Abstract

Kitui district is a semi-arid region characterized by erratic and unreliable rainfall. Despite this, the main economic activity is rain-fed agriculture, with irrigation agriculture taking place on small parcels adjoining riparian reserves. During the dry season, local people travel long distances in search of water, necessitating groundwater potential mapping to support exploitation and complementing other water sources in the district. In this study geospatial technologies are used to identify and map groundwater potential zones using climate, geophysical and geological data. These datasets were appropriately weighted in a modified DRASTIC based overlay scheme. Land-cover data was derived from landsat imagery classification, with lineament density obtained from the same satellite products. A groundwater potential zones map was generated which showed that the central and eastern regions of Kitui district are the most suitable for groundwater exploitation. Existing water points (which were not considered in the study) are situated in this region, hence validating the study.

Key words: Groundwater prospecting, DRASTIC, lineament density, land-cover classification.