On July 10, 2012, the airborne flight and ground observation was synchronously carried out in the PLMR quadrat of Yingke Oasis and the Huazhaizi Desert. PLMR (Polarimetric L-band Multibeam Radiometer) is a dual-polarized (H/V) L-band microwave radiometer with a center frequency of 1.413 GHz, a bandwidth of 24 MHz, and a resolution of 1 km (relative flight height of 3 km).The radiometer has 6 beams to observe synchronously, and the incident angles are ±7º，±21.5º，±38.5º, and the sensitivity is less than 1K. The flight observation mainly covers the artificial oasis eco-hydrological test area in the middle reaches. This ground-synchronized data set provides a basic ground dataset for developing and validating passive microwave remote sensing inversion soil moisture algorithms. Quadrat and sampling strategy: The observation area is located in the transition zone between the southern margin of Zhangye Oasis and Anyang beach desert, the west side of Zhang (Zhangye)-Da (Daman) highway. It is divided into two parts by the main canal of the Dragon Canal from North to South. The Southwest area is a desert quadrat with the size of 1 km×1 km. The desert is relatively homogeneous, so soil moisture of 5 points in the 1 km quadrat are collected (1 point of each corner and the center point, in the actual measurement process, several extra points can be measured along the road). The four corner points are 600 meters away from each other,except the diagonal direction. And the southwest corner point is Huazhaizi Desert Station, for the convenience of comparison with weather station data. On the northeast side, a large size quadrat of 6 km×1.6 km is selected for simultaneous observation of the oasis underlying surface.In order to obtain the brightness temperature comparison with the PLMR observation, the quadrat was chose based on the following factors :surface coverage representative, avoiding the residential and greenhouses, crossing the oasis farmland and part of the Southern desert, accessibility, and observation time(road consumption). Taking the resolution of PLMR observations into consideration, in the synchronous observation, 11 sampling lines (East-West distribution) were collected with an interval of 160 meters from the East to the West. Each line from the North to the South was separated by 21 points with an interval of 80 meters. And 4 Hydraprobe Data Acquisition System (HDAS, Reference 2) were used to measure simultaneously. Measurement contents: About 230 points of the quadrat were collected, 2 observations were performed on each point, that is, 2 observations were performed on each sampling point of the film mulched corn field, 1 inside the film (marked as a in the data record), 1 outside the film (marked as b in the data record). Since the HDAS system useed the POGO portable soil sensor, the soil temperature, soil moisture (volumetric water content), loss tangent, soil electrical conductivity, soil complex dielectric real part and imaginary part were obtained by observation. No special simultaneous sampling of vegetation was carried out on the same day. Data: The data set includes two parts: soil moisture observation and vegetation observation. The former saves the data as a vector file, the spatial position is the position of each sampling point (WGS84+UTM 47N), and the measurement information of soil moisture is recorded in the attribute file.
0 2019-09-14
"Heihe River Basin Ecological hydrological comprehensive atlas" is supported by the key project of Heihe River Basin Ecological hydrological process integration research. It aims at data arrangement and service of Heihe River Basin Ecological hydrological process integration research. The atlas will provide researchers with a comprehensive and detailed background introduction and basic data set of Heihe River Basin. The TM image index map of Heihe River Basin is one of the basic geographic part of atlas, with a scale of 1:2500000, positive axis equal product conic projection and standard latitude of 25 47 N. Data source: TM image index data, Heihe River basin boundary.
0 2020-03-03
The VEGETATION sensor sponsored by the European Commission was launched by SPOT-4 in March 1998. Since April 1998, SPOTVGT data for global vegetation coverage observation has been received by Kiruna ground station in Sweden. The image quality monitoring center in Toulouse, France is responsible for image quality and provides relevant parameters (such as calibration coefficient number). Finally, the Belgian flemish institute for technological research (Vito)VEGETATION processing Centre (CTIV) is responsible for preprocessing into global data of 1km per day. Pretreatment includes atmospheric correction, radiation correction, geometric correction, production of 10 days to maximize the synthesized NDVI data, setting the value of -1 to -0.1 to -0.1, and then converting to the DN value of 0-250 through the formula DN= (NDVI+0.1)/0.004. The dataset is a long-time series vegetation index dataset of Qinghai Lake Basin, which is mainly aimed at normalized difference vegetation index (NDVI). It includes spectral reflectance of four bands synthesized every 10 days from 1998 to 2008 and maximum NDVI for 10 days, with a spatial resolution of 1km and a temporal resolution of 10 days.
0 2020-10-09
This dataset includes the observational data that were collected by two sets of Cosmic-ray Soil Moisture Observation System (COSMOS), named crs_a and crs_b, which were installed near the Daman Superstation in the flux observation matrix from 1 June through 20 September 2012. The land cover in the footprint was maize crop, and the site was located with the cropland of the Daman Irrigation District, Zhangye, Gansu Province. Crs_a was located at 100.36975° E, 38.85385° N and 1557.16 m above sea level; Crs_b was located at 100.37225° E, 38.85557° N and 1557.16 m above sea level. The bottom of the probe was 0.5 m above the ground; the sampling interval was 1 hour. The raw COSMOS data include the following: battery (Batt, V), temperature (T, ℃), relative humidity (RH, %), air pressure (P, hPa), fast neutron counts (N1C, counts per hour), thermal neutron counts (N2C, counts per hour), sample time of fast neutrons (N1ET, s), and sample time of thermal neutrons (N2ET, s). The distributed data include the following variables: Date, Time, P, N1C, N1C_cor (corrected fast neutron counts) and VWC (volume soil moisture, %), which were processed as follows: 1) Quality control Data were removed and replaced by -6999 when (a) the battery voltage was less than 11.8 V, (b) the relative humidity was greater than 80% inside the probe box, (c) the counting data were not of one-hour duration and (d) then neutron count differed from the previous value by more than 20%. 2) Air pressure correction An air pressure correction was applied to the quality-controlled raw data according to the equation contained in the equipment manual. The procedure was previously described by Jiao et al. (2013) and Zreda et al. (2012). 3) Calibration After the quality control and corrections were applied, soil moisture was calculated using the equation in Desilets et al. (2010), where N0 is the neutron counts above dry soil and the other variables are fitted constants that define the shape of the calibration function. Here, the parameter N0 must be calibrated using the in situ observed soil moisture within the footprint. This procedure was previously described by Jiao et al. (2013) and Zreda et al. (2012) 4) Computing the soil moisture Based on the calibrated N0 and corrected N1C, the hourly soil moisture was computed using the equation from the equipment manual. This procedure was previously described by Jiao et al, (2013) and Zreda et al. (2012) For more information, please refer to Liu et al. (2016) (for multi-scale observation experiment or sites information), Zhu et al. (2015) (for data processing) in the Citation section.
0 2019-09-14
The accurate estimation of sapwood area and heartwood area is the main means to convert the transpiration water consumption scale. In October 2011, this project investigated the sapwood and heartwood of 98 Populus euphratica in Ejin Oasis and measured the width of sapwood and heartwood. The relation curve of sapwood area with DBH and height was established. Please refer to LI Wei, SI Jianhua,FENG Qi, YU Teng fei. Response of Transpiration to Water Vapour Pressure Defferential of Populus euphratica. Journal of Desert Research, 2013, 33(5): 1377-1384. for details.
0 2019-09-15
The 1:1,000,000 Antarctic settlements data set includes vector spatial data of Antarctic settlements and its related attributes：City name (ENG_NAME), city population (CNTEY_NAME), (CNTRY_CODE), etc. The data comes from the 1:100,000 ADC_WorldMap global data set，The data through topology, warehousing and other data quality inspection，Data through the topology, into the library，It's comprehensive, up-to-date and seamless geodigital data. The world map coordinate system is latitude and longitude, WGS84 datum surface，Antarctic specific projection parameters（South_Pole_Stereographic）.
0 2019-09-15
This data is from "China 1:100,000 land use data".China 1:100,000 land use data was constructed in three years based on Landsat MSS, TM and ETM remote sensing data by using satellite remote sensing as a means to organize remote sensing science and technology teams from 19 institutes affiliated to the Chinese academy of sciences (cas) in the "eighth five-year plan" major application project "national macro survey and dynamic research on remote sensing of resources and environment". The landuse data of guizhou province in the late 1980s adopted a hierarchical land cover classification system, which divided the country into 6 primary categories (farmland, woodland, grassland, water area, urban and rural areas, industrial and mining areas, residential land and unused land) and 31 secondary categories.It is the most accurate land use data product in China and has played an important role in national land resource survey, hydrological and ecological research.
0 2020-03-30
This dataset contains data on river water level and flow velocity at No.3 in the intensive runoff observation in the middle reaches of Heihe River runoff from July 28, 2014 to December 31, 2014. The observation point is located at Heihe Bridge, Lan-Xin Railway, Zhangye City, Gansu Province. The riverbed is gravel and the section is stable. The latitude and longitude of the observation point is N39°2'33.08", E100°25'49.42", the altitude is 1443 meters, and the river channel width is 50 meters. The water level observation is measured by SR50 ultrasonic range finder with a frequency of 60 minutes. The flow profile observation is conducted by StreamPro micro ADCP. The data declaration includes the following two parts: Water level observation, the observation frequency is 60 minutes, unit (cm); data covering time period from July 28, 2014 to December 31, 2014; Flow observation, unit (m3); monitoring flow and obtaining water level flow curve according to different water levels. The process of the runoff changing is obtained by observing the water level process. The missing data is uniformly represented by the string -6999. For hydrometeorological network or site information, please refer to Li et al. (2013). For observation data processing, please refer to He et al. (2016).
0 2019-09-13
The dataset of airborne WiDAS mission was obtained in the Zhangye-Yingke-Huazhaizi flight zone on Jul. 11, 2008. Intra-band data available for general users include Level-2C data (after geometric, radiometric and atmospheric corrections), Level-1B browse image (after intra-band matching) and Level-2B browse image (after registration). The raw data, Level-1A, and data processing parameters were filed; applications would be evaluated prior to access. Data processing started in Aug. 2008 and ended in Apr. 2009, and in Nov. 2009, CCD data were reprocessed to adjust radiometric calibration. The flying time of each route was as follows: {| ! id ! flight ! relative height ! starttime ! endtime ! data size ! data state ! data quality ! ground targets |- | 1 || 3#6 || 3196.6m || 13:23:54 || 13:31:18 || 112 || processed;complete || good || Huazhaizi desert plot 1 |- | 2 || 3#10_1 || 3167.6m || 13:36:06 || 13:44:34 || 128 || processed;complete || good || Zhangye city, the wetland park, Yingke weather station maize field, Yingke wheat field, and Huazhaizi desert maize plot |- | 3 || 3#10_2 || 1607.2m || 13:52:14 || 13:59:34 || 111 || processed;complete || good || Zhangye city, the wetland park, Yingke weather station maize field, Yingke wheat field, and Huazhaizi desert maize plot |- | 4 || 3#10_3 || 823.3m || 14:13:46 || 14:14:34 || 133 || processed;complete || good || Zhangye city, the wetland park, Yingke weather station maize field, Yingke wheat field, and Huazhaizi desert maize plot |}
0 2019-05-23
This dataset contains the automatic weather station (AWS) measurements from site No.13 in the flux observation matrix from 6 May to 20 September, 2012. The site (100.37852° E, 38.86074° N) was located in a cropland (maize surface) in Daman irrigation district, which is near Zhangye, Gansu Province. The elevation is 1550.73 m. The installation heights and orientations of different sensors and measured quantities were as follows: air temperature and humidity (HMP45D; 5 m, towards north), air pressure (CS100; 2 m), rain gauge (TE525M; 10 m), wind speed and direction (034B; 10 m, towards north), a four-component radiometer (CNR4; 6 m, towards south), two infrared temperature sensors (IRTC3; 6 m, vertically downward), soil temperature profile (AV-10T; 0, -0.02, -0.04, -0.1, -0.2, -0.4, -0.6, and -1.0 m), soil moisture profile (EC20-5; -0.02, -0.04, -0.1, -0.2, -0.4, -0.6, and -1.0 m), and soil heat flux (HFT3; 3 duplicates with one below the vegetation and the other between plants, 0.06 m). The observations included the following: air temperature and humidity (Ta_5 m and RH_5 m) (℃ and %, respectively), air pressure (press, hpa), precipitation (rain, mm), wind speed (Ws_10 m, m/s), wind direction (WD_10 m, °), four-component radiation (DR, incoming shortwave radiation; UR, outgoing shortwave radiation; DLR_Cor, incoming longwave radiation; ULR_Cor, outgoing longwave radiation; Rn, net radiation; W/m^2), infrared temperature (IRT_1 and IR_2, ℃), soil heat flux (Gs_1, below the vegetation; Gs_2 and Gs_3, W/m^2), soil temperature profile (Ts_0 cm, Ts_2 cm, Ts_4 cm, Ts_10 cm, Ts_20 cm, Ts_40 cm, Ts_60 cm, and Ts_100 cm, ℃), and soil moisture profile (Ms_2 cm, Ms_4 cm, Ms_10 cm, Ms_20 cm, Ms_40 cm, Ms_60 cm, and Ms_100 cm, %). The data processing and quality control steps were as follows. (1) The AWS data were averaged over intervals of 10 min; therefore, there were 144 records per day. The missing data were filled with -6999. (2) Data in duplicate records were rejected. (3) Unphysical data were rejected. (4) In this dataset, the time of 0:10 corresponds to the average data for the period between 0:00 and 0:10; the data were stored in *.xlsx format. (5) Finally, the naming convention was AWS+ site no. Moreover, suspicious data were marked in red. 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 2019-09-12
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