Geospatial assessment of surface water irrigation potential using geospatial technology: the case of abaalemu watershed, baro-akobo river basin, Ethiopia.

Abstract

study was conducted in Abaalemu watershed, Baro-Akobo river basin. The objective of the study was to assess the level of suitability and potential of the watershed for surface irrigation by using integrated approach that includes Geographic Information System (GIS) and Remote Sensing (RS). To identify suitable land for surface irrigation the physical land suitability parameters were used; such as slope, soil depth, texture, and land use land cover and drainage. After that they were reclassified by using Arc GIS spatial analyst (re-class) tools based on their suitability level and each parameters analyze individually by Geospatial analyst tools. After reclassification process, weight was assigned for each criteria using multi-criteria evaluation method using AHP procedures developed. Afterwards, all the standardized criteria were combined to perform weighted overlay analysis using Arc GIS spatial analyst (overlay) tools and thematic maps showing potential suitable site for irrigation were prepared. The result of the weight overlay analysis revealed that out of the total area that is 4786 ha, 254 ha (5.30 %) of the study area is found to be highly suitable for surface irrigation potential because it fulfill the environmental and socio economic criteria. In addition, 3746 ha (78.78 %) of the study area is moderately suitable for surface irrigation and about 583 ha (12.18 %) of the study area are found to be less suitable but the remaining of the study area which is 203 ha (4.27 %) is permanently not suitable for irrigation because this area is built up area. Generally above 80 % of the study area is suitable for surface irrigation. Therefore in order to gain additional suitable land for surface irrigation potential in the study area other suitability factors like chemical properties of soil, water quality, environmental, economic and social terms should be assessed to get a reliable result.