Assessment of Groundwater Potential for irrigation using GIS and Remote Sensing techniques: the case of Horro Woreda, Horro Guduru Wollega Zone, Oromia

ABSTRACTS Groundwater is a valuable and important natural resource in the world and it is the most fundamental for the growth and development of one country. However, estimating the potential of groundwater and its recharge zone has still uncertain due to the nature of groundwater. The general objective of the study was to assess groundwater potential for irrigation in the Horro district using GIS and RS techniques. In this study, sentinels_2 satellite images with resolution 10m and 20m were used to produce LULC and lineament of the area while drainage, slope and geomorphology of the area were generated from Digital Elevation Model (DEM) with resolution 30m and other secondary data were used for study of the area. For this purpose, eight groundwater occurrence and movement controlling parameters (i.e., Geology, rainfall, geomorphology, slope, drainage density, soil, land use/land cover, and lineament density) were prepared and transformed into raster data using ArcGIS software. These eight total layers were considered proxies to signify groundwater occurrence and analyzed in GIS environment with a consistency ratio (CR = 0.03). The hierarchical ranking was conducted using a pairwise comparison matrix in the IDRISI software in order to estimate the final normalized weights of the layers. The weighted overlay technique to integrate the layers for the creation of the GWPZs map of the study area. The map has been categorized into five zones (viz., very high, high, moderate, low, and very low) representing (31.63, 35.16, 16.97, 12.08, and 4.16)% of the study area, respectively. The study concludes that majority of the area covered by very high and high potential zones as it is supported by borehole wells and the new generated predicted groundwater potential map. In the study, groundwater potential areas of the district were delineated with potential availabilities levels. So, it was recommended to apply as source of water for irrigation activities in the district.