Estimation of ungauged Hwanggang dam inflow using Sentinel-2 optical satellite imagery

The Hwanggang Dam in North Korea is located upstream of the Imjin River which is a shared river on the border. It is known to have a reservoir capacity of 350 million cubic meters, which is about 1.5 times larger than Paldang Dam in South Korea, and releases a discharge largely for generating hydroelectric power and partly for transferring to the Yesung River basin. Due to the special national security issues in the region, data sharing between the south and north Koreas is not made, and flood damage risk due to heavy storm and unauthorized discharge is remained in the south Korean-side downstream region. However, It is still difficult to forecast the flood because the operating information of the Hwanggang Dam is not shared. In this study, a dam inflow and reservoir water level change modeling system was constructed using lumped hydrological model and reservoir operation algorithm based on AutoROM. Dam inflow was verified indirectly using remotely sensed water level derived by Sentinel-2 optical satellite and 10m high-resolution terrain map. Coefficient of determination (R2) derived as 0.76 for water level changing from Jan. 2017 to Aug. 2020.