The SRTM sensor has two bands, namely C-band and X-band. The SRTM we are using now comes from the C-band. The publicly released SRTM digital elevation products include DEM data at three different resolutions: * SRTM1 covers only the continental United States, with a spatial resolution of 1s; * SRTM3 data covers the world with a spatial resolution of 3s. This is the most widely used dataset. The elevation reference of SRTM3 is the geoid of EGM96 and the horizontal reference is WGS84. The nominal absolute elevation accuracy is ± 16m, and the absolute plane accuracy is ± 20m. * SRTM30 data also covers the world, with a resolution of 30s. There are multiple versions of SRTM data. The early SRTM data was completed by NASA's "JPL" (Jet Propulsion Laboratory) ground data processing system (GDPS). The data is called SRTM3- 1. The National Geospatial Intelligence Agency has further processed the data, and the lack of data has been significantly improved. The data is called SRTM3-2. This dataset is mainly the fourth version of SRTM terrain data obtained by CIAT (International Center for Tropical Agriculture) using a new interpolation algorithm. This method better fills the SRTM 90 data hole. The interpolation algorithm comes from Reuter et al. (2007). The data of SRTM is organized as follows: every 5 latitude and longitude grids is divided into a file, which are divided into 24 rows (-60 to 60 degrees) and 72 columns (-180 to 180 degrees). The file naming rule is srtm_XX_YY.zip, where XX indicates the number of columns (01-72), and YY indicates the number of rows (01-24). The resolution of the data is 90 m. Data use: SRTM data uses a 16-bit value to represent the elevation value (-/ + / 32767 meters), the maximum positive elevation is 9000 meters, and the negative elevation (12,000 meters below sea level). -32767 standard for empty data.
CGIAR-CSI
The ages of glacial traces of the last glacial maximum, Holocene and little ice age in the Westerlies and monsoon areas were determined by Cosmogenic Nuclide (10Be and 26Al) exposure dating method to determine the absolute age sequence of glacial advance and retreat. The distribution of glacial remains is investigated in the field, the location of moraine ridge is determined, and the geomorphic characteristics of moraine ridge are measured. According to the geomorphic location and weathering degree of glacial remains, the relationship between the new and the old is determined, and the moraine ridge of the last glacial maximum is preliminarily determined. The exposed age samples of glacial boulders on each row of moraine ridges were collected from the ridge upstream. This data includes the range of glacier advance and retreat in Karakoram area during climate transition period based on 10Be exposure age method.
SHANG Cheng
This dataset is the Digital Elevation Model （DEM）in the Qilian Mountain， spatial resolution 30m. This dataset is based on the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model （ASTER-GDEM）. The data set has a vertical accuracy of 20 m and a horizontal accuracy of 30 m. Through the data download, preprocessing and splicing, the 30m×30m DEM data of Qilian Mountain is generated. This data set can extract a large amount of surface morphology information, which is an important basic data for terrain analysis and feature recognition in Qilian Mountain. The data will serve the ecological environment monitoring, ecological environmental protection and treatment project implementation, hydrology and water resources analysis and evaluation in Qilian Mountain area.
QI Yuan, ZHANG Jinlong, ZHOU Shengming, WANG Hongwei
The data is the large-scale DSM data of debris flow gully area generated by using the purchased resource No. 3 satellite remote sensing image of the demonstration area and based on the stereo image pair matching method. The processing method is as follows: (1) Due to the large amount of cloud and shadow noise in the original image, this study uses IDL language to develop and form a special denoising and information completion program for satellite images in cloudy mountainous areas. (2) The emmetropia correction image is used as the left image and the front view correction image is the right image. Envi is used for DSM production. (3) Using aster-dem data with 30 m resolution, at least 4 typical ground control points are selected for geographic correction to ensure that the geographic coordinate error is in the order of 1 ". (4) Cross entropy, root mean square error and area error information entropy are used as accuracy evaluation indexes. Compared with the DSM obtained from the original data, it is verified that the imaging accuracy of the processed DSM is improved.
HUANG Fang , PENG Shuying
Based on the distribution locations of the Qinghai toad-headed lizard (Phrynocephalus vlangalii) collected by field investigation and literature investigation, combined with five climate factors from WorldClim database, the current (1960-1990) and future (2061-2080) climate data were input into the trained species distribution model to predict the current and future suitable habitats. The prediction results shows that the lizard will lose a lot of original habitats under the climate change, and the protection measures for the lizard species should focus on the eastern margin of Qinghai-Tibet Plateau, the northern and eastern parts of Qaidam Basin. The model also predicts that after the climate change, new suitable habitats will appear in areas that were not suitable for the Qinghai toad-headed lizard. However, due to the very limited diffusion ability of reptiles (the maximum annual diffusion distance recorded in the literature is less than 500m), the newly emerging suitable habitats may not be used by the Qinghai toad-headed lizard. Meanwhile, based on the physiological, life history, behavior and morphological data of three altitudinal populations of the Qinghai toad-headed lizard collected by field work, and combined with microclimate data, the physiological consequences of climate change on the Qinghai toad-headed lizard in the current suitable distribution area were predicted by using the mechanism niche model. The prediction results of the model show that, whether in the SSP245 or SSP585 climate change scenarios, the activity time of the lizard will increase in most areas (> 93%) of the current suitable distribution area, and the thermal safety threshold will decrease in all places of the current suitable distribution area. The increase of activity time of high-altitude populations is less than that of low-altitude populations, but the decrease of thermal safety threshold is greater than that of low-altitude populations. The results reveal that climate change may have a greater impact on lizard populations in high altitude areas.
ZENG Zhigao
This data set is a digital elevation model of the Tibetan Plateau and can be used to assist in analysis and research of basic geographic information for the Tibetan Plateau. The raw data were the Shuttle Radar Topography Mission (SRTM) data, which were provided by Global Land Cover Network (GLCN), and the raw data were framing data , using the WGS84 coordinate system, including latitude and longitude, with a spatial resolution of 3″. After the mosaic processing, the Nodata (null data) generated in the mosaic process were interpolated and filled. After filling, the projection conversion process was performed to generate data as Albers equal area conical projection. After the conversion projection, the spatial resolution of the data was 90 m. Finally, the boundary of the Tibetan Plateau was used for cutting to obtain DEM data. This data table has two fields. Field 1: value Data type: long integer Interpretation: altitude elevation Unit: m Field 2: count Data type: long integer Interpretation: The number of map spots corresponding to the altitude elevation Data accuracy: spatial resolution: 90 m
Food and Agriculture Organization of the United Nations
The data is from JAXA earth observation research center（ http://www.eorc.jaxa.jp/ALOS/en/aw3d30/ ）The product is alos World 3D - 30m (aw3d30). Select and download the map by importing the SHP boundary of Sichuan Tibet traffic corridor, and merge it into one by using relevant software. The format is raster data, the spatial resolution is 30m, and the data size is 1.3GB. The DEM data can generate topographic factor data such as slope, aspect and river network by using relevant software. They are the basic data for topographic analysis of Sichuan Tibet traffic corridor, help to understand the geomorphic form of the basin, and are also the key factors for disaster zoning research and risk assessment. The acquisition of high-precision DEM is of great significance for disaster risk management and decision-making level and reducing the loss of major geological disasters.
SUI Tianbo
The data comes from radar topographic mapping SRTM product, and the download address is http://gdex.cr.usgs.gov/gdex/ 。 Import the SHP boundary of Sichuan Tibet traffic corridor on the download website to select the map within the study area and merge it into one by using ArcGIS software. The accuracy of the data is 90m, and the format is grid data. The data size is 136mb. The area is Sichuan Tibet traffic corridor. This data is applicable to the extraction of 1:100000 relevant topographic data, such as slope, aspect, river network and other topographic factor data. As the basic data for the topographic analysis of Sichuan Tibet traffic corridor, it is helpful to understand the topographic and geomorphic characteristics of the whole region and is of great significance to the disaster risk management and decision-making level of a large region.
WANG Lixuan
The SRTM (Shuttle Radar Topography Mission) data were obtained from the Endeavour space shuttle jointly launched by NASA and NIMA in February 2000. The SRTM system on the Endeavour had been collecting data for 222 hours and 23 minutes. It covered more than 80% of the global land surface from 60° north latitude to 56° south Latitude, including the whole territory of China. The radar image data acquired by the program have been processed for more than two years to form a digital terrain elevation model. The raw data of this data set were downloaded from the SRTM data distribution website (http://srtm.csi.cgiar.org). For the convenience of using the data, based on the framing of STRM data, we use Erdas software to splice and prepare the STMR mosaic of the Tibetan Plateau. The accuracy is 30 meters, and the data are in geoTIFF format. The raw data of this data set was downloaded from the SRTM data distribution website (http://srtm.csi.cgiar.org). The SRTM data provides a file for each latitude and longitude square. There are two kinds of longitude files, which are 1 arc-second and 3 arc-second, denoted SRTM1 and SRTM3, or 30-m and 90-m data. This data set comprises SRTM3 data with a resolution of 90 m, and the version is SRTM V4.1 (GeoTIFF format).
Food and Agriculture Organization of the United Nations（FAO）
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.
HUANG Huabin
SRTM (Shuttle Radar Topography Mission) is by NASA and the national geospatial intelligence agency (NGA) cooperation to build the global 3 d graphics data project.In February 2000, the SRTM system mounted on the U.S. space shuttle endeavour collected radar image data between latitude 60 ° north and latitude 57 ° south, and acquired radar image data covering more than 80% of the world's land surface.After more than two years of processing, the digital terrain elevation model was made. This data set including the heihe river basin SRTM points picture and Mosaic two kinds of data, and the points of the graph is SRTM version 4 data by the CGIAR - CSI (international centre for tropical agriculture, http://srtm.csi.cgiar.org/) treatment, compared with the previous version has greatly improved, including: 1) use a lot of interpolation algorithm, 2) use more auxiliary DEM data to fill the blank spots and blank area, 3) compared with the third version of the data and migration half a yuan.The Mosaic map is obtained by splicing on the basis of sub-map. The sub-charts include srtm_56_04,srtm_56_05,srtm_57_04 and srtm_57_054. The data are 16 bit values representing the elevation value (-/+/32767 m). The maximum positive elevation is 9000 m and the maximum negative elevation is 12,000 m below sea level.Null data is identified by -32767.Divide the file into 24 rows (-60 to 60 degrees) and 72 columns (-180 to 180 degrees) per 5 latitude and longitude squares.
TYLER B. STEVENS
The DEMs of the typical glaciers on the Tibetan Plateau were provided by the bistatic InSAR method. The data were collected on November 21, 2013. It covered Puruogangri and west Qilian Mountains with a spatial resolution of 10 meters, and an elevation accuracy of 0.8 m which met the requirements of national 1:10 000 topographic mapping. Considering the characteristics of the bistatic InSAR in terms of imaging geometry and phase unwrapping, based on the TanDEM-X bistatic InSAR data, and adopting the improved SAR interference processing method, the surface DEMs of the two typical glaciers above were generated with high resolution and precision. The data set was in GeoTIFF format, and each typical glacial DEM was stored in a folder. For details of the data, please refer to the Surface DEMs for typical glaciers on the Tibetan Plateau - Data Description.
JIANG Liming
The ASTER Global Digital Elevation Model (ASTER GDEM) is a global digital elevation data product jointly released by the National Aeronautics and Space Administration of America (NASA) and the Ministry of Economy, Trade and Industry of Japan (METI). The DEM data were based on the observation results of NASA’s new generation of Earth observation satellite, TERRA, and generated from 1.3 million stereo image pairs collected by ASTER (Advanced Space borne Thermal Emission and Reflection Radio meter) sensors, covering more than 99% of the land surface of the Earth. These data were downloaded from the ASTER GDEM data distribution website. For the convenience of using the data, based on framing the ASTER GDEM data, we used Erdas software to splice and prepare the ASTER GDEM mosaic of the Tibetan Plateau. This data set contains three data files: ASTER_GDEM_TILES ASTERGDEM_MOSAIC_DEM ASTERGDEM_MOSAIC_NUM The ASTER GDEM data of the Tibetan Plateau have an accuracy of 30 meters, the raw data are in tif format, and the mosaic data are stored in the img format. The raw data of this data set were downloaded from the ASTERGDEM website and completely retained the original appearance of the data. ASTER GDEM was divided into several 1×1 degree data blocks during distribution. The distribution format was the zip compression format, and each compressed package included two files. The file naming format is as follows: ASTGTM_NxxEyyy_dem.tif ASTGTM_NxxEyyy_num.tif xx is the starting latitude, and yyy is the starting longitude. _dem.tif is the dem data file, and _num.tif is the data quality file. ASTER GDEM TILES: The original, unprocessed raw data are retained. ASTERGDEM_MOSAIC_DEM: Inlay the dem.tif data using Erdas software, and parameter settings use default values. ASRERGDEM_MOSAIC_NUM: Inlay the num.tif data using Erdas software, and parameter settings use default values. The original raw data are retained, and the accuracy is consistent with that of the ASTERGDEM data distribution website. The horizontal accuracy of the data is 30 meters, and the elevation accuracy is 20 meters. The mosaic data are made by Erdas, and the parameter settings use the default values.
METI, National Aeronautics and Space Administration
This data set is mainly the SRTM terrain data obtained by International Center for Tropical Agriculture （CIAT）with the new interpolation algorithm, which better fills the data void of SRTM 90. The interpolation algorithm was adpoted from Reuter et al. (2007). SRTM's data organization method is as follows: divide a file into 24 rows (-60 to 60 degrees) and 72 columns (-180 to 180 degrees) in every 5 degrees of latitude and longitude grid, and the data resolution is 90 meters. Data usage: SRTM data are expressed as elevation values with 16-bit values (-/+/32767 m), maximum positive elevation of 9000m, and negative elevation (12000m below sea level). For null data use the -32767 standard.
Food and Agriculture Organization of the United Nations（FAO）
The data is vectorized from the national 1 ∶ 100W digital geological map spatial database. According to the regional scope of Sichuan Tibet traffic corridor and the division mode of 1:100w topographic map, the geological maps of h45, h46, H47, h48, i45, i46, I47 and i48 are used. The data source format is WP area file, which is converted into SHP format vector file by relevant software, which can be viewed and edited by arcigs software. This data contains basic geological information such as stratum, stratum symbol and rock type. The acquisition of geological data can basically understand the stratum and lithology within the scope of Sichuan Tibet traffic corridor, which is conducive to tracing the geological conditions of debris flow and landslide disasters.
WANG Lixuan
Based on China's daily meteorological elements data set and National Geographic basic data, the extreme precipitation, extreme temperature, drought intensity, drought frequency and other indicators in Hengduan Mountain area were calculated by using rclimdex, nspei and bilinear interpolation methods. The data set includes basic data set of disaster pregnant environment, basic data set of extreme precipitation index, basic data set of extreme temperature index, basic data set of drought intensity and frequency. The data set can provide a basic index system for regional extreme high temperature, precipitation and drought risk assessment.
SUN Peng
Hengduanshan multi-scale disaster causing, disaster pregnant and disaster bearing data spatiotemporal unified data set includes a series of geomorphic data derived from elevation data, annual average normalized vegetation index data, annual average temperature and rainfall data, and night light data of viirs. The geomorphological data cover Hengduanshan area, the vegetation and climate data cover the Qinghai Tibet Plateau, and the nighttime lamp index data cover the whole country. Data collection time varies according to different sources, with the earliest in 2000 and the latest in 2018. The data set is mainly prepared for disaster and risk assessment. In this data set, these data are processed by resampling, spatial correction, optical correction, geomorphic factor calculation, spatial statistics and other processes. The accuracy of the data is consistent with the original accuracy of the data source, and has not been processed by fuzzy processing such as downsampling. In the process of processing, the scientific standard process is used to distinguish continuous and discontinuous data, so as to minimize the data loss in the process of processing.
TANG Chenxiao
1) Data content (including elements and significance) This data set contains information of flow direction, accumulation of vector river network of Lancang Mekong River Basin. <br><br> 2) Data sources and processing methods In this data set, the remote sensing stream buring (RSSB) method (Wang et al., 2021) is adopted, and the high-precision elevation model MERIT-DEM and Sentinel-2 optical imagery are fused. <br><br> 3) Data quality description Validations show that this data set has high spatial accuracy (Wang et al, 2021). <br><br> 4) Data application achievements and Prospects This data set provides basic information of river networks, which can be used for hydrological model, land surface model, earth system model, as well as for mapping and spatial statistical analysis.
WANG Zifeng
1) Data content (including elements and significance) This data set contains information of flow direction, accumulation of vector river network of Lancang Mekong River Basin. <br><br> 2) Data sources and processing methods In this data set, the remote sensing stream buring (RSSB) method (Wang et al., 2021) is adopted, and the high-precision elevation model MERIT-DEM and Sentinel-2 optical imagery are fused. <br><br> 3) Data quality description Validations show that this data set has high spatial accuracy (Wang et al, 2021). <br><br> 4) Data application achievements and Prospects This data set provides basic information of river networks, which can be used for hydrological model, land surface model, earth system model, as well as for mapping and spatial statistical analysis.
WANG Zifeng
1) Data content (including elements and significance) This data set contains information of flow direction, accumulation of vector river network of Lancang Mekong River Basin. <br><br> 2) Data sources and processing methods In this data set, the remote sensing stream buring (RSSB) method (Wang et al., 2021) is adopted, and the high-precision elevation model MERIT-DEM and Sentinel-2 optical imagery are fused. <br><br> 3) Data quality description Validations show that this data set has high spatial accuracy (Wang et al, 2021). <br><br> 4) Data application achievements and Prospects This data set provides basic information of river networks, which can be used for hydrological model, land surface model, earth system model, as well as for mapping and spatial statistical analysis.
WANG Zifeng
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