Studies On Distributed Land Surface Hydrological Model

Although most GCMs include land surface hydrological processes, the land surface parameterization in GCMs are still simpler than the common used hydrological model. To improve the land surface hydrological processes modeling in GCMs, proper hydrological model should be selected. The GCMs' modeling precision will be improved while the runoff calculation be replaced by hydrological model's.Since Xin'Anjiang model has a lot of advantages to be used in the study of gridded-distributed hydrologicl model, it is used in the runoff modeling in wet area in this study. So far, there is no mature hydrological model can be used in arid area. Shan Bei model was put forward by Dr Zhao Renjun for many years. It can be properly used in arid area but it has no more development recent years just because of the strict request for the data. In this study, the Shanbei model's infiltration excess runoff calculation method is investigated to Xin'Anjiang model, which makes the model includes infiltration excess runoff and saturation excess runoff calculation.Firstly, on the basis of raster DEM data , digital basin is established in the Shui Yangjiang basin in An Hui province. The Xin'anjiang Model is applied to discharge modeling. The modeling results shows the runoff of this basin can be modeled well and the hour-model behaves better than day-model.Secondly, to improve the evapotranspiration calculation of Xin'anjiang Model, the aerodynamics resistance is used to replace the former K coefficient method. The result shows that the model improved performs better than the former model in evapotranspiration and runoff modeling.At last, by adding the infiltration excess runoff calculation of Shan Bei model to Xin'anjiang Model, this model is used in HEIFE experiment area. The result shows that this model can be used in arid area and does well in runoff modeling. By analyzing the rainfall-soil moisture plots and rainfall-runoff plots, we may draw the conclusion that the design of this model is reasonable.The Rivertools is also used in this study to generate the river network of a given basin, which can be used to calculate the river length and drainage area etc.