Spatial and Temporal Analysis of the Land Use and Land Cover Changes in Gatumba Mining Landscape, Rwanda

Abstract

Mining activities are one of the main driving forces of land use and land cover changes. While opencast mining is continuously carried out, land cover change assessment is of paramount importance for sustainable land resource management and use as a tool for policymakers to understand the mininginduced changes and their response to water flow, forest, and soil in a mining landscape. In Gatumba Region of the Western part of Rwanda, mining activities are still inadequately undertaken and the surrounding environment is affected by artisanal and small scale mining practices. Soil erosion, barren waste rock dumps, and polluted rivers reflect the lack of implementation of proper environmental protection measures. This study aims to spatially and temporally analyse the land use and cover changes induced by the mining activities in Gatumba mining landscape for optimization of land use planning and management of the mined and restoring the degraded mining landscapes in Rwanda. Landsat images were used to generate the land use/cover maps for the periods of 1999, 2008 and 2015 by using maximum likelihood pixel-based classification method. The comparison of land use/land cover maps during those periods derived from toposheet and multispectral satellite imagery interpretation indicates that there is a significant increase in bare soil, built-up areas at the rate of 0.63% and 45.43% respectively. Over a period of 16 years, mining areas has increased progressively from 2.85 Km² to 5.55 Km²representing 3.95% of the total land coverage. The expansion has taken place especially in central and southern part of Gatumba. It is also noted that substantial amount of the agriculture land and forest area vanished during the period of study which may be due to rapid population growth and the development of rural centers. The information obtained from change detection of land use/land cover helps in providing optimal solutions for land management, planning for the mining sites, monitoring of the related environmental effects and restoration of the degraded mining landscapes in Rwanda.