Overview to Potential Sources, Soil Salinization and Expansion Level of Lake Basaka, Central Rift Valley Region of Ethiopia

摘要

The aim of this overview is extended to indicate the Potential Sources, Soil salinization and expansion level of lake Basaka. Lake Basaka is located in the middle Awash River Basin, Central Rift Valley of Ethiopia at about 200 km south East of the capital city, Addis Ababa. The lake is expanding as opposed to the other rift valley lakes in Ethiopia, which are shrinking, Lake Basaka is found to be expanding at an alarming rate. This overview indicates the expansion area/level/ of the lake is challenging the socio-economics and environment of the region significantly. With this point of view the lake's expansion is due to the agricultural sugarcane farm land use type near Beseka Lake and mostly due to the increased ground water flux to the lake. The potential sources or ground water flux to the lake could be an increase of ground water recharge following the establishment of irrigation schemes in the region, subsurface inflow from far away due to rift system influence, and Lake Neotectonism. The significant expansion of Lake Basaka during the past 35 years started after the introduction of Matahara sugar state. The expansion is affecting both the ground water dynamics and soil salinization of the nearby sugarcane Plantation and, if it continuous, the sustainability of the plantation itself is under great risk. The future expansion of the highly saline lake may be aggravated towards the east and Northeast direction due to the topography of the area. This has the potential to displace Matahara town and impact the sugar Plantation during the next two-three decades years. Assuming the past trends, the lake isexpected to join Awash River, thereby impacting all downstream irrigation developments in the Awash basin, and affecting the livelihood of the people depending on the water resources of this basin. Generally, the lake's has poor water quality and its expansion rate damaging effect to the region, and mitigation measures are very important for sustainable lake management.