The data set contains the flux observation data of large aperture scintillator at areau station upstream of heihe hydrometeorological observation network.Two large aperture scintillation devices of BLS450 and zzlas type were set up in the upstream areau station respectively. The north tower was the receiving end of zzlas and the transmitting end of BLS450, and the south tower was the transmitting end of zzlas and the receiving end of BLS450.The observation time is January 1, 2017, solstice, December 31, 2017.The station is located in the grass daban village, a soft township, qilian county, qinghai province.The latitude and longitude of the north tower is 100.4712e, 38.0568n, and the latitude and longitude of the south tower is 100.4572e, 38.0384 N, with an altitude of about 3033m.The effective height of the large aperture scintillator is 9.5m, the optical diameter length is 2390m, and the sampling frequency is 1min. Large aperture flicker meter raw observation data for 1 min, data released for after processing and quality control of data, including sensible heat flux is mainly combined with the automatic meteorological station observation data, based on similarity theory alonzo mourning - Mr. Hoff is obtained by iterative calculation, the quality control of the main steps include: (1) excluding Cn2 reach saturation data (BLS450: Cn2 > 7.25 e-14, zzlas: Cn2 > 7.84 E - 14).(2) data with weak demodulation signal strength (BLS450: Mininum X Intensity <50) were eliminated;Zzlas: Demod>-20mv);(3) data at the time of precipitation were excluded;(4) data of weak turbulence under stable conditions were excluded (u* < 0.1m/s).In the iterative calculation process, for BLS450, Thiermann and Grassl(1992) stability universal function was selected.For zzlas, select Andreas 1988's stability universal function.Please refer to Liu et al(2011, 2013) for detailed introduction.From April 16 to May 26, 2017, the measurement signal of large aperture scintillator was relatively small, resulting in a large number of missing data. Several notes on the released data :(1) the upstream LAS data is mainly BLS450, the missing time is supplemented by zzlas observation, and the missing time of both is marked by -6999.(2) data table head: Date/Time: Date/Time (format: yyyy/m/d h:mm), Cn2: structural parameters of air refraction index (unit: m-2/3), H_LAS: sensible heat flux (unit: W/m2).The meaning of data time, such as 0:30 represents the average between 0:00 and 0:30;The data is stored in *.xls format, please refer to the references for details. Please refer to Li et al. (2013) for hydrometeorological network or site information, and Liu et al. (2011) for observation data processing.
LIU Shaomin, LI Xin, CHE Tao, XU Ziwei, ZHANG Yang, TAN Junlei
The dataset of intensive rain gauges observations was obtained in the arid region hydrology experiment area, in cooperation with dual polarized doppler radar observations. There was no single dataset for the upper stream observations for the poor quality; the middle stream dataset was collected by 29 RG3-M self-recording rain gauges: the northernmost (100.36°E, 39.16°N), the southernmost (100.34°E, 38.61°N), the easternmost (100.62°E, 38.87°N), and the westernmost (100.26°E, 38.82°N). Rain gauges R02-R09 measured from May 18 to Oct. 9, 2008, and R10-R30 from May 26 to Oct. 9, 2008. The technique criterions of these rain gauges were : (1) caliber: 165mm×254mm (2) the temperature range: 0°C —+70°C (3) resolution: 0.2mm (4) the measuring range: 0—320cm (5) the measuring accuracy: 1%
CHU Rongzhong, ZHAO Guo
The dataset of ground truth measurement synchronizing with ALOS PALSAR was obtained in the Linze station foci experimental area on Jun. 27, 2008. The data were in FBD mode and HH/HV polarization combinations, and the overpass time was approximately at 23:41 BJT. Soil moisture (0-5cm) was acquired by the cutting ring (50cm^3) meanwhile in the west-east desert strip (the corner point in 40 subplots) and north-south strip (the corner point and the center point in 40 subplots). The quadrate location was listed in coordinates.xls file and 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.
BAI Yanfen, SHU Lele, SONG Yi, WANG Yang, DONG Jian, YU Yingjie
This dataset includes 12 scenes, covering the artificial oasis eco-hydrology experimental area of the Heihe River Basin, which were acquired on (yy-mm-dd) 2012-05-30, 2012-06-15, 2012-06-24, 2012-07-10, 2012-08-02, 2012-08-11, 2012-08-18, 2012-08-27, 2012-09-03, 2012-09-12, 2012-09-19, 2012-09-28. The data were all acquired around 12:00 (BJT) at Level 1A, i.e., without atmospheric and geometric correction. ASTER dataset was purchased from Japan Aerospace Exploration Agency (JAXA).
Japan Aerospace Exploration Agency (JAXA)
The dataset of continuous LST (Land Surface Temperature) observation was obtained by the automatic thermometer in the Linze grassland foci experimental area. Six devices numbered from #1 to #6 were used. Observations were carried out in the reed plot A, the saline plots B and C, the alfalfa plot D, the barley plot E and the temporary farmland on Jun. 10 and 11, 2008 and in plots A, B and E on Jul. 11, 2008. Observation time and the land surface radiative temperature were archived in Word, txt and Excel format. See WATER: Dataset of setting of the sampling plots and stripes in the foci experimental of Linze station area for more information.
HUANG Chunlin, CHAO Zhenhua, GE Chunmei, HU Xiaoli, LIU Chao, NIAN Yanyun, WANG Shuguo, WANG Xufeng, WU Yueru, WANG Jing
The albedo product was obtained based on the visible and near-infrared hyperspectral radiometer (29 June, 2012) which covered the artificial oasis eco-hydrology experimental area (5.5 km*5.5 km)with a 5 m spatial resolution.
XIAO Qing, Wen Jianguang
This dataset contains the flux measurements from the Daman superstation eddy covariance system (EC) at the lowest layer in the flux observation matrix from 25 May to 15 September, 2012. The site (100.37223° E, 38.85551° N) was located in a cropland (maize surface) in the Daman irrigation district, which is near Zhangye, Gansu Province. The elevation is 1556.06 m. The EC was installed at a height of 4.5 m; 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/m2), 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.
LIU Shaomin, LI Xin, XU Ziwei
Zhanye Airport desert observation system can offer in situ calibration data for TASI, WiDAS and L band sensor used in aerospace experiment. Observation Site: This point is located in a large, homogeneous and flatten desert near by Zhangye Airport. The main vegetation type is Sparse and low shrub. The coordinates of this site: 38°4′41.30" N, 100°41′48.10" E. Observation Instrument: The observation system consists of two SI-111 infrared radiometers (Campbell, USA), one installed vertically downward to land surface, another face to south of zenith angle 35°. SI-111 sensor installed at 4.0 m height. Observation Time: This site operates from 10 June, 2012 to today. 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: Land surface infrared temperature (by SI-111), sky infrared temperature (by SI-111) 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, land surface infrared temperature @ 4.0 m height; SBT_Sur, body temperature of SI-111 sensor (℃) measured land surface. 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.
MA Mingguo
This data set contains the observation data of vorticity correlation-meter at da-sharon station, upstream of heihe hydrometeorological observation network, from January 1, 2014 to December 31, 2014.The station is located in qilian county, qinghai province.The longitude and latitude of the observation point are 98.9406e, 38.8399N and 3739 m above sea level.The rack height of the vortex correlativity meter 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 (Li7500) 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.After October 20, 10Hz data was missing due to the data storage problem of the memory card, which was replaced by 30min flux data output 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), stability Z/L (dimensionless), 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 Liu et al.(2018), and for observation data processing, please refer to Liu et al.(2011).
LIU Shaomin, LI Xin, CHE Tao, XU Ziwei, ZHANG Yang, TAN Junlei
Input and output table of Heihe River Basin in Gansu Province in 2002 and 2007, including 144 departments
DENG XiangZheng
The dataset of airborne microwave radiometers (L&K) mission was obtained in the A'rou-Biandukou flight zone on Mar. 19, 2008. The frequency of L bands was 1.4 GHz with back sight of 35 degree and dual polarization (H&V) was acquired; and the frequency of K band was 18.7 GHz at the nadir view angle without polarization. The plane took off at Zhangye airport at 9:25 (BJT) and landed at 12:50 along the scheduled lines at the altitude about 4100m and speed about 260km/hr. The raw data include microwave radiometer (L&K bands) data and GPS data; the former are instantaneous non-imaging observation recorded in text, which will be converted into brightness temperatures according to the calibration coefficients (filed with raw data together), and the latter are aircraft longitude, latitude and attitude. Moreover, based on the respective real-time clock log, observations by the microwave radiometer and GPS can be integrated to offer coordinates matching for the former. Yaw, flip, and pitch motions of aircraft were ignored due to the low resolution of microwave radiometer observations. Observation information can also be rasterized, as required, after calibration and coordinates matching. L&K bands resolution (x) and footprint can be approximately estimated as x=0.3H (H is relative flight height) for L band and x=0.24H for K band.
WANG Shuguo, WANG Xufeng, CHE Tao, ZHAO Kai, JIN Jinan, XIAO Qing, Liu Qiang
This set of data is the simulation result of the newly developed land eco-hydrological model CLM_LTF.This model is on top of the land-surface process model CLM4.5 developed by NCAR, coupling the groundwater lateral flow module and considering the role of human irrigation. The model runs from 1981 to 2013, with a spatial resolution of 30 arc seconds (0.0083 degrees), a time step of 1,800 seconds, and a simulation range of the heihe river basin.Air force in 1981-2012 is used by the Chinese academy of sciences institute of the qinghai-tibet plateau of qinghai-tibet plateau more layers of data assimilation and simulation center development areas of China high space-time resolution ground meteorological elements drive data set, air is forced to use 2013 national meteorological information center of wind pressure high resolution made by the wet precipitation temperature radiation data set.The land cover data is a 1km land cover grid data set for the MICLCover heihe river basin, and the irrigation data is shown in "monthly 30-arcsecond resolution surface water and groundwater irrigation data set for the heihe river basin 1981-2013" of the scientific data center for cold and dry regions.The mode output is the monthly average. The document is described as follows: Groundwater depth data: heihe_zwt.nc 2cm soil moisture data: heihe_h2osoi_2cm. nc 100cm soil moisture data: heihe_h2osoi_100cm.nc Evaporation data: Heihe_evaptanspiration. Nc The data is in netcdf format.There are three dimensions, which are month, lat, and lon. Where, month is a month, and the value is 0-395, representing each month from 1981 to 2013. Lat is grid latitude information, and lon is grid longitude information. The data is stored in the data variable. The underground water depth data is in m, the soil moisture data is in m^3/m^3, and the evapotranspiration data is in mm/month
XIE Zhenghui
In the growing season of 2012, four typical shrub communities observed precipitation stem stream and penetrating rainfall during the experiment period.Data content: test date;Stem flow rate;Penetration rainfall, interception. Method of observation: water penetration was measured using a circular iron vessel with a diameter of 15 cm and a height of 10 cm.Since jinrumei, seabuckthorn and jinjijicinus shrub could not be observed on a single plant, after the canopy canopy density of the sample plots was determined, 9 water receivers were placed in each sample plot, so that there were water receivers under different canopy closures.This method of observing rain penetration allows for better collection of rain penetration from different parts of the underbrush.Due to the difficulty of observation and the lack of herbaceous vegetation, the interception of herbaceous under shrub was neglected.Takashima is centered on the stem, which is near the stem. One is placed at the edge of the crown and one at the middle of the crown and spoke. The Angle between each 3 containers is 120°.Six of each shrub were selected for stem flow observation.A single shrub was measured on the lower stems of all branches, and the stem flow of the trunk of the cluster shrub was measured by standard branch method, that is, the basal diameter of each branch of the selected shrub was measured.Under brush all branch stem, the use of polyethylene plastic hose cut open, card on the thickets stems directly, with a plastic adhesive tape and glass, the plastic tube directly connected to the trunk stem flow collection bottle, bottle thickness and plastic pipe, avoid rain and penetrate the rain into the collection bottle, before use after artificial experiments can precisely collect trunk stem flow.In order to reduce the error caused by evaporation in the measurement process, the penetrating rainfall and the flow of the trunk and stem were measured in time after the rain, such as the rain at night, and the samples were taken early in the morning on the second day. Data processing: the penetration rainfall is multiplied by 1.78 (conversion coefficient of different diameters of 20 cm and 15 cm) and replaced by the corresponding penetration rainfall (mm) at standard 20 cm.The measured water volume of each trunk flow collection bottle was divided by the projection area of the standard branch to obtain the trunk flow rate of the branch. The trunk flow rate of the standard branch was multiplied by the number of branches of the whole shrub to obtain the trunk flow rate of the whole shrub.According to the principle of water balance, the redistribution process of rainfall by shrub can be divided into three parts: interception, trunk flow and penetrating rainfall: IC = P - SF - TF Where, P is the rainfall outside the forest;TF is the penetrating rainfall;SF is the flow rate of the trunk.IC is the interception amount of the irrigation layer.According to the measured data of the stem flow through the rain trunk, the interception was obtained by using the above equation.
SONG Yaoxuan, LIU Zhangwen
The site No. 1 EC towers were used for the intercomparison field in the Yingke irrigation district (1552.75 m, 38°59′51.71″ N, 100°24′38.76″ E). The land surface is homogeneous and dominated by vegetables in the middle reaches of the Heihe River Basin. The precipitation comparison dataset was collected between 12 June, 2012, and 22 November, 2012. The dataset includes data for five different rain gauge types, i.e., pit gauge, Chinese standard manual precipitation gauge, siphon rain gauge, tipping bucket gauge, and weighting gauge. The mountain heights for these gauges were 0.0, 0.7, 1.2, 1.5, and 1.5 m, respectively. The data were recorded every 1 hour, 1 day, 10 minutes, 10 minutes, and 10 minutes, respectively. The main objective of the data collection was to perform an intercomparison of in situ rainfall measurements. The data processing and quality control steps were as follows: 1) The water level data which collected from the hydrological station were averaged over intervals of 10 min for a total of 144 records per day. The missing data were denoted by -6999. 2) Data out the normal range records were rejected. 3) Unphysical data were rejected. For more information, please refer to Liu et al. (2016) (for multi-scale observation experiment or sites information), He et al. (2016) (for data processing) in the Citation section.
ZHANG Jian, NING Tianxiang, HUANG Xiaoming, JIANG Heng, LIU Shaomin, LI Xin
The content is 32 rainfall interception data of Picea crassifolia forest from May 24 to September 3, 2013. The sample plot is set in Qinghai Spruce Forest with an altitude of 2800m, the sample plot size is 30m × 30m, 90 rain cones with a diameter of 20cm are arranged in the sample plot with an interval of 3M, and 20 water tanks with two specifications (I is 200cm * 20cm, II is 400cm * 20cm) are arranged to observe the interception data in the forest. A dsj2 (Tianjin Meteorological Instrument Factory) siphon rain gauge was set up in the open land about 50m away from the sample site to observe the rainfall and rainfall characteristics outside the forest. After the end of each precipitation event and the stop of penetrating rain in the forest, measure and record the water quantity in each rain cone with a rain gauge.
MA Wenying, ZHAO Chuanyan
1. Data overview The data set of the base camp integrated environmental observation system is a set of ENVIS (IMKO, Germany) which was installed at the base camp observation point by qilian station.It is stored automatically by ENVIS data mining system. 2. Data content This data set is the scale data from January 1, 2012 to December 31, 2012.Including air temperature 1.5m, humidity 1.5m, air temperature 2.5m, humidity 2.5m, soil moisture 0cm, precipitation, wind speed 1.5m, wind speed 2.5m, wind direction 1.5m, geothermal flux 5cm, total radiation, surface temperature, ground temperature 20cm, ground temperature 40cm, ground temperature 60cm, ground temperature 80cm, ground temperature 120cm, ground temperature 160cm, CO2, air pressure. 3. Space and time scope Geographical coordinates: longitude: 99° 53’e;Latitude: 38°16 'N;Height: 2980.2 m.
CHEN Rensheng, HAN Chuntan
This dataset includes eight scenes, covering the artificial oasis eco-hydrology experimental area of the Heihe River Basin, which were acquired on (yy-mm-dd hh:mm) 2012-05-24, 2012-06-04, 2012-06-26, 2012-07-07, 2012-07-29, 2012-08-09, 2012-08-14, 2012-08-25. The data were all acquired around 19:00 (BJT) at StripMap mode with product level of MGD. Within them, the former six images are of HH/VV polarization with low incidence angle (22-24°), while the later two images acquired on 2012-08-14 and 2012-08-25 are of VV/VH polarization with higher incidence angle (39-40°). TerraSAR-X dataset was acquired from German Space Agency (DLR) through the general proposal of “Estimation of eco-hydrological variables using TerraSAR-X data in the Heihe River Basin, China” (project ID: HYD2096).
German Space Agency (DLR)
A land surface temperature and upward/downward shortwave radiation observation system was set up on the roof, which locate on the edge of No.4 eddy covariance system (EC4) of the MUlti-Scale Observation EXperiment on Evapotranspiration over heterogeneous land surfaces 2012 (MUSOEXE-12). This observation site can offer in situ calibration data for TASI, WiDAS and L band sensor used in aerospace experiment. Observation Site: This point is located in a large and homogeneous adobe roof in Shiqiao Village, Xiaoman Town, Zhangye City. Land surface of observation site is relatively flat and uniform, and also not tall trees around. It’s about 20 meters away from southwest No.4 eddy covariance system (EC4) observation points. The coordinates of this site: 38°52′38.50″ N,100°21′27.00″ E。 Observation Instrument: Observation system is composed of a SI-111 infrared radiometer (Campbell, USA) installed vertically downward, two CMP3 pyranometer (Kipp&Zonen, Netherlands) one upward, another downward. Observation height is 1.0 m, data logging by a Campbell CR850 logger. Sensor orientation: Observation mounting arm has 3 m long, parallel to roof edge, azimuth angle: 156° (East by south 66°) Observation Time: This site operates from 23 June, 2012 to 20 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: Land surface (adobe roof) temperature, downward/upward total solar radiation, surface albedo. Dataset is stored in *.dat file, which can be read by Microsoft excel or other text processing software (UltraEdit, et. al). Table heads meaning: Rs_downwell, downward shortwave radiation (W/m^2); Rs_upwell, upward (reflect) shortwave radiation (W/m^2); albedo, calculate by Rs_upwell/ Rs_downwell. SBT_C, body temperature of SI-111 sensor (℃); Target_C, Target of surface temperature (℃). 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.
MA Mingguo
The 30 m / month synthetic photosynthetic effective radiation absorption ratio (fAPAR) data set of Heihe River basin provides the monthly Lai synthetic products from 2011 to 2014. This data uses the characteristics of HJ / CCD data of China's domestic satellite, which has both high time resolution (2 days after Networking) and spatial resolution (30 m), to construct multi angle observation data set, considering different vegetation types, based on land cover classification map, combined with 30 m /Monthly synthetic leaf area index (LAI) products were produced by fapar-p model based on energy conservation. Based on the principle of energy conservation, the algorithm considers the multiple bounces between vegetation, soil and vegetation, as well as the influence of various factors such as sky scattered light. By analyzing the process of the interaction between photons and canopy, from the point of view that the movement of photons in the canopy is equal to the probability of re collision when multiple scattering occurs, a uniform and continuous vegetation fAPAR model is established. In addition, the effects of various factors on the fAPAR model were analyzed, including soil and leaf reflectance, aggregation index, and G function. The algorithm is highly dynamic, and can get better results for different soil background, vegetation type, radiation conditions, light and observation geometry, weather conditions. Compared with the data of corn canopy par measurement in Yingke irrigation area of Zhangye City, Gansu Province on July 8, 2012, the 30 m / month fAPAR product has a high consistency with the ground observation data, and the error with the observation value is less than 5%. In a word, the 30 m / month synthetic photosynthetic effective radiation absorption ratio (fAPAR) data set of Heihe River Basin comprehensively uses the multi temporal and multi angle observation data to improve the estimation accuracy and time resolution of parameter products, and better serves the application of remote sensing data products.
FAN Wenjie, LIU Qinhuo, ZHONG Bo, WU Junjun, WU Shanlong
The data set contains eddy covariance System observation data of Daman super station which is located in the middle reaches of the Heihe Hydro-meteorological Observation Network from January 1, 2017 to December 31, 2017. The site is located in Daman Irrigation District, Zhangye, Gansu Province, and the underlying surface is corn. The latitude and longitude of the observation point is 100.37223E, 38.85551N, and the altitude is 1556.06m. The mount height of the Eddy Covariance System is 4.5 m, the sampling frequency is 10 Hz, the ultrasonic orientation is positive North, and the distance between the ultrasonic wind speed temperature meter (CSAT3) and the CO2/H2O analyzer (Li7500) is 17 cm. The original observation data of the Eddy Covariance System is 10 Hz, and the released data is a 30-minute data processed by Eddypro software. The main steps of the processing include: outlier eliminating, delay time correction, coordinates rotation (secondary coordinates rotation), frequency response correction, ultrasonic virtual temperature correction and density (WPL) correction, etc. Meanwhile, the quality evaluation of each flux value was performed,mainly includes atmospheric stability (Δst) test and turbulence similarity (ITC) test. The 30-min flux value output of Eddypro software was also screened: (1) Data from the instrument error was eliminated; (2) Data obtained with one hour before and after precipitation was removed; (3) Data with a deletion rate greater than 10% of the 10 Hz raw data every 30 minutes was eliminated; (4) Observation data of weak turbulence at night (u* less than 0.1 m/s) was excluded. The average period of observation data is 30 minutes, 48 data per day, and the missing data is marked as -6999. The data of April 3 and 4 was missing due to Li7500 calibration of the eddy system; data from August 29 to September 5 was missing due to collector problem. Published observation data include: Date/Time, wind direction(°), horizontal wind speed(m/s), lateral wind speed standard deviation(m/s), ultrasonic virtual temperature (°C), water vapor density (g/m3), carbon dioxide concentration(mg/m3), friction velocity (m/s), length (m), sensible heat flux(W/m2), latent heat flux (W/m2), carbon dioxide flux (mg/(m2s)), sensible heat flux quality identification QA_Hs, latent heat flux quality identification QA_LE, carbon dioxide flux quality identification QA_Fc. The quality identification of sensible heat, latent heat, and carbon dioxide flux is divided into three levels (quality mark 0: (Δst <30, ITC<30); 1: (Δst <100, ITC<100); the rest is 2). The meaning of the data time, such as 0:30 represents an average data of 0:00-0:30; the data is stored in *.xls format. For hydro-meteorological network or station information, please refer to Liu et al. (2018). For observation data processing, please refer to Liu et al. (2011).
LIU Shaomin, LI Xin, CHE Tao, XU Ziwei, REN Zhiguo, TAN Junlei
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