Surface Water Body Extraction for Landsat-8 (OLI) Imagery Using Water-Indices Methods and SCM Techniques

In the last decades, the most widely used way to identify and analyse the water portion is from satellite images. Many popular algorithms are involved in detecting the change in the water body over a period in the reservoir using Landsat-8 (OLI) satellite images. It is worthwhile to identify the surface water areas and changes in water content of the Nagarjuna Sagar Reservoir (NSR). The spatial and spectral multi-band water indices methods including modified normalised difference water index (MNDWI) and automatic water extraction index (AWEI), as well as classification techniques such as supervised spectral correlation mapper (SCM), were used for evaluating the changes in the surface water portion. The accuracy assessment is carried out using the water indices methods and classification techniques. The results showed that MNDWI achieved an overall accuracy of 96.64%, AWEI of 96.16% and SCM of 97.98%. This showed that the SCM method proved to be superior compared to the MNDWI and the AWEI techniques.