Mapping and Monitoring Inland Water Bodies: a Case Study of Madurai, Tamil Nadu

Inland water bodies (IWBs) such as lakes, tanks, ponds, and wetlands are essential as they provide numerous hydrological and biogeochemical services such as water storage, irrigation, flood protection, and groundwater recharge. Despite having all the benefits, the increase in population and urbanization leads to the deterioration of these IWBs. Therefore, there is a need for mapping and estimating the water volume of IWBs. To address this need, we mapped and estimated the volume of IWBs in the Madurai district of Tamil Nadu, India, using a machine learning and linear regression method. We used 431 Multispectral Sentinel-2 surface reflectance imageries from 2019-2021 (3 years) and mapped IWBs using the Random Forest algorithm. The overall, producer, and user accuracy for the IWBs map were 98%, 96%, and 95%, respectively. We estimated the IWBs volume using a regression model. The overall water volume of IWBs in the Madurai district is ~ 0.024 km
³
. This framework offers a better understanding of the hydrological potential of IWBs for storing water and managing irrigation needs.