IRRIGATION POTENTIAL AREA ASSESSMENT USING GIS AND REMOTE SENSING, THE CASE OF SIDAMA ZONE, SNNPR

ABSTRACT The present study was focused on irrigation potential area mapping based on GIS and Remote Sensing techniques in Sidama zone.irrigation potential assessment were demarcated by integrating six thematic layer such as Soil drainage,Soil texture,soild epth,slope,landuse/land cover,distance to water supply.the thematic layer had been organized from satellite images and available secondary data.the data include SRTM DEM 30m, ISRIC Afsis soil data 250m,landsat8 images,distance to water supply. The methodological approach consisted of processing Landsat8 images,SRTM DEM and ISRIC soil data ; using appropriate packages software erdas imagine 2014 and ArcGIS10.5.Landsat8 Satellite image was become used to decided a land use and land cover classification of the study area and the SRTM DEM satellite image determined slope classification and watershed delineation.and the soil types and soil mapping units of the study area would be delineated, classified, characterized and mapped as per FAO UNESCO-ISRIC and world soil reference base (WRB) 2006 profile description guideline. Weighted overlay analysis was performed using the six thematic layer in ARC GIS 10.5 software.among the six parameter the higest value given to distance to water supply where as the lowest value given to land use /land cover. According to the result irrigation potential area map classified into four different Suitablity classes highly suitable,moderately suitable,marginally suitable area and not suitable area. Therefore based on suitability level about 23.43% which accounts for a total area of 155,003ha of the study area categorized as highly suitable for irrigation, 24.95% which accounts for 165,055ha of the study area categorized as moderately suitable for irrigation, the remaining 51.63% of the study area not suitable. This implies that half of the study area not suitable for irrigation potential. So that, the current study was assessed only slope, land use land cover and soil physical properties and distance to water supply but the effect of the factors such as, socioeconomic factors, soil moisture, and specific crop based analysis, environmental issues, soil chemical properties, method of irrigation system and other relevant parameters should be studied to get sound and reliable result on assessment of irrigation development in the study area.