HiWATER: Simultaneous observation dataset of river surface temperature in the middle reaches of the Heihe River Basin on Jul. 3 and Jul. 4, 2012

The aim of the simultaneous observation of river surface temperature is obtaining the river surface temperature of different places, while the sensor of thermal infrared go into the experimental areas of artificial oases eco-hydrology on the middle stream. All the river surface temperature data will be used for validation of the retrieved river surface temperature from thermal infrared sensor and the analysis of the scale effect of the river surface temperature, and finally serve for the validation of the plausibility checks of the surface temperature product from remote sensing. 1. Observation sites and other details Ten river sections were chosen to observe surface temperature simultaneously in the midstream of Heihe River Basin on 3 July and 4 July, 2012, including Sunan Bridge, Binhe new area, Heihe Bridge, Railway Bridge, Wujiang Bridge, Gaoya Hydrologic Station, Banqiao, Pingchuan Bridge, Yi’s Village, Liu’s Bridge. Self-recording point thermometers (observed once every 6 seconds) were used in Railway Bridge and Gaoya Hydrologic Station while handheld infrared thermometers (observed once of the river section temperature for every 15 minutes) were used in other eight places. 2. Instrument parameters and calibration The field of view of the self-recording point thermometer and the handheld infrared thermometer are 10 and 1 degree, respectively. The emissivity of the latter was assumed to be 0.95. All instruments were calibrated on 6 July, 2012 using black body during observation. 3. Data storage All the observation data were stored in excel.

HiWATER: Dataset of hydrometeorological observation network (eddy covariance system of Zhangye wetland station, 2013)

This dataset contains the flux measurements from the Zhangye wetland station eddy covariance system (EC) in the middle reaches of the Heihe hydrometeorological observation network from 15 September, 2012, to 21 November, 2013. The site (100.446° E, 38.975° N) was located in the desert steppe surface, near Zhangye city in Gansu Province. The elevation is 1460 m. The EC was installed at a height of 5.2 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 (Gill&Li7500A) was 0.25 m. The 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 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), as 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), which represent high-, medium-, and low-quality data, respectively. In addition to the above processing steps, the half-hourly flux data were screened using 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 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, and the missing data were replaced with -6999. Suspicious data were marked in red. Due to the calibration of CO2/H2O gas analyzer and CF card storage problem, data during 28 May to 30 May, and 21 November to 31 December, 2013 were missing. 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 *.xls format. For more information, please refer to Li et al. (2013) (for hydrometeorological observation network or sites information), Liu et al. (2011) (for data processing) in the Citation section.

WATER: Dataset of ground truth measurement synchronizing with the airborne WiDAS mission and  Envisat ASAR in the Linze station foci experimental area on July 11, 2008

The dataset of ground truth measurement synchronizing with the airborne WiDAS mission and Envisat ASAR was obtained in the Linze station foci experimental area on Jul. 11, 2008. WiDAS, composed of four CCD cameras, one mid-infrared thermal imager (AGEMA 550), and one infrared thermal imager (S60), can acquire CCD, MIR and TIR band data. The data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:26 BJT. The simultaneous ground data included the following items: (1) soil moisture (0-5cm) measured once by the cutting ring method at the corner points of the 40 subplots of the west-east desert transit zone strip , once by the cutting ring method in the nine subplots of the north-south desert transit zone, nine times in the LY06 and LY07 strips quadrates,and once by the cutting ring and once by ML2X Soil Moisture Tachometer in the Wulidun farmland. The preprocessed soil volumetric moisture data were archived as Excel files. (2) the surface radiative temperature measured by three handheld infrared thermometer (5# and 6# from Cold and Arid Regions Environmental and Engineering Research Institute, and one from Institute of Geographic Sciences and Natural Resources, which were all calibrated) in LY06 and LY07 strips (49 points and repeated three times), and Wulidun farmland quadrates (various points and repeated three times). Data were archived as Excel files. (3) spectrum of maize, soil and soil with known moisture measured by ASD Spectroradiometer (350~2 500 nm) from BNU and the reference board (40% before Jun. 15 and 20% hereafter) in Wulidun farmland. Raw spectral data were binary files , which were recorded daily in detail, and pre-processed data on reflectance (by ViewSpecPro) were archived as Excel files. (4) maize BRDF measured by ASD Spectroradiometer (350~2 500 nm) from BNU, the reference board (40% before Jun. 15 and 20% hereafter), two observation platforms of BNU make and one of Institute of Remote Sensing Applications make in Wulidun farmland. Raw spectral data were archived as binary files, which were recorded daily in detail, and pre-processed data on reflectance and transmittivity were archived as text files (.txt). (5) LAI measured in the maize quadrate, poplar quadrate and desert scrub quadrate in Wulidun farmland, the desert transit zone strips and the poplar forest quadrate by the fisheye camera (CANON EOS40D with a lens of EF15/28), shooting straight downwards, with exceptions of higher plants, which were shot upwards. Data included original photos (.JPG) and those processed by can_eye5.0 (in excel). (6) LAI of maize measured by LAI2000 in Linze station quadrates and Wulidun farmland quadrates. Data educed from LAI2000 periodically were archived as text files (.txt) and marked with one ID. Raw data (table of word and txt) and processed data (Excel) were included. Besides, observation time, the observation method and the repetition were all archived. (7) LAI measured by the ruler and the set square in B2 and B3 of Linze station quadrates. 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.

HiWATER:Dataset of the chamber soil respiration in the middle of Heihe River Basin (2012)

During the period of middle stream experiment in 2012, closed chamber and gas chromatography method was used to measure soil respiration of different land surface, including farmland, orchard, wetland, sparse grassland (Huazhaizi), Gobi, desert. Instrument: Assimilation Chamber Measuring method: Assimilation chamber consists of two parts: the base and the box. Base made of PVC material, the bottom buried in the soil. The box is made of stainless steel cubes, with one open side. When measuring the box cover on the base, air in the box was sampled using injector. The extracted air was injected into the gas sampling bag, and shipped back to the laboratory analysis of the concentration of CO2 by gas chromatography in Institute of Botany, The Chinese Academy of Sciences. Using the difference of concentration of CO2 at two times to calculate soil respiration. Each measurement points are located three repeat. After five minutes sealed box cover start mining the 1st sample, and then taken once every sample interval of 10 minutes, four times in total mining. Date content: Data content includes header information and once every 10 days three times repeated observations and the average of the three times. Measuring location: Gobi (Bajitan Gobi station), Wetland (Zhangye wetland Station), Sparse grassland (Huazhaizi desert steppe Station), Desert (Shenshawo sandy desert Station), Orchard (site No.17 eddy covariance system), Maize Farmland (Daman Superstation) Measuring time: 16-6-2012, 28-6-2012, 9-7-2012, 18-7-2012, 30-7-2012, 11-8-2012, 21-8-2012, 2-9-2012, 13-9-2012, 22-9-2012 (UTC+8).

WATER: Dataset of airborne imaging spectrometer (OMIS-II) mission in the Zhangye-Yingke-Huazhaizi flight zone on Jun. 16, 2008

The dataset of airborne imaging spectrometer (OMIS-II) mission was obtained in the Zhangye-Yingke-Huazhaizi flight zone on Jun. 16, 2008. Data after radiometric correction and calibration and geometric approximate correction were released. The flying time of each route was as follows: {| ! id ! flight ! file ! starttime ! lat ! long ! alt ! image linage ! endtime ! lat ! long ! alt |- | 1 || 3-1 || 2008-06-16_14-26-53_DATA.BSQ || 14:44:01 || 38.992 || 100.446 || 3250.7 || 6698 || 14:51:28 || 38.744 || 100.286 || 3237.7 |- | 2 || 3-2 || 2008-06-16_14-52-37_DATA.BSQ || 14:55:47 || 38.731 || 100.284 || 3214.9 || 7202 || 15:03:47 || 38.981 || 100.445 || 3237.6 |- | 3 || 3-3 || 2008-06-16_15-04-57_DATA.BSQ || 15:09:29 || 38.989 || 100.457 || 3230.2 || 6740 || 15:16:58 || 38.739 || 100.297 || 3236.0 |- | 4 || 3-4 || 2008-06-16_15-18-07_DATA.BSQ || 15:21:19 || 38.728 || 100.296 || 3200.6 || 7256 || 15:29:23 || 38.979 || 100.457 || 3170.8 |- | 5 || 3-5 || 2008-06-16_15-30-32_DATA.BSQ || 15:35:06 || 38.983 || 100.466 || 3221.9 || 6627 || 15:42:28 || 38.736 || 100.307 || 3227.9 |- | 6 || 3-6 || 2008-06-16_15-43-37_DATA.BSQ || 15:47:39 || 38.726 || 100.308 || 3249.2 || 7013 || 15:55:27 || 38.975 || 100.467 || 3219.1 |- | 7 || 3-7 || 2008-06-16_15-56-36_DATA.BSQ || 16:00:46 || 38.981 || 100.476 || -1.0 || 6639 || 16:08:09 || 38.732 || 100.317 || 3276.8 |- | 8 || 3-8 || 2008-06-16_16-09-18_DATA.BSQ || 16:13:15 || 38.723 || 100.317 || 3212.7 || 7106 || 16:21:09 || 38.973 || 100.479 || 3216.1 |- | 9 || 3-9 || 2008-06-16_16-22-18_DATA.BSQ || 16:26:28 || 38.981 || 100.490 || 3218.6 || 6850 || 16:34:05 || 38.725 || 100.325 || 3235.9 |- | 10 || 3-10 || 2008-06-16_16-35-14_DATA.BSQ || 16:39:23 || 38.716 || 100.326 || 3261.3 || 7056 || 16:47:14 || 38.967 || 100.488 || 3208.4 |- | 11 || 3-11 || 2008-06-16_16-48-23_DATA.BSQ || 16:52:44 || 38.976 || 100.501 || 3204.8 || 6902 || 17:00:24 || 38.725 || 100.338 || 3230.1 |- | 12 || 3-12 || 2008-06-16_17-01-33_DATA.BSQ || 17:05:19 || 38.710 || 100.336 || 3253.8 || 7033 || 17:13:08 || 38.965 || 100.500 || 3225.6 |- | 13 || 3-13 || 2008-06-16_17-14-17_DATA.BSQ || 17:19:01 || 38.973 || 100.511 || 3224.8 || 6831 || 17:26:36 || 38.722 || 100.349 || 3230.1 |- | 14 || 3-14 || 2008-06-16_17-27-46_DATA.BSQ || 17:32:06 || 38.706 || 100.346 || 3233.7 || 3235 || 17:35:44 || 38.830 || 100.426 || 3235.1 |- | 15 || 3-15 || 2008-06-16_17-36-54_DATA.BSQ || 17:35:51 || 38.8334 || 100.428 || 3235.8 || 3625 || 17:39:52 || 38.963 || 100.511 || 3250.6 |}

WATER: Dataset of ground truth measurements synchronizing with Landsat TM in the Biandukou foci experimental area (Mar. 17, 2008)

The dataset of ground truth measurements synchronizing with Landsat TM was obtained in the Biandukou foci experimental area from 11:10-13:30 on Mar. 17, 2008. Those provide reliable ground data for objects modelling and background modelling, remote sensing image simulation and scaling. Simultaneous with the satellite overpass, numerous ground data were collected, spectrum (ASD Fieldspec FRTM (Boulder, Co, USA), 350nm-2500nm, 3nm for the visible near-infrared band and 10nm for the shortwave infrared band), the surface temperature, atmospheric parameters, the soil profile gravimetric moisture (0-1cm, 1-3cm and 3-5cm), the shallow layer frost depth and the soil roughness in C1, G1, W1, W2, B1 and B2, mostly the grassland, the wheat stubble land, the deep plowed land and the rape stubble land. The quadrates of 90m×90m and 450m×450m were compartmentalized into 81 subgrids of 10m×10m and 50m×50m. Based on the resolution of 30m×30m and 150m×150m, the influence of adjacent eight pixels on the center pixel was studied. Section lines of each subgrid were adopted to acquire the pixel spectrum, which were measured more than once for the mean value. The spectrum data were archived in the ASCII format, with the first five rows as the file header and the following two columns as wavelength (nm) and reflectance (percentage) respectively. The .txt file was not reflectance but intermediate file for further calculation. Raw data were binary files direct from ASD (by ViewSpecPro). The surface radiative temperature and the physical temperature were measured by the handheld infrared thermometer. Besides, the cover type was also recorded. The data can be opened by Microsoft Office. Atmospheric parameters were measured by CE318 to retrieve the total optical depth, aerosol optical depth, Rayleigh scattering coefficient, column water vapor in 936 nm, and various parameters at 550nm to obtain horizontal visibility with the help of MODTRAN or 6S. Those provide reliable data for atmosphere correction of the same period in this area. The gravimetric soil moisture (samples from 0-1cm, 1-3cm and 3-5cm) was measured by the microwave drying method. The frost depth by the chopstick and the ruler. The soil was considered frozen when it was hard and with ice crystal. The data can be opened by Microsoft Office. Nine data files were included, TM data, CE318 data, B1, B2, C1, G1, W1 and W2.

HiWATER: Dataset of thermal infrared spectrum observed by BOMEM MR304 in the middle reaches of the Heihe River Basin

This dataset includes the emissivity spectrum (8-14 µm) of typical ground objects in Zhangye City, Zhangye airport, desert and farmland at Wuxing experiment area. The data was measured by the BOMEM MR304 FTIR (Fourier Transform Infrared Spectrometer). A. Objective The objective of the thermal infrared (TIR) spectrum measurement lies in: Radiometric calibration for the airborne TIR sensor, land surface emissivity products validation and collecting typical surface spectrum working as priori knowledge in land surface temperature inversion and ecological and hydrological models. B. Instruments and theory Instruments: BOMEM MR304 FTIR, Mikron M340 blackbody, BODACH BDB blackbody, diffused golden plate, Fluke 50-series II thermometer Measurement theory: The target radiance is directly measured by the MR304 FTIR under clear-sky condition while the atmospheric downward radiance is obtained through a diffused golden plate, and emissivity is retrieved by the Iterative Spectrally Smooth Temperature and Emissivity Separation (ISSTES) algorithm C. Experiment site and targets 29-5-2012: Stone bricks, grassland and asphalt, etc at square of Zhangye. 20-6-2012: Roof of the building in Zhangye, water and sand sample collected from the desert, etc. 30-6-2012: Cement road at Zhangye airport, desert around the Zhangye airport. 3-7-2012: Corn leaves, soil and road in the farmland at Wuxing village, Zhangye City. 4-7-2012: Corn leaves, wheat canopy at Xiaoman town, Zhangye City. 10-7-2012: Bricks of Runquanhu park, Zhangye City. 13-7-2012: Corn leaves and other plants at Wuxing village, Zhangye City. D. Data processing The original data collected by BOMEM FTIR is firstly calibrated using the calibration data and get the radiance spectrum of the targets and sky (*.rad), then, the radiance data is converted to the easy readably text file (ASCII format). The time used in this dataset is in UTC+8 Time.