Use of GIS and geospatial techniques to model spatial variability of geogenic arsenic in groundwater systems of Geita district in the Lake Victoria basin of western Tanzania

Abstract

For the past few decades, sporadic studies in African continent have reported elevated concentrations of arsenic (As) in several sources of drinking water of some countries posing a serious health risk mainly to rural communities. In Tanzania, As concentrations above WHO guideline (10 µg/L) for drinking water have been reported in parts of Lake Victoria basin where special interested has shifted to groundwater as a primary source of drinking water. In this study, GIS and geospatial methods were used to describe the spatial variability of As concentrations in the vicinity of gold mining areas. Around 92% of drinking water sources had As above 10 µg/L and the percentage varied between sources. Similarly, a significant positive global Moran's I indicated clustering of As concentrations in space with highest spatial variability in the rural settings posing a health risk to rural communities in Geita district.