Current Browsing: Canopy interception

HiWATER:Dataset of Hydrometeorological observation network (Thermal Dissipation sap flow velocity Probe-2014)

The data set contains the observation data of thermal diffusion fluid flow meters at the downstream mixed forest station and eupoplar forest station of the hydrometeorological observation network from January 1 to December 31, 2014. La shan au in the study area is located in the Inner Mongolia autonomous region of mesozoic-cenozoic in iminqak, according to the different height and diameter at breast height of iminqak, choose sampling tree installation TDP (Thermal Dissipation SAP flow velocity Probe, Thermal diffusion flow meter), domestic TDP pin type Thermal diffusion stem flow meter, the model for TDP30.The sample sites are TDP1 point and TDP2 point respectively, which are located near the mixed forest station and populus populus station.The height of the sample tree is TDP2 and TDP1 from high to low, and the diameter of the chest is TDP1 and TDP2 from large to small, so as to measure the trunk fluid flow on behalf of the whole area.The installation height of the probe is 1.3 meters and the installation orientation is due east and west of the sample tree. The original observation data of TDP is the temperature difference between probes, which is collected once for 10s and the average output period is 10 minutes.The published data are calculated and processed trunk flow data, including flow rate (cm/h), flux (cm3/h) and daily transpiration (mm/d) per 10 minutes.Firstly, the liquid flow rate and liquid flux were calculated according to the temperature difference between the probes, and then the transpiration Q per unit area of the forest zone was calculated according to the area of Euphrates poplar forest and the distance between trees at the observation points.At the same time, post-processing was carried out on the calculated rate and flux value :(1) data that obviously exceeded the physical significance or the instrument range were removed;(2) the missing data is marked with -6999;Among them, the data of TDP2 was missing due to power supply problems from 1.1-2.8 days, and the data of the third group of probes was missing from 2.8-3.13 days due to the problems of the third group of probes.(3) suspicious data caused by probe fault or other reasons shall be identified in red, and the data confirmed to have problems shall be removed. Please refer to Li et al.(2013) for hydrometeorological network or site information, and Qiao et al.(2015) for observation data processing.


Datasets of rainfall characteristics for intceotion of alpine shrubs in Hulu Watershed in the upstream of Heihe River Basin

This data set is the precipitation characteristic data in the precipitation interception data of alpine shrub in hulugou basin in the upper reaches of Heihe River in 2012. The observation date is from October 2, 2011 to September 24, 2012. The observation contents include precipitation, precipitation duration, precipitation intensity and frequency of throughfall. The observation data are recorded by self recording rain gauge and artificial rain gauge.


Interception data of precipitation for alpine shrubs in Hulu watershed (2012)

In the growing season of 2012, four typical shrub communities observed precipitation stem stream and penetrating rainfall during the experiment period.Data content: test date;Stem flow rate;Penetration rainfall, interception. Method of observation: water penetration was measured using a circular iron vessel with a diameter of 15 cm and a height of 10 cm.Since jinrumei, seabuckthorn and jinjijicinus shrub could not be observed on a single plant, after the canopy canopy density of the sample plots was determined, 9 water receivers were placed in each sample plot, so that there were water receivers under different canopy closures.This method of observing rain penetration allows for better collection of rain penetration from different parts of the underbrush.Due to the difficulty of observation and the lack of herbaceous vegetation, the interception of herbaceous under shrub was neglected.Takashima is centered on the stem, which is near the stem. One is placed at the edge of the crown and one at the middle of the crown and spoke. The Angle between each 3 containers is 120°.Six of each shrub were selected for stem flow observation.A single shrub was measured on the lower stems of all branches, and the stem flow of the trunk of the cluster shrub was measured by standard branch method, that is, the basal diameter of each branch of the selected shrub was measured.Under brush all branch stem, the use of polyethylene plastic hose cut open, card on the thickets stems directly, with a plastic adhesive tape and glass, the plastic tube directly connected to the trunk stem flow collection bottle, bottle thickness and plastic pipe, avoid rain and penetrate the rain into the collection bottle, before use after artificial experiments can precisely collect trunk stem flow.In order to reduce the error caused by evaporation in the measurement process, the penetrating rainfall and the flow of the trunk and stem were measured in time after the rain, such as the rain at night, and the samples were taken early in the morning on the second day. Data processing: the penetration rainfall is multiplied by 1.78 (conversion coefficient of different diameters of 20 cm and 15 cm) and replaced by the corresponding penetration rainfall (mm) at standard 20 cm.The measured water volume of each trunk flow collection bottle was divided by the projection area of the standard branch to obtain the trunk flow rate of the branch. The trunk flow rate of the standard branch was multiplied by the number of branches of the whole shrub to obtain the trunk flow rate of the whole shrub.According to the principle of water balance, the redistribution process of rainfall by shrub can be divided into three parts: interception, trunk flow and penetrating rainfall: IC = P - SF - TF Where, P is the rainfall outside the forest;TF is the penetrating rainfall;SF is the flow rate of the trunk.IC is the interception amount of the irrigation layer.According to the measured data of the stem flow through the rain trunk, the interception was obtained by using the above equation.


HiWATER: The multi-scale observation experiment on evapotranspiration over heterogeneous land surfaces (MUSOEXE-12)-dataset of flux observation matrix (thermal dissipation sap flow velocity Probe) from Jun to Sep, 2012

This dataset includes observational data of sap flow from 14 June to 21 September, 2012. The study area was located in the irrigation area within the middle reaches of the Heihe River Basin, China. Sample trees were selected for installing TDP (thermal dissipation sap flow velocity probe) instruments according to their height and diameter at breast height (DBH); only Popolusgansuensis trees were selected in this study. The TDP instrument is made in China; the model type was TDP30. There were 3 TDP observation sites, i.e., TDP-1, TDP-2 and TDP-3, which were located near the LAS4_S, EC6 and EC8 sites, respectively. The order of tree heights was TDP-2 > TDP-1 > TDP-3, and the order of DBH was TDP-2 > TDP-3 > TDP-1. At each site, 3 representative trees were selected to measure the sap flow. Three TDPs were mounted on the stem of each tree, one each for the southeast, southwest and north directions; the mounting height is 1.3 meters. Each TDP had two probes. The raw TDP data included the temperature difference between the two probes at a frequency of 30 s. The released data include the 10 minute-averaged sap flow rate (cm/h), sap flow flux (cm^3/h), and daily transpiration (mm/d). The sap flow rate and the sap flow flux were calculated according to the temperature difference between the two probes; the shelter-forest transpiration per unit area (Q) was calculated based on the area of shelterbelts and density of Popolusgansuensis trees at each site. The data preprocessing steps included the following. (1) Unphysical data were excluded. (2) Missing data were filled with -6999. (3) Suspicious data, which were most likely caused by probe failure, were marked in red; confirmed bad data were excluded. For more information, please refer to Liu et al. (2016) (for multi-scale observation experiment or sites information), Qiao et al. (2015) (for data processing) in the Citation section.


WATER: Dataset of forest canopy gap fraction above the rain gauges observed by the camera at the super site around the Dayekou Guantan forest station

The dataset of forest canopy gap fraction above the rain gauges observed by the camera (PENTAX K100D, 2400×1600) was obtained at the super site (100m×100m, Qinghai spruce) around the Dayekou Guantan forest station from 9:00-10:40 on Jun. 4, 2008. Observation items included the ground-based LiDAR scanning, the total station measuring, DGPS, tally investigation, LAI, canopy spectrum, camera observations of the canopy, soil evapotranspiration, the soil frozen tube observations, surface roughness, precipitation interception, soil moisture and dry-wet weight of the forest component. A subplot (25m×25m) was chosen for precipitation interception observations with different canopy density, and 32 sets of photos were taken 1m above the ground. Through studying those photos, the number and location of rain gauges could be determined; and then the canopy density could also be further developed.