Qilian Mountains integrated observatory network: Dataset of Heihe integrated observatory network (phenology camera observation data set of Daman Superstation-2021)

The dataset contains the phenological camera observation data of the Daman Superstation in the midstream of Heihe integrated observatory network from January 1 to December 31, 2021. The instrument was developed and data processed by Beijing Normal University. The phenomenon camera integrates data acquisition and data transmission functions. The camera captures data by look-downward with a resolution of 1280×720. For the calculation of the greenness index and phenology, the relative greenness index (GCC, Green Chromatic Coordinate, calculated by GCC=G/(R+G+B)) needs to be calculated according to the region of interest, then the invalid value filling and filtering smoothing are performed, and finally the key phenological parameters are determined according to the growth curve fitting, such as the growth season start date, Peak, growth season end, etc. For coverage, first, select images with less intense illumination, then divide the image into vegetation and soil, calculate the proportion of vegetation pixels in each image in the calculation area. After the time series data is extracted, the original coverage data is smoothed and filtered according to the time window specified by the user, and the filtered result is the final time series coverage. This data set includes relative greenness index (Gcc). Please refer to Liu et al. (2018) for sites information in the Citation section.

0 2022-06-16

Qilian Mountains integrated observatory network: Dataset of Heihe integrated observatory network (Large aperture scintillometer of Daman Superstation, 2021)

This dataset contains the flux measurements from the large aperture scintillometer (LAS) at Daman Superstation in the Heihe integrated observatory network from January 1 to December 31 in 2021. There were two types of LASs at Daman Superstation: BLS900 and RR-RSS460, produced by Germany. The north tower was set up with the BLS900 receiver and the RR-RSS460 transmitter, and the south tower was equipped with the BLS900 transmitter and the RR-RSS460 receiver. The site (north: 100.379° E, 38.861° N; south: 100.369° E, 38.847° N) was located in Daman irrigation district, which is near Zhangye, Gansu Province. The underlying surfaces between the two towers were corn, orchard, and greenhouse. The elevation is 1556 m. The effective height of the LASs was 24.1 m, and the path length was 1854 m. The data were sampled 1 minute at both BLS900 and RR-RSS460. The raw data acquired at 1 min intervals were processed and quality controlled. The data were subsequently averaged over 30 min periods, in which sensible heat flux was iteratively calculated by combining Cn2 with meteorological data according to the Monin-Obukhov similarity theory. The main quality control steps were as follows: (1) The data were rejected when Cn2 exceeded the saturated criterion (BLS900:Cn2>7.25E-14,RR-RSS460:Cn2>7.84 E-14). (2) The data were rejected when the demodulation signal was small (BLS900:Average X Intensity<1000;RR-RSS460:Demod>-20mv). (3) The data were rejected when collected during precipitation. (4) The data were rejected if collected at night when weak turbulence occurred (u* was less than 0.1 m/s). In the iteration process, the universal functions of Thiermann and Grassl (1992) and Andreas (1988) were selected for BLS900 and RR-RSS460, respectively. Detailed can refer to Liu et al. (2011, 2013). Due to instrument adjustment and inadequate power supply, the date of missing data for the large aperture scintillator is: 2021.05.15-2021.06.10. Several instructions were included with the released data. (1) The data were primarily obtained from BLS900 measurements, and missing flux measurements from the BLS900 instrument were substituted with measurements from the RR-RSS460 instrument. The missing data were denoted by -6999. (2) The dataset contained the following variables: Date/time (yyyy/m/d h:mm), the structural parameter of the air refractive index (Cn2, m-2/3), and the sensible heat flux (H, W/m^2). In this dataset, a time of 0:30 corresponds to the average data for the period between 0:00 and 0:30, and the data were stored in *.xlsx format. 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 2022-06-04

Ground observation dataset of corn biomass, vegetation coverage, leaf area index and plant height at Daman station in the middle reaches of Heihe River (growth period in 2020)

This dataset is a continuous ground observation data of vegetation coverage (%), biomass (g/plant), leaf area index (LAI) and plant height (cm) of seed corn during the growing period in 2020 at Daman Station ( 38.85551N,100.37223E)in the middle reaches of the Heihe River. Ground observation was carried out in three sample plots. Biomass observation included fresh and dry aboveground biomass, fresh and dry underground biomass (fresh and dry root weight), vegetation coverage was observed by digital camera, leaf area index was observed by LAI 2200, and plant height was observed by tape measure. The observation period was from May 31 to September 22, 2020. Observation parameters were observed every 5 days before July 31 and every 10 days thereafter, and a total of 19 observations were carried out during the whole growing period. The dataset can provide data basis for inversion and validation of surface vegetation parameters.

0 2021-10-26

Ground observation dataset of corn biomass, vegetation coverage, leaf area index and plant height at Daman station in the middle reaches of Heihe River (growth period in 2019)

This dataset is a continuous ground observation data of vegetation coverage (%), biomass (g/plant), leaf area index (LAI) and plant height (cm) of seed corn during the growing period in 2019 at Daman Station ( 38.85551N,100.37223E)in the middle reaches of the Heihe River. Ground observation was carried out in three sample plots. Biomass observation included fresh and dry aboveground biomass, fresh and dry underground biomass (fresh and dry root weight), vegetation coverage was observed by digital camera, leaf area index was observed by LAI 2200, and plant height was observed by tape measure. The observation period was from May 17 to September 23, 2019, in which LAI started from June 11. Observation parameters were observed every 5 days before July 31 and every 10 days thereafter, and a total of 20 observations (LAI was 15) were carried out during the whole growing period. The dataset can provide data basis for inversion and validation of surface vegetation parameters.

0 2021-10-26

Ground observation dataset of corn biomass, vegetation coverage, leaf area index and plant height at Daman station in the middle reaches of Heihe River (growth period in 2018)

This dataset is a continuous ground observation data of vegetation coverage (%), biomass (g/plant), leaf area index (LAI) and plant height (cm) of field corn during the growing period in 2018 at Daman Station ( 38.85551N,100.37223E)in the middle reaches of the Heihe River. Ground observation was carried out in three sample plots. Biomass observation included fresh and dry aboveground biomass, fresh and dry underground biomass (fresh and dry root weight), vegetation coverage was observed by digital camera, leaf area index was observed by LAI 2200, and plant height was observed by tape measure. The observation period was from May 26 to September 26, 2018, in which LAI started from May 30. Observation parameters were observed every 5 days before July 31 and every 10 days thereafter, and a total of 22 observations (LAI was 20) were carried out during the whole growing period. The dataset can provide data basis for inversion and validation of surface vegetation parameters.

0 2021-10-26

Ground observation dataset of corn biomass, vegetation coverage, leaf area index and plant height at Daman station in the middle reaches of Heihe River (growth period in 2017)

This dataset is a continuous ground observation data of vegetation coverage (%), biomass (g/plant), leaf area index (LAI) and plant height (cm) of seed corn during the growing period in 2017 at Daman Station ( 38.85551N,100.37223E)in the middle reaches of the Heihe River. Ground observation was carried out in three sample plots. Biomass observation included fresh and dry aboveground biomass, fresh and dry underground biomass (fresh and dry root weight), vegetation coverage was observed by digital camera, leaf area index was observed by LAI 2200, and plant height was observed by tape measure. The observation period was from May 15 to September 21, 2017, in which LAI started from June 6. Observation parameters were observed every 5 days before July 31 and every 10 days thereafter, and a total of 21 observations (LAI was 17) were carried out during the whole growing period. The dataset can provide data basis for inversion and validation of surface vegetation parameters.

0 2021-10-26

Ground observation dataset of corn biomass, vegetation coverage, leaf area index and plant height at Daman station in the middle reaches of Heihe River (growth period in 2016)

This dataset is a continuous ground observation data of vegetation coverage (%), biomass (g/plant), leaf area index (LAI) and plant height (cm) of seed corn during the growing period in 2016 at Daman Station ( 38.85551N,100.37223E)in the middle reaches of the Heihe River. Ground observation was carried out in three sample plots. Biomass observation included fresh and dry aboveground biomass, fresh and dry underground biomass (fresh and dry root weight), vegetation coverage was observed by digital camera, leaf area index was observed by LAI 2200, and plant height was observed by tape measure. The observation period was from May 19 to September 5, 2016, in which LAI started from May 30. Observation parameters were observed every 5 days before July 31 and every 10 days thereafter, and a total of 18 observations (LAI was 9) were carried out during the whole growing period. The dataset can provide data basis for inversion and validation of surface vegetation parameters.

0 2021-10-26

Ground observation dataset of corn biomass, vegetation coverage, leaf area index and plant height at Daman station in the middle reaches of Heihe River (growth period in 2015)

This dataset is a continuous ground observation data of vegetation coverage (%), biomass (g/plant), leaf area index (LAI) and plant height (cm) of seed corn during the growing period in 2015 at Daman Station ( 38.85551N,100.37223E)in the middle reaches of the Heihe River. Ground observation was carried out in three sample plots. Biomass observation included fresh and dry aboveground biomass, fresh and dry underground biomass (fresh and dry root weight), vegetation coverage was observed by digital camera, leaf area index was observed by LAI 2200, and plant height was observed by tape measure. The observation period was from May 10 to September 21, 2015, in which LAI started from May 25. Observation parameters were observed every 5 days before July 31 and every 10 days thereafter, and a total of 21 observations (LAI was 18) were carried out during the whole growing period. The dataset can provide data basis for inversion and validation of surface vegetation parameters.

0 2021-10-26

Land Surface Albedo Dataset of Typical Stations in Middle Reaches of Heihe River Basin based on UAV Remote Sensing (2020, V1)

Surface albedo is a critical parameter in land surface energy balance. This dataset provides the monthly land surface albedo of UAV remote sensing for typical ground stations in the middle reaches of Heihe river basin during the vegetation growth stage (June to October) in 2020 (The data of Huazhaizi station in August is not available because of technical problem). The algorithm for calculating albedo is an empirical method, which was developed based on a comprehensive forward simulation dataset based on 6S model and typical spectrums. This method can effectively transform the surface reflectance to the broadband surface albedo. The method was then applied to the surface reflectance acquired by UAV multi-spectral sensor and the broadband surface albedo with a 0.2-m spatial resolution was eventually obtained.

0 2021-07-11

Qilian Mountains integrated observatory network: Dataset of Heihe integrated observatory network (leaf area index of Daman Superstation, 2020)

This dataset contains the LAI measurements from the Daman superstation in the middle reaches of the Heihe integrated observatory network from June 1 to September 20 in 2020. The site (100.376° E, 38.853°N) was located in the maize surface, near Zhangye city in Gansu Province. The elevation is 1556 m. There are 6 observation samples, each of which is about 30m×30m in size, and the latitude and longitude are (100.376°E, 38.853°N), (100.377° E, 38.858°N), (100.374°E, 38.855°N), (100.374°E, 38.858°N), (100.371°E, 38.854°N), (100.369°E, 38.854°N). Five sub-canopy nodes and one above-canopy node are arranged in each sample. The data is obtained from LAINet measurements; the four-steps are performed to obtain LAI: the raw data is light quantum (level 0); the daily LAI can be obtained using the software LAInet (level 1); further the invalid and null values are screened and using the 7 days moving averaged method to obtain the processed LAI (level 2); for the multi LAINet nodes observation, the averaged LAI of the nodes area is the final LAI (level 3). The released data are the post processed LAI products and stored using *.xls format. For more information, please refer to Liu et al. (2018) (for sites information), Qu et al. (2014) for data processing) in the Citation section.

0 2021-07-08