Spatiotemporal Landuse Land Cover Changes in Walmara District, Central Oromia, Ethiopia

摘要

The rapidly changing landuse/landcover at various scales mainly during the past recent decades have caused the degradation of biodiversity and this in turn has affected the human wellbeing in Ethiopia. However, adequate study is lacking particularly in Walmara district where intensive cereal based faming system is exerted by the rapidly increasing rural population growth. Hence, the aim of this study was to examine the spatiotemoral pattern of the landuse/landcover change that has taken place in 1985 and in 2017. For this, two Landsat images (30×30m resolution) were used to analyze temporal landuse/landcover changes with the application of Geographic information system (GIS) techniques and remote sensing (RS) using Quantum GIS (version: 2.18). Here, a supervised image classification technique was applied with Maximum likelihood classification algorism. With this analysis six main landuse/land cover types namely, cropland, grassland, forest land, settlement, wetland and water body were identified. In 1985 the areas of cropland (52816ha), grass land (16755ha), forest land (4633ha), wetland (1665ha), settlement (1124ha) and waterbody (125ha), while in 2017, the areas of cropland (64984ha), grass land (2442), forest land (4329ha), wetland (1404ha), settlement (3790ha) and waterbody (170ha). These results show that over the last thirty years, in the study district, the area covered by crops has increased by 15.8%, settlement area by 3.5% while, in contrast, the areas covered by grassland has shrunk by 18.6%, forest area by 0.4% in 2017. The major reasons for such rapid changes in landuse/landcover in the study are land exploration for agricultural purpose and built ups for settlement and small scale factories. Overall, the present finding suggest the essence of devising integrated landuse policy and plan to sustainably utilize the limited land and land resources and to reduce the impact of climate change that is occurring mainly due to the unwise use of these resources.