Antarctic ice sheet surface elevation data (2003-2009)

The Antarctic ice sheet elevation data were generated from radar altimeter data (Envisat RA-2) and lidar data (ICESat/GLAS). To improve the accuracy of the ICESat/GLAS data, five different quality control indicators were used to process the GLAS data, filtering out 8.36% unqualified data. These five quality control indicators were used to eliminate satellite location error, atmospheric forward scattering, saturation and cloud effects. At the same time, dry and wet tropospheric, correction, solid tide and extreme tide corrections were performed on the Envisat RA-2 data. For the two different elevation data, an elevation relative correction method based on the geometric intersection of Envisat RA-2 and GLAS data spot footprints was proposed, which was used to analyze the point pairs of GLAS footprints and Envisat RA-2 data center points, establish the correlation between the height difference of these intersection points (GLAS-RA-2) and the roughness of the terrain relief, and perform the relative correction of the Envisat RA-2 data to the point pairs with stable correlation. By analyzing the altimetry density in different areas of the Antarctic ice sheet, the final DEM resolution was determined to be 1000 meters. Considering the differences between the Prydz Bay and the inland regions of the Antarctic, the Antarctic ice sheet was divided into 16 sections. The best interpolation model and parameters were determined by semivariogram analysis, and the Antarctic ice sheet elevation data with a resolution of 1000 meters were generated by the Kriging interpolation method. The new Antarctic DEM was verified by two kinds of airborne lidar data and GPS data measured by multiple Antarctic expeditions of China. The results showed that the differences between the new DEM and the measured data ranged from 3.21 to 27.84 meters, and the error distribution was closely related to the slope.

0 2020-08-13

Distribution data of geomorphic surface near Zhengyi gorge in the middle reaches of Heihe River (2012-2013)

From 2012 to 2013, the geomorphic surface near the Zhengyi gorge in the middle reaches of the Heihe River was investigated, mainly including the 4-level river terrace. The data are mainly obtained through field investigation, and analyzed and mapped indoors to obtain the distribution map of geomorphic surface at all levels near the middle reaches of Zhengyi gorge.

0 2020-07-30

Geomorphic surfaces deforming along the Heihe River Basin (2012-2013)

The Trimble 5800 GPS was used to measure the carrier phase of the terrace surface in real time, and the elevation data of the terrace surface was obtained.The deformation characteristics and amplitude of the terrace are analyzed.The data include the deformation of landform near zhengyi gorge in the middle reaches of heihe river and the deformation of landform near yingluo gorge in the upper reaches of heihe river.

0 2020-07-30

Topography of the Heihe River Basin

"Heihe River Basin Ecological hydrological comprehensive atlas" is supported by the key project of Heihe River Basin Ecological hydrological process integration research. It aims at data arrangement and service of Heihe River Basin Ecological hydrological process integration research. The atlas will provide researchers with a comprehensive and detailed background introduction and basic data set of Heihe River Basin. Comprehensive atlas of ecological hydrology of Heihe River Basin: topographic map of Heihe River Basin, scale 1:2500000, positive axis isometric conic projection, standard latitude: 25 47 n. Data source: 1:1 million landform data of Heihe River Basin, river data of Heihe River Basin, residential area data of Heihe River Basin, administrative boundary data of Heihe River Basin. According to the distribution, topography and topography of Heihe River Basin, it can be divided into four areas: high mountain area of Qilian Mountain, plain area of Hexi Corridor, middle mountain area of North Mountain of corridor and Ejina Basin.

0 2020-07-30

Distribution data of geomorphic surface in the upper reaches of Heihe River

The landform near Qilian in the upper reaches of Heihe River includes the first level denudation surface (wide valley surface) and the Ninth level river terrace. The stage surface distribution data is mainly obtained through field investigation. GPS survey is carried out for the distribution range of all levels of geomorphic surface. The field data is analyzed in the room, and then combined with remote sensing image, topographic map, geological map and other data, the distribution map of all levels of geomorphic surface in the upper reaches of Heihe river is drawn. The age of the denudation surface is about 1.4ma, and the formation of Heihe terrace is later than this age, all of which are terraces since late Pleistocene.

0 2020-07-28

1:250000 DEM map of the middle reaches of Heihe River (2005-2007)

DEM (digital elevation model) is the abbreviation of digital elevation model, which is an important original data for watershed terrain and feature recognition. The principle of DEM is to divide the watershed into M rows and N columns of quadrilateral (cell), calculate the average elevation of each quadrilateral, and then store the elevation in a two-dimensional matrix. Because DEM data can reflect the local terrain features of a certain resolution, a large amount of surface morphology information can be extracted by DEM, which includes the slope, slope direction and the relationship between cells of watershed grid unit [7]. At the same time, the surface water flow path, river network and watershed boundary can be determined by certain algorithm. Therefore, to extract basin features from DEM, a good basin structure model is the premise and key of the design algorithm.

0 2020-07-28

Slope and aspect data of 34 key nodes of Pan third pole (2000-2016)

"Digital data including slope and aspect (slope and aspect) data are the basic data of GIS, and can be used as two important indicators to describe the terrain feature information, which can not only indirectly express the relief shape and structure of the terrain, It includes hydrological model, landslide monitoring and analysis, surface material movement, soil erosion, land use planning, etc The basic data of geoscience analysis model. At present, slope and aspect data are generally calculated by certain calculation model on digital elevation model (DEM). This data takes 34 key nodes of Pan third pole as the research area, takes DEM data with resolution of 30 meters as the base, realizes the digital simulation of slope and aspect in terrain data (that is, the digital expression of slope and aspect in terrain surface data), and finally obtains the slope and aspect data of pan third pole key nodes. The data area is 34 key nodes of Pan third pole (Abbas, Astana, Colombo, Gwadar, Mengba, Teheran, Vientiane, etc.).

0 2020-07-21

Basic datasets of the Tibetan highway in Chinese Cryospheric Information System

Chinese Cryospheric Information System is a comprehensive information system for the management and analysis of cryospheric data over China. The establishment of Chinese Cryospheric Information System is to meet the needs of earth system science, and provide parameters and verification data for the development of response and feedback models of permafrost, glacier and snow cover to global changes under GIS framework. On the other hand, the system collates and rescues valuable cryospheric data to provide a scientific, efficient and safe management and analysis tool. Chinese Cryospheric Information System selected three regions with different spatial scales as its main research areas to highlight the research focus. The research area along the Qinghai-Tibet highway is mainly about 700 kilometers long from Xidatan to Naqu, and 20 to 30 kilometers wide on both sides of the highway. The datasets of the Tibetan highway contains the following types of data: 1. Cryosphere data.Including: snow depth distribution. 2. Natural environment and resources.Include: Digital elevation topography (DEM) : elevation elevation, elevation zoning, slope and slope direction; Fundamental geology: Quatgeo 3. Boreholes: drilling data of 200 boreholes along the qinghai-tibet highway. Engineering geological profile (CAD) : lithologic distribution, water content, grain fraction data, etc 4. Model of glacier mass equilibrium distribution along qinghai-tibet highway: prediction of frozen soil grid data. The graphic data along the qinghai-tibet highway includes 13 map scales of 1:250,000.The grid size is 100×100m. For details, please refer to the documents (in Chinese): "Chinese Cryospheric Information System design. Doc", "Chinese Cryospheric Information System data dictionary. Doc", "Database of the Tibetan highway. Doc".

0 2020-06-23

1:150,000 desertification type and land division map of Naiman Banner

This data is digitized from the "Naiman Banner Desertification Types and Land Consolidation Zoning Map" of the drawing. The specific information of this map is as follows: * Editors: Zhu Zhenda and Qiu Xingmin * Editor: Feng Yushun * Re-photography and Mapping: Feng Yushun, Liu Yangxuan, Wen Zi Xiang, Yang Taiyun, Zhao Aifen, Wang Yimou, Li Weimin, Zhao Yanhua, Wang Jianhua * Field trips: Qiu Xingmin and Zhang Jixian * Cartographic unit: compiled by Desert Research Office of Chinese Academy of Sciences * Publishing House: Shanghai China Printing House * Scale: 1: 150000 * Published: May 1984 * Legend: Severe Desertification Land, Intensely Developed Desertification Land, Developing Desertification Land, Potential Desertification Land, Non-desertification Land, Fluctuating Sandy Loess Plain, Forest and Shrub, Saline-alkali Land, Mountain Land, Cultivated Land and Midian Land 2. File Format and Naming Data is stored in ESRI Shapefile format, including the following layers: Naiman banner desertification type map, rivers, roads, reservoirs, railways, zoning 3. Data Attributes Desertification Class Vegetation Background Class Desertified land and cultivated sand dunes under development. Midland in Saline-alkali Land Severely desertified land Reservoir Trees and shrubbery Mountain Strongly developing desertified land Potential desertified land Lakes Non-desertification land Undulating sand-loess plain 2. Projection information: Angular Unit: Degree (0.017453292519943295) Prime Meridian: Greenwich (0.000000000000000000) Datum: D_Beijing_1954 Spheroid: Krasovsky_1940 Semimajor Axis: 6378245.000000000000000000 Semiminor Axis: 6356863.018773047300000000 Inverse Flattening: 298.300000000000010000

0 2020-06-09

Atlas of 1:100,000 deserts in the upper reaches of the Yellow River (2000)

一. An overview This data set is a 1:100,000 distribution map of China's deserts as the data source, and it is tailored according to the river basin boundary. It mainly reflects the geographical distribution, area size, mobility and fixation degree of deserts, sandy land and gobi in the upper reaches of the Yellow River.The information source of this data set is Landsat TM image in 2000. Using remote sensing and geographic information system technology, according to the requirements of 1:100,000 scale thematic mapping, the thematic mapping of China's deserts, sandlands and gobi was carried out. 二. Data processing instructions This data set takes the 1:100,000 distribution map of China's deserts as the data source and is tailored according to the basin boundary.The information source of this data set is Landsat TM image in 2000. Using remote sensing and geographic information system technology, according to the requirements of 1:100,000 scale thematic mapping, the thematic mapping of China's deserts, sandlands and gobi was carried out.According to the system design requirements and related standards, the input data is standardized and uniformly converted into various data input standard formats. 三. data content description This data set is divided into desert and non-desert category, the non-desert code is 999. The desert is divided into three categories, namely desert (land), gobi and saline-alkali land, and the classification code is 23410, 2342000 and 2343000 respectively.Among them, deserts (land) are divided into four categories, namely mobile desert (land), semi-mobile desert (land), semi-fixed desert (land) and fixed desert (land). The classification codes are 2341010, 2341020, 2341030 and 2341040. 四. Data usage instructions It can make the resources, environment and other related workers understand the desert type, area and distribution in the upper reaches of the Yellow River, and make the classification and evaluation of the wind and sand hazards in ningmeng river section.

0 2020-06-08