Abstract:
Landuse activities have both direct and indirect impacts on the quality of water resources, be it surface water or groundwater sources. In addition, once polluted groundwater bodies may not recover from that pollution. The unsaturated soil zone overlying groundwater sources is known to act as a natural protective cover to groundwater bodies, but in volcanic basaltic medium, most of the time, the depth of unsaturated zone is either very small or almost inexistent. In addition, presence of fractures, lava tunnels, and caverns, render groundwater bodies very vulnerable to pollution. Thus groundwater resources in volcanic media cannot rely on the protection cover of their unsaturated zone. In Mauritius, all the aquifers of the island are volcanic in nature and are characterised by high permeability, and are hence quite vulnerable to landuse activities. The present study investigates the impact of landuse activities on groundwater quality in volcanic basins, and the applicability of the water quality indexing technique as a reliable groundwater quality indicator in such type of geological environment. An integral part of any water quality monitoring program is the reporting of results to people who are not conversant with the technical aspects of data collection, analysis and interpretation. This poses a particular problem in the case of water quality monitoring because of the complexity associated with analysing a large number of measured variables. Water quality indexing method is a simpler and concise way of reporting such information.
