Impact of mining on land use land cover change and water quality in the Asutifi North District of Ghana, West Africa

Abstract

Surface and groundwater are important resources for human life and health. Land use changes and mining activities, however, have the potential to compromise the safety of these resources. This study aims to investigate the land cover conditions before and during mining activities and assess the impact on forests, surface, and groundwater resources in the Asutifi North District, Ghana. Landsat data of 30 m resolution was used to assess the land cover change from 2000 to 2020. A cross-sectional analysis of data between April to June 2004 to 2019 was used to assess water quality. The overall accuracy of the land cover classification ranged between (91.33–99.41)% and (78.01–85.95)% respectively for ground-truth validation and validation using the MODIS annual 500 m land cover dataset. Forest cover decreased by 11.47% while agriculture doubled from 12.13% to 24.06% between 2000 and 2020. The introduction of mining is responsible for major land cover changes including the conversion of forest to agricultural land through shifting cultivation. For a general assessment of water quality, the percentage of pH, TB, TDS, NH3, Mg and SO4 measurements outside the EPA admissible limits for drinking water is 16.67%, 83.33%, 0.69%, 0%, 10.42%, and 16.67% respectively. Turbidity is the most impacted water quality parameter affected by land cover changes while NH3 is the least impacted parameter. The incidences of water quality outside EPA/WHO limits for drinking water at all monitoring points call for education and collective action to safeguard water sources from further deterioration. It is necessary mining companies adhere to environmental protection guidelines.