Groundwater research, Sub-saharian Africa

Name of project:
Village hydrogeology (Hydraulique villageoise)
Country: Area of study:
Mali, Cameroon, Centrafrican Rep., Mauritania, Burkina Faso Several areas within these countries
Customer:
Lotti & Ass., Unigeo (Rome, Italy); Geolab, Arlab (France)
Project objectives:
To carry out preliminary geological investigations in support of water research for supply of single villages in areas of impervious hard rocks (crystalline, carbonates)
Composition of the working group:
GEOMAP
Personnel involved:
2 geologists photointerpreters
Number man/months:
Project steps:
The investigation started with a preliminary study of satellite imagery at smaller scales (1:100,000, 1:50,000) aimed at interpreting the structural setting of the area and at assessing the kinematic characteristics of the different fracture trends.
A second phase was carried out at local scale and was based on the interpretation of high resolution images or aerial stereo pairs at the scale of 1:10,000, involving an area of approximately 4 sq. km centred on each village.
The fracture traces, representing preferential zones of groundwater flowing in hard rocks, were mapped, classified according to their length and conspicuousness and were interpreted relative to the geological units outcropping and/or known in the subsurface. Furthermore, the intersections of two or more fractures were identified and classified as nodal points, being interpreted as preferential locations of groundwater occurrence.
This type of investigation was employed as guide to the planning of geophysical surveys and to select the location for drilling wells. The activity in this field has covered more than 1000 villages, with an average success of 90%.
Start (year/month): End (year/month): Value of the project:
1983 1993