Cold and Arid Research Network of Lanzhou university (Phenology camera observation data set of Liancheng Station, 2021)

The data set contains the phenological camera observation data of Sidalong station of Lanzhou University cold and arid area scientific observation network in Heihe River Basin from February 1, 2021 to September 15, 2021. The longitude and latitude of the observation points are 99.926e, 38.428n and 3146m above sea level. The data is processed using the software package independently developed by Beijing Normal University. The phenological camera collects data in a downward way. The resolution of shooting data is 2592 * 1944, and the shooting time and frequency can be specified. For the calculation of greenness index phenological period, it is necessary to calculate the relative greenness index according to the region of interest (GCC, green chromatographic coordinate formula is GCC = g / (R + G + b), and R, G and B are the pixel values of red, green and blue channels of the image), then fill in the invalid values and filter and smooth them, and finally determine the key phenological period parameters according to the growth curve fitting, such as the start date, peak and end date of the growth season; For the coverage, data preprocessing is carried out first, the image with less strong illumination is selected, and then the image is divided into vegetation and soil. The proportion of vegetation pixels in the calculation area of each image is calculated as the corresponding coverage of the image. After the time series data is extracted, the original coverage data is smoothed and filtered according to the time window specified by the user. The filtered result is the final time series coverage. This data set includes the relative greenness index (GCC).

0 2022-05-17

Cold and Arid Research Network of Lanzhou university (eddy covariance system of Sidalong station, 2021)

This dataset contains the flux measurements from the Sidalong station eddy covariance system (EC) in the middle reaches of the Heihe integrated observatory network from January 1 to Dec 19 in 2021. The site (99.926E, 38.428N) was located on a forest in the Kangle Sunan, which is near Zhangye city, Gansu Province. The elevation is 3146 m. The EC was installed at a height of 4.0 m above the canopy , 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 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. 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.

0 2022-05-17

Cold and Arid Research Network of Lanzhou university (an observation system of Meteorological elements gradient of Sidalong Station, 2021)

This dataset includes data recorded by the Cold and Arid Research Network of Lanzhou university obtained from an observation system of Meteorological elements gradient of Sidalong Station from January 1 to December 31, 2021. The site (99.926°E, 38.428°N) was located on a forest in the Kangle Sunan, which is near Zhangye city, Gansu Province. The elevation is 3146 m. The installation heights and orientations of different sensors and measured quantities were as follows: air temperature and humidity profile (1, 2, 13, 24, and 48 m), wind speed and direction profile (windsonic; 1, 2, 13, 24, and 48 m), air pressure (1.5 m), rain gauge (24 m), infrared temperature sensors (4 m and 30m, vertically downward), photosynthetically active radiation (4 m and 30m), soil heat flux (-0.05 m and -0.1m), soil temperature/ moisture/ electrical conductivity profile -0.05, -0.1m, -0.2m, -0.4m and -0.6mr), four-component radiometer (30 m, towards south), sunshine duration sensor(30 m, towards south). The observations included the following: air temperature and humidity (Ta_1_1_1, Ta_1_2_1, Ta_1_13_1, Ta_1_24_1 and Ta_1_48_1; RH_1_1_1, RH_1_2_1, RH_1_13_1, RH_1_24_1 and RH_1_48_1) (℃ and %, respectively), wind speed (WS_1_1_1, WS_1_2_1, WS_1_13_1, WS_1_24_1, and WS_1_48_1) (m/s), wind direction (WD_1_1_1, WD_1_2_1, WD_1_13_1, WD_1_24_1, and WD_1_48_1) (°), air pressure (PA_1_1_1) (hpa), precipitation (P_1_24_1) (mm), four-component radiation (SWIN_1_30_1, incoming shortwave radiation; SWOUT_1_30_1, outgoing shortwave radiation; LWIN_1_30_1, incoming longwave radiation; LWOUT_1_30_1, outgoing longwave radiation; RN_1_30_1, net radiation) (W/m^2), infrared temperature (TC_1_4_1, TC_1_30_1) (℃), photosynthetically active radiation (PPFD_1_4_1, PPFD_1_30_1) (μmol/ (s m^2)), soil heat flux (SHF_1_5_1, SHF_1_10_1) (W/m^2), soil temperature (TS_1_5_1, TS_1_10_1, TS_1_20_1, TS_1_40_1 and TS_1_60_1) (℃), soil moisture (SWC_1_5_1, SWC_1_10_1, SWC_1_20_1, SWC_1_40_1 and SWC_1_60_1) (%, volumetric water content),soil water potential (SWP_1_5_1, SWP_1_10_1, SWP_1_20_1, SWP_1_40_1 and SWP_1_60_1)(kpa), soil conductivity (EC_1_5_1, EC_1_10_1, EC_1_20_1, EC_1_40_1 and EC_1_60_1)(μs/cm), Sun_time_1_30_1 (h). 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. Missing or abnormal data is replaced 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: 2021-6-10 10:30.

0 2022-05-17

Dataset of shrub interception and transpiration in Tianlaochi watershed of Qilian Mountain (2012)

This data includes three parts of data, namely shrub water holding experiment, shrub interception experiment and shrub transpiration experiment data. Shrub water holding experiment: select the two shrub types of Caragana jubata and Potentilla fruticosa, respectively pick the branches and leaves of the two vegetation types, weigh their fresh weight, carry out water holding experiment, measure the saturated weight of branches and leaves, dry weight of branches and leaves, dry weight of branches and leaves after completion, and finally obtain the data of branches, leaves and total water holding capacity. Shrub interception experiment: two shrubs, Caragana jubata and Potentilla fruticosa, were also selected and investigated. 30 rain-bearing cups were respectively arranged under the two shrubs. after each rainfall, penetration rainfall was measured and observed from June 1, 2012 to September 10, 2012. Shrub Transpiration Experiment: Potentilla fruticosa on July 14, Caragana jubata on August 5, Salix gilashanica on August 15, 2012. The measurement is made every hour according to the daily weather conditions.

0 2020-07-30

Soil physical properties - soil bulk density and mechanical composition dataset of Tianlaochi Watershed in Qilian Mountains

A total of 137 soil samples of different vegetation types, different altitudes and different terrains were collected from June 2012 to August 2012. The soil layer of each sample point was divided into three layers of 0-10cm, 10-20cm and 20-30cm, with an altitude of 2700-3500m m. The vegetation types were divided into five types: Picea crassifolia forest, Sabina przewalskii, subalpine scrub meadow, grassland and dry grassland. At the same time of sampling, hand-held GPS is used to record the location information and environmental information of each sampling point, including longitude, latitude, altitude, slope, aspect, terrain curvature, vegetation type, soil thickness, maximum root depth, etc. Soil bulk density: The measurement method of soil bulk density is to put the sample into an envelope and dry it in an oven at 105℃ for 24 hours, then take it out and place it for 30 minutes to weigh. The ratio of the weighing result to the volume of the ring cutter is the soil bulk density, and the unit is g/cm3. Soil mechanical composition: hydrometer method is used to measure the soil mechanical composition, which includes the content of soil sand, silt and clay.

0 2020-03-15

Canopy interception dataset of Picea crassifolia in Tianlaochi watershed of Qilian Mountain

The data are from 2011 to 2012. A 30m×30m Picea crassifolia canopy interception sample plot was set up in the Picea crassifolia sample plot at an altitude of 2800m m. A siphon raingauge model DSJ2 (Tianjin Meteorological Instrument Factory) was set up on the open land of the river about 50m from the sample plot to observe the rainfall outside the forest and its characteristics. Penetrating rain in the forest adopts a combination of manual observation and automatic observation. Automatic observation is mainly realized through a penetrating rain collection system arranged in the interception sample plot, which consists of a water collecting tank and an automatic recorder. Two 400cm×20cm water collecting tanks are connected with DSJ2 siphon rain gauge, and the change characteristics of penetrating rain under the forest are continuously recorded by an automatic recorder. Due to the spatial variability of the canopy structure of Picea crassifolia forest in the sample plot, a standard rainfall tube for manual observation is also arranged in the sample plot to observe the penetrating rain in the forest. Ninety rainfall tubes with a diameter of 20cm are arranged in the sample plot at intervals of 3m. After each precipitation event ends and the penetrating rain in the forest stops, the amount of water in the rain barrel will be emptied and the penetrating rain in the barrel will be measured with the rain cup.

0 2020-03-14

Dataset of water level at the Sidalong Sub-Basin in Qilian Mountain (2011)

This data is the water level data of 2011-2012, which is observed by water level recorder. From July 14 to September 9, 2011, the observation was recordered every five minutes; from June 4 to July 10, 2012, the observation was recordered every ten minutes. The data content is the temperature and atmospheric pressure inside the hole, and the data is the daily scale data. The data shall be opened with HOBO software.

0 2020-03-14

Coverage data of Picea crassifolia sample in Tianlaochi watershed of Qilian Mountain

The data is a fisheye photo above the interception barrel of the Picea crassifolia plot in the Tianlaochi small watershed of Qilian Mountain. The plot has a latitude and longitude of 38.44N, 99.91E, and an altitude of 2793m. Photo DSC_0008——DSC_0097 corresponds to Fisheye photos above interception barrels 1 to 90 respectively. The camera is directly above the interception barrel and the lens is 1m above the ground. It is used to estimate the cover or LAI of Qinghai spruce forest, and the pictures are processed with Gap Light Analyzer software.

0 2020-03-13

Dataset of automatic meteorological observations at the Sub-Basin in Qilian Mountain (2011-2012)

The data set contains observation data from the Tianlaochi small watershed automatic weather station. The latitude and longitude of the station are 38.43N, 99.93E, and the altitude is 3100m. Observed items are time, average wind speed (m/s), maximum wind speed (m/s), 40-60cm soil moisture, 0-20 soil moisture, 20-40 soil moisture, air pressure, PAR, air temperature, relative humidity, and dew point temperature , Solar radiation, total precipitation, 20-40 soil temperature, 0-20 soil temperature, 40-60 soil temperature. The observation period is from May 25, 2011 to September 11, 2012, and all parameter data are compiled on a daily scale.

0 2020-03-13

Grassland interception dataset of Tianlaochi watershed in Qilian Mountain

This data includes experimental data of grassland interception control and observation data of maximum water holding capacity of grassland. The maximum water holding capacity experiment was carried out in 2011. The main vegetation types selected are Carex, Polygonum viviparum, Plantago asiatica and Potentilla chinensis. The maximum water holding capacity experiment was carried out on each type of samples and the samples were photographed. The specific data obtained are shown in the document. The grassland canopy interception was carried out in the growing season of 2012, and was completed by artificial rainfall control experiment. At the end of the growing season, the main types of grassland in the basin were sampled according to grazing and grazing ban. During artificial rainfall, rainfall and penetrating rainfall are recorded every 1min. Finally, the grassland canopy interception is calculated by the difference between rainfall and penetrating rainfall.

0 2020-03-12