GIS Based Assessment of Suitability area of Rainwater Harvesting in Daro Labu District, Oromia, Ethiopia

Abstract

Rainwater harvesting is the process of intercepting, conveying and storing rainfall for future uses. The aim of the research was to assess and mapping suitability area of water harvesting site in Daro Labu District. Various methodologies to identify suitable sites and techniques for rainwater harvesting were use. GIS is the recent technology of spatiotemporal data used to assess the factor of influences for rainfall and runoff depth estimation. The influence factors for the assessment was climate data, soil texture and depth, land use and land cover type, slope difference were use. The SCS–CN for rainfall used to runoff depth estimation and volume from the land surface depends on the level of antecedent moisture condition (AMC.) The length of wet and dry season of the study area were known with antecedent moisture condition of II, I III by having the values of 82, 67and 91 respectively. The annual of 20 years average rainfall was 925.2 mm with maximum and minimum of 1134 mm and 737.3 mm respectively with average annual runoff depth of estimate was 185.3 mm.  From the estimated annual runoff, the volume of water harvested was about 2.89 x 10⁸ m³. From the total area of (156064.72 ha), the suitability map of the study area shows very highly, highly, low  and not potential accounts by coverage areas about 8.2%, 16.6%, 63.5%, and) 7.5% respectively. The runoff in the study area was affected by geomorphological factors, land use change, topography, soil texture and depth, affects the runoff rate and volume significantly.

Key words: ArcGIS, Rainwater Harvesting, SCS-Curve Number, Suitability area Daro Labu

DOI: 10.7176/JEES/12-10-04

Publication date:October 31^st 2022