Gis-Based Analysis Of Causes, Extent And Consequences Of Depletion Of lake Abijata, Central Rift Valley Of Ethiopia

Abstract

Lake Abijata suffers from water level fluctuation due to several natural and anthropogenic factors. As it located at terminal position (no surface water outflow), it highly affected by the fluctuation. This fluctuation is disturbing the stability of the lake ecosystem and imposing very serious impacts on the lives of plants, fish and many birds in and around the lake. Hence, studying of the cause, extent and consequences of shrinking of the lake was found to be very important. The main purpose of this study is to identify the factors that contribute to the water level fluctuation, to quantify the extent of fluctuation and impacts of shrinking of the lake on its ecosystem, eco-tourism and fishing activities. The research methodology includes computing of annual water abstraction, annual rainfall, annual maximum temperature and multi-satellite image analysis. The result of the study revealed that the shrinking of the Lake Abijata water level is caused by natural factors such as increasing in temperature and decreasing of rainfall in the area and human activities ( over use of water for irrigation and production of soda ash). Lake Abijata is dramatically reduced in size (about 43.13% of its area between 1985 and 2015) due to both natural factors and human activities (the most dominant one). Due to decreasing of Lake Abijata water level and increasing of alkalinity of lake water, natural ecosystem of the lake is highly affected. This also totally changed the socio-economic setup of the area. Since Lake Abijata is seriously, affected, special attention is needed to conserve the water in the lake by controlling the excessive use of water and save the lives lake ecosystem including fauna and flora.