Leaf area index (LAI), as a structural parameter of vegetation canopy, is an important input parameter for many inversion models such as energy and biomass inversion model. Firstly, vegetation points and ground points are separated in Terrasolid software. Then the transmittance of laser points is calculated, and the transmittance is the proportion of ground points to all points. After laser pulse hits the canopy, some energy passes through the voids between branches and leaves and continues to move forward until the energy is blocked, so some laser points will finally reach the ground. In this study, the ratio of the energy passing through the avoids to the energy of the canopy is used as the Laser Penetration Index (LPI). The LPI of each sample point at each scale in the study area was calculated.
0 2019-09-14
The Global LAnd Surface Satellite albedo product was produced by using MODIS data product of 1km Surface reflectance (MOD/MYD09GA), Angular Bin inversion algorithm and statistics-based Temporal Filter algorithm based on statistical knowledge.This data set is in the GLASS global products using the two tiles covering the heihe river basin (h25v04, h25v05), after a Mosaic, projection transformation, and cutting the heihe river basin 1 km resolution epicontinental black empty albedo (black - sky albedo) and white empty albedo (white - sky albedo) data sets, including both Albers and UTM projection method, are raw format, space vector boundary of heihe river basin is the scope of the rectangle, temporal resolution for eight days.
0 2020-03-08
The dataset of sun photometer observations was obtained in the Zhangye city foci experimental areas (38°56′8.9″N, 100°27′8.3″E, 1400m) from Mar. 30 to Apr. 2, 2008. Measurements were carried out by CE318 for 1640nm, 1020nm, 936nm, 870nm, 670nm, 550nm, 440nm, 380nm and 340nm, and column water vapor by 936 nm data on Mar. 30 and 31, Apr. 1 and 2, 2008. Accuracy of CE318 could be influenced by local air pressure, instrument calibration parameters, and convertion factors. (1) Most air pressure was derived from elevation-related empiricism, which was not reliable. For more accurate result, simultaneous data from the weather station are needed. (2) Errors from instrument calibration parameters need correcting. Thus field calibration based on Langly or interior instrument calibrationcin the standard light is required. (3) Convertion factors for retrieval of aerosol optical depth and the water vapor of the water vapor channel were also from empiricism, and need further checking. Raw data were archived in k7 format and can be opened by ASTPWin. ReadMe.txt is attached for detail. Preprocessed data (after retrieval of the raw data) in Excel format are on optical depth, rayleigh scattering, aerosol optical depth, the horizontal visibility, the near surface air temperature, the solar azimuth, zenith, solar distance correlation factors, and air column mass number. Langley was used for the instrument calibration. Two parts are included in CE318 result data (see “Geometric Positions and the Total Optical Depth of Each Channel” and “Rayleigh Scattering and Aerosol Optical Depth of Each Channel”).
0 2019-05-23
The data was compiled from "China's 1:100,000 wetland data". "China 1:100,000 wetland data" mainly reflects the information of marshes and wetlands throughout the country in the 2000s, and is represented by geographical coordinates in decimal scale. The main contents include: types of marshes and wetlands, types of water supply, types of soil, types of main vegetation, and geographical regions.The information classification and coding standard of China sustainable development information sharing system was implemented.Data source of this database: 1:20 swamp map (internal version), 1:500 000 swamp map (internal version) of qinghai-tibet plateau, 1:100 000 swamp survey data and 1:400 000 swamp map of China;The processing steps are as follows: data source selection, preprocessing, marshland element digitization and coding, data editing and processing, establishment of topological relationship, edge-to-edge processing, projection transformation, connection with attribute database such as geographical name and acquisition of attribute data.
0 2020-05-28
This dataset contains the flux measurements from the A’rou superstation eddy covariance system (EC) in the upperstream reaches of the Heihe integrated observatory network from January 1 to December 31 in 2018. The site (100.372° E, 38.856° N) was located in the Daban Village, near Qilian County in Qinghai Province. The elevation is 3033 m. The EC was installed at a height of 3.5 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 insufficient power supply, data were missing occasionally. 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 (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
This dataset contains the flux measurements from site No.4 eddy covariance system (EC) in the flux observation matrix from 31 May to 17 September, 2012. The site (100.35753° E, 38.87752° N) was located in a residential area in Yingke irrigation district, which is near Zhangye, Gansu Province. The elevation is 1561.87 m. The EC was installed at a height of 4.2 m (6.2 m after 19 August); 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 0.17 m. Raw data acquired at 10 Hz were processed using the Edire post-processing software (University of Edinburgh, http://www.geos.ed.ac.uk/abs/research/micromet/EdiRe/), including 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. Moreover, 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), which was proposed by Foken and Wichura [1996]: class 1 (level 0: Δst<30 and ITC<30), class 2 (level 1: Δst<100 and ITC<100), and class 3 (level 2: Δst>100 and ITC>100), representing high-, medium-, and low-quality data, respectively. 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 before or after 1 h of precipitation were rejected; (3) incomplete 30 min data were rejected when the missing data constituted more than 3% of the 30 min raw record; and (4) data were rejected at night when the friction velocity (u*) was less than 0.1 m/s. There were 48 records per day; the missing data were replaced with -6999. Moreover, suspicious data were marked in red. 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/m^3), CO2 mass density (CO2, mg/m^3), friction velocity (ustar, m/s), stability (z/L), sensible heat flux (Hs, W/m^2), latent heat flux (LE, W/m^2), carbon dioxide flux (Fc, mg/ (m^2s)), 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 *.xlsx format. For more information, please refer to Liu et al. (2016) (for multi-scale observation experiment or sites information), Xu et al. (2013) (for data processing) in the Citation section.
0 2019-09-15
According to the global soil map. Net standard, the 0-1m soil depth is divided into 5 layers: 0-5cm, 5-15cm, 15-30cm, 30-60cm and 60-100cm. According to the principle of soil landscape model, the spatial distribution data products of soil silt content in different layers are made by using the digital soil mapping method. The American system classification is used as the standard of soil particle classification. The source data of this data set comes from the soil profile data integrated by the major research plan integration project of Heihe River Basin (soil data integration and soil information product generation of Heihe River Basin, 91325301). Scope: Heihe River Basin; Projection: WGS · 1984 · Albers; Spatial resolution: 100M; Data format: TIFF; Dataset content: hh_silt_layer1.tif: 0-5cm soil silt content; hh_silt_layer2.tif: 5-15cm soil silt content; hh_silt_layer3.tif: 15-30cm soil silt content; hh_silt_layer4.tif: 30-60cm soil silt content; hh_silt_layer5.tif：60-100cm soil silt content;
0 2020-06-01
It includes the social and economic data of Gansu, Qinghai and Inner Mongolia from 2000 to 2012. The specific indicators include GDP, income, population, employment, medical care, education, land area, finance and a series of social and economic indicators;
0 2020-07-28
This dataset includes daily water vapor and precipitation isotopes (δ18O and δD) and daily meteorological parameters including temperature, relative humidity, vapor concentration, air pressure, and precipitation amount at Nanjing, eastern China. Water vapor isotopes (δ18Ov and δDv) were online measured during November 2012 to December 2018 by a Wavelength Scanned Cavity Ring-Down Spectrometer (WS-CRDS, model: Picarro L2120-i) at the Station for Observing Regional Processes of the Earth System of Nanjing University (SORPES-NJU, 32.12°N, 118.95°E, 55 m above sea level) on the Xianlin Campus of the Nanjing University, about 20 km east of downtown Nanjing in the Eastern China. The uncertainties were determined to be less than 0.2‰ for δ18Ov and 1.0‰ for δDv. Precipitation isotopes were also measured by Picarro L2120-i during September 2011 to December 2018, with the analytical uncertainty of less than 0.1‰ for δ18O and 0.5‰ for δD.
3792 2020-09-21
The Antarctic Peninsula is also called "Palmer peninsula" or "Graham land". Located in the southwest polar continent, it is the largest peninsula in the Antarctic continent and the farthest peninsula extending northward into the ocean (63 ° south latitude), bordering the Weddell Sea and berengske sea in the East and West. The Antarctic Peninsula is known as the "tropics" of Antarctica. This is a typical sub polar marine climate. Compared with the Antarctic continent, it is one of the warmest and wettest regions in Antarctica. There are a small number of pioneer plants distributed on the islands in the marginal area, mainly bryophytes and lichens. The plant abundance data products of Antarctic Peninsula and its surrounding areas are matched with remote sensing images through measured spectra, and the end element spectra of moss, lichen, rock, sea and snow are extracted with pure pixel PPI. The linear mixture model (LMM) is applied to calculate.
0 2019-10-26
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