Hydrological response to meteorological drought in Chirchik river basin of Western Tian-Shan

This study investigated the link between meteorological and hydrological droughts in two rivers with and without glaciers in Сhirchik river basin of Western Tian Shan. Observed monthly hydrometeorological data was used to estimate Standardized Precipitation Indexes (SPI) and Standardized Streamflow Indexes (SSI) to analyze the hydrological response of snow-glacier fed Pskem and snow-rain fed Ugam rivers in the region. The Pearson correlation coefficient has been used to estimate statistical relations between SPI and SSI indices for the selected rivers. The SPI-SSI correlation coefficient has shown a positive trend with an increase in timescales, and it was more evident in indexes between the 6-month to 12-month  timescales in both rivers. The statistical relationships between the meteorological and hydrological drought indexes showed that the SPI-SSI relationship varies with river flow generation and its dynamics, and it was more in the Ugam River than the Pskem River. That indicates snow-dominated Ugam River is more prone to meteorological droughts, whereas the glaciers in the Pskem River basin were buffering hydrological drought and its frequency and severity. Obtained results allow better-informed forecasting of hydrological droughts in the river basin and, consequently, enable efficient water management in agricultural and hydropower sectors.