain, West Bengal, India

Land use land cover dynamics and its impact on SWL fluctuation in shallow alluvial aquifers of the Purba Bardhaman plain, West Bengal, India

Tracing nitrate contamination sources and dynamics in an unconfined alluvial aquifer system (Velika Gorica well field, Croatia).

Nitrate ions (NO3-) are one of the most common contaminants in the groundwater of the Zagreb alluvial aquifer, which hosts strategic groundwater reserves of the Republic of Croatia and supplies drinking water to one million inhabitants of the capital city. To better understand the origin and the dynamics of NO3- in the unsaturated and saturated zones, the stable isotopes of nitrogen (δ15N) and oxygen (δ18O) in dissolved nitrate, combined with physico-chemical, hydrogeochemical and water stable isotope data, were used in the current work, together with statistical tools and mixing models. The study involved monthly sampling of groundwater, surface water, precipitation and soil water samples. Additionally, the isotopic composition of total nitrogen (δ15Nbulk) was determined in solid samples representing the local nitrate sources. The combination of a nitrous oxide isotopic analyzer and the titanium(III) reduction method provides reliable measurements of δ15NNO3 and δ18ONO3, with optimal stability achieved under specific conditions. Nitrate in the study area predominantly originates from organic sources, with nitrification as the main biogeochemical process, while denitrification was identified at sampling sites under specific anaerobic conditions. Although statistical analysis can be a valuable tool, it should be applied with caution if NO3- originates from multiple sources. The isotopic composition of water showed that groundwater is predominantly recharged by the Sava River but its contribution varied spatially. The results also show the existence of a different recharge source in the southern part of the aquifer. Our findings highlighted the importance of employing a diverse range of analytical methods to obtain reliable and comprehensive understanding of nitrate contamination. By integrating multi-method approaches, stakeholders can better understand the complexities of groundwater contamination and implement more targeted measures to safeguard the water supplies for future generations.

Assessment of Groundwater Quality in the Alluvial Aquifer Using GIS and Water Quality Indices in the Feija Plain, South-East Morocco

Assessment of Groundwater Quality in the Alluvial Aquifer Using GIS and Water Quality Indices in the Feija Plain, South-East Morocco

Three-dimensional saturated-unsaturated flow to a well in an alluvial fan wedge-shaped aquifer

Three-dimensional saturated-unsaturated flow to a well in an alluvial fan wedge-shaped aquifer

Compartmentalisation and Hydrogeological Parameters of the Karst Aquifer System in Central Region of Minas Gerais State, Brazil

ABSTRACTThe Environmental Protection Area of Lagoa Santa Karst (EPA) is a critical karst region in Brazil, renowned for its rich biodiversity and archaeological significance, including discoveries by researchers such as Peter W. Lund and the oldest human skeleton in the Americas, Luzia. However, the region faces threats from rapid socioeconomic and industrial development, stressing its vulnerable aquifer systems. This study updates the hydrogeological conceptual model for the EPA using well log data, map algebra and hydrodynamic parameters obtained through the Agarwal (1980) recovery method . It builds on models by De Paula (Conceptual Model in Pelitic‐Carbonate Aquifers in the Lagoa Santa Karst APA Region, MG, 2019) and refined by Dantas et al. (Journal of South American Earth Sciences, 2023, 123, 104219), reassessing the boundaries of various aquifer units. Horizontal compartmentalisation in the karst‐fissured aquifer was achieved by combining transmissivity and porosity data, while vertical separation was determined based on water entry density and productivity, identifying four zones of increased karstification. In the fissured aquifer, vertical limits align with those established by Dantas et al. (Journal of South American Earth Sciences, 2023, 123, 104219), confirming the anisotropy and heterogeneity of the karst‐fissured and fissured aquifers, and the isotropy and productivity of the alluvial aquifers. These findings provide crucial insights for managing aquifer reserves and mitigating water conflicts in the EPA region.

Sources and fates of NO3− and PO43− in an alluvial plain wetland - Insights from the Auzon oxbow and the alluvial aquifer of the Allier (Auvergne, France)

Sources and fates of NO3− and PO43− in an alluvial plain wetland - Insights from the Auzon oxbow and the alluvial aquifer of the Allier (Auvergne, France)

Removal of Sulfur Content in Groundwater Using Marble Filter in a Cascade Design

Alluvial aquifer are one of Malaysia’s most abundant groundwater resources, highly demanded in East Coast area. However, the presence of sulfur in these aquifers causes the emission of hydrogen sulfide gas. This research aimed to provide an alternative study for removing sulfur using marble filter media in a cascade column design, where water flows from the highest to the lowest column. Two groups of marble sizes were involved in this filter: pebbles and sand-sized particles. The treatment used raw groundwater with the highest concentration of total sulfur being 537.1 ppm. Sand-sized marble had the highest efficiency of sulfur removal, reaching 98.3% at a flow rate of 0.011 l/s. As a result of the effective filtration, the true color reached 33-34 pt/Co, significantly reduced from the source value of 1000-1012 pt/Co. The application of marble for treating groundwater with the sulfur issue is still novel and promising for groundwater filtration, potentially benefiting consumers facing this problem.

Hydrogeological, Hydrochemical, and Geophysical Analysis of a Brine-Contaminated Aquifer Addressing Non-Unique Interpretations of Vertical Electrical Sounding Curves

A comprehensive hydrogeological, geophysical, and hydrochemical investigation was conducted in southeastern Hitchcock County, Nebraska, within the Driftwood Creek alluvial aquifer. This study assessed groundwater contamination stemming from the surface disposal of saline wastes from oilfield activities. A contaminated area, initially identified through regional groundwater sampling, was examined in detail. Monitoring wells were installed, and groundwater and soil samples were collected for chemical analysis. Surface electrical resistivity surveys were also performed to delineate contamination patterns. The findings revealed that the groundwater contamination originated from the leaching of residual evaporative salts through the vadose zone, beneath an abandoned emergency-evaporation brine storage pit. Data from down-hole specific conductance logs, water quality analyses, and computer-generated interpretations of surface electrical resistivity indicated that contaminant migration was primarily influenced by gravity, bedrock topography, and the local hydraulic gradient. An initial surface electrical resistivity profile survey was conducted to optimize the placement of monitoring wells and soil sampling sites within the vadose zone. Following well installation, a contaminant source with complex brine contamination patterns was detected within the shallow aquifer. Vertical electrical soundings were then carried out as the final investigative step. The data from these soundings, combined with test hole records, water level measurements, brine contaminant distribution, and soil analyses, were refined through a computer program employing the method of steepest descent. By incorporating known layer thicknesses and resistivities as constraints, this approach minimized the common issue of non-unique electrical sounding interpretations, providing information on the distribution of brine contaminants within the alluvial aquifer.

Integrated Simulation of Groundwater Flow and Nitrate Transport in an Alluvial Aquifer Using MODFLOW and MT3D: Insights into Pollution Dynamics and Management Strategies

This study employs an integrated numerical modeling approach using MODFLOW and MT3D to simulate groundwater flow and nitrate transport in the alluvial aquifer of Hennaya plain. The groundwater flow model was calibrated and validated against observed hydraulic heads, showing excellent agreement in both steady-state and transient conditions, with a correlation coefficients (R2) of 0.99 and 0.987, respectively. Meticulous calibration yielded adjusted hydraulic conductivity values between 10−1 and 10−11 m/s, with effective porosity ranging from 0.03 to 0.34 and total porosity values varying from 0.29 to 0.38 across the aquifer. Water budget analysis revealed that the aquifer’s primary recharge occurs from the southern side. Nitrate transport modeling indicated that advection is the dominant process, with contaminants migration predominantly occurring from south to north, following the groundwater flow direction. Pollution levels were found to decrease gradually with distance from sources, confirming agricultural activities and sewage disposal as primary contributors to nitrate contamination. Predictive scenarios over a 40-year period explored various management strategies, which suggest that maintaining current nitrogen input rates will lead to continued increases in nitrate pollution, while a 50% reduction in agricultural inputs could significantly improve groundwater quality. However, even with substantial reductions, nitrate concentrations are not expected to reach levels safe for drinking within the simulation timeframe. This study underscores the need for immediate and sustained action to address nitrate pollution in the Hennaya Plain aquifer, emphasizing the importance of stringent nitrogen management practices, particularly in the agricultural sector.

Equity Assessment of Groundwater Vulnerability and Risk in Drinking Water Supplies in Arid Regions

Groundwater is a vital drinking water source, especially in arid regions, sustaining both urban and rural populations. Its quality is influenced by natural (hydrogeological) and human-driven (demographic, policy) factors, which may pose significant public health risks, especially for communities relying on unregulated water supplies. This study addresses critical gaps by examining groundwater vulnerability and contamination disparities, emphasizing their implications for public health and equitable resource management. It analyzes the impact of socio-hydrogeological factors on arsenic and nitrate levels in groundwater-supplied systems in Arizona, U.S. Methods include spatial analysis, ANOVA, multivariate regression, and cluster analysis. Significant disparities in arsenic and nitrate contamination, including exceedances of regulatory limits, were observed across supply types, aquifer characteristics, jurisdictional oversights, and groundwater management areas. Domestic wells and community water systems showed distinct contamination risks. Groundwater vulnerability was influenced by geological differences (karst vs. alluvial aquifers) and regulatory oversight, with Tribal and State systems facing unique challenges and resource needs. Socioeconomic disparities were evident, with minority communities, institutional facilities, rural areas, and specific housing types disproportionately exposed to higher contaminant levels. These findings unveil the intersection of race, socioeconomic status, and public health risks, offering an adaptable framework for addressing similar groundwater challenges in arid and semi-arid regions globally. This study is innovative in its focus on policy distinctions between private and regulated wells, karst and alluvial aquifers, and State and Tribal jurisdictions. It emphasizes the need for targeted vulnerability assessments and remediation strategies that integrate geological, hydrological, and regulatory factors to address risk disparities in vulnerable communities. These environmental inequities underscore the urgent need for stronger regulations and strategic resource allocation to support marginalized communities. The study recommends enhancing monitoring protocols, prioritizing resource distribution, and implementing targeted policy interventions to ensure equitable and sustainable access to safe drinking water in arid regions.

Investigating Induced Infiltration by Municipal Production Wells Using Stable Isotopes of Water (δ18O and δ2H), Four Mile Creek, Ohio

Many municipalities around the world place their production wells in shallow alluvial aquifers that are adjacent to streams. Pumping these wells then induces the infiltration of surface water into the aquifer, allowing the greater extraction of water without significantly depleting the aquifer. However, induced infiltration poses a risk of introducing contamination from surface water into groundwater systems. The goal of this study was to quantify the amount of induced infiltration due to municipal pumping at the Four Mile Creek well field in Oxford, Ohio, using stable isotopes of water oxygen (δ18O) and deuterium (δ2H). In areas of municipal pumping, we sampled water from the production wells, Four Mile Creek, and from monitoring wells that we hypothesized to be both influenced and not influenced by induced infiltration. Samples were collected over 10 months in 2012 and over 12 months in 2021. In 2012, surface water δ18O values ranged from −3.89 to −8.04‰, and δ2H ranged from −26.55 to −55.65‰ at sampling sites. PW1 δ18O values ranged from −4.71 to −7.39‰ with a mean of −6.61 and −32.01 to −47.86‰ with a mean of −42.74‰ for δ2H. PW2 δ18O values ranged from −5.74 to −7.34‰, with a mean of −6.45‰, and δ2H ranged from −36.29 to −47.82‰ with a mean of −42.43‰. PW3 had lower values of both δ18O and δ2H, ranging from −6.36 to −8.02‰ and −47.7 to −40.35‰, and with means of −7.08 and −45.11, respectively. In 2021/2022, surface water δ18O values ranged from −5.32 to −7.93‰, and the δ2H ranged from −36.14 to −50.56‰. PW1 δ18O values ranged from −6.15 to −7.54‰ with a mean of −7.13‰, and δ2H ranged from −43.52 to −49.01‰ with a mean of −45.99‰. PW2 δ18O values ranged from −5.72 to −7.34‰, with a mean of −6.70‰, and δ2H ranged from −36.69 to −46.14‰, with a mean of −43.61‰. Using the time averaged values of δ18O of groundwater, production wells and surface water, the percentages of surface water resulting from induced infiltration in 2012 were 57%, 59% and 15% at the three wells, respectively, while in 2021, PW1 had 35% and PW2 91%. The amount of induced infiltration was apparently related to the pumping rates of the production wells, the length of time of pumping and the distance between Four Mile Creek and production wells. Our results indicate that stable isotopes of water provide a reliable method of quantifying groundwater/surface water interaction in alluvial aquifers.

Psycho-Chemical Characteristic of Groundwater Quality in Hard Rock and Alluvium Aquifers in Pangkalpinang City, Bangka Belitung Islands Province

Abstract The people of Pangkalpinang City generally use water sourced from groundwater and from the reservoirs of former tin mining excavations commonly called “Kolong.” However, the quality of the Kolong water used has a pH that tends to be acidic, while the groundwater quality has yet to be detected. In line with these problems, this study aims to analyze groundwater quality based on groundwater’s Psycho-Chemical properties associated with the lithology distribution in the study location. There are 3 rock units in the research location: the phyllite rock unit, classified as hard rock, sandstone unit, and alluvium unit. The results obtained in the comparison of Psycho-Chemical parameters of groundwater based on lithology spread over 98 observation wells are in the phyllite rock unit; there are 9 observation wells with pH 4.67-6.26; EC 72-291 μS/cm; and TDS 38-142 mg/L. The sandstone rock unit has 57 observation wells with pH 4.36-8.41, EC 36-5394 μS/cm, and TDS 17-2732 mg/L. The alluvium unit has 32 observation wells with pH 4.68-8.54, EC 32-12333 μS/cm, and TDS 16-6167 mg/L. A comparison of groundwater quality characteristics based on the physico-chemical properties of water with the distribution of lithology illustrates that the quality of groundwater in the phyllite rock unit has a low pH (acidic), so it must get treatment first to be suitable for use by the community as clean water. At the same time, the results of the analysis of groundwater Psycho-Chemical parameters for EC and TDS values in sandstone and alluvium units are in the Slightly Brackish and Brackish categories, where this can be caused by several factors, such as the possibility of contamination by salt water (geogenic) or contamination by human activities (anthropogenic) so that further research needs to be done to find out the source of groundwater pollution at the research site.

Assessment of the dynamics of heavy metal contamination in the alluvial aquifer of the Drean plain, El Taref (North-Eastern Algeria) using GIS indices and water quality analysis

The study was conducted to assess the quality of shallow groundwater in the Drean plain, with a focus on the concentration of heavy metals. The indices employed included the water quality index (WQI), heavy metal pollution index (HPI), and metal index (MI). Spatial distribution maps of heavy metals, as well as pollution indices, were developed based on twenty samples. The physicochemical parameters, including T, pH, EC, DO, and TDS, were measured using standard techniques. Heavy metals, including iron (Fe), lead (Pb), zinc (Zn), chromium (Cr), manganese (Mn), and cadmium (Cd), were analysed through spectrophotometry. The average concentrations of Mn, Cr, Cd, and Pb exceeded the World Health Organization (WHO) drinking water standards, with respective values of 0.16 mg/L, 0.06 mg/L, 0.28 mg/L, and 0.38 mg/L. According to the water quality index (WQI), which ranges from 21 to 800, approximately 50% of the water samples was classified as highly polluted and therefore not recommended for consumption. According to the metal index (MI), the average value is 6.77, with 80% classified as highly polluted. The average value of the heavy metal pollution index (HPI) was 2201, indicating that the water in the plain is severely polluted for consumption, with 100% of the samples classified as unfit for consumption. The study underlines the urgency of reducing the health risks to the urban population and recommends continuous monitoring of the area to assess the evolution of the pollution.

Application of VES and Physicochemical Analysis for the Evaluation of Dissolved Minerals in the Alluvial Aquifers of Part of Yenagoa, Bayelsa State

The sufficient provision and sustenance of quality water have been of a fundamental consequence in the social and economic developmental activities of humans over the years, especially in Bayelsa state and Nigeria at large, where developmental activities are on the increase. Potable water is essential to humans and animals alike, for personal, communal, industrial and societal uses. This study seeks to investigate the concentration of dissolved minerals, using an integrated approach of VES data and physicochemical analysis of ground water samples in parts of Bayelsa state, south-south Nigeria. Vertical Electrical Sounding was implemented in ten stations and interpreted using IPI2WIN software. The results from the VES interpretation revealed that the area is constituted of four to five geoelectric layers. Four distinct sounding curve types (H, HK, K and KH) were identified; with the H and K type curves being dominant. The dominant curve types show that the area has two main hydrologic regimes (of low and high Iron (Fe) concentration). The results show that in VES stations with K-type curve, the stratigraphy consists of the three to four layers, with varying thickness and corresponding resistivities; with the third or fourth layers identified as the aquifer layer. At H-type curve locations, the stratigraphy consists of the top soil, the clay layer, and the sand layer, which was identified as the aquifer. The physicochemical characteristics of water samples, collected from drilled boreholes in the vicinity of the VES locations of the study area, were analyzed for prominent physical and chemical constituents, including EC, pH, TDS, Na, K, Ca, Mg, Fe, Cl, SO, NO, and HCO. Physicochemical analysis was achieved using the standard APHA methods and compared with WHO standard. The results showed that the concentration of the chemical constituents varied spatially in the study area. The analysis revealed that 90% of the mean concentration of measured parameters were within the WHO’s standard in all the samples, except for Mn (with a value of 0.532 mg/L) and Fe<sup>2+</sup> (with a value of 0.88 mg/L) which was seen to be high in five of the boreholes in locations with H-type curves, hence correlating areas of high groundwater contamination to VES stations of the H-Curve type. The high Mn and Fe concentrations in the groundwater of some of the locations, makes the water unsuitable for drinking and may require treatment. Further analysis of the ground water samples, indicated that, Chloride and Sulphate are the predominant anions while, Calcium and Magnesium are the predominant cations in groundwater within the study area.

Understanding dominant hydrological processes and mechanisms of water flow in a semi-arid mountainous catchment of the Cape Fold Belt

Improving our understanding of streamflow characteristics, water storage, and dominant flowpaths in mountainous regions is important as mountains play a vital role in delivering water to lowlands, particularly in semi-arid areas. This work characterized water sources, flowpaths, and streamflow characteristics in the semi-arid, mountainous Kromme catchment in Eastern Cape Province of South Africa. Precipitation, shallow and deep groundwater levels, and streamflow data were analysed to identify patterns that indicate the occurrence and/or dominance of certain processes, responses, and flowpaths. Results of the study demonstrated how the catchment responds to rainfall events across seasons and rainfall intensities. Steep and rocky areas that make up much of the catchment contributed to significant flood peaks after high-intensity storms. Quick and slow responses in flow after rainfall events indicated the dominance of both surface and subsurface flowpaths respectively. Furthermore, surface and subsurface flows were significant in recharging the floodplain alluvial aquifer as well as maintaining streamflow during dry periods. Average annual runoff coefficients were low (0.09), which implied large evapotranspiration (ET) withdrawals from dominant flowpaths and/or storage in inactive groundwater. The Kromme catchment has a sizeable floodplain with large alluvial aquifers, which make significant contributions to catchment storage and outflows. Overall, the catchment streamflow was sustained by baseflow (for ∼50% of the time). Recession patterns suggested that the channel receives flow from different storages with the alluvial and bedrock aquifers as main contributors. Flow contributions had different rates with maximum recession periods up to 22 days, indicative of interflow dominance and floodplain drainage. Throughout the monitoring period, the river system was gaining flow at the different monitored sites during both low and high flow conditions. The channel was also gaining from the mountain bedrock through tributary flows and from the alluvial aquifer. A conceptual model of flowpaths and processes at the catchment scale is presented to improve the understanding of catchment scale hydrological processes in a semi-arid meso-scale mountainous environment.

Application of Hydrochemical Parameters as Tool for Sustainable Management of Water Supply Network

Effective management of Water Supply Systems (WSSs) is crucial for ensuring safe drinking water. The WSS of Varaždin County is a complex network involving three groundwater sources: Bartolovec and Vinokovščak wellfields (alluvial aquifers) and Bela karstic spring. To achieve a comprehensive characterization of WSSs, routine laboratory data was integrated with stable isotopes and geochemical modeling. Within this study, all measured parameters remain below the Maximum Contaminant Level (MCL), ensuring water safety for human consumption. The Piper diagram identified variations in water sources based on their chemical composition, providing a simplified overview of mixing patterns within WSSs. Among the modeling approaches, inverse modeling (IM) was found to be more reliable than forward modeling (FM) and mass balance modeling (MB). Despite the limited capacity of δ18O to provide accurate mixing results, it was revealed that the reservoir water was in equilibrium with the air (no evaporation effects), indicating well-sealed reservoirs. Mixing modeling showed that the western, southwestern, and northern parts of the WSS mixed all three sources, whereas the eastern and southeastern areas primarily relied on the deeper aquifer of the Bartolovec source, indicating potential vulnerability. Strict validation criteria ensured the reliability of results, demonstrating the effectiveness and applicability of geochemical modeling in water security management plans.