Identification and Mapping of groundwater Potential Recharge Areas in the Dosso region (Southwestern of Niger) by using Multicriteria Analysis Method

Código

I-EBHE0011

Autores

ABDOU ALI Ibrahim

Tema

WG 1.06: Water for biodiversity in a changing world

Resumo

Groundwater is the main source of water supply in the Dosso region which is located in the southwestern part of the Iullemmeden Basin in Niger republic (West Africa). Despite the arid to semi-arid climate that characterizes this region, groundwater recharge is occuring mainly through rainfall. This recharge of water which is an essential element in the hydrological cycle is prefentially done according to zones which can also be vulnerable to groundwater pollution. The main objective of this study is to identify and mapped the potential recharge areas. A methodology based on a multicriteria analysis integrating GIS and remote sensing was used to map the potential recharge areas. After processing the Landsat satellite images of Dosso region, all the parameters influencing the hydrological recharge processes were obtained and integrated into GIS. These parameters are: soil types, land cover, fracture density, drainage density, lithology and slope. The map of potential recharge areas obtained shows that the majority of the study areas has great recharge potential. According to this study, this great potentiality could be linked to: the sandy nature of the soil, the cultivable areas, the presence of fractures and density of hydrographic network. This map also confirmed that areas with high recharge potential are located in the beds of ponds and "dallols" (wide dry valleys), which thus become more vulnerable areas. This map of potential recharge areas constitutes therefore a tool for decision makers.