Hydrologie : recherche actuelle

Impact of Land Use Land Cover Dynamics on Water Balance, Lake Ziway Watershed, Ethiopia

Abstract

Tesfalem Abraham, Behailu Nadew

Quantification of Land Use Land Cover (LULC) change influence river basin on hydrology will enable local government and policy makers to formulate and implement effective and appropriate strategies to minimize the effect of future LULC change. In this research Soil and Water Assessment Tool (SWAT) with Sequential Uncertainty Fitting Intervals (SUFI-2) was used for analyzing the LULC changes on the Water balance of Katar and Meki River Basins, in the Rift Valley of Ethiopia. LULC map of 1996 and 2014 was used for the change analysis and the results revealed that the reduction of Forest and expansion of Agriculture and Built-up areas have an influence on the surface water spatial distribution and the water balance components. During the land use change periods, the increment of annual surface runoff from 67.54 mm to 129.14 mm has resulted from Katar river basin and 40.64 mm to 59.56 mm has resulted from Meki river basins. This result has revealed that the above land use changes are the main contributors to the increment of surface runoff on both river basins. With this regard, major changes from the Forested region on both river basins have resulted in runoff depth increment. Forexample, runoff depth increment of 4-53 mm to 10-65 mm on Katar river basin and 2-34 mm to 23-60 mm range from Meki river basin mainly from forested regions resulted. Therefore, LULC change is becoming a serious threat to Katar and Meki river basin, hence appropriate measures should have to be taken for the stabilization of the land cover change with the regional development plan. Furthermore, the outcome of this study serves for policymakers as a valuable information for the planning of best land management strategies and priorities for the region.