Digital elevation model of SRTM in the Yellow river upstream (2000)

Ⅰ. Overview The SRTM (Space Shuttle Radar Topographic Mapping Mission) was performed by NASA, the Geospatial Intelligence Agency, and German and Italian space agencies in February 2002. A total of 222 hours and 23 minutes of data collection was performed by the US space shuttle Endeavour onboard the SRTM system, and 9.8 trillion bytes of radar images were collected between 60 degrees in North America and 56 degrees in south latitude with an area of ​​more than 119 million km2 Data, Fei changed more than 80% of the earth's surface, this data set covers the entire territory of China. It took two years to process, and finally obtained a global digital elevation model (DEM) with a plane longitude of ± 20m and an elevation longitude of ± 16m. Ⅱ. Data processing description The processing of SRTM data is done by the Ground Data Processing System (GDPS). The GDPS consists of three parts: (1) an interferometric processor, which uses the interferometric processor to convert the data into elevation maps and radar image bands; (2) a mosaic processor, which is used to compile collected global airborne data Draw a mosaic map of continental elevation data and images; (3) Verification system is responsible for checking the quality of the mosaic map and providing accuracy maps. These processors are currently installed on JPL workstations, and the next step is to install them on a set of supercomputers for the systematic processing of real SRTM data. As this work progresses, JPL will release auxiliary data to the work. Ⅲ. Data content description SRTM data provides a file for each latitude and longitude grid. There are two types of longitude: 1 arc-second and 3 arc-second. Called SRTM1 and SRTM3, or 30m and 90m data. This dataset uses SRTM3 data with 90m resolution. Each file contains elevation data of 1201 × 1201 sampling points. The data format is DEM format. The spatial position of each picture frame is shown in the attached picture (1-25 thousand pictures in the country). Ⅳ. Data usage description SRTM data has computable and visual functions, and has broad application prospects in various fields, especially in the fields of surveying and mapping, surface deformation, and military. Specifically, it mainly includes the following aspects: In scientific research, SRTM data plays a very important role in geology, geophysics, seismic research, level modeling, volcano monitoring, and registration of remote sensing images. Using high-precision digital terrain elevation data to build a three-dimensional three-dimensional model of the ground, which is superimposed on the ground image, can observe slight changes in the earth's surface. In civil and industrial applications, SRTM data can be used for civil engineering calculations, reservoir dam site selection, land use planning, etc. In terms of communications, digital terrain data can help businesses build better broadcast towers and determine the best In terms of aviation safety, the use of SRTM digital elevation data can establish an enhanced aircraft landing alarm system, which greatly improves the aircraft landing safety factor. In the military, SRTM data is the basic information platform of C4ISR (Army Automatic Command System). It is necessary to study the structure of the battlefield, the direction of the battlefield, the presetting of the battlefield, the deployment of operations, the concentration of forces in the delivery, the protection conditions, and logistics support Essential.

1:1 million soil types map of the Yellow River Upstream (2009)

Ⅰ. Overview FAO (Food and Agriculture Organization of the United Nations) and IIASA (International Institute for Applied Systems Analysis) combined the soil information of all regions and countries in the world with the world soil map of FAO-UNESCO, formed a new soil database - Harmonized World Soil Database (HWSD). The data source in China is 1:1 million soil data provided by Nanjing Soil Research Institute of the second national land survey. The database will be of great significance to improve people's understanding of current and future soil productivity, soil carbon storage, land resources, water resources and soil degradation. Ⅱ. Data processing description The data comes from the Harmonized World Soil Database (HWSD) constructed by FAO and IIASA. The data in China comes from the 1:1 million soil data provided by Nanjing Soil Research Institute of the second national land survey. The main soil classification system is FAO-90. Ⅲ. Data content description The main fields of soil attribute table include: SU_SYM90 (soil name in FAO90 soil classification system): SU_SYM85 (FAO85 classification); T_TEXTURE (top soil texture); DRAINAGE (19.5); ROOTS: String (depth classification with obstacles to the bottom of soil); SWR: String (soil water content characteristics); ADD_PROP: Real (agricultural use related in soil unit) Specific soil type); T_GRAVEL: Real (gravel volume percentage); T_SAND: Real (sand content); T_SILT: Real (silt content); T_CLAY: Real (clay content); T_USDA_TEX: Real (USDA soil texture classification); T_REF_BULK: Real (soil bulk weight); T_OC: Real (organic carbon content); T_PH_H2O: Real (PH); T_CEC_CLAY: Real (cation exchange of clayey soil); T_CEC_SOIL: Real (cation exchange capacity of soil); T_BS: Real (basic saturation); T_TEB: Real (exchangeable base); T_CACO3: Real (carbonate or lime content); T_CASO4: Real (sulfate content); T_ESP: Real (exchangeable sodium salt); T_ECE: Real (conductivity). The attribute field beginning with T_ represents the upper soil attribute (0-30cm), and the attribute field beginning with S_ represents the lower soil attribute (30-100cm) (FAO 2009). Ⅳ. Data usage description Through this database, people's understanding of current and future soil productivity, soil carbon storage and global soil carbon storage will be improved. It can help people to understand the limitation of land and water resources, and correctly assess the risk of soil degradation, especially soil loss. Through understanding the physical and chemical properties of soil, it can also help people to obtain the following information, such as the filtering function of soil on waste, the impact on biological growth, etc. The potential of soil production and the response of soil to climate change were correctly judged.

1:100,000 soil database in the upper reaches of the Yellow River (1995)

一.An overview The 1:100,000 soil database in the upper reaches of the Yellow River was tailored from the 1:100,000 soil database in China.The 1:100,000 soil database of China is based on the 1:100,000 soil map of the People's Republic of China compiled and published by the national soil census office in 1995.The database adopts the traditional "soil genetic classification" system, and the basic mapping unit is subcategories, which are divided into 12 classes of soil, 61 classes of soil and 227 classes of soil, covering all kinds of soil and its main attribute data in China. 二. Data processing instructions The 1:1 million soil database of China was established by the soil resources and digital management innovation research team led by shi xuezheng of nanjing soil research institute, Chinese academy of sciences, after four years.The database consists of two parts: soil spatial database and soil attribute database.The establishment of the database was funded by the knowledge innovation program of the Chinese academy of sciences and completed under the leadership of liu jiyuan and zhuang dafang. 三. data content description The soil spatial database, 1:1 million digitized soil maps of the country, is based on the 1:1 million soil maps of the People's Republic of China compiled and published by the national census offices in 1995.The digitized soil map faithfully reflects the appearance of the original soil map and inherited the mapping unit when the original soil map was compiled. Most of the basic mapping units are soil genera, which are divided into 12 classes, 61 classes and 235 subclasses. It is the only and most detailed digitized soil map in China. The soil attribute database, whose attribute data is quoted from the soil species record of China, is divided into six volumes, and nearly 2,540 soil species are collected.Soil property data can be divided into soil physical properties, soil chemical properties and soil nutrients.Soil physical properties soil particle composition and soil texture, soil chemical properties such as PH value, organic matter, soil nutrients include all N, all P, all K and effective P and effective K. 四. Data usage instructions Soil types and soil properties are an important content in the study of physical geography. With the help of 1:100,000 soil database in the upper reaches of the Yellow River, the type, quantity and spatial distribution of soil resources in the upper reaches of the Yellow River as well as the soil environment and characteristics can be understood and analyzed.This data set is of great significance for the early warning of large-scale soil erosion and the prediction of natural disasters in the upper reaches of the Yellow River.