Method Research Of Spatial Interpolation For The Stratum Attitude Based On GIS

The occurrence of landslides has an intrinsic relationship with slope aspect, attitude of stratum, lithology of stratum. In recent years, GIS technology becomes more and more important in landslide hazard research. For specific Digital Elevation Model (DEM), using certain GIS software module can directly generate slope aspect. But confined by landscape topography, measure instruments and other factors, the fetch of attitude of stratum usually gets limited number of attitude points. By using the interpolation methods in the GIS software directly, it only generate stratigraphic attitude surface with low precision. This paper discusses how to use related function in GIS software to generate stratigraphic attitude surface with high precision, based on limited number of attitude points.This paper first introduces the concept of spatial interpolation, classification, and then compares the advantages and disadvantages of several common interpolation algorithms. With the complex characteristics of the geological phenomena, interpolation can not rely on a fixed, single interpolation. Therefore, doing the spatial interpolation for the stratigraphic attitude should base on using general interpolation methods, improve the related methods according to the principle of geosciences and the constraints, thus propose the best interpolation method.On this basis, this paper describes the stratigraphic attitude spatial interpolation theory in detail:because the unconformity contact, folds, and faults usually changes the attitude of the original stratum, the interpolation should emphasize on taking these constraint factors into account, partition the exist data area, and make the stratum in each partition accord with the whole conformity contact relation. The process of attitude point interpolation includes preprocessing the original data, partition, selecting an interpolation method, implementation and evaluation.Finally this paper takes Xinping county in Yunnan province for an example, due to its complex geological structure and serious. landslide, and then describes how to use the related functions in ArcGIS in detail, to generate stratigraphic attitude surface with high precision. This solution uses multiple methods to increase the number of sampling points, makes the distribution much evener and increases the follow-up interpolation accuracy effectively. To generate the stratigraphic attitude surface, this paper uses Certain Interpolation method, Geostatistical Interpolation method, and triangulated irregular network (TIN model), and then chooses the stratigraphic attitude surface of Tension Splines Interpolation, High Surface Function Interpolation and TIN, to generate angle orientation. Setting the known attitude points file as the standard, this paper evaluates the three methods, and gets the conclusion that the Tension Splines Interpolation is more suitable for the spatial interpolation of the stratum attitude.