Landsat TM mosaic image of the Heihe River Basin (2010)

The Landsat TM Mosaic Image of the Heihe River Basin can be effectively applied to monitoring land-use change of the basin, which reflects the current situation of the Heihe River Basin in 2010, and provides a reliable basis for ecological planning and restoration. This mosaic image collected the TM images released by the USGS for free in 2010 (data from July to September 2010, totally 21 scenes, the maximum cloud amount is less than 10%), and the preprocessed images were geometrically registered by topographic maps(polynomial geometry correction method), then a geometrically-corrected digital mosaic map was generated, which was of high quality after a certain accuracy evaluation. The images were stored in ERDAS IMG format, and the most abundant bands 5, 4 and 3 combination, with three colors: red, green, and blue were selected to generate a color composite image. The combined composite image not only is similar to natural color, which is more in accordance with people's visual habits, but also can fully display the differences in image features because of the rich amount of information.

0 2020-06-08

The resident site distribution data of the Heihe River Basin

This data mainly includes the distribution of city, county, township and village level residential areas in the Heihe River Basin, and the data base year is 2009. The data is based on the existing data of residential areas in Heihe River Basin, the latest Google electronic map and the atlas of Gansu Province. There are two main attributes of the data, i.e. residential area classification and total name. The residential area classification is classified according to level 1 - City, level 2 - County, level 3 - Township and level 4 - village.

0 2020-06-05

Grain size distribution of soil particles dataset of the Heihe basin

The source data of this data set comes from the 1:1 million soil map of China (Shi et al., 2004) and 8595 soil sections in the second Soil Census. The polygonal connection method is used to connect the soil profile with the soil map to obtain the soil sand, silt and clay content map. The distance between the profile and the map spot, the number of soil profiles and the information of soil classification are taken into account. Please refer to related papers and web pages for specific instructions. Data characteristics Projection: GCS_Krasovsky_1940 Coverage: Heihe River Basin Resolution: 0.00833 degrees (about one kilometer) Data format: FLT, tiff Value range: 0% - 100% Document description Floating point grid files include: Sand1.flt, clay1.flt - content of sand and clay in the surface layer (0-30cm). Sand2.flt, clay2.flt - sand and clay content in the bottom layer (30-100cm). Psd.hdr – header file: Ncols - number of columns Nrows - number of rows Xllcorner - lower left latitude Yllcorner - lower left longitude Cellsize - cell size NoData_Value – null byteorder - LSBFIRST, Least Significant Bit First TIFF grid files include: Sand 1.tif, clay 1.tif - the content of sand and clay in the surface layer (0-30cm). Sand 2.tif, clay 2.tif - sand and clay content in the bottom layer (30-100cm). For data details, please refer to: http://globalchange.bnu.edu.cn/research/soil

0 2020-06-05

Primary road network dataset of the Heihe Rriver basin (2010)

Data overview: this set of data mainly includes the spatial distribution of major roads in the heihe river basin, the attributes include road classification and road coding, and the data base year is 2010. Data preparation process: this set of data is based on the topographic map, remote sensing image and the latest road traffic map updated by the transportation department of gansu province in 2009. Data description: there are two important attributes of the data, namely, road classification and road code. The road classification is divided into national road, provincial road, county road, township road and private road. The road code is defined in accordance with the highway grade code of the traffic department.

0 2020-06-05

The Heihe River basin boundary (1985、1995、2000、2005、2010)

Heihe river basin is the second largest inland river basin in China. In the past 30 years, a relatively perfect drainage observation system has been established in heihe river basin, which has become an important inland river research base in China.River basin is an important natural research unit, but the boundary of heihe river basin is not unified. In order to facilitate the use of data by users, we collected and sorted out 5 kinds of heihe river basin boundaries commonly seen in the literature: 1) from 1985 to 1986, China began to conduct systematic research on the heihe river basin as a whole. On the basis of basic investigation and a large number of data mastered, the early heihe river basin map was drawn with an area of 138,900 km ^ 2.The whole basin is divided into three hydrologic balance zones, which are: the balance zone of heihe main stream system, the balance zone of beida river main stream system and the balance zone of ma ying - feng leshan front water system. 2) sub project national key scientific research project of the ninth five-year plan "in heihe river basin water resources reasonable use and the economic society and ecological environment coordinated development research", considering the integrity of the county-level administrative units, on the basis of the first basin boundary using the administrative boundary of basin boundary was revised, formed the "digital heihe" published information system (http://heihe.westgis.ac.cn) of the heihe river basin boundary, watershed area of 128700 km ^ 2.The division of hydrological unit inherits the original idea and is divided into three river systems, namely the eastern river system, the central river system and the western river system. 3) in the comprehensive control plan of heihe river basin of the ministry of water resources, the area of heihe river basin is determined as 142,900 km ^ 2, and the hydrologic unit is divided into two independent water systems in the central and western regions and the east, with an area of 27,000 km2 and 116,000 km ^ 2 respectively. 4) in 2002-2006 in the national integrated water resources planning, "the Yellow River" (piece of) integrated water resources planning working group in 2005, the establishment "the northwest rivers and water resources and its exploitation and utilization of investigation evaluation report, briefly, to the secondary and tertiary area as the unit of water resources, to complete a series of natural geography and social economy statistical tables, maps and other data.In this comprehensive plan, the area of heihe river basin is about 151,700 km ^ 2, and the plan does not give a more detailed sub-watershed division plan. 5) based on the high-precision digital elevation model (SRTM and ASTER GDEM), the boundary of heihe river basin was determined by using the GIS hydrologic analysis method.The boundary has been verified by remote sensing and field investigation, and the present situation of modern water resources utilization is considered in the process of basin boundary determination and sub-basin division.

0 2020-06-05

The 30-m land cover data of Tibetan Plateau (2010)

These data contain two data files: GLOBELAND30 TILES (raw data) and TIBET_ GLOBELAND30_MOSAIC (mosaic data). The raw data were downloaded from the Global Land Cover Data website (GlobalLand3) (http://www.globallandcover.com) and cover the Tibetan Plateau and surrounding areas. The raw data were stored in frames, and for the convenience of using the data, we use Erdas software to splice and mosaic the raw data. The Global Land Cover Data (GlobalLand30) is the result of the “Global Land Cover Remote Sensing Mapping and Key Technology Research”, which is a key project of the National 863 Program. Using the American Landsat images (TM5, ETM+) and Chinese Environmental Disaster Reduction Satellite images (HJ-1), the data were extracted by a comprehensive method based on pixel classification-object extraction-knowledge checks. The data include 10 primary land cover types—cultivated land, forest, grassland, shrub, wetland, water body, tundra, man-made cover, bare land, glacier and permanent snow—without extracting secondary types. In terms of accuracy assessment, nine types and more than 150,000 test samples were evaluated. The overall accuracy of the GlobeLand30-2010 data is 80.33%. The Kappa indicator is 0.75. The GlobeLand30 data use the WGS84 coordinate system, UTM projection, and 6-degree banding, and the reference ellipsoid is the WGS 84 ellipsoid. According to different latitudes, the data are organized into two types of framing. In the regions of 60° north and south latitudes, the framing is carried out according to a size of 5° (latitude) × 6° (longitude); in the regions of 60° to 80° north and south latitudes, the framing is carried out according to a size of 5° (latitude) × 12° (longitude). The framing is projected according to the central meridian of the odd 6° band. GLOBELAND30 TILES: The original, unprocessed raw data are retained. TIBET_ GLOBELAND30_MOSAIC: The Erdas software is used to mosaic the raw data. The parameter settings use the default value of the raw data to retain the original, and the accuracy is consistent with that of the downloading site.

0 2020-06-03

The NPP products of MODIS in Sanjiangyuan (1985-2015)

The data set contains NPP products data produced by the maximum synthesis method of the three source regions of the Yellow River, the Yangtze River and the Lancang River. The data of remote sensing products MOD13Q1, MOD17A2, and MOD17A2H are available on the NASA website (http://modis.gsfc.nasa.gov/). The MOD13Q1 product is a 16-d synthetic product with a resolution of 250 m. The MOD17A2 and MOD17A2H product data are 8-d synthetic products, the resolution of MOD17A2 is 1 000 m, and the resolution of MOD17A2H is 500 m. The final synthetic NPP product of MODIS has a resolution of 1 km. The downloaded MOD13Q1, MOD17A2, and MOD17A2H remote sensing data products are in HDF format. The data have been processed by atmospheric correction, radiation correction, geometric correction, and cloud removal. 1) MRT projection conversion. Convert the format and projection of the downloaded data product, convert the HDF format to TIFF format, convert the projection to the UTM projection, and output NDVI with a resolution of 250 m, EVI with a resolution 250 m, and PSNnet with resolutions of 1 000 m and 500 m. 2) MVC maximum synthesis. Synthesize NDVI, EVI, and PSNnet synchronized with the ground measured data by the maximum value to obtain values corresponding to the measured data. The maximum synthesis method can effectively reduce the effects of clouds, the atmosphere, and solar elevation angles. 3) NPP annual value generated from the NASA-CASA model.

0 2020-06-03

The digital elevation model of the Tibetan Plateau (2000)

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

0 2020-06-03

The slope map of the Tibetan Plateau (2000)

This data set contains the digital slope distribution and slope degree data of the Tibetan Plateau, which can be used to assist in basic geographic information analysis and research work on the Tibetan Plateau region. The raw data were the Shuttle Radar Topography Mission (SRTM) data provided by Global Land Cover Network (GLCN) using the WGS84 coordinate system, and the raw data were framing data, including latitude and longitude data, with a spatial resolution of 3″. After the mosaic processing, the Nodata (null data) generated in the mosaic process were interpolated and filled, and after filling, a projection conversion process was performed to generate an equal-area conical projection of the data bit Albers, after conversion projection, the spatial resolution was 90 m. Finally, the boundary of the Tibetan Plateau was used for cutting to obtain DEM data. Use the spatial analysis module under ArcMap to calculate the slope aspect and generate the slope map. Field: value Data type: floating point Interpretation: slope degree Dimension: degree Data accuracy: spatial resolution 90 m

0 2020-06-03

Global river and lake vector dataset (2010)

River and lake resources are important components for studying the Earth ecological environment, affecting global ecosystems, heat, material exchange and balance and serving as an important basis for studying changes in the global environmental mechanism. At present, the lack of global lake vector data with large-scale, high-precision, and large-range has hindered hydrological research on rivers and lakes. Taking the data collection of global rivers and lakes of Jun Chen as the source data and combining the domestic high-resolution image GF data of 2 to 3 years before and after 2010, a data set of global rivers and lakes was generated. This data set makes up for the shortcomings of low precision in some areas and is an editable lake and river vector data set with high accuracy.

0 2020-06-03