Multi-scale rasterization of contracted land vector data based on grid purity index

摘要

The project of registration and certification for rural contracted land in China has collected high precision geospatial vector data which was produced by surveying and mapping technology. However, the application of this data has been limited due to information security and intellectual property protection. An effective approach for decreasing spatial precision and promoting data sharing & application is rasterization of vector data which would be much easier for overlay analysis with other grids such as remote sensing data. In this study we start with calculation of contracted land area in each grid which is used for multi-scale rasterization of vector data based on grid purity index. Then the grid data are verified by error analysis of area and standard deviation ellipse model. Finally we have compared the spatial patterns of rural contracted land in multi-scale girds. The result show that there are minor variations in contracted land area and spatial patterns before and after the rasterization of vector data. The spatial patterns of contracted land expressed by grid purity index are much more accurate and detailed than binary results.