Research On The Technical Factors Impacting On The Investigation Of Sloping Farmland

The method which Slope land Analysis of Digital Elevation Mode not only more fast and simple than the use of topographic maps and field survey, but also be achieved at interior. It is the best way to investigate slope land. However, such as the different algorithms for deriving slopes, as well as Digital Elevation Mode space data resolution and many other technical issues being in the use of Digital Elevation Mode to investigation sloping farmland, And these technical issues must be affect the results of sloping land survey. Depending on topography selection of a suitable algorithm of slope to build slope calculation model and choose a suitable grid size of Digital Elevation Model to be the first problem to be solved when investigate slope land at a regional.This thesis researches mainly analysis the statistical indicators of different algorithms for deriving slopes on the through Statistical Analysis , To determine the effects of the different algorithms for deriving slopes of a discrepancy between the statistical indicators, To determine an appropriate algorithms for deriving slope by means of sequencing analysis and build of the different topography of the slope algorithm models, In addition analysis with the changes in the size of the Digital Elevation Mode grid resolution the changes of regular pattern and the level of the area of the slope rank, To determine whether the different space data resolution influence mountain areas of sloping land investigate , and then analysis of qualitative and quantitative relationship between the statistical indicators and the resolution of the Digital Elevation Mode and finalization of an appropriate resolution, combined with other technologies of Digital Elevation Mode investigate law to determine the integrity of sloping land workflow.Through a preliminary study, the following understandings have been reached: 1. The impact of slope land survey there are technical factors in the performance of digital elevation model, the resolution of digital elevation models as well as the gradient algorithm.2. The performance of contour lines of the digital elevation model can not be carried out in the computer analysis of the gradient. TIN manifestations of the digital elevation model complex data structures, will reduce the slope of the analysis of computer speed, the impact of slope farmland in the process of investigation. The performance of the rules of the form of grid digital elevation model data structure is simple and can be compressed to use, the survey will not affect the speed of sloping land suitable for sloping land used in the investigation.3. Resolution of five meters between the twenty five meters digital elevation model range will lower the rate of slope land survey, the impact of slope farmland in the process of investigation. one hundred meters and meters digital elevation model range from a flat on the ground of the role of low-level area of the gradient increases, high-level area of the gradient decreased, affecting the outcome of the sloping land to investigate the accuracy of the survey in the mountainous areas of sloping land should be used for the twenty five meter resolution digital elevation model.4. In accordance with the direction of the gradient component calculated X and Y direction of the gradient algorithm for different components, will have five gradient algorithm, the five slope gradient algorithm under the different values, and the formation of sloping land survey results, there are more Large differences in the slope land in the course of the investigation should be based on the different topography of the slope calculation to choose suitable algorithm, to build the calculation model of the gradient.(1)Determine an algorithm for computing slope when investigate the plain areas of sloping land.When use of digital elevation model to investigate the slope land in the plain areas, you can choose one of five algorithms for deriving slopes. Sloping land in the investigation of selection on GIS platform, combined with computer processing of digital elevation model of time and treatment data on the stability, the author proposed to use ArcGIS or SuperMap software.(2)Determine an algorithm for computing slope when investigate the hill areas of sloping land.Recommend the anti-third-order differential power algorithm when investigate slope land in hilly areas,the slope calculation model is the anti-third-order differential power distance. Recommend MapGIS investigate slope land as adopted by the GIS platform.(3)Determine an algorithm for computing slope when investigate the highland areas of sloping land.The highland areas of investigation at the time recommend the use of sloping land away from the square of the right of anti-third-order differential algorithm, Sloping land in the survey should be used ArcGIS.