Mapping of land-use/land-cover changes and its dynamics in Awash River Basin using remote sensing and GIS

Abstract

Understanding the dynamics of land-use and land-cover change at a basin scale, including its driving causes, is vital for the development and planning of appropriate environmental management policies and strategies. The aim of this research was to analyse and understand the long-term dynamics of land-use/land-cover changes and population growth in the Awash River Basin (ARB) using remote sensing and Geographic Information System (GIS). Landsat images for 1988, 2002, and 2018 were processed, classified and analysed. The accuracy assessment showed that the classification was relatively acceptable and effective in detecting the long-term land-use changes in ARB. Cropland increased by 12% between 1988 and 2002, and by 2018 it had increased by 15%. Similarly, the built-up area expanded by 52 km2 (184%) between 1988 and 2002, and by 2018 it had reached 225%. The analysis showed that the cropland and built-up area expanded at the expense of forest and shrubland, with shrubland and forest reducing by 4% and 25% respectively over the 30 year study period. Higher levels of deforestation, combined with population growth, urbanization and cropland expansion, have impacted on the available water resources and runoff in the area. The findings from this study can help in the design of sustainable environmental management strategies and practices to ensure the sustainability of the ecosystem and natural resources. The results can also be used to address food security issues in the ARB since we see an increasing trend in population growth with a commensurate decrease in agricultural land, thereby increasing food security concerns.