Monitoring Secchi disk transparency of Warasgaon reservoir of Pune by using LISS III sensor

Secchi disk transparency (SDT) is the simplest and the most efficient measure to monitor water quality of the reservoir. The nutrients from the agriculture fields, sewage from human settlements and industries drain into reservoirs and lakes. It contributes to the increasing level of suspended particles, algal growth and coloring of water and reduces transparency of water. These changes can be detectable by remote sensors. In this study LISS III sensor of Resourcesat-2 used to model SDT of Warasgaon reservoir, Pune. The green (r = 0.75), red (r = 0.79) and NIR (r = 0.75) bands of LISS III showed good correlation with observed SDT, while band ratios Red/NIR (r = 0.81) and NIR/SWIR (r = 0.81) showed significant correlations. Several linear and multiple linear regression models developed from the in-situ measurements of SDT and the radiance value of LISS III image. The multiple linear regression model based on green, red, NIR and red/SWIR found to be the best fit (r = 0.88) to the in-situ data. The results showed that the Warasgaon reservoir was oligotrophic in condition during the December 2012.