Spatiotemporal changes in snow cover and their relationship with drought events in the Lake Urmia basin

Using a MODIS daily snow-cover product, MOD10A1F, the spatiotemporal pattern of the snow cover area (SCA) in the Lake Urmia Basin and its relationship with drought was analysed from October 2000 to September 2020. There was high inter-annual variability in the SCA, and the annual trends for the SCA and snow line elevation were non-significant. Moreover, no significant trend was detected for snow depletion curve indices. The role of evaporation and evaporative demand of the atmosphere in reducing the SCA is more significant than the role of precipitation in increasing the SCA. The remarkable result was the high correlation of the SCA with the Standardized Evapotranspiration Deficit Index (SEDI), which shows the ability of the SEDI to represent the simultaneous effect of evaporation and evaporative demand of the atmosphere in controlling the SCA and reveals the importance of this index in monitoring and forecasting snow cover.