Extraction of Bolshaya Saryoba Lake Features Using Sentinel – 2A Imagery

Abstract

Satellite remote sensing has been widely used over the last 10 years for lake monitoring. Researchers have proposed a range of surface water extraction techniques, among which index-based methods are common due to their simplicity and cost-effectiveness. In this study, the following water indices were employed namely, normalized difference vegetation index (NDVI), Normalized difference moisture index (NDMI), Modified Normalized Difference Water Index (MNDWI), and their changes using Sentinel – 2 A images. The values of the NDVI and NDMI indices were determined, allowing us to evaluate and conduct a time analysis of the state of the territory adjacent to the lake and the objects located on it (species composition, closeness, vegetation condition, heterogeneity of the degree of moisture of vegetation and soils, exposure of slopes and surface angles, soil colour under sparse vegetation, etc.). Moreover, ISODATA unsupervised classification algorithm was applied to create the lake surface mask. As a result, drastic changes in the lake in terms of size were identified.