Assessment of the ecological status of lake Boyuk Ala Gol based on geographic information systems (Case study of Kalbajar District)

High-mountain lakes play a crucial role in mitigating climate impacts, regulating water flow, recharging groundwater, and ensuring ecological stability. Mapping their extent and monitoring changes is essential to prevent the loss of these ecosystems. However, research on monitoring high-mountain lakes is limited globally, and the subject has not received sufficient attention. This study utilized Geographic Information Systems (GIS) and remote sensing techniques to analyze changes in the surface area of ​​Boyuk Alagol between 1990 and 2023. The research employed the Shuttle Radar Topography Mission (SRTM) digital elevation model to generate slope and Topographic Wetness Index (TWI) maps, while Landsat 4-5 TM and Landsat 8 satellite imagery were used to calculate the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI), as well as to perform supervised classification for various years. Over the past thirty-three years, the lake lost 2.45% of its total surface area, corresponding to an annual reduction of 3.1 km². Research shows that GIS and remote sensing methods are effective for determining the boundaries, mapping, and assessing the dynamics of lakes and wetlands.