Monitoring of Fragile Ecosystems with Spectral Indices Using Sentinel-2A MSI Data in Shahdagh National Park

Abstract

Studying ecosystems using remote sensing technologies is very relevant since it checks the accuracy of the results of modern research. This study aims to monitor environmental changes in ecosystems of the Shahdagh National Park and its surrounding areas in Azerbaijan using Sentinel 2A MSI data. The study aimed to examine and monitor changes in vegetation, water resources, and drought conditions of the study area in recent years. For analyzing and observing these ecosystems Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), and Normalized Difference Drought Index (NDDI) were calculated using multi-band methods. Obtained indices were compared and changes were investigated analyzing satellite-derived methods. For proper monitoring and assessment of relevant ecosystems, there had been determined 3,825 fishnet points for the study area. This made it possible to compare and coordinate the results of the indices more accurately. After linking fishnet points to raster indices, classification had been made for measuring ecosystems indicators. Vegetation assessments revealed a partial expansion of sparse vegetation or bare rocks, river valleys, as well as nival, subnival, and partial subalpine meadows from 15.1% to 18.1%. Another growth indicator is a significant increase of dense forest ecosystems from 2.3% to 9.2%. According to the results decreases are observed in sparse forests, arable lands, pastures, and shrubs, which are more sensitive to anthropogenic factors. Monitoring of the indices shows that low-humidity areas increase as droughts intensify, especially in plain areas. Finally, the study revealed that the introduction of a specially protected regime within the national park makes ecosystems more sustainable.