Monitoring land-use and land-cover changes due to extensive urbanization in the Odaw River Basin of Accra, Ghana, 1991-2030

Excessive urban growth has led to degradation in ecosystems in most underdeveloped countries. Using Landsat data and combination of unsupervised and supervised classification methods, extent and trends of variations in the urban environment of Odaw River Basin (ORB) in Accra from 1991 to 2016 were assessed. Evaluation of land-use and land-cover (LULC) assessment of revealed that the ORB has been subjected to four diverse rates of land degradation during the periods of 1991, 2002, 2011, and 2016. This is as a result of upsurge in settlement of about 238.20%. The Markov chain and cellular automation integrated model simulated the 2016 LULC patterns successfully due to the results of the comparison with the classified 2016 LULC. The expected LULC patterns for 2030 revealed that land degradation will be substantial in the northern, western, and the eastern portions of ORB where open forest, bare land, and closed forest are, respectively, transformed to settlement. These outcomes will provide a reference base for further research on hydrological response to the changing land use and land cover while helping the environmentalist fight against flooding in the study area.