Assessment of environmental impact of gemstone mining in Ijero-Ekiti, Nigeria

Purpose. To examine the environmental impacts of gemstone mining activities on the people of Ijero-Ekiti, Ekiti State, Nigeria. Methods. Soil and water test were carried out on samples from the mine and its environment. Remote sensing as a tool for environmental assessment was introduced to generate the Normalized Difference Vegetation Index (NDVI) and Land Use Land Cover maps using ArcGIS 10 software. Findings. Water test carried out on stream, well and pond shows that some of the samples are slightly acidic. Total Dissolved Solid and hardness analysis show ranges lower than the acceptable limit given by Nigerian Industrial Standard and the World Health Organization (WHO). Iron concentration was found to be exceptionally higher than the permissible standard given by the WHO rendering the water resources unfit for drinking. Soil test carried out in the area proved that the soil is good for agriculture as it is high in nitrogen and organic matter content. Originality. This assertion can be back up by the results of the NDVI analysis which shows an increase in vegetation index from 0.2190 in the year of 1991 to 0.2435 in the year of 2013. Land use change detection analysis also showed a slight change in land use over the year from 2005 to 2010. This may be attributed to the fact that the gemstone mining is conducted on a small scale. Practical implications. Test results can be used in making recommendations to the community. Farmers cultivating land where samples S1 and S4 were taken need to apply fertilizer to bring up the percentage of organic matter of the soil. Provision of drinkable water sources should be made to the community. Remote sensing as the applied tool has proved its usefulness in environmental degradation assessing. It gives the possibility of generating an environmental database for impact assessment in regional context which can be a difficult task when carried out by the conventional method.