GIS ASSESSMENT FOR GROUNDWATER QUALITY OF DISTRICT MULTAN, PAKISTAN

Groundwater is a major source of freshwater for agricultural and domestic purposes. For conservation of freshwater resources, the identification and management of groundwater quality is essential. Increased exploitation of groundwater and rapid urbanization is causing deterioration of groundwater quality. This study focused on the groundwater quality of District Multan, Pakistan by selecting eighty-three sites and sampling of sixteen groundwater quality parameters including pH, temperature, color, dissolved oxygen (DO), turbidity, electrical conductivity (EC), total dissolved solids (TDS), chlorides, calcium (Ca), magnesium (Mg), total alkalinity (TA), copper (Cu), iron (Fe), nickel (Ni), lead (Pb) and cobalt (Co). Presence levels of all these parameters were incorporated in geographic-information-system (GIS) and their spatial distribution was mapped through interpolations using inverse-distance weighting (IDW) teclmique. The results indicated that DO was <3 mg/L in southwest and southeast of study area. Forty-four locations had high turbidity (5-86.68 NTU). TDS concentrations (>1000 mg/L) was found in northeast and southeast. The EC was high (1500 to 3000 S/cm) in northeast and southeast. The observed level of iron was high (0.3 to 2.63 mg/L) in southeast and north side. Fifty-four locations had higher Pb concentrations (0.01 to 0.268 mg/L) and concentrations of Co (0.1 to 0.19mg/L) in drinking water source. Some of the parameters show very high level at few sampling sites which may not represent the entirely- specified region.