A spatial assessment of environmental vulnerability in the Akhangaran river basin, Uzbekistan

Abstract

In the context of increasing anthropogenic pressure and the need for objective environmental monitoring, spatial assessment of ecological vulnerability that takes into account natural and technogenic factors has become an important scientific task. The aim of this study was to assess the ecological vulnerability of the Akhangaran River Basin (Uzbekistan) using a comprehensive geographic information system approach. The materials used included multitemporal Landsat 8 and Landsat 9 satellite imagery from 2022 to 2025, cadastral land-use data, the Copernicus GLO-30 Digital Elevation Model, and OpenLandMap soil bulk density data. Data processing was carried out in Google Earth Engine, including the derivation of spectral indices such as the Normalised Difference Vegetation Index, Normalised Difference Drought Index, Normalised Difference Built-up Index, Bare Soil Index, Land Surface Temperature, and Clay Mineral Ratio. Based on the normalised parameters, an integrated Ecological Vulnerability Index was developed using a correlation-weighted scheme that accounts for indicator multicollinearity. Results showed that 59.6% of the basin area falls within zones of high vulnerability. A clear spatial differentiation was identified: while mountainous forest areas retain relative ecological resilience, agricultural, industrial, and residential zones are characterised by elevated environmental stress, soil compaction, and pronounced thermal anomalies. The practical significance of this research lies in the potential application of its findings to state environmental and land monitoring, as well as in the identification of priority areas for environmental management. Future research may focus on  improving the indicator set and adapting the proposed methodology to other river basins and natural-technogenic geosystems in Uzbekistan.