Relationships between reservoir water quality and catchment habitat type

Abstract

Numerous catchment characteristics including topography, geology, soil and vegetation are reported to exert a strong influence on mean surface water properties. The present study employs a geographical information system (GIS) approach to examine, for the first time, the relationship between reservoir water quality [dissolved organic carbon (DOC) concentration, colour, nitrate concentration and pH] and catchment Phase 1 Habitat coverage. Analysis was conducted on two occasions and at two different spatial scales. Numerous statistically significant correlations were identified, suggesting the use of Phase 1 Habitat data could help improve predictive models of surface water quality. The occurrence and strength of correlations varied seasonally in response, we argue, to temporal variations in hydrological regime and anthropogenic activity. The data also suggest that the proximity of habitat types to the reservoir is significant in affecting reservoir water quality. The findings are used to recommend suitable measures for drinking water companies to mitigate against water quality issues.