Research On Runoff And Sediment Of Small Basin In Loess Area Based On DEM

Distributed hydrological model has been widely applied in the hydrologic field such as scale problem, eco-hydrological process, human activity and climate changes since it reflects the spatial distribution characteristics of landform, soil, vegetation, land use, and rainfall within the watershed. The development of computer technology, remote sensing and other interdisciplinary fields has proved to be a significant technology support for data collecting and solving arithmetic problems in this field. In short, distributed hydrological model has a promising future in the hydrological modeling development. According to the current study status and needs, the content of this thesis is following variety of aspects. Firstly, the methods to extract basin information are summarized, studied and formulated, including the pre-process of DEM, the determination of flow direction, the creation of drainage networks, the extract of river system, the division of sub basin. Secondly, the distributed hydrological model for the arid region is established which is considering the conservancy engineering, integrating the traditional hydrological model for arid region, lag-and-route method and Muskingum method. Based on the distributed hydrological model for the arid region, the distributed silty model for the arid region is established. Finally, considering the temporal and spatial variable characteristics of the climate, vegetation and underlying condition these two models are applied on the basis of 1:40000 DEM for flood and silt simulation to 11 floods from 1970 to 1989 of the Chabagou basin which is on the Wuding River, one tributary of the Yellow River. The results show that the calculation results are almost identical to the observed data, prove the rationality and reliability of these two models and indicate the practicability and popularization of these two models.