Estimation of Water Spread Area in Selected Tanks of Cuddalore District of Tamil Nadu Using Sentinel-1A SAR Data

The most important aspect of water resource planning and management is mapping and regular monitoring of surface water bodies. Remote sensing has become most widely used method for measuring and monitoring of water body dynamics due its temporal and spatial availability of high-resolution data. A study was conducted to map and estimate the water spread area in the tanks of Kattumannarkoil block of Cuddalore district of Tamil Nadu using Sentinel-1A SAR satellite data. European Space Agency’s Sentinel-1A data provides high quality SAR data which is used widely for monitoring of crop and water resources. The acquisition and preprocessing of satellite data was done using Google Earth Engine. The obtained satellite image from Google Engine was processed using ArcGIS. The water spread area was derived from the processed data using thresholding approach. The back-scattering values generated through pre-processing ranges from -18.00 db to -28.12 db for August 2022 (Pre-rainy season), -15.85 to -26.96 for December 2022 (Post-rainy season) and -15.55 to -24.82 for April 2023(Summer time). The estimated water spread area in selected 12 Tanks were 37.191 ha, 58.34 ha and 59.971 ha on 19th August 2022, 17th December 2022 and 16th April 2023 respectively.