Abstract

A majority of the population of Bénin lives along coastal regions whose basins are made up of quaternary sediment. These sediments contain aquifers -- water-bearing strata of permeable rocks -- which supply water to urban and rural populations. Not much is known about how the rock formations affect the rational use of water resources. Problems such as the influx of salt water, the contamination of the water table with domestic and industrial pollutants, and the excessive lowering of the groundwater level have become serious. In this project the quaternary formations and the related hydrogeological systems will be defined and the use of water resources will be evaluated.

Post-Project Summary

Water samples were taken regularly at 18 sites for chemical and geochemical analyses. The plan had been to make intensive use of shallow, medium, and deep shafts. For administrative reasons, however, only two were used and a third was described for correlation purposes. The researchers conducted some geophysical tests, studies of the micro-fauna, and granulometric analyses. The research work made it possible to determine the chemical quality of the water in the test samples, to identify certain areas where there was a risk of pollution of surface waters from human and animal waste and deeper level salt water influx, and to put together a stratigraphic correlation of the basin. The research work was the subject of two papers at an international symposium in Ottawa in 1987 and was used by two Beninese researchers for preparing their Doctoral theses.

Recipient Institution(s)