Multivariate Statistical Approach for the Assessment of Salinity in the Periphery of Karachi, Pakistan

To understand the Hydro-Geochemistry of urban and semi urban areas of Karachi, located in an arid region of Pakistan, various physico-chemical parameters were investigated. Only continuously pumped productive deep and shallow wells and tube wells were chosen for the analysis for their best ecological functions including drinking, domestic, industrial and agricultural activities. Multivariate statistical techniques were used to interpret complex data matrices to better understand the water quality and ecological status of the studied system. The study further suggested that the extent of salinity appears to be as function of magnesium salts rather than calcium salt. Over pumping of local groundwater causes land subsidies and gradual salinization by Sea water. The problem of salinization was further multiplied in the study area because if its nearness to the Arabian Sea. Factor loading of total alkalinity and bicarbonates indicates that total alkalinity was mainly due to chloride of sodium. The present study suggested that regular monitoring of ground water is an important step to avoid human health risks and to assess its quality for various ecological purposes. Studies further suggested that, the extent of salinity appears to be as a function of magnesium salts rather them calcium salt.