Evaluation of land use/land cover changes due to gold mining activities from 1987 to 2017 using landsat imagery, East Cameroon

Abstract

Gold mining activities began around 1934 at the artisanal stage and became semi-mechanized around 2004 in eastern Cameroon, with the emergence of exploration and mining companies in the region. This paper aims at monitoring Land Use and Land Cover (LULC) changes between 1987 and 2017 among Betare-Oya, Ngoura and Batouri Districts which are witnessing extensive gold mining activities, assessing the dynamics between LULC types and understanding the anthropogenic impact of gold mining activities during this period. A series of Landsat images acquired in 1987, 2000, and 2016/2017 were used to examine LULC change trajectories at per-pixel scale with the post-classification change detection techniques based on the matrix of changes. A supervised classification by the maximum likelihood algorithm composed of five classes—Bare land, Settlements, Water bodies, Vegetation and Mine activities, was designed for this study, in order to classify Landsat images into thematic maps. This research revealed spatio-temporal change patterns, various composition and rates among the three study areas. Also, it shows the strong appearance and emergence of mining activities between 2000 and 2017 are coupled with increase in settlement surfaces and major changes in environment in the study areas. The LULC change analysis over time for the study areas have provide the current change trends. This study stresses the usefulness of Landsat TM/ETM + and Landsat Data Continuity Mission (LDCM) data and highlights the data processing methods for long-term monitoring of artisanal mining activities impacts on the environment.