Using Landsat 5 imagery in the assessment of groundwater resources in the crystalline rocks around Dutsin-Ma, northwestern Nigeria

Landsats TM imagery of January 1986 covering Dutsin-Ma and the surrounding areas in northwestern Nigeria was used for the assessment of groundwater resources in the crystalline rocks (Basement Complex) terrian. Employing ER Mapper (5.2), surface indicator for the occurrence of groundwater such as thriving vegetation in non-irrigated lands, and fracture were identified. These were interpreted vis-a-vis the tectonic development of the area. Lineaments interpreted as fractures show two prominent strike maxima that lie between 000°and 030°, with the more common lying between 000°and 010°. These strike maxima correspond to the stress axis of the Pan African orogeny. The lushness of vegetation along these strikes is higher than in the neighbouring areas and indicate the presence of groundwater. On the basis of lineament density and relative lushness of the vegetal cover, the area was divided into three main hydrogeological zones namely, the zones with the highest, intermediate, and least groundwater potential, for which ground truthing is recommended for their confirmation. Geophysical surveys for the siting of boreholes are also recommended parallel to strikes between 270°and 300°. It is judged that the groundwater resource for this area is low because of the general lack of moist or seepage areas, the low threshold value (0.12) of Normalized Difference Vegetation Index (NDVI), and the generally dispersed nature of the vegetation.