Spatio- temporal assessment of land use and land cover changes due to mining activities in Gatumba Region, Rwanda

Abstract

In mining areas, the surrounding land use/ land cover patterns are rapidly ruined and changed for the profit of minerals extraction. Landscapes are affected while mining industry is developing. Gatumba region renowned for its minerals potential, mining activities are still inadequately developed and the environment suffers from the artisanal and small scale mining practices. Soil erosion, barren waste rock dumps, open adits and polluted rivers provide an image of lack of proper environmental protection measures. This study aims to evaluate the spatial temporal assessment of mining activities on land use/land cover change in Gatumba region, determine driving forces and environmental impacts of mining activities considering its implications in coming days. Landsat images were used to generate required land use/land cover maps during the periods of 1999, 2008 and 2015. Land use/land cover maps were produced using maximum likelihood for pixel-based classification method concerning of grouping pixels with the same spectral signature. The results of field observation and questionnaire survey helped to investigate the important driving forces of mining activities with associated negative environmental impacts. Bare soil coupled with built up, water body, forest and vegetation classes were depicted from land use/land cover patterns but mostly mining areas. Over the period of 16 years, mining areas has increased progressively from 2.85Km2 to 5.55Km2 representing 3.95% of the total land coverage. There were also gains on water body and bare soil & built up by the proportion of 0.63% and 45.43% respectively. In contrast, vegetation and forest realized losses of 2.62% and 47.38% respectively considering the total land coverage. Mining activities are widespread in the central and southern part of Gatumba region. The history of mining, mineral potential contained in a shallow and loose rock “pegmatite” accompanied with quartz veins and the fact of lack other work that pay sufficiently are the main driving forces of mining activities in Gatumba. The use of spades and picks incite soil erosion from the current and abandoned mine sites, river pollution, crops and forest are damaged. In spite of continuing mining activities, local people are aware of degrading environment targeting income from minerals. Practical regulations and policies for the rehabilitation of the damaged environment are not sensitized. Therefore, the enforcement of policies and guidance to rehabilitate the degraded environment should be considered while developing professionalism mining with modern equipment.