Assessing Land-Use/Land-Cover Changes and Spatio-Temporal Expansion Process of Assela Town, Arsi Zone, Ethiopia

Urbanization has a pivotal role for land-use and land-cover changes and ecological degradation in return with some socio-economic benefits. Hence, it is very important to have frequent urban information to secure urban land use sustainability so as to minimize its impacts on urban ecology. This study was aimed at to map and quantify Land-use/Land-cover change and spatio-temporal expansion process of Assela Town between 1985 and 2013. Integrated Remote Sensing (RS) and Geographical Information System (GIS) techniques were applied. The Land-use/Land-cover and urban expansion dynamics of the town was the result of remotely sensed multi-temporal satellite imageries interpretation traced back to 1985, 1993, 2001 and 2013 respectively. Land-use/Land-cover area changes detection and conversion to urban landscape comparison between each study period was computed. The supervised image classification method with maximum likelihood probability algorithm has been employed for the land -cover classification in ERDAS IMAGINE 10 software. Finally, urban (Built-up) area expansion of the town over1985-2013 was analyzed using map overlay techniques with consecutive population growth. The results of the study reveals that urbanization of the town between 1985 and 2013 is expanded by 995.31 ha (291.64 %) from 341.28 ha to 1336.59 respectively, while farmland, plantation and bare land was increased by 502.65ha (43.67 %), 118.17ha (33.49 %), 69.57ha (32.58 %) respectively. Land-use/Land-cover change detection of the study periods also indicates that the area of shrub, grazing land and water have been decreased 1537.56 ha (87.62 %), 148.14 ha (22.63 %), 0.45 ha (8.19 %) in the study period lasted between 1985- 2013 respectively.