Investigation of groundwater resources in the Komadugu Yobe Valley (Lake Chad Basin, Niger) using MRS and TDEM methods

Abstract

Groundwater resources quantification and management is a key issue for agricultural development in the Komadugu Yobe (KY) River valley region in the semiarid part of the Lake Chad Basin. To improve the knowledge of available groundwater resources in this poorly-documented area, a geophysical survey across the river valley was conducted near the town of Diffa, southeast Niger. The goal was to estimate the hydrogeological properties of Quaternary formations to a depth of ~100 m. Numerical modeling showed that sedimentary deposits composed of thin clayey, loamy, and sandy layers could not be accurately resolved in detail by non-invasive geophysical methods due to the limited spatial resolution of the methods. The use of the Time Domain Electromagnetic (TDEM) method alone was not sufficient to estimate aquifer parameters and the Magnetic Resonance Sounding method (MRS) was used to supplement the geophysical dataset. A twelve kilometer long profile (117 TDEM and 11 MR soundings) was...