Characterization of Groundwater Recharge Using the Water Table Fluctuation Method in the Koda Catchment, Mali

Abstract

Groundwater is significantly requested in all the activities of the inhabitants of the Koda catchment. The knowledge on the approximate quantity of annual precipitation of water achieving groundwater table is then the key word on water resources management system, in particular for the decision makers of the Koda Catchment. Due to the lack of the measurement of historical observation data, the groundwater resources dynamics are poorly understood in this catchment. The main objective of this paper is to estimate the annual groundwater recharge from the annual precipitation of the Koda catchment using Water Table Fluctuation method WTF. The annual rainfall data and monthly piezometric level data have been used to estimate the annual groundwater recharge from 3 piezometers and 4 shallow wells. The values of recharge obtained from the three monitoring piezometers are ranged from 61 mm to 173 mm, i.e. to 7% and 29 % of annual rainfall while for the four wells the mean recharge is varying from 26 mm to 186 mm corresponding to 3% and 26 % of the annual precipitation. The results of the current study can be used for well managing the groundwater resources in the Koda where the surface water resources are limited.