From 1000 AD to the present, the concentration of methane in the atmosphere has increased significantly in the ice cores of the Antarctic and Arctic. These data came from the Tasmanian laboratory of Australia, where the high resolution data were obtained by using wet extraction of ice core samples, and the same measurement and calibration procedures were applied to all samples. The results are consistent with the results of internationally renowned ice core greenhouse gas laboratories such as the University of Bern, the University of Copenhagen and the University of Ohio. The physical meaning of each variable: First column: time; second column: methane concentration value
0 2020-10-14
By applying supply-demand balance analysis, the water resource supply and demand of the whole river basin and each county or district were calculated, and the results were used to assess the vulnerability of the water resources system in the basin. The IPAT equation was used to establish a future water resource demand scenario, which involved setting various variables, such as the future population growth rate, economic growth rate, and water consumption per unit GDP. By taking 2005 as the base year and using assorted forecasting data of population size and economic scale, the future water demand scenarios of various counties and cities from 2010 to 2050 were predicted. By applying the basic structure of the HBV conceptual hydrological model of the Swedish Hydro-meteorological Institute, a model of the variation trends of the basin under a changing climate was designed. The glacial melting scenario was used as the model input to construct the runoff scenario in response to climate change. According to the national regulations of the water resource allocation in the basin, a water distribution plan was set up to calculate the water supply comprehensively. Considering the supply and demand situation, the water resource system vulnerability was evaluated by the water shortage rate. By calculating the grain production-related land pressure index of the major counties and cities in the basin, the balance of supply and demand of land resources in scenarios of climate change, glacial melting and population growth was analysed, and the vulnerability of the agricultural system was evaluated. The Miami formula and HANPP model were used to calculate the human appropriation of net primary biomass and primary biomass in the major counties and cities in the future, and the vulnerability of ecosystems from the perspective of supply and demand balance was assessed.
0 2019-09-12
This dataset contains the flux measurements from the Huazhaizi station eddy covariance system (EC) in the midstream reaches of the Heihe integrated observatory network from January 1 to December 31 in 2018. The site (100.3201° E, 38.7659° N) was located in the Zhangye City in Gansu Province. The elevation is 1731 m. The EC was installed at a height of 4.5 m, and the sampling rate was 10 Hz. The sonic anemometer faced north, and the separation distance between the sonic anemometer and the CO2/H2O gas analyzer (CSAT3&Li7500A) was 0.15 m. The raw data acquired at 10 Hz were processed using the Eddypro post-processing software, including the spike detection, lag correction of H2O/CO2 relative to the vertical wind component, sonic virtual temperature correction, coordinate rotation (2-D rotation), corrections for density fluctuation (Webb-Pearman-Leuning correction), and frequency response correction. The EC data were subsequently averaged over 30 min periods. The observation data quality was divided into three classes according to the quality assessment method of stationarity (Δst) and the integral turbulent characteristics test (ITC): class 1-3 (high quality), class 4-6 (good), class 7-8 (poor, better than gap filling data), class9 (rejected). In addition to the above processing steps, the half-hourly flux data were screened in a four-step procedure: (1) data from periods of sensor malfunction were rejected; (2) data collected before or after 1 h of precipitation were rejected; (3) incomplete 30 min data were rejected when the missing data constituted more than 10% of the 30 min raw record. There were 48 records per day, and the missing data were replaced with -6999. Suspicious data were marked in red. Data during May 13 to July 12 and July 16 to August 21, 2018 were missing due to the malfunction of CO2/H2O gas analyzer. The released data contained the following variables: data/time, wind direction (Wdir, °), wind speed (Wnd, m/s), the standard deviation of the lateral wind (Std_Uy, m/s), virtual temperature (Tv, ℃), H2O mass density (H2O, g/m3), CO2 mass density (CO2, mg/m3), friction velocity (ustar, m/s), stability (z/L), sensible heat flux (Hs, W/m2), latent heat flux (LE, W/m2), carbon dioxide flux (Fc, mg/ (m2s)), quality assessment of the sensible heat flux (QA_Hs), quality assessment of the latent heat flux (QA_LE), and quality assessment of the carbon flux (QA_Fc). In this dataset, the time of 0:30 corresponds to the average data for the period between 0:00 and 0:30; the data were stored in *.xls format. Detailed information can be found in the suggested references. For more information, please refer to Liu et al. (2018) (for sites information), Liu et al. (2011) for data processing) in the Citation section.
0 2020-07-25
The dataset of airborne Polarimetric L-band Multibeam Radiometers (PLMR) was acquired on 5 July, 2012, located in the middle reaches of the Heihe River Basin. The aircraft took off at 10:50 am (UTC+8) from Zhangye airport and landed at 12:20 pm, with the flight time of 1.5 hours. The flight was performed in the altitude of about 2000 m and at the speed of about 220-250 km during the observation, corresponding to an expected ground resolution of about 600 m. The PLMR instrument flown on a small aircraft operates at 1.413 GHz (L-band), with both H- and V-polarizations at incidence angles of ±7.5°, ±21.5° and ±38.5°. PLMR ‘warm’ and ‘cold’ calibrations were performed before and after each flight. The processed PLMR data include 2 DAT files (v-pol and h-pol separately) and 1 KMZ file for each flying day. The DAT file contains all the TB values together with their corresponding beam ID, incidence angle, location, time stamp (in UTC) and other flight attitude information as per headings. The KMZ file shows the gridded 1-km TB values corrected to 38.5 degrees together with flight lines. Cautions should be taken when using these data, as the RFI contaminations are often higher than expected at v-polarization.
0 2019-05-23
Er’ba Reservoir surface temperature of water body can offer in situ calibration data for TASI, WiDAS and L band sensor used in aerospace experiment. Observation Site: This site is 14 KM away from East of ZhangYe city. It’s located in Er’ba village, JianTan town, ZhangYe city. The coordinates of this site: 38°54′57.14" N, 100°36′57.39" E. Observation Instrument: The observation system consists of two SI-111 infrared radiometers (Campbell, USA) and two 109SS temperature probes (Campbell, USA). Two SI-111 sensors, one installed vertically downward to water surface, another face to south of zenith angle 35°. Temperature probes float under water surface at 0 cm. SI-111 sensor installed at 3.0 m height, 3.4 m away from water edge. Observation Time: This site operates from 27 May, 2012 to 27 September, 2012. Observation data laagered by every 5 seconds uninterrupted. Output data contained sample data of every 5 seconds and mean data of 1 minute. Accessory data： Water surface infrared temperature (by SI-111), sky infrared temperature (by SI-111), water surface temperature (by 109ss) can be obtained. Dataset is stored in *.dat file, which can be read by Microsoft excel or other text processing software (UltraEdit, et. al). Table heads meaning: TarT_Atm, Sky infrared temperature (℃) @ facing south of zenith angle 35°; SBT_Atm, body temperature of SI-111 sensor (℃) measured sky; TarT_Sur, water surface infrared temperature @ 3.0 m height; SBT_Sur, body temperature of SI-111 sensor (℃) measured water surface; WaterT_1, WaterT_2, water surface temperature (℃) measured by 109SS temperature probes. Dataset is stored day by day, named as: data format + site name + interval time + date + time. The detailed information about data item showed in data header introduction in dataset.
0 2019-09-12
This data set contains the eddy correlativity observation data of huazhaizi desert station in the middle reaches of heihe hydrometeorological observation network from January 1, 2016 to December 31, 2016.The station is located in zhangye city, gansu province.The longitude and latitude of the observation point are 100.3201E, 38.7659N and 1731.00m above sea level.The rack height of the vortex correlator is 4.5m, the sampling frequency is 10Hz, the ultrasonic orientation is due north, and the distance between the ultrasonic wind speed and temperature meter (CSAT3) and CO2/H2O analyzer (Li7500A) is 15cm. The original observation data of the vortex correlativity instrument is 10Hz, and the published data is the 30-minute data processed by Eddypro software. The main processing steps include: outliers, delay time correction, coordinate rotation (quadratic coordinate rotation), frequency response correction, ultrasonic virtual temperature correction and density (WPL) correction.Quality assessment for each intercompared to at the same time, mainly is the atmospheric stability (Δ st) and turbulent characteristics of similarity (ITC) test.The 30min pass value output by Eddypro software was also screened :(1) data when instrument error was eliminated;(2) data of 1h before and after precipitation are excluded;(3) remove the data with a missing rate of more than 10% in the original 10Hz data within every 30 minutes;(4) the observation data of weak turbulence at night (u* less than 0.1m/s) were excluded.The average observation period was 30 minutes, 48 data per day, and the missing data was marked as -6999.Suspicious data caused by instrument drift, etc., shall be marked in red font.On April 24, solstice and April 25, due to the calibration of vortex correlator Li7500A, data was missing.When the 10Hz data of the vortex correlator is missing, the data is filled by the data collected by the collector. The published observational data include:Date/Time for the Date/Time, wind Wdir (°), Wnd horizontal wind speed (m/s), standard deviation Std_Uy lateral wind speed (m/s), ultrasonic virtual temperature Tv (℃), the water vapor density H2O (g/m3), carbon dioxide concentration CO2 (mg/m3), friction velocity Ustar) (m/s), Mr. Hoff length L (m), sensible heat flux Hs (W/m2), latent heat flux LE (W/m2), carbon dioxide flux Fc (mg/(m2s)), the quality of the sensible heat flux identifier QA_Hs, the quality of the latent heat flux identifier QA_LE,Quality indicator for co2 flux QA_Fc.The quality of the sensible heat and latent heat, carbon dioxide flux identification is divided into three (quality id 0: (Δ st < 30, the ITC < 30);1: (Δ st < 100, ITC < 100);The rest is 2).The meaning of data time, such as 0:30 represents the average of 0:00-0:30;The data is stored in *.xls format. For information of hydrometeorological network or station, please refer to Li et al. (2013), and for observation data processing, please refer to Liu et al. (2011).
0 2020-03-04
This data comes from the National Geographic Information Resources Catalogue Service System, which was provided free to the public by the National Basic Geographic Information Center in November 2017. In order to use the data more conveniently, the source of the three rivers is spliced and cut as a whole, so as to facilitate the use of the source area of the three rivers. The data trend is 2017. This data set is composed of 1:1 million residential areas in Sanjiangyuan area, including residential land (RESA) and residential place (RESP) layers, RESP residential area (point) layers, including ordinary houses, grazing areas and so on.
0 2019-05-20
The dataset of ground truth measurements synchronizing with Envisat ASAR and ALOS PALSAR was obtained in the Linze station foci experimental area on May 24, 2008. The data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:34 BJT. Observation items included: (1) soil moisture (0-5cm) measured once by cutting ring method at corner points of the 40 subplots of the west-east desert transit zone strip, one time by cutting ring method in nine subplots of the north-south desert transit zone, strip and once by the cutting ring and three times by ML2X Soil Moisture Tachometer in the center points of nine subplots of Wulidun farmland quadrates . The preprocessed soil volumetric moisture data were archived as Excel files. (2) surface radiative temperature by measured two handheld infrared thermometer (5# and 6# from Cold and Arid Regions Environmental and Engineering Research Institute which were both calibrated) in 40 subplots of the west-east desert transit zone strip (repeated 14-30 times each), and nine subplots of the north-south desert transit zone strip (repeated 12-30 times). There are 34 sample points in total and each was repeated three times synchronizing with the airplane. Photos were taken. Data were archived as Excel files. (3) LAI, the plant height and the spacing measured by the ruler and the set square in Wulidun farmland quadrates and Linze station quadrates. Part of the samples were also measured by LI-3100. Data were archived as Excel files. See the metadata record “WATER: Dataset of setting of the sampling plots and stripes in the Linze station foci experimental area” for more information of the quadrate locations.
0 2019-05-23
From May 2008 to July 2008, several synchronous observation quadrats were set up in the intensive observation area of Linze grassland. According to the spatial resolution of transit sensing, a 1.8km × 1.8km quadrat h and five 360m × 360m quadrats a, B, C, D and E are set up within 2km × 2km around Linze grassland station. There are 64 sampling points in sample h, numbered H01 to H64, and the distance between two adjacent points is 250m, mainly for MODIS synchronization. The sample a, B, C, D and e of 360m × 360m contains 49 sample points, the sample spacing is 60m, and the sample number is 01-49 (for example, sample a is a01-a49). The surface type of sample a is Phragmites australis, the surface type of sample B is saline alkali, and there are sparse Phragmites australis. The surface type of sample C is saline alkali, and Phragmites australis is more sparse than that of sample a. the surface type of sample D is alfalfa, and the surface type of sample e is alfalfa The type of table is barley field. A small sample of 120m × 120m is nested in each sample of a, B, C, D and e. the spacing of sample points in the small sample is 30m (see "sample distribution. PDF" in the data folder). Quadrats a, B, C, D, e and their nested small quadrats are mainly for ASAR, PALSAR, aster and airborne OMIS, widas synchronization. In addition, there are 7 microwave synchronous transects with 25 sampling points in each transect. The interval between the transects is 200m, and the interval between the sampling points on the transect is 100m. The No. l3-11 indicates the No. 11 sampling point on the No. 3 transect. PR2 is a 3 grid × 3 grid quadrat, and the distance between sampling points is 30 m. The number is pr11. There are also two PR2 transects, a total of 11 transects. The coordinates of all sample points are in Excel.
0 2021-03-10
The dataset of ground truth measurement synchronizing with MODIS was obtained in the Linze grassland foci experimental area on Jun. 2, 2008. Measurements were carried out twice at intervals of 125m in four quadrates (2km×2km), which were H01-H08, H09-H16, H17-H24 and H25-H32 respectively. Simultaneous ground data were mainly the canopy temperature, the half-height temperature, the land surface radiative temperature and the soil temperature (0-5cm) by the probe thermometer. For soil moisture, the soil temperature, soil moisture, the loss tangent, soil conductivity, and the real part and the imaginary part of soil complex permittivity were acquired by the POGO soil sensor, and soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring inNo.1 quadrats (H01-H08), No.2 (H09-H16) and No.3 (H17-H24); and in No.4 quadrat 4 (H25-H32), soil moisture, soil conductivity, the soil temperature, the real part of soil complex permittivity were acquired by WET, soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring. Complementary measurements were carried out on Jun. 3, 2008. The soil temperature, soil moisture, the loss tangent, soil conductivity, the real part and the imaginary part of soil complex permittivity were acquired by the POGO soil sensor, and soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring in H41-H48, H49-H56 and H57-H64; and in H33-H40, soil moisture, soil conductivity, the soil temperature, and the real part of soil complex permittivity were acquired by WET, soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring. Data were archived in Excel format. See WATER: Dataset of setting of the sampling plots and stripes in the Linze station foci experimental area for more information.
0 2019-05-23
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