Data set of soil non-point source pollution in urbanization area of Heihe River Basin, Qinghai Tibet Plateau (2020)

The dataset contains the distribution of soil heavy metal in the upper and middle areas of Heihe River Basin. In August 2020, 49 soil samples were obtained from a field investigation in the Heihe River Basin. The soil samples were brought back to the laboratory for preliminary classification and removal of impurities. Then the soil samples were naturally air-dried, mixed evenly, ground with a ball mill, and screened to obtain the test samples. Next, the samples were heated and digested in the ST-60 automatic digestion instrument. Finally, the content of heavy metals in the soil, including Cd, Zn, Cu, Ni, Cr, As, and Pb were determined (mg/kg as unit) by ICP-AES spectrometer after making up to volume. The detection limit of Cd was 0.0002, Zn and Cu were 0.001, Ni and Cr were 0.001, As and Pb were 0.003. Our dataset is reliable and can be used to analyze the distribution patterns of heavy metal elements in the soil in the urbanized area of Tibetan plateau.

0 2021-06-17

Qilian Mountains integrated observatory network: Dataset of Heihe integrated observatory network (automatic weather station of desert station, 2020)

This dataset includes data recorded by the Heihe integrated observatory network obtained from the automatic weather station (AWS) at the desert station from January 1 to December 31, 2020. The site (100.9872°E, 42.1135°N) was located on a desert surface in the desert, which is near Ejin Banner, Inner Mongolia Autonomous Region. The elevation is 1054 m. The installation heights and orientations of different sensors and measured quantities were as follows: air temperature and humidity profile (HMP45AC; 5 and 10 m, north), wind speed profile (010C; 5 and 10 m, north), wind direction (020C, 10m), air pressure (CS100; 2 m), rain gauge (TE525M; 10 m), four-component radiometer (CNR1; 6 m, south), two infrared temperature sensors (SI-111; 6 m, south, vertically downward), soil heat flux (HFP01; 3 duplicates, -0.06 m), soil temperature profile (109ss-L; 0, -0.02, -0.04, -0.1, -0.2, -0.4, -0.6, -1.0 m), soil moisture profile (ML3; -0.02, -0.04, -0.1, -0.2, -0.4, -0.6, -1.0 m). The observations included the following: air temperature and humidity (Ta_5 m and Ta_10 m; RH_5 m and RH_10 m) (℃ and %, respectively), wind speed (Ws_5 m and Ws_10 m) (m/s), wind direction (WD_10 m) (°), air pressure (press) (hpa), precipitation (rain) (mm), 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 IRT_2) (℃), soil heat flux (Gs_1, Gs_2, and Gs_3) (W/m^2), soil temperature (Ts_0 cm, Ts_2 cm, Ts_4 cm, Ts_10 cm, Ts_20 cm, Ts_40 cm, Ts_60 cm, Ts_100 cm) (℃), soil moisture (Ms_2 cm, Ms_4 cm, Ms_10 cm, Ms_20 cm, Ms_40 cm, Ms_60 cm, Ms_100 cm) (%). The data processing and quality control steps were as follows: (1) The AWS data were averaged over intervals of 10 min for a total of 144 records per day. The missing data were denoted by -6999. (2) Data in duplicate records were rejected. (3) Unphysical data were rejected. (4) The data marked in red are problematic data. (5) The format of the date and time was unified, and the date and time were collected in the same column, for example, date and time: 2020-6-10 10:30. (6) Finally, the naming convention was AWS+ site no. Moreover, suspicious data were marked in red. For more information, please refer to Liu et al. (2018) (for sites information), Liu et al. (2011) for data processing) in the Citation section.

0 2021-05-31

Qilian Mountains integrated observatory network: Dataset of Heihe integrated observatory network (eddy covariance system of Daman Superstation, 2020)

This dataset contains the flux measurements from the Daman superstation eddy covariance system (EC) in the midstream reaches of the Heihe integrated observatory network from January 1 to December 31 in 2020. The site (100.37223° E, 38.85551° N) was located in the Zhangye City in Gansu Province. The elevation is 1556.06 m. The EC was installed at a height of 4.5 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 (CSAT3&Li7500A) was 0.17 m. The raw data acquired at 10 Hz were processed using the Eddypro post-processing software, 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): class 1-3 (high quality), class 4-6 (good), class 7-8 (poor, better than gap filling data), class9 (rejected). 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 collected before or after 1 h of precipitation were rejected; (3) incomplete 30 min data were rejected when the missing data constituted more than 10% 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. 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/m3), CO2 mass density (CO2, mg/m3), friction velocity (ustar, m/s), stability (z/L), sensible heat flux (Hs, W/m2), latent heat flux (LE, W/m2), carbon dioxide flux (Fc, mg/ (m2s)), 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. Detailed information can be found in the suggested references. For more information, please refer to Liu et al. (2018) (for sites information), Liu et al. (2011) for data processing) in the Citation section.

0 2021-05-31

Qilian Mountains integrated observatory network: Dataset of Heihe integrated observatory network (eddy covariance system of A’rou Superstation, 2020)

This dataset contains the flux measurements from the A’rou superstation eddy covariance system (EC) in the upperstream reaches of the Heihe integrated observatory network from January 1 to December 31 in 2020. The site (100.372° E, 38.856° N) was located in the Daban Village, near Qilian County in Qinghai Province. The elevation is 3033 m. The EC was installed at a height of 3.5 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 (CSAT3&Li7500A) was 0.15 m. The raw data acquired at 10 Hz were processed using the Eddypro post-processing software, 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): class 1-3 (high quality), class 4-6 (good), class 7-8 (poor, better than gap filling data), class9 (rejected). 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 collected before or after 1 h of precipitation were rejected; (3) incomplete 30 min data were rejected when the missing data constituted more than 10% of the 30 min raw record. There were 48 records per day, and the missing data were replaced with -6999. Suspicious data were marked in red. Due to the malfunction of instruments, data were missing during 23-29 August. 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/m3), CO2 mass density (CO2, mg/m3), friction velocity (ustar, m/s), stability (L), sensible heat flux (Hs, W/m2), latent heat flux (LE, W/m2), carbon dioxide flux (Fc, mg/ (m2s)), 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. Detailed information can be found in the suggested references. For more information, please refer to Liu et al. (2018) (for sites information), Liu et al. (2011) for data processing) in the Citation section.

0 2021-05-31

Dataset of ecological survey in the urbanized area of Tibetan Plateau (2019-2020)

This dataset includes photosynthetic parameters and leaf area index of major vegetation types in the urbanized area of Tibetan Plateau (Huangshui river basin, Heihe river basin and major towns on the Tibetan Plateau). 1) Objectives The ecological survey data can be used for the parameterization and validation of ecohydrological models in the urbanized areas of the Tibetan Plateau. 2) Instrument of the observation: LI-6800 Portable Photosynthesis System and LAI-2200 Plant Canopy Analyzer 3) Time and sites of observations: The measurements were conducted in the Heihe River Basin from July to August in 2019, and in the Huangshui River Basin and key urban areas on the Tibetan Plateau from July to August in 2020. 4) Measured parameters and data processing Considering the needs of the ecohydrological models, we selected 12 main indexes from the original data measured by LI-6800 and LAI-2200, such as E: evapotranspiration rate (mol m⁻² s⁻¹), A: net photosynthesis rate (µmol m⁻² s⁻¹), Ci: intercellular CO2 concentration (µmol mol⁻¹). 5) Data storage The dataset was stored in Excel format, other ancillary data include the longitude and latitude of sample site and the main vegetation types, etc.

0 2021-05-21