Remote Sensing and GIS Based Potential Landslide Hazard Zonation in Ambo Woreda: Central Ethiopia

Abstract

Landslide hazard is becoming a serious problem in many parts of the world because of its frequent occurrence and related effects it is causing to human and properties. Areas of high altitude and steep slopes were susceptible to landslide hazards depending on their soil type, geology, land use/ land cover, proximity to road and streams, aspects, seismic level and ground water level variation. Even though there are problems related to landslide hazards in the region where Ambo woreda is located, there was significant landslide related scientific studies conducted in the area. The current study was aimed to prepare landslide hazard zonation map for Ambo Woreda based on landslide hazard causal factors including spatial rainfall distribution, local geology, slope, elevation, aspect, soil type, LULC, distance from stream and land slide inventory data based on Geographical Information System and remote sensing techniques. As a result 921 polygons covered an area of 32.9km 2 (3.43%) of the total study area was found with past landslide hazards. Past landslide hazard areas were studied to investigate the contribution of each landslide causing factors and to map the potential landslide hazard zones of Ambo woreda. Consequently the study area was categorized in to four levels of Potential Landslide Hazard Zones termed as very high, high, moderate, low and very low. The total area of about 959.7km 2 , was classified as 14.7%, 53.28%, 23.43%, 4.99% and 3.6% among the very high, high, moderate, low and very low potential landslide hazard zones respectively. The presence of very high and high potential landslide hazard levels in wider area of Ambo woreda can be used as a warning message for local planners and the community to urgently plan for the reduction of potential landslide disaster risk reduction using various practices such as intensive soil and water conservation works and enhancing landslide disaster preparedness activities.