TEMPORAL VARIABILITY OF TEMPERATURE AND SNOWMELT IN ZOMIN DISTRICT WITH NDSI-BASED ANALYSIS (2020–2024)

This study analyzes springtime cryospheric dynamics in the Zomin District for 2020–2024 by integrating reanalysis and multispectral satellite observations within Google Earth Engine (GEE). Daily ERA5-Land aggregates were used to derive 2 m air temperature (°C) and snow/ice melt for March–June each year, generating day-of-year, year-segmented time series. Landsat 8 (Collection 2, TOA) imagery was processed to compute the Normalized Difference Snow Index (NDSI) using green and SWIR bands (B3, B6); mean seasonal NDSI maps and interannual NDSI time series were produced over the region of interest. Results highlight clear seasonal signals and topographically-driven spatial heterogeneity; differences in temperature and modeled melt correspond to interannual changes in mean NDSI and indicate varying contributions of sub-basins to potential runoff. The workflow demonstrates a reproducible approach for monitoring seasonal cryosphere indicators and assessing hydrological implications for local water resources and hazard preparedness.