Assessment of hydro-climatological drought conditions for Hong-Thai Binh river watershed in Vietnam using high-resolution model simulation

Understating hydro-climatological conditions in a transboundary is always challenging because of issues in sharing available data among riparian countries. The present study has explored the hydro-climatological drought conditions over Hong-Thai Binh river watershed (H-TBRW) based on the downscaled rainfall and reproduced streamflow by the state-of-the-art coupled regional hydroclimate model. The standardized precipitation index (SPI) and streamflow drought index (SDI) indicators are used to define the climatological and hydrological drought conditions, respectively. Both SPI and SDI are derived from the precipitation and streamflow data reproducibility for the H-TBRW during 1950-2015. The results demonstrate a slight increasing trend in both climatological and hydrological conditions. Over the H-TBRW, results reveal that the Da and Thao rivers strongly expect drought conditions; meanwhile, the remaining rivers are very likely to experience similar drought conditions as in the past.