Landuse and Landcover Change Detection between 1985- 2005 in Parts of Highland of Eastern Ethiopia using Remote Sensing and GIS Techniques
要旨An attempt has been taken to access the pattern and driving forces of landuse and landcover changes in the area between Harer and Dire Dawa, Eastern Ethiopia highland. At this end, Landsat satellite images of 1985 and 2003 were used to produce ten classes of land use using Geographical Information System (GIS) with field verification. The unsupervised and supervised classification was done in ERDAS, V.8.6 with accuracy assessment of 88% and landuse maps of the area were prepared in ArcGIS software. The results show many changes among the landuses and landcovers in the year between 1985 and 2003. The highest change is observed in grasslands which is decreased by 42.4% (716.7 ha).The highest rate of changes are seen in temporal cropland which is -393.4 ha in every year and bare land which is 171.6 ha/year. Beside grasslands, shrubs and temporal cropland are also decreased in size by 20.7% and 25.4% respectively in 2003, when compared with 1985. Conversely, perennial cropland, marshy area, residents and wood lands increased by 26.6%, 705.9%, 109.7% and 7.3% respectively, in the last 20 years. These land area / covers increased mainly at the expense of grass lands and shrubs. All the landuse/landcover changes are mainly due to their conversion to agriculture lands. Population growth, topography of the area, unwise use of land and other socio-economic activities are major driving forces for the observed changes. Hence different landuse practices, environmental rehabilitation programs and family planning education are some of the appropriate interventions.