1. Overview of data Based on the Google earth image data in 2012, the land use types of wetland parks were vectorized by visual interpretation method, which provided the data basis for wetland ecosystem service assessment. 2. Data content Land use types include wetland, farmland (corn, vegetables, wheat), water area, forest land, construction land, bare land, etc. Scale: 1: 50,000; Coordinate system: WGS84; Data type: vector polygon; Storage format: Dbf/Shp/Jpeg 3. Space-time range Coverage: Zhangye National Wetland Park; Total area: 46.02 square kilometers.
Taking Landsat series data as the main data source, including KH in 1965 (only including Gurinai and Guaizi Lake), MSS in 1975, TM in 1990, 1995, 2006 and 2010, and ETM in 2000. Before information extraction, remote sensing images are preprocessed by image synthesis, mosaic, fusion, geometric correction and image enhancement. In the process of correction, ETM + image in 2000 is corrected by 1:100000 topographic map and used as reference image. The 4, 3 and 2 band standard pseudocolor synthesis scheme is selected for image synthesis; during correction, 7 × 8 control points are evenly selected on each image, and the average positioning error is less than 1 pixel, that is, the ground distance is less than 30m. In other years, the datum image of 2000 is used as the reference image for image registration, so that the pixels with the same name on different images have the same geographical coordinates. After correction and registration, the whole image maintains the 30 m spatial resolution of TM. Through field correction, the accuracy of qualitative analysis can be ensured to be over 95%.
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LinksNational Tibetan Plateau Data Center
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