Climatic model of the river runoff with 1/3 degree resolution is presented in the paper. The model is the linear reservoir model i.e., each cell in the model is the reservoir or the cascade of the reservoirs. The speed of the output from the cell is depended linearly of the input to the cell and the slope of the cell and inversely proportional to distance between the cells. The flow is separated into the surface flow, river runoff, and ground flow, which is determined in accordance with the ground surface model. Siberian region in the model is divided to eight watersheds, which include Ob–Irtysh, Pur, Yenisei, Lena, Anadyr, Indigirka, Kolyma, Amur. Data of the NCEP/NCAR reanalysis was used for the numerical modeling for the Ob–Irtysh watershed in the Western Siberia. The control data about the river discharge was taken from results of measurements on the hydrological station Ob-Salechard.
mathematical modeling, climatic river runoff, Ob river basin