Morphological changes in the lower reach of Megech River, Lake Tana Basin, Ethiopia

Abstract

This study examined and identify, map the plan-form changes and to evaluate, investigate and explore the effect and impact or influence of drivers/catchment process induces for the plan-form changes along a 44.43-km stretch of Lower Reach of Megech River, Lake Tana Ethiopia, for the last 30 years by using secondary climate data, catchment characteristics, field observation, key informant interview and Satellite images of the year 1984, 1995, 2000, 2006, 2009 and 2014. For data preparation and analysis, Image analysis software (ERDAS 2014), Arc GIS and Terrain analysis tools were used. Lower reach of Megech River has undergone major plan-form changes for the past 30 years. At a distance about 19.3 km from the Lake, the river abounded the old channel course and shifted from west to east and developed new channel which directly drains to Lake Tana. The sinuosity of Megech River shows an overall increase of 8.2% for the 30-year study period. Generally, the plan form alteration of Megech River at different reach is due to natural and artificial influences. Hence, appropriate river engineering works should be practiced so as to minimize the negative aspects of channel bank retreats.