Geospatial Assessment of Impacts of Sand Mining Activities in Zanzibar

Abstract

This study assessed the impacts of sand mining activities in Zanzibar by using geospatial technology, focusing on three villages in the North 'B' district of Unguja: Donge-Muwanda, Mchangani, and Misufini. Geospatial technology was employed, utilizing two distinct datasets to analyse the spatial extent of environmental degradation due to sand mining. The first dataset comprised of geographic coordinates of sampled mining sites, acquired through field survey by using the Global Positioning System (GPS). The second dataset involved satellite imagery obtained from the Google Earth application. These datasets were utilized to find the area, volume, and depth of mining sites and create three-dimensional (3D) models for each sand mining site by using ArcMap software and Surfer 19 software. The Google Earth images from 2020, 2021, 2022, and 2023 were utilized to determine changes in vegetation cover before and after the mining activities in the study area. The key finding of the study indicates that there is a high extent of environmental degradation caused by intensive sand mining activities, impacting both the community and environment in surrounding sand mining areas. The study suggests that the results should be used to emphasize the importance of existing policies, guidelines, and laws related to sand mining.