Abstract: Heilongjiang (Amur) River is a boundary river in high latitude cold region with prominent flood control problems, yet few studies have been carried out from the perspective of the river basin. This paper establishes a spatial information database of the Heilongjiang basin and constructs a physically-based distributed hydrological model or GBHM-HLJ model. This model uses a generalized model, featured with an exponential variation in the hydraulic conductivity of frozen soil with temperature, to simulate the influence of soil freezing and thawing cycles on water flow. For model calibration and validation periods, the Nash-Sutcliffe efficiency coefficients of daily discharge at the ten main stations are all greater than 0.73, and the coefficients of determination of monthly discharge all greater than 0.82. The simulated monthly average of snow precipitations over the basin is compared with the FY-3C satellite remote sensing data of 2014-2019, showing a coefficient of determination of 0.83. For the main stream control station Khabarovsk in the period of 1960-1990, this efficiency coefficients of its daily discharge and annual maximum daily discharge simulations are 0.90 and 0.72, respectively. Our model lays a basis for further hydrological study of the basin and its main and tributary streams.

Key words: distributed hydrological model, cold region, flood, soil hydraulic conductivity, Heilongjiang (Amur) River, boundary river