Spatial Information Technology-based Check-dam System Planning in the Hongshimao Watershed of the Loess Plateau, China

摘要

China suffers severe environmental and ecosystem degradation, especially intensive wind and water erosion in the Loess Plateau. At present, check-dams which are constructed to trap the upstream eroded soil and reduce water runoff have been demonstrated to be an effective measure for soil and water conservation. Traditional workflow for check-dam system planning, a time consuming and uneconomical way, cannot meet the requirement of supporting scientific and quick check-dam engineering. Therefore, spatial information technologies, including remote sensing (RS), geographic information system (GIS) and 3-dimension visualization(3D), play a key role in supporting check-dam system planning. In the study, the Hongshimao watershed in the loess plateau was selected. A digital terrain map covering the study area, at a scale of 1: 10 000 was collected for generating Digital Elevation Model (DEM). SPOT-5 images in XS and pan modes were orthorectified and fused using PANSHARP method. Based on DEM, hydrological analysis was used to generate thc river network. The fused image was classified to update the land use cover. A 3D visualization system for check-dam system planning(VGE-3DDamPlanning) was developed for scientific and quick check-dam system planning using C + +, OpenGL and FLTK. In the support of soil and hydrology models specifically used in check-dam system planning, a check-dam scheme with different type check-dams in the study area was achieved through VGE-3DDamPlanning. The results of this study show that RS can provide an up-to-date land use information, spatial analysis can extract available thematic information, and VGE-3DDamPlanning can mostly facilitate the process of check-dam system planning. Spatial information technologies have great potential for scientific decision making for soil and water conservation projects.