2009 Volume 22 Issue 3 Pages 177-187
The objective of this study is to develop a hydrological model that can estimate daily discharge over a long period of the Lena River basin.
The hydrological model developed by this study is composed of a land surface model that can take the heat/water exchange of the vegetation, snow and soil into consideration and an runoff model based on the flood routing in the river channel network, with the outflow water from the soil calculated by the land surface model to be the input value to the runoff model.
In the Lena River basin, the slow components of stream flow and the river ice during winter season have large effects to the hydrograph. Taking their effects into consideration, the following 2 processes were added to the runoff model; 1) 30 % of the outflow from the soil calculated by the land surface model regarded as the slow outflow component was given as the input to the outflow model through the storage function model and 2) The river ice thickness was calculated, letting the unfrozen portion flow down.
The stream discharge was calculated for the period from 1987 to 2003 using the above hydrological model, and as a result, it was possible to exactly reproduce the actual measured hydrograph throughout the entire period. The results show that the hydrological model developed in this study is effective for simulation of the water cycle in the Northern Regions.
