The fractional vegetation cover observation was carried out for the typical underlying surface in the lower reaches of the Heihe River Basin during the aviation flight experiment in 2014. The observation started on 24 July, 2014 and finished on 1 August, 2014. 1. Observation time On days of 24 July, 27 July, 30 July, 31 July and 1 August, 2014 2. Samples method Large areas with homogeneous vegetation (greater than 100 m * 100 m) were chosen as the observation samples. And forty field samples were selected according to the characteristics of vegetation distribution in the low reaches. The land-use types including the cantaloupe, the Tamarix chinensis, the reeds, the weeds, the Karelinia caspica, the Sophora alopecuroides and so on. 3. Observation methods 3.1 Instruments and measurement method Digital photography measurement is implemented to measure the FVC. Plot positions, photographic method and data processing method are dedicatedly designed. In field measurements, a long stick with the camera mounted on one end is beneficial to conveniently measure various species of vegetation, enabling a larger area to be photographed with a smaller field of view. The stick can be used to change the camera height; a fixed-focus camera can be placed at the end of the instrument platform at the front end of the support bar, and the camera can be operated by remote control. 3.2 Photographic method The photographic method used depends on the species of vegetation and planting pattern. A long stick with the camera mounted on one end is used for the Tamarix chinensisi and reeds. For the Tamarix chinensisi and reeds, rows of more than two cycles should be included in the field of view (<30), and the side length of the image should be parallel to the row. If there are no more than two complete cycles, then information regarding row spacing and plant spacing are required. The FVC of the entire cycle, that is, the FVC of the quadrat, can be obtained from the number of rows included in the field of view. For other vegetation , the photos of FVC were obtained by directly photographing for the lower heights of the vegetation. 3.3 Method for calculating the FVC The detail method of the FVC calculation can be found in the reference below. Many methods are available to extract the FVC from digital images, and the degree of automation and the precision of identification are important factors that affect the efficiency of field measurements. This method, which is proposed by the authors, has the advantages of a simple algorithm, a high degree of automation and high precision, as well as ease of operation (see the reference). 4 Data storage The observation recorded data were stored in excel and the original FVC data were stored in photos.
0 2019-09-12
This data set contains meteorological element observation data from January 1, 2015 to September 9, 2015 from the aruyangpo station, upstream of heihe hydrometeorological observation network.The station is located in yangpo, north of ahrou township, qilian county, qinghai province.The latitude and longitude of the observation point is 100.5204E, 38.0898N and 3529m above sea level.The air temperature and relative humidity sensors are located at 5m, facing due north.The barometer is installed in the anti-skid box on the ground;The tilting bucket rain gauge is installed at 10m;The wind speed and direction sensor is set at 10m, facing due north;The four-component radiometer is installed at 6m, facing due south;Two infrared thermometers are installed at 6m, facing due south, and the probe facing vertically downward;Two photosynthetically active radiators were installed at 6m, facing due south, and one probe was vertically upward and downward.The soil temperature probe is buried at 0cm on the surface and 4cm underground, 10cm, 20cm, 40cm, 80cm, 120cm, 160cm, 2m to the south of the meteorological tower.The soil water probe is buried at 4cm, 10cm, 20cm, 40cm, 80cm, 120cm and 160cm underground, 2m to the south of the meteorological tower.The soil heat flow plates (3 pieces) are buried in the ground 6cm underground, 2m to the south of the meteorological tower. Observation projects are: air temperature and humidity (Ta_5m, RH_5m) (unit: c, percentage), pressure (Press) (unit: hundred mpa), precipitation (Rain) (unit: mm), wind speed (WS_10m) (unit: m/s), wind (WD_10m) (unit: degrees), the radiation of four component (DR, UR, DLR_Cor, ULR_Cor, Rn) (unit: watts per square meter), the surface radiation temperature (IRT_1, IRT_2) (unit:(unit: Ts_0cm, Ts_4cm, Ts_10cm, Ts_20cm, Ts_40cm, Ts_80cm, Ts_120cm, Ts_160cm) (unit: Celsius), soil moisture (Ms_4cm, Ms_10cm, Ms_20cm, Ms_40cm, Ms_80cm, Ms_120cm, Ms_160cm) (unit:Volumetric water content, percentage), upward and downward photosynthetically active radiation (PAR_up, PAR_down) (in micromol/m2 seconds). Processing and quality control of observed data :(1) ensure 144 pieces of data every day (every 10min), and mark by -6999 in case of data missing;Due to the damage of wind direction sensor, data was missing between July 2015 and September 2015;The station was demolished after September 9;(2) excluding the time with duplicate records;(3) data that obviously exceeds the physical significance or the range of the instrument is deleted;(4) the part marked with red letter in the data is the data in question;(5) date and time have the same format, and date and time are in the same column.For example, the time is: September 10, 2015, 10:30;(6) the naming rule is: AWS+ site name. 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).
0 2020-04-10
The dataset of albedo observations was obtained by the shortwave radiometer (1#: CMP3-060580 and 2#: CMP3-060584 from Institute of Remote Sensing Applications) in the arid region hydrology experiment area from May 20 to Jul. 14, 2008. The dataset of ground truth measurement was synchronizing with WiDAS (Wide-angle Infrared Dual-mode line/area Array Scanner), OMIS-II, Landsat TM, ASTER, Hyperion and CHRIS. Observation items included: (1) Albedo in Yingke oasis and Huazhaizi desert steppe foci experimental area. Yingke maize field was measured on May 28 and 30, Jun. 3, 16, 20, 27 and 29, Jul. 11 and 14, 2008, Yingke wheat field on May 20 and 29, Jun. 1, 4, 6, 9, 15 and 24, Jul. 7 and 14, 2008, Huazhaizi desert No. 2 plot on Jun. 14, 22 and 30, 2008 and the flax field on Jun. 23, 2008. (2) Albedo in Linze foci experimental area. Maize was measured on May 25, 2008 and desert and alfalfa on May 24, 2008. (3) Albedo in Biandukou foci experimental area. The rape field, the grassland and the barley were measured on Jun. 24, 2008, and barley on Jul. 6, 2008. (4) Zhangye intensive experimental area. The intra-city grassland and the roof of Jingdu Hotel were measured on May 27, 2008. Besides the shortwave radiometer, the digital multimeter (UNIT) was also used for voltage measuring. Raw data were archived in paper forms and Excel after input into the computer. Besides, shorter plants were chosen for measurements as the platform was not high enough. And the distance between the probe and the plant was shorter during the later observation period.
0 2019-05-23
The dataset of the albedo measurements was obtained by the shortwave radiometer (KippZonen CMP3, 310nm-2800nm, 1m above the ground) in the Linze station foci experimental area. Sand, psammophyte and withered annual herbs in A9 of the south-north desert strip and LY07, and flax, maize and tomatoes in Linze station were measured on May 28, Jun. 5, 6, 15, 22, 25, 30 and Jul. 4, 2008. Voltage was measured manually by the digital multimeter (UNIT) at intervals of 2 minutes for albedo from May 28 to Jun. 22; self-recording Campbell CR1000 was used at intervals of 1s from Jun. 25 to Jul. 4. TIMESTAMP (observation time), SOLAR_UP_AVG (downward shortwave radiation), SOLAR_DOWN_AVG (upward shortwave radiation), SOLAR_NET_AVG (net radiation)= SOLAR_UP_AVG - SOLAR_DOWN_AVG, albedo_Avg (albedo) = SOLAR_DOWN_AVG / SOLAR_UP_AVG, batt_volt_Min (voltage), and ptemp (CR1000 temperature) were all recorded. Manual data were archived as Excel files and the self-recording data in .dat, which were processed into Excel.
0 2019-05-23
The dataset of albedo observations was obtained in the Linze grassland foci experimental area. Measurements were carried out by using the shortwave radiometer (the upward radiometer: 071392; the downward radiometer: 071389) in the reed plot A, the saline plots B and C, the alfalfa plot D, the barley plot E and the temporary cement floor. Manual work was applied before Jun. 6, 2008 with the probe 1.3m-1.46m high and automatic observations hereafter with the probe 1.20m or 1.30m. Observation site cover type observation date Plot E barley May 25, 2008 Plot D alfalfa May 26, 2008 Plot D alfalfa May 27, 2008 Plot E cumin May 28, 2008 Plot E cumin May 30, 2008 Plot A reed Jun. 1, 2008 Plot B saline Jun. 2, 2008 Plot A reed Jun. 3, 2008 Temporary cement floor Jun. 4, 2008 Vicinity of plot E Jun. 6, 2008 Plot A reed Jun. 20, 2008 Plot A reed Jun. 22, 2008 Plot D alfalfa Jun. 23, 2008 Plot E barley Jun. 24, 2008 Plot E barley Jul. 11, 2008 Self-recording observations included: TIMESTAMP: observation time SOLAR_UP_AVG: downward shortwave radiation SOLAR_DOWN_AVG: upward shortwave radiation SOLAR_NET_AVG: net radiation = SOLAR_UP_AVG - SOLAR_DOWN_AVG albedo_Avg: albedo = SOLAR_DOWN_AVG / SOLAR_UP_AVG batt_volt_Min: voltage ptemp: CR1000 temperature Data were archived in Excel file. See WATER: Dataset of setting of the sampling plots and stripes in the foci experimental area of Linze station for more information.
0 2019-09-13
In mid July 2011, the photosynthetic organs (leaf or assimilating branches) of typical desert plants were collected and determined by laboratory. The indicators include: leaf water potential, total leaf water content, relative water content, dry weight water content, leaf dry matter content, specific leaf area, specific leaf volume, free water, bound water, etc.
0 2019-09-15
1. data description Soil temperature monitoring in typical soil profile of hongnigou is divided into seven layers, with depth distribution of 20cm, 40cm, 60cm, 80cm, 120cm, 160cm and 230cm.The frequency of observation is 1 time /60 minutes.The time range of observation data is from August 25, 2013 to May 1, 2014. 2. Sampling location The soil temperature monitoring point of the typical soil profile in the small basin of cucurbitou was set in the middle and lower part of the red mud ditch, and its geographical coordinates were 99 ° 52 '25.98 "E, 38 ° 15' 36.11" N. 3. Test method Soil Temperature was observed using HOBO Pendant® Temperature/Light Data Logger 64k-ua-002-64 Temperature recorder.
0 2020-06-01
The dataset of position of the sampling plots and stripes was obtained in A1, A2, A3, L1, L2, L3, L4, L5 and L6 of the A'rou foci experimental area. The quadrates were changed from 4×4 into 3×3 subsites during the foci experimental period, with each one spanning a 30×30 m2 plot. The centers and corners of each subsite were collected. As for the sampling lines, samples were collected every 100 m along them from south to north. The points were named in the form of L1-1, indication No. 1 point in No. 1 line. The coordinates and elevation of each sampling point were included in the dataset in Excel format.
0 2019-05-23
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
This data set contains the eddy correlation-meter observation data of the mixed forest station downstream of heihe hydrometeorological observation network from January 1, 2014 to December 31, 2014.The station is located in Inner Mongolia ejin banner four road bridge, under the surface is populus and tamarix.The longitude and latitude of the observation point are 101.1335e, 41.9903n and 874 m above sea level.The rack height of the vortex correlativity instrument is 22m, 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 17cm. 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 0.2m/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. 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 Li et al.(2013), and for observation data processing, please refer to Liu et al.(2011).
0 2020-03-04
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