Land Second Survey, Spatial Data Quality Checks And Processing Methods

Data is the blood of GIS. Its quality will have a direct impact on the accuracy and reliability of the Analysis and the decision about Applied Systems based on vector data, and affect the success or failure of database construction and whether data can be effectively applicated. Therefore, how to control the quality of vector data has become one very important issue in today's GIS project.This paper based on participating in the second national land survey, rural part, in Yunnan Province, summed up the spatial data quality problems existed before storage. The quality of line elements is the key of spatial data quality issues. By using the existing data quality control software, and combining the function modules automatically inspection lines having dangles developed in this paper, arcs overlap, intersection, a total of points, having dangles in the problem of topological relations of lines elements were automatically checked and handled,data quality standards are ensured, and the requirements of the database building were met. For the other problems in the work, the paper also designed a automatic inspection function which applied to find the problem of a DLTB which has more than one kinds land groups and the contradiction between drainage and the contour line, and the preservation in the form of wrong record, then the operator could easily modify it according to actual situation. In addition, solutions for some problems in the work were proposed, such as a line having dangles, the contridiction between drainage and the contour line, drainage flow problems, uncertainty on the joinpoints of rural sector.According to the requirements of building database of the second survey data, this paper studied the automatic inspection and automatic processing algorithms of spatial data before storage. Using ArcEngine, take Microsoft's Visual Studio.net2005 as a development platform in order to realize automatically inspection and processing functions for the quality of land survey data. In the design process, it was paid attentioned that the design of inspection and processing functions didn't depend on the data processed, which ensured that the application of development function was not limited to the study of regional and specific data, so it had some versatility. Finally, take the second land survey data of Honghe, Yunnan, for example, and carry out the actual operation to test the correctness of the development function.