GIS Based Identification of Water harvesting potential Area in the Bale
Lowland of South Eastern Ethiopia
Abstract
Assessment of potential surface runoff harvesting sites is an important
undertaking in a country like Ethiopia, where high spatial variability
in rainfall and recurrent drought and flash floods are common. In this
study, the geographical information system (GIS)-based multi-Criteria
Evaluation is used to select the potential rainwater harvesting sites in
Oromia, Bale lowland, Ethiopia. Analytic Hierarchy Process (AHP) is used
for standardization of the criteria, and Weight overlay analysis of
multicriteria for a combination of multi-layers using ArcGIS 10.8. Six
criteria layers, including slope, runoff, soil depth, precipitation,
soil texture, and the land use land cove are derived to identify
rainwater-harvesting catchment. The analysis, shows that of the total
500 km 2 of the catchment area, 29.18 % of the area
has highly suitable, 40 .87 of the area has Suitable ,22.49% of the
total area has moderately suitable ,6.98% of the area has marginally
suitable and 0.5 % of the area is not suitable for runoff water
harvesting at the study area. It was noted that providing accurate and
precise spatial representation of the physiology and land use for the
analysis of runoff generation potential site within the study area is an
important step in developing an integrated strategy for surface
rainwater harvesting plan the study area.