Regional Scale Effect Of The Erosion Terrain Factor

Topographical factors for soil erosion studies are an important factor, terrain factor scale effect has been much research institute confirmed. In this paper, the Loess Plateau typical loess hilly and gully region - HuangPu River in Shaanxi Province for the study area, From the introduction of new data sources and new methods of data scaling approach, Set up multi-resolution of DEM, As a basis for extraction of different resolution DEM of the terrain factor, and with changing in DEM resolution scale effect arising were discussed. The main contents of the study and results are as follows.1. New data scaling method, the experimental data are through the aerial survey method to obtain high-precision discrete elevation data, using data on pumping dilute algorithm to generate the different density of data that is different spacing of the elevation sampling points (equivalent to original measurement data). Through experiments with different densities of the substantial elevation data.2. Set up different resolution DEM, using access to the different density of discrete points for the basic data, information content-based analysis method, points painted "root mean square slope and grid size" of the curves to determine the best data of different densities raster size, that resolution. And through interpolation set up the corresponding resolution DEM, and quality evaluating. Eventually be 2.5m, 5m, 10m resolution DEM.3. Topographic factor analysis of the scale effect, set up at the foundation on DEM extraction, including slope, slope length, profile curvature, contour length / curvature, as well as hydrological and soil erosion model has an important impact on the gully network, saddle points, ridge lines, topographical factors such as river length, and then analyze their changes with the resolution changes. The research findings show: slope and curvature of the resolution dependence of the strongest, with the grid size increases, the average slope become smaller, the minimum slope larger Maximum smaller curvature is the same; slope length dependence on the grid size are different, grid size mainly have an impact on long value; contour length of the grid size and contour spacing are dependent on the relationship there is, the smaller the contour interval on the grid size dependence of the stronger; different sizes of grid size of DEM data gully The major impact of the micro-water rivers are the details of small rivers, on the whole the distribution of valley networks have little effect. From the ridge line and the saddle point of the experimental results, the grid size of its impact smaller, and even higher resolution when the data extraction will produce some "errors."...