Land use and land cover change and its implications in Kagera river basin, East Africa

摘要

The Kagera basin has experienced major land use/cover changes in tropical forests, woodlands, and savannas due to the incessant conversion of land to agricultural and settlement use. While the land use/cover change has accelerated land degradation, biodiversity loss, and climate change in the region, few studies exist on the drivers and implications of land use/cover dynamics in the basin. The study quantified the historical land use/cover changes beginning from 1984 to 2011 and predicted future changes using multi-level data-sets. We also examined population growth and government policies as they relate to land cover/use change. Data-sets from disparate sources consisting of multi-temporal satellite images, digital elevation model, population, and relevant ancillary data were used in the study. A combination of post-classification change detection method, intensity analysis, and Markov chain models were used to analyze and evaluate historical land use/cover changes and predict future change scenarios. We observed a major expansion of agriculture land at the loss of woodland savanna. Overall, change is more pronounced and fast during the period 1984-1994 and relatively slow during 1994-2011. Category and transition intensities were more pronounced in 1984-1994 than 1994-2011. These changes suggest policy intervention from government and individual response during the period 1994-2011. In addition, the study identified population growth, settlement expansion, and local policies as key drivers of land use/cover change. Future scenarios indicate: (1) increase in agriculture land use, (2) loss in woodland savanna and forest cover, and (3) significant wetland loss to agriculture.