Development of computer automated decision support system for surface water quality assessment

The Overall Index of Pollution (OIP) is a single number that expresses the overall water quality by integrating measurements of 14 different physicochemical, toxicological, and bacteriological water quality parameters. It provides a simple and concise method for water quality classification as, ‘Excellent’, ‘Acceptable’, ‘Slightly Polluted’, ‘Polluted’, and ‘Heavily Polluted’. OIP values range from 0 to 16. A high OIP value signals poor water quality, while a low value signals good water quality based on the classification scheme developed for India. In this paper, we present a computer-automated, user-friendly, and standalone Surface Water Quality Assessment Tool (SWQAT), which calculates OIP values and displays it on Google map. The software is developed in VB.Net and SQL database. The software application is demonstrated through water quality assessment of two rivers of India, namely Cauvery and Tungabhadra. OIP values are estimated at 10 sampling stations on the river Cauvery and at eight sampling stations on the river Tungabhadra. The Cauvery river OIP scores in the range 0.85–7.91 while for Tungabhadra river, it is in range 2.08 to 8.97. The results are useful to analyze the variations in the water quality of different sites at different times. SWQAT improves understanding of general water quality issues, communicates water quality status, and draws the need for and effectiveness of protection measures.

► Decision support system entitled as ‘SWQAT’ has been developed.
► The software provides surface water quality assessment.
► Fourteen water quality parameters are used for computation of dynamic OIP.
► OIP values and water quality classifications are mapped on Google Earth.