Application And Research On Stream Flow Simulation And Soil Moisture Simulation Based On Distributed Hydrologic Models

Distributed hydrological models are useful tools for simulating natural hydrological cycle, accessing the varying of the stream flow and the water storage. Distributed hydrological models can not only accurately simulate the stream flow in real world, but also objectively reflect the influence of the stream flow and the water storage caused by the difference of spatial distribution in climate and land surface factor.This thesis presented an interesting study on the adaptability of distributed hydrological models in two distinct climates. The area controlled by the Madao hydrological station at Baohe River and the area controlled by the Yingluoxia hydrological station at Heihe River, representing two distinct climates regimes respectively, are selected as the target regions. The arid climate takes the predominant in the former target region, while the humid climate takes the predominant in the later. Based on the 90m-resolution grid-based digital elevation model data, the digital drainage networks are generated to simulate the stream flow processes and the soil moisture by three hydrological models, including Xinanjiang Model, TOPMODEL and Improved TOPMODEL.In Yingluoxia catchment, the years from 1990 to 1993 are selected as the calibration period and the years from 1994 to 2000 are selected as the verification period for daily stream flow simulation and soil moisture simulation. Contemporarily in Baohe catchment, the years from 1981 to 1983 are selected as the calibration period and the years from 1984 to 1985 are selected as the verification period for daily stream flow simulation and soil moisture simulation. Meanwhile, the results of three hydrological models and two target region are analyzed and compared with each other respectively.Through the above-mentioned studies, primary conclusions can be drawn as follows:First, RS and GIS is the basis of constructing a distributing hydrological model. Second, three hydrological models can be adapted to the medium-sized and large-scaled catchment. Third, in the regards of the results of the stream flow simulation about two target regions, the results indicate that the simulation results about the Baohe catchment are better than those about the Yingluoxia catchment. In other words, all three models used in this thesis perform better at humid areas than in dry areas. Forth, in the regards of the results of simulation about three hydrological models, the results show that all three models used in this thesis are suitable to the target regions in simulation accuracy. Improved TOPMODEL performs best in three hydrological models, Xinanjiang Model performs worse than Improved TOPMODEL, and TOPMODEL performs worst in all three. Fifth, in the regards of the results of the soil moisture simulation about two target regions, the results indicate that, corresponding to the climate situation that Baohe catchment is humid while Yingluoxia catchment is arid, both the average and the Maximum about Baohe catchment are higher than those about the Yingluoxia catchment. Finally, in the regards of the vary of the soil moisture simulation with seasonal alternation, the results indicate that, corresponding to the climate that it is rainy in summer while it is arid in winter, soil moisture simulation results in winters are lower than those in summers.