EVALUATING THE IMPACTS OF CLIMATE CHANGE ON SURFACE WATER AVAILABILITY FOR CROP PRODUCTION IN WERII WATERSHED, NORTHERN ETHIOPIA

Abstract

This study focuses on Evaluating the Impacts of Climate Change on Surface Water Availability for Crop Production in werii watershed, Northern Ethiopia. Projected future climate variables were obtained from CORDEX-Africa program for Representative Concentration Pathway (RCP) of two scenarios (RCP 4.5 and RCP 8.5) which were used for future climatic conditions of the one future periods; (2041 – 2070). Sen’s estimator and Mann-Kendall’s statistical tests were used for trend detection using XLSTAT software. HEC-HMS was used to estimate water availability and CROPWAT model was used for estimation of crop water requirement and irrigation water requirement. The study results indicate that the decreasing trend in current annual rainfall. However, current average temperature and evapotranspiration reveals increasing trend. The average temperature and evapotranspiration showed increasing trend in both scenarios. The impact of climate change on Maize crop shows that crop water requirement and irrigation water requirement in the future is expected to increase in the study area. The impact of climate change on available water content of Werii river watershed shows that the runoff depth is expected to decline by 3.74% and 2.31% for Rcp 4.5 and Rcp 8.5 scenarios, respectively. Generally, the volume of available water content of Werii River watershed is expected to decrease in the future, therefore the need for adequate provision of irrigation and drainage infrastructures which could be regarded as critical for climate change adaptation.