Using Remote Sensing and Geographic Information Systems to Determine Suitable Borehole Sites in Kitui County, Kenya

Abstract

Water is considered a powerful natural resource in the world: a source of life, the backbone of growth and prosperity. The increasing demands for water against the limited natural sources and its increasing scarcity have a possibility of resulting in devastating conflicts and calamities. The economic and social developments anticipated by the vision 2030 blueprint will require much more resources in terms of quantity and quality than at present. The country, therefore, aims to manage water sources effectively and efficiently while starting new ways of harvesting rain and groundwater. Groundwater is harvested through digging up of wells in areas where the water table is very shallow and sinking boreholes where the water table is very deep. The objective of this study was to determine the most suitable areas in Kitui County where boreholes can be drilled by incorporating different hydrogeological factors using GIS and Remote Sensing. This was done by identifying the different hydrogeological factors that determine potential borehole sites and applying the factors in a multi-criteria weighted overlay to determine the potential borehole sites and thereafter mapping the potential zones in the area of study. Groundwater potential areas in Kitui County were effectively mapped through the integration of factors that affect the occurrence of groundwater. From the final suitability map, it’s clear that the western part of the county is unsuitable for borehole siting. The southern areas of the county are occupied by Tsavo national park which is a protected area hence no drilling can take place there. The central part of the county is the most suitable area for borehole drilling as they have a higher lineament density. Geospatial technologies should be embraced in carrying out suitability studies due to their improved accuracy as they can delineate the appropriate areas for groundwater exploration and borehole sitting and time conscious thus facilitating studies over large areas. The county government of Kitui County should sink more boreholes in the central part of Kitui County that this study found to be suitable for borehole sinking.