Abstract
In Ethiopia, the population number was increasing continuously with agricultural land expansion for the last five decades. In this regard, it is essential to study the history of land-use/land-cover dynamics to make reliable and adequate information for future planning and management by using advanced technologies.
This study is about the historical change of LULC since 1985 and the identification of potential deforestation risk areas in Ankasha Guwagusa Woreda. Multi-temporal Landsat imageries (1985, 1996, 2006, and 2018) and SRTM Digital Elevation Model (DEM) were used combined with secondary data, Google Earth, and field data for this study. The supervised classification method (Maximum Likelihood Algorithm) was used to produce LULC map. Also, five deforestation factors were selected based on literature and considering infrastructure, topographic, and socio-economic status of the area to identify the current deforestation risk area. These are slope, proximity to the road, population density, proximity to the river, and proximity to town. Analytical Hierarchy Process (AHP) technique was used for weight assessment for each factor. Hence, the result from 1985 to 1996 show cropland, bare-land, and built-up were increasing with 835 ha, 186.54 ha and 112. ha, respectively. In contrast, forests and water body was decreased. In the second period (1996‒2006) forest, cropland, and built-up increased with 1094 ha, 2185.7 ha, and 346.78 ha, respectively. In the final period (2006‒2018,) cropland, bare-land, and water body decreased by 1802.5 ha, 39.44 ha, and 3.25 ha but forest and built-up increased by 772.91 ha and 1072.28 ha, respectively. The results from deforestation risk map show that 154.16 ha, 3064.37 ha, 4308.23 ha, and 79.52 ha area of forest is identified as extreme, high, moderate, and low-risk zone, respectively. Accordingly, the result indicates the study area was under continually spontaneous LULCC for the last thirty-three years. The most interesting result was the dynamics of forest cover that show a significant decrease in the first study period but increases in the second and third periods. However, the natural forest was decreasing continuously. The reason is probably recently appeared plantation forest expansion with two major species Eucalyptus spp. and Acacia decurions or else uprising of the integrated watershed development campaign since 2000. In conclusion, the area was highly influenced by anthropogenic factors such as agricultural land expansion and urbanization. In the future, community-based land-use land-cover planning and sustainable forest management system is recommended to protect, conserve, and rehabilitate the remaining natural environment.
Keywords: Ankasha Guwagusa; Landsat; Land-use change; Modeling deforestation.
