Assessment of Groundwater Recharge and Quality in Urban Sedimentary Basins Using Geophysical and Geochemical Methods

Project Abstract

Groundwater serves as a vital resource for urban populations, providing essential water for domestic, industrial, and agricultural use, yet its sustainability is increasingly threatened by rapid urbanization, pollution, and altered recharge processes. This research investigates the dynamics of groundwater recharge and assesses the water quality within urban sedimentary basins through an integrated approach combining geophysical and geochemical methods. The study aims to identify recharge zones, understand the subsurface hydrogeological framework, and evaluate the extent of pollution affecting groundwater sources in the area. Methodologically, the research employs electrical resistivity tomography (ERT) and seismic refraction surveys to delineate subsurface stratigraphy, aquifer boundaries, and potential recharge pathways, complemented by the use of digital elevation models (DEMs) and remote sensing data to map surface hydrological features. Water samples were systematically collected from various boreholes and wells across the basin to analyze parameters such as pH, total dissolved solids (TDS), heavy metals, and major ions, providing insights into the geochemical composition and pollution levels. The geophysical data are processed using specialized software to generate detailed subsurface images that reveal layer continuity, depth to aquifer, and zones of preferential recharge, while geochemical analyses interpret water-rock interactions, cyclic patterns, and sources of contamination. The findings indicate that recharge predominantly occurs through specific stratigraphic interfaces, surface runoff areas, and urban green spaces, with distinct variations in aquifer properties across the basin. Results from water quality assessments highlight areas with elevated levels of contaminants, linked to anthropogenic activities such as waste disposal, industrial discharges, and improper sewage management. The research also uncovers correlations between geophysical signatures and geochemical indicators, enabling the identification of vulnerable zones requiring targeted intervention. Furthermore, the study demonstrates the importance of integrated geophysical and geochemical approaches in providing comprehensive groundwater assessments in complex urban environments. The implications of these findings are critical for urban water resource management, pollution control, and sustainable development planning. Recommendations for groundwater protection include implementing pollution mitigation strategies, regulating urban runoff, and promoting judicious groundwater extraction practices. This study contributes to the body of knowledge on urban hydrogeology, emphasizing the need for continuous monitoring and integrated approaches to ensure the sustainable utilization of groundwater in sedimentary basins subjected to urban pressures. Overall, the research provides a scientific basis for policymakers, water resource managers, and urban planners to develop more effective groundwater management strategies tailored to the unique hydrogeological and environmental challenges of urban sedimentary landscapes.

Project Overview

What This Project Is About

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This project looks at how groundwater, which is the water stored underground in soil and rocks within urban areas, gets replenished and the quality of this water. It involves studying how rainwater soaks into the ground and mixes with existing groundwater, and whether the water is clean or polluted. To do this, the project uses special tools and methods that can "see" underground without digging large holes, as well as analyzing the water samples to check for contaminants. The goal is to better understand how urban areas affect underground water and how to keep it safe and plentiful for people and plants.

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The Problem It Addresses

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Many cities face challenges with underground water because of pollution from factories, vehicles, and improper waste disposal. Also, urban development can change how water naturally moves underground, leading to areas with too little recharge or polluted water supplies. However, there is limited detailed information about how much water is replenishing the underground reservoirs and how clean that water is. This project aims to fill that gap by providing detailed data that can help manage and protect urban groundwater resources better, ensuring safe water for the community and sustainable city planning.

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Objectives of the Project

1. Identify how much groundwater is being recharged in an urban sedimentary basin.
2. Evaluate the quality of groundwater concerning pollutants and natural minerals.
3. Use geophysical techniques to map the underground layers that store water.
4. Use geochemical analysis to assess water composition and sources of pollution.
5. Determine the impact of urban activities on groundwater recharge and quality.

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What You Will Do Step by Step

1. Select a specific urban area with sedimentary rocks for study.
2. Collect water samples from different underground locations and surface sources.
3. Conduct geophysical surveys like electrical resistivity to see underground layers.
4. Analyze water samples in the lab for mineral content and pollutants.
5. Interpret geophysical data to understand underground structure and flow paths.
6. Compare water quality results across different sites to identify problem areas.
7. Assess how urban land use influences groundwater recharge and pollution.
8. Compile findings into a report with recommendations for sustainable groundwater use.

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Expected Outcome

By the end of the project, you should have a clear picture of how much underground water is being replenished and how pure it is. This information can help governments and communities better protect and manage their groundwater supplies, especially in urban areas where land use changes and pollution are common. The project will also demonstrate how combined geophysical and geochemical methods are useful tools for studying underground water, providing a basis for future research and practical solutions to groundwater problems in cities.