Developing GIS based Coastal Water Quality Index for Rameswaram Island, India positioned in Gulf of Mannar Marine Biosphere Reserve

Abstract

This paper employs widely used Water Quality Index (WQI), which synthesizes biological and physiochemical parameters into one single number that can be straightforwardly understood by decision makers and public. Rameswaram Island is one of the highly populated Islands of India, embraces with density of economically/ecologically important species and is most significantly located between Palk Bay and Gulf of Mannar. Water quality data obtained from 25 sampling sites around Rameshwaram Island between April 2011 and March 2012. The key parameters included for development of Water Quality Index were pH, temperature, turbidity, suspended solids, dissolved oxygen and biochemical oxygen demand using multiplicative water quality index. WQI lies in the “Good” category for all the seasons except summer, which falls under “Moderate”. Station 5B shows “Moderate” WQI in all the seasons because of the pilgrimage and tourism activities as well as the settlement at Rameswaram discharging municipal sewage. The use of the indices on a continuous basis provides long-term data which is helpful for decision making and management.