GASH RIVER FLASH FLO ODS CHALLENGES TO KA SSALA TOWN: MITIGATION AND RISK MANAGEMENT

The Gash River originates from the Eritrean Highlands and the Ethiopian Plateau. It is a seasonal flashy river with high variation in flow during the wet season. It has a catchment area of 21000 km 2 , a river length of 200 km and a slope of approximately 200 cm/km. The mean annual discharge is 680 million cubic meter. The river basin experiences considerable socio economic activities, environmental issue s and flooding of approximately 1 in 5 years. The River Gash is a source of frequent terror to the inhabitants on both sides of its banks especially the Kassala town, which is very severely attacked by several damaging high floods. Almost half the city wa shed out by the most damaging flood of 2003. This paper examines the history of the river behavior aiming to identify the main causes of flood risks and banks failure due to the floods. The paper will also review the structural and non - structural efforts to combat the flood damaged and manage its risks. Therefore, the protection works constructed on the river course to protect the city and the agriculture farms is discussed. The causes of the 2003 - year damaging flood and its negative impacts are thoroughly studied. The lessons learned are reported. The paper concentrates on the non - structural methods for flood risk management, uses space technology in identifying the flood damage potential, and discusses the means and modalities for risk management, prepar edness and warning systems. Attempts to find ways and means for mitigation measures pointed ou