Integrated hydrogeophysics, geochemistry, and monitoring for characterization of groundwater resources in Eastern Senegal

Groundwater in southeastern Senegal faces pressures from climate variability, overabstraction, and geogenic contamination. As part of a Geoscientists Without Borders initiative, we conducted an integrated geoscientific investigation in Saraya, Eastern Senegal, to map groundwater potential, assess water quality, and build local capacity. Transient electromagnetic (TEM) soundings and electrical resistivity tomography (ERT) profiles were acquired, supported by targeted geological mapping and groundwater sampling.

Geophysical imaging identified fractures and deep regolith as the main water-bearing units, though highly variable in extent. The town of Badioula shows promising aquifer continuity with generally good water quality, while Saraya was characterized by poorer water quality.

To complement the geophysical surveys, real-time monitoring was piloted using a LoRa-based network with water level and electrical conductivity sensors linked to a weather station. The system captured rainfall-driven recharge responses and conductivity fluctuations, providing a blueprint for cost-effective monitoring in remote regions.

This integrated approach underscores the value of combining TEM, ERT, geochemistry, and low-cost monitoring to guide sustainable groundwater abstraction in crystalline basement terrains. Beyond technical outcomes, the project strengthened local expertise through MSc training, outreach, and workshops, highlighting hydrogeophysics as a tool for water security.