Assessment of climate variability impact on water supply sustainability in rural areas of northern Ethiopia

Climate variability can affect sustainability of water resources in rural areas. The impact of climate variability is greater for areas having low annual rainfall and complex topography. The objective of this study was to investigate spatial and temporal variability of climate and its impact on sustainability of rural water supplies in northern Ethiopia. Station-based climate data of six meteorological stations were gathered from Ethiopian Meteorology Institute (EMI) with varied recorded periods. Rainfall trend analysis was conducted using the Mann-Kendall test and Sen's slope estimator. Rate of water yield for hand-dug wells and springs was measured using pumping and recovery tests. Results of this study showed that no significant trends were detected for annual and seasonal rainfall of all stations, except the summer rainfall of Dengolat station. Average monthly minimum and maximum temperatures in the last 3 decades have been increasing by 0.68 and 0.34 degrees C, respectively. Yield test results of wells and springs of the study area varied from 0.01 to 1.34 L per second (l/s). Yield test results for wells and springs showed that only 19% of the water supply schemes satisfy the daily domestic consumption of 25 L/capita/day. The study implied that water yield of the water supply schemes is impacted by temporal and spatial climate variability. Water yield of wells and springs was positively correlated with annual rainfall, but negatively correlated with slope gradient of the study area. Water yield of the water supply schemes located nearby to check dams, reservoirs, ponds, and perennial rivers was relatively better compared to others schemes.