The data set of forest and grass vegetation coverage map in the upper reaches of Luohe River in Jingbei province includes Wuqi County of Shaanxi Province, Zhidan County of Shaanxi Province, Pengyang County of Ningxia Hui Autonomous Region and Yuanzhou District of Ningxia Hui Autonomous Region in 2013, 2014, 2015, 2016 and 2017 The formula is TIF, and the data is named in the form of "key management area + administrative region + year + forest and grass vegetation coverage map", such as "forest and grass vegetation coverage map of ×× key management area ×× County ×× year". The vegetation coverage is divided into six grades: high coverage, medium and high coverage, medium and low coverage, low coverage and bare land. Gauss Kruger is used for projection of all thematic maps, and CGCS2000 is used as coordinate system.
The data sources are ZY-3 and GF-1 satellite images, which are mainly obtained from the information center of the Ministry of water resources.
Based on the method of remote sensing estimation, the normalized vegetation index (NDVI) was used to estimate the vegetation coverage using the pixel bisection model method. Firstly, the NDVI of each pixel is calculated by using the near-infrared band and red band data of multispectral images, and then the vegetation coverage of the whole region is calculated by using the model, and the vegetation coverage is classified according to the classification rules. Finally, the land use type data obtained from remote sensing interpretation and the vegetation coverage data estimated based on remote sensing are used for superposition operation to obtain each pixel Vegetation coverage information of each pixel.
1. The remote sensing images are preprocessed by radiation correction, orthorectification, fusion and mosaic. 2. The actual surface area corresponding to the minimum patch area is not less than 0.1 Hm2, the polygon has no overlap, no gap, and the patch attribute has no vacancy or redundancy. 3. Before remote sensing image interpretation, remote sensing image, typical survey and field comparison were used to establish the remote sensing interpretation marks of forest and grass plot. 4. Based on the remote sensing image, combined with the interpretation signs, extract the land use types. 5. Review of interpretation results: extract no less than 5% of the total map spots for verification. 6. The number of field verification samples and results meet the requirements of technical specification for remote sensing monitoring of soil and water conservation (sl592-2012). For the verification map spots, 10% of the verification samples are selected for field verification.
This work is licensed under
CC BY 4.0 (Creative Commons Attribution 4.0 International License).
CSTR:11738.11.ncdc.HHSTBC.2020.164
10.12072/ncdc.HHSTBC.db0006.2021
