Integrating Satellite Data and In-situ Observations for Trophic State Assessment of Renuka Lake, Himachal Pradesh, India
Year: 2024
Type: article
Abstract: The present study focuses on estimating the Trophic State Index (TSI) of Renuka Lake, the smallest Ramsar site in India, utilizing in-situ observed Secchi disk transparency (SDT) and satellite data. Site-specific algorithms were developed by establishing the relationship between the spectral band ratio of Landsat 8 OLI and LISS-III with that of in-situ measured SDT data. Notably, the exponential regression model outperformed other regression models (linear, logarithmic, polynomial, and power), achieving a better model output (R2=0.94). Additionally, water quality parameters, namely pH and dissolved oxygen (DO), were measured using the TROLL 9500 multi-parameter instrument. Various interpolation methods were applied to the in-situ data, with the exponential regression model yielding the most accurate results.This method was subsequently selected to generate two-dimensional water-quality images of Renuka Lake. The combined analysis of in-situ and satellite-derived trophic status indicates the eutrophic to hypereutrophic condition of the lake’s eastern and western parts. Satellite imagery spanning 2010-2019 consistently reveals a eutrophic state in the lake, with fluctuations in intensity over the period. The sustained eutrophic condition is attributed to escalating human-induced activities surrounding the lake, particularly in the western region.
Authors: Sujit Kumar Jally, Rakesh Kumar, Sibabrata Das
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $575
OpenAlex ID: W4404978460