Brief Introduction：The high-cold regions in China include the Qinghai Tibetan Plateau, and the alpine regions of Gansu, Inner Mongolia and Xinjiang, with a total area of about 2.9 million square kilometers. Due to the complexity of topography and geomorphology, the worldwide researches more and more focus on the surface processes of the Qinghai Tibetan Plateau and its adjacent areas. The High-cold Region Observation and Research Network for Land Surface Processes & Environment of China (HORN) has gradually formed. It integrates 17 stations of Chinese Academy of Sciences, for long term observations and researches of land surface processes, including glaciers, permafrost, lades, alpine ecosystem in the high-cold regions of China. It provides a platform support for integrated researches of earth system, through condensation of scientific problems, integration of monitoring resources, improvement of observation capability and level, long-term continuous monitoring of surface processes and environmental changes in cold regions. It also provides data support for revealing the law of climate change and water resources formation and transformation in the headwaters of big rivers, exploring the changes of ecosystem structure and service function, grasping the mechanism of natural disasters such as ice and snow freezing and thawing, and promoting the sustainable development of regional economy and society, etc. A network integrated center is set up to organize research and carry out the specific implementation of network construction. It consists of an office, an observation technology service group and a data integration management group. The participating units of HORN should sign construction/research contracts in order to implement contract-based management, perform all tasks in the contracts and accept the examination and acceptance of the network organization. The network construction should give priority to scientific research, coordinated development, relatively balanced allocation of infrastructure and observation instruments, and free sharing of data within the network. For the principle of sharing and opening, the observatories of the network are open to the whole country. The network cooperates with relevant units through consultation, agreement or contract according to specific tasks and costs; the original observation data are gradually shared based on the principle of first the network, then the department and then the society. The network carries out planned and coordinated cooperation with foreign scientific research institutions and universities, which can improve the level of network observation and expand the content of observation through the cooperation. The HORN is managed by the Chinese Academy of Sciences in the allocation of funds and resources.
Number of Datasets：465
The dataset focuses on the distribution of sampling plots and stripes in the Yingke oasis and Huazhaizi desert steppe foci experimental areas. (1) YKLZYMD-the maize field plot (180m×180m) at Yingke Weather Station It matches No. 10 flight route. Five subplots were selected, including three maize subplots and 2 wheat subplots. The maize subplots, labeled as YKLZYMD01, YKLZYMD02 and YKLZYMD03, were planted in different directions with a ridge sturctrue, which was composed of single row of maizes and bare soils. The distance of adjacent maize rows, as well as the width of bare soil was 0.5m . YKLZYMD05 (2.46m×1m, along the ridge) was located in the northwest of the plot and interplanted with wheat and soy bean. YKLZYMDD06 was exclusively wheat, and 10 rows (1.5m) vertical to the ridge and 1m along the ridge were measured. This is a key experimental area for canopy spectrum, component reflectance spectra, BRDF, albedo, the photosynthetic rate, FPAR, structural parameters, vegetation coverage, the radiative temperature, surface emissivity, atmospheric parameters and soil moisture. (2) YKXMD-Yingke wheat plot (180m×170m) It matches No. 11 flight route. Wheat and maize were interplanted. Three subplots with the same size (3.4m * 3.4m) were selected for the measurement of vegetaion structural parameters, BRDF, the radiative temperature, vegetation coverage and soil moisture. (3) HZZHMZYMD-Huazhaizi maize plot (240m×240m) It is located between No. 9 and No. 10 flight routes. The maize seed dominates, and wheat, alfalfa and tomatoes were planted. 4 maize subplots and one wheat subplot were chosen to collect the canopy temperature, spectrum, structural parameters and vegetation coverage. (4) HZZHMYD1-Huazhaizi desert No. 1 plot (240m×240m) It is located within No. 4 flight route. 3 subplots (30m×30m) were chosen for reflectance spectra, BRDF, vegetation coverage, emissivity, the radiative temperature, soil moisture, atmospheric parameters by sunphotometer CE318 and surface roughness. In cooperation with experiments in Huazhaizi desert plots and Yingke weather station, simultaneous airborne multiangular thermal infrared camera&CCD-ground observations, simultaneous airborne hyperspectral imager (OMIS)-ground observations, simultaneous OMIS/TM/ASTER/Hyperion/CHRIS/ASAR-ground observations were all accomplished. (5) HZZHMYD2-Huazhaizi desert No. 2 plot It matches No. 5 flight route. Three subplots (10m×10m) for coverage and the radiative temperature and one (30m×30m) for simultaneous temperature and spectrum were chosen. (6) HZZHMYD3-Huazhaizi desert No. 3 plot (30m×30m) It is an intensive plot without simultaneous airporne or spaceborne measurement. (7) DJCYMYD-the maize field at the resort It is an intensive plot (30m×30m) with the maize seeds, mainly for the measurement of radiative temperature and soil moisture. (8) DJCDMD-the barley field at the resort It is mainly for radiative temperature data. (9) DJCDBC-the calibration field at the resort It is located at the ICBC resort. The reflectance spectra of the basketball court, the pool and the vegetation were collected used for radiative calibration of CCD camera in visible and near infrared spectra range. The dataset also includes geographic infomation of each sample point.
2019-05-23 0 0 View Details
The dataset of photosynthesis was observed by LI-6400XT Portable Photosynthesis System in the artificial oasis eco-hydrology experimental area of the Heihe River Basin. Observation items included two main crops in the middle reaches of Heihe river: wheat and maize, which located in the town of Pingchuan in Linze and the Super Station of Wuxing, respectively. Observation periods lasted from mid-May to September. This dataset included the raw observation data and the pretreatment data of wheat and maize observed by LI-6400 during the observation periods. Objectives of observation: The photosynthetic datasets can be used in the study of plant physiological ecology characteristic and the simulation and validation for the eco-hydrological models. Instrument and theory of the observation: (1) Measuring instrument: LI-6400XT Portable Photosynthesis System; (2) Measuring theory: Using the infrared gas analyzer to measure the change of CO2 concentration, and then measuring the differences of CO2 concentration between the sample chamber and the referenced chamber so as to acquire the net productivity of the leaf. Time and site of observation: (1) Observation site of the wheat: in the town of Pingchuan in Linze; Observation time: 2012-05-17，2012-06-08 to 2012-6-13; (2) Observation site of the maize: in the Super Station of Wuxing; Observation time: from 2012-05-19 to 2012-08-15. The time used in this dataset is in UTC+8 Time. Data processing: The raw data of LI-6400 were archived in text format and can be opened by text editor or excel, the preprocessed data were in Excel format. Every time period of observation was archived in a single document, named as “date + type + time”, every leaf was recorded 3 times, and then added a remark.
2019-05-23 0 0 View Details
The dataset of soil frozen penetration measured by the soil frozen tube was obtained at the super site (100m×100m, pure Qinghai spruce) around the Dayekou Guantan forest station. Observation time was 8:00 each morning from Jun. 1 to Dec. 31, 2008. The soil frozen tube was laid beneath the spruce for diurnal soil frozen depth changes and the maximum depth (cm) was recorded.
2019-05-23 0 1 View Details
The dataset of ground truth measurements synchronizing with Landsat TM was obtained in the Linze grassland and Linze station foci experimental area on Sep. 23, 2007 during the pre-observation periods, and one scene was captured well. These data can provide reliable ground data for retrieval and validation of land surface temperatures with EO-1 Hyperion remote sensing approaches. Observation items included: (1) the land surface radiative temperature by the hand-held infrared thermometer, which was calibrated; (2) GPS by GARMIN GPS 76; (3) atmospheric parameters at Daman Water Management office measured by CE318 (produced by CIMEL in France). The total optical depth, aerosol optical depth, Rayleigh scattering coefficient, column water vapor in 936 nm, particle size spectrum and phase function were then retrieved from these observations. The optical depth in 1020nm, 936nm, 870nm, 670nm and 440nm were all acquired by CE318. These data include the raw data in .k7 format and can be opened by ASTPWin software. ReadMe.txt is attached for detail. Processed data (after retrieval of the raw data) in Excel contain 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. (4) ground-based land surface temperature measurements by the thermal imager in the Heihe gobi, west of Zhangye city.
2019-05-23 0 0 View Details
This dataset contains the flux measurements from the Zhangye wetland station eddy covariance system (EC) in the flux observation matrix from 25 June to 26 September, 2012. The site (100.44640° E, 38.97514° N) was located in a wetland surface, which is near Zhangye city, Gansu Province. The elevation is 1460.00 m. The EC was installed at a height of 5.2 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 (Gill&Li7500A) was 0.25 m. Raw data acquired at 10 Hz were processed using the Eddypro post-processing software (Li-Cor Company, http://www.licor.com/env/products/ eddy_covariance/software.html), including spike detection, lag correction of H2O/CO2 relative to the vertical wind component, sonic virtual temperature correction, angle of attack 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 : 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.
2019-05-23 0 0 View Details
The concentration data set of persistent organic pollutants in the atmosphere, lake water and fish bodies in Namco from 2012 to 2014 includes concentration time series of atmospheric gaseous organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), atmospheric gaseous polycyclic aromatic hydrocarbons (PAHs), atmospheric particulate PAHs, dissolved persistent organic pollutants (POPs) in lake water, POPs in suspended particles of lake water and POPs in bodies of Gymnocypris namensis. The contents of the data set are all measured data. (1) The atmospheric samples were collected from the Integrated Observation and Research Station of Multisphere in Namco by the atmospheric active sampler. The flow rate of the sampler is 60 L min-1, which collects data every other day. One sample is generated every half month, and the sampling volume is approximately 600 m³. Each sample includes a glass fiber filter (GFF, 0.45 μm, Whatman) that adsorbs particulate POPs and a polyurethane foam (PUF, 7.5 x 6 cm) that collects gaseous POPs. (2) Fifteen sampling points were selected along Namco to collect surface lake water samples at a water depth of 0-1 m and with a volume of 200 L. The total suspended particulates are obtained by filtering the water samples with a 0.7 μm GFF membrane, and then the dissolved POPs in the water are collected using a solid phase extraction column packed with XAD-2. (3) Gymnocypris namensis is the most widely distributed fish in Namco. A total of 35 samples of different sizes were collected, and the concentration of POPs in the back muscle samples was analyzed. Each medium sample was prepared and analyzed by the Key Laboratory of Tibetan Environment Changes and Land Surface Processes of CAS. The sample preparation steps include Soxhlet extraction, silica-alumina column purification, removal of macromolecular impurities by a GPC column, concentration and constant volume. The analytical test instrument was a gas chromatography-mass spectrometer (GC-MS, Finnigan-Trace GC/PolarisQ) manufactured by American Thermoelectric Corporation. The column separating OCPs and PCBs was a CP-Sil 8CB capillary column (50 m × 0.25 mm × 0.25 μm), and the column separating PAHs was a DB-5MS capillary column (60 m × 0.25 mm × 0.25 μm). Sampling and laboratory analysis procedures followed strict quality control measures with lab blanks and field blanks. The detection limit of the compound is the average of the concentration of the corresponding compound in the field blank plus 3 times the standard deviation; if the compound is not detected in the field blank, the signal-to-noise ratio, 10 times the lowest concentration of the working curve, will be considered as the detection limit. Data below the detection limit are considered undetected and labeled as BDL; data marked in italics are detected by 1/2 times the detection limit. The recovery of PAHs is between 65% and 92%, the recovery of OCPs is between 64% and 112%, and the sample concentration is not corrected using recovery.
2019-04-20 0 2 View Details
The dataset of automatic meteorological observations was obtained at the Dadongshu mountain snow observation station (E100°14′/N38°01′, 4101m) from Oct. 29, 2007 to Oct. 1, 2009. The experimental area with a flat and open terrain was slightly sloping from southeast to northwest. With alpine meadow and stones, and snow in autumn, winter and spring, the landscape was ideal. Observation items were multilayer (2m and 10m) of the wind speed, the air temperature and air humidity, the air pressure, rain and snow gauges, snow depth, four components of radiation, the multilayer soil temperature (5cm, 10cm, 20cm, 40cm, 80cm, and 120cm), soil moisture (5cm, 10cm, 20cm, 40cm, 80cm, and 120cm), and soil heat flux (5cm & 15cm). The raw data were level0 and the data after basic processes were level1, in which ambiguous ones were marked; the data after strict quality control were defined as Level2. The data files were named as follows: station+datalevel+AMS+datadate. Level2 or above were strongly recommended to domestic users. As for detailed information, please refer to Meteorological and Hydrological Flux Data Guide.
2019-05-23 0 2 View Details
This dataset contains eddy correlation instrument observation data from the Huyanglin station downstream of the Heihe Hydrological and Meteorological Observation Network from January 1, 2014 to December 31, 2014. The site is located in Sidaoqiao, Ejin Banner, Inner Mongolia, and the underlying surface is Populus euphratica. The latitude and longitude of the observation point is 101.1236E, 41.9928N, and the altitude is 876m. The vortex correlator has a height of 22 m and a sampling frequency of 10 Hz. The ultrasonic orientation is in the north direction, 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 correlation meter is 10 Hz, and the released data is 30 minutes of data processed by Eddypro software. The main steps of the processing include: outlier removal, time-lag correction, coordinate rotation (secondary coordinate rotation), frequency response correction, ultrasonic virtual temperature correction and density (WPL) correction, etc. At the same time, the quality evaluation of each flux value is conducted, it mainly contains atmosphere state stability test(Δst) and integrated turbulence characteristic test(ITC). The 30-min flux value output by Eddypro software was also screened: (1) data from the instrument error was eliminated; (2) data 1 h before and after precipitation was removed; (3) data from the deletion rate greater than 10% within every 30 min of the 10 Hz raw data. (4) eliminating observation data of weak turbulence at night (u* less than 0.1 m/s). The average time period of observation data is 30 minutes, 48 data per day, and the missing data is labeled -6999. Abnormal data caused by instrument drift and other reasons are marked in red. From February 21 to March 13, the data is missing due to problems in memory card and wireless transmission module. Published observations include: date/time Date/Time, wind direction Wdir(°), horizontal wind speed Wnd(m/s), lateral wind speed standard deviation Std_Uy(m/s), ultrasonic virtual temperature Tv(°C), 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)), 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 of 0:00-0:30; the data is stored in *.xls format. For hydrometeorological network or site information, please refer to Li et al. (2013). For observation data processing, please refer to Liu et al. (2011).
2019-07-24 0 2 View Details
The dataset of ground truth measurements synchronizing with ALOS PALSAR was obtained in the Linze station foci experimental area on Jul. 10, 2008. The ALOS PALSAR data were in FBS mode and HH polarization combinations, and the overpass time was approximately at 23:39 BJT. Soil moisture (0-5cm) data were measured by the cutting ring method (50cm^3) in LY07 and LY08 quadrates (repeated nine times). The quadrate location information was listed in coordinates.xls 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.
2019-05-23 0 0 View Details
Data source: China l Meteorological Administration Network; Data Content: Daily Rainfall Data Series of Heihe River Basin from 1990 to 2004; Evaporation Data of Heihe River Basin from 2000 to 2012. Data Spatial Range: Rainfall Data (Yingluoxia, Shandan, Gaoya, Pingchuan, Ganzhou Pingshan Lake, Zhengyixia Gorge, Liyuan River); Evaporation Data (Zhangye, Gaotai, Dingxin, Jiuquan, Jinta, Shandan, Ejina, Hequ)
2019-07-19 0 1 View Details