Mapping suitability for solar-powered irrigation systems using GIS–AHP in Baringo County, Kenya

Abstract

Solar-powered irrigation Systems (SPIS) are critical for agricultural production enhancement, food security and climate change adaptation, especially in Arid and Semi-Arid Lands (ASAL). There is increased attention towards shifting to more abundant and cleaner energy potential sources for revitalising irrigation strategies in ASAL areas. This study employed a geospatial approach to identify suitable locations for solar-powered irrigation systems (SPIS) in Baringo County, Kenya. Based on an integrated use of GIS spatial analysis and analytical hierarchy procedure (AHP), suitable locations for solar-powered irrigation were mapped. Precipitation, irrigated areas, proximity to rivers, slope, and solar radiation were analysed and processed to derive spatially explicit SPIS suitability classes ranging from very low to very high suitability. The thematic layers were assigned weights based on Saaty’s AHP method, where weights for each factor were determined from a pairwise comparison matrix, and a Weighted Linear Combination (WLC) approach was used to derive the final suitability classes for the county. The findings reveal that approximately 58% of Baringo County falls within the moderately suitable category for SPIS implementation, while 24% of the area demonstrates high suitability. In contrast, only 0.8% of the county’s land area was classified as either very low or very high suitability. These results offer critical insights for guiding spatially informed planning and investment in suitable, solar-powered agricultural infrastructure within the region. Furthermore, the findings of the study contribute to the ongoing initiatives on the expansion of irrigable land using low-cost and innovative technologies such as SPIS to put marginally arable land under productive use in Kenya.