| Popis: |
Ethiopia is endowed with immense water and land resources that could be tapped and used for irrigation development. However, little has been done so far due mainly to lack of comprehensive knowledge on the potential of these resources. This study was, therefore, taken up to assess the irrigation potential in data scarce Jewuha watershed of the middle Awash River Basin. The study was used different data inputs collected from various sources and field observations. It includes primary data such as ground control point for outlet selection and major crops adopted in the area through interview of local farmers and secondary data like hydro-meteorological data, soil map, land use land cover map, road map and agronomic data. FAO land evaluation framework in the GIS environment, CROPWAT software and SWAT model were applied sutability, crop water requirement and surface water potential analysis, respectively. The calibration and validation of the SWAT model showed that the model has performed well to simulate the hydrology of the watershed with a coefficient of determination (R2), Nash-Sutcliffe efficiency (NSE) and Percent of bias (PBIAS) of 0.74, 0.73 and 0.80 for calibration and 0.71, 0.70 and 7.90 for validation, respectively. The irrigation suitability analysis reveals 35140ha, 40044ha and 40108ha of the area are suitable for surface, sprinkler and drip irrigation systems, respectively. From a combined analysis of the available land and water resources, the gross irrigation potential of the area is estimated to be 12,997ha, of which 3098ha of land is exclusively suitable for surface irrigation and 9,899ha is suitable for pressurized irrigation systems. In conclusion, greater than half of the area in the watershed is suitable for both irrigation systems but it is more suitable for pressurized irrigations due to this as recommendation providing either sprinkler or drip irrigation system is more suitable than surface irrigation systems |
