CN-121998257-A - Method, device, equipment and medium for observing and decomposing carbon exchange flux

CN121998257ACN 121998257 ACN121998257 ACN 121998257ACN-121998257-A

Abstract

The invention relates to the technical field of ecological and meteorological intersection, in particular to a method, a device, equipment and a medium for observing and decomposing carbon exchange flux. According to the invention, the qualified data are screened through triple indexes of turbulence exchange intensity, energy closure degree and atmospheric stability, so that observation errors caused by insufficient turbulence development, energy non-closure or theoretical assumption failure under complex topography are effectively eliminated, and the reliability of basic data is greatly improved. And secondly, the flux contribution model is combined with the high-precision vegetation subareas, so that the accurate tracing and mathematical decomposition of the mixed flux are realized, and the technical bottleneck that the actual fluxes of different vegetation subareas cannot be distinguished under heterogeneous mats in the traditional method is broken through. Finally, by establishing the response relation between the flux of each vegetation area and the meteorological conditions, a carbon exchange process with long time sequence and spatial resolution is rebuilt, so that high-precision and positionable scientific data support is provided for evaluating and managing the carbon sink function of forests, particularly complex terrain areas.

Inventors

XU LI
CHEN ZHI
ZHU XIANJIN

Assignees

中国科学院地理科学与资源研究所

Dates

Publication Date: 20260508
Application Date: 20260129

Claims (10)

1. A method of observing and decomposing carbon exchange flux, the method comprising: Acquiring in-situ observation data of a source region at a plurality of moments, wherein the in-situ observation data comprise carbon exchange flux and environmental meteorological data; Determining whether the in-situ observation data at each moment meets the index requirement or not by adopting a turbulence exchange intensity index, an energy closure index and an atmosphere stability index which are determined by the in-situ observation data, and obtaining in-situ observation data at the corresponding moment meeting the index requirement; determining flux contribution degrees of all points of a source region at corresponding moments by adopting a preset flux contribution degree model based on in-situ observation data at corresponding moments meeting index requirements; Based on the flux contribution degree of each point of the source region and the source region topographic vegetation map, the flux contribution degree of each vegetation region of the source region is statistically determined; Decomposing the carbon exchange flux according to the flux contribution degree of each vegetation zone based on in-situ observation data at the corresponding moment meeting the index requirement to obtain the carbon exchange flux of each vegetation zone at the corresponding moment meeting the index requirement; And constructing a relation between the carbon exchange flux of each vegetation area and the environmental meteorological data, and determining the carbon exchange flux of each vegetation area at each moment by combining the environmental meteorological data at each moment.
2. The method of claim 1, wherein determining whether the in-situ observed data at each time satisfies the index requirement using the turbulence exchange intensity index, the energy closure index, and the atmospheric stability index determined from the in-situ observed data, and obtaining the in-situ observed data at the corresponding time satisfying the index requirement, comprises: Determining a turbulence exchange intensity index based on a preset table look-up method; determining an energy closure index based on the ratio of the wave to the venturi of the latent heat flux, the sensible heat flux, the net radiation, and the soil heat flux; determining an atmospheric stability index based on the detected height and Mo Ningao cloth Hall length determined by Mo Ningao cloth Hough similarity theory; Determining a turbulence exchange intensity index value, an energy closure index value and an atmosphere stability index value at each moment by adopting in-situ observation data at each moment; Determining whether the turbulence exchange intensity index value, the energy closure index value and the atmospheric stability index value at each moment meet the preset index requirement, and retaining in-situ observation data at the corresponding moment meeting the preset index requirement.
3. The method of claim 1, wherein decomposing the carbon exchange flux according to the flux contribution of each vegetation zone based on in-situ observed data at the respective time of meeting the index requirement to obtain the carbon exchange flux of each vegetation zone at the respective time of meeting the index requirement comprises: Dividing in-situ observation data at corresponding moments meeting index requirements into two groups of a first preset time period and a second preset time period according to differences of dominant factors of carbon exchange flux; sequencing the in-situ observation data of each group according to preset environmental meteorological data, selecting carbon exchange flux in a plurality of adjacent in-situ observation data after sequencing and flux contribution degree of each vegetation zone, and adopting least square fitting to obtain the carbon exchange flux of each vegetation zone in each group.
4. The method of claim 3, wherein constructing a relationship between each vegetation zone carbon exchange flux and environmental meteorological data comprises: Determining environmental weather data corresponding to each vegetation zone based on the environmental weather data in the plurality of in-situ observation data selected from each group; and constructing a fitting relation between the carbon exchange flux of each vegetation zone and the environmental meteorological data corresponding to each vegetation zone by adopting a nonlinear fitting method.
5. The method according to claim 1, wherein the method further comprises: Calculating the carbon exchange flux at the corresponding moment based on the carbon exchange flux of each vegetation zone and the flux contribution degree of each point of the source zone at the corresponding moment; the calculated carbon exchange flux is compared with the obtained carbon exchange flux at the corresponding moment, and whether to re-decompose the carbon exchange flux of each vegetation region is determined based on the comparison result.
6. The method of claim 1, wherein the predetermined flux contribution model comprises a two-dimensional flux contribution region model.
7. The method of claim 2, wherein the predetermined index requirements include a turbulence exchange intensity index value greater than a predetermined threshold, an energy closure index value greater than 0.5 less than 2, and an atmospheric stability less than-1.
8. A device for observing and decomposing carbon exchange flux, the device comprising: the data acquisition module is used for acquiring in-situ observation data of the source region at a plurality of moments, wherein the in-situ observation data comprise carbon exchange flux and environmental meteorological data; The data screening module is used for determining whether the in-situ observation data at each moment meets the index requirement or not by adopting the turbulence exchange intensity index, the energy closure index and the atmosphere stability index determined by the in-situ observation data, so as to obtain the in-situ observation data at the corresponding moment meeting the index requirement; The contribution degree determining module is used for determining the flux contribution degree of each point of the source region at the corresponding moment by adopting a preset flux contribution degree model based on in-situ observation data at the corresponding moment meeting the index requirement; the regional statistics module is used for statistically determining the flux contribution degree of each vegetation zone of the source zone based on the flux contribution degree of each point of the source zone and the source zone topography vegetation map; the regional exchange quantity determining module is used for decomposing the carbon exchange flux according to the flux contribution degree of each vegetation zone based on in-situ observation data at the corresponding moment meeting the index requirement to obtain the carbon exchange flux of each vegetation zone at the corresponding moment meeting the index requirement; The relation construction module is used for constructing a relation between the carbon exchange flux of each vegetation zone and the environmental meteorological data and determining the carbon exchange flux of each vegetation zone at each moment by combining the environmental meteorological data at each moment.
9. An electronic device, comprising: A memory and a processor in communication with each other, the memory having stored therein computer instructions, the processor executing the computer instructions to perform the method of observing and resolving carbon exchange flux of any one of claims 1 to 7.
10. A computer-readable storage medium having stored thereon computer instructions for causing a computer to perform the method of observing and decomposing carbon-exchange flux according to any one of claims 1 to 7.

Description

Method, device, equipment and medium for observing and decomposing carbon exchange flux Technical Field The invention relates to the technical field of ecological and meteorological intersection, in particular to a method, a device, equipment and a medium for observing and decomposing carbon exchange flux. Background The vorticity correlation technique is a core method for observing forest carbon exchange flux. As an important index for representing the net CO 2 absorption capacity of the ecosystem, the carbon exchange flux can be quantified by a box method, a vorticity correlation method and other ways, but the application of the box method in observing the carbon exchange flux of the forest is limited by the high vegetation structure of the forest ecosystem. The related vorticity technology calculates covariance of vertical wind speed and CO 2 concentration by observing high-frequency CO 2 concentration and three-dimensional wind speed above the canopy, so as to quantify forest carbon exchange flux, overcome the limitation that a box method cannot observe high and large vegetation carbon exchange flux, and become a core means for accurately observing forest carbon exchange flux. However, observing the forest carbon exchange flux based on the vorticity correlation technique needs to be carried out under ideal conditions of full turbulence exchange, unstable atmosphere, neutrality and the like, but faces the actual conditions of low turbulence exchange intensity, atmosphere junctions and the like, so that the observed carbon exchange flux deviates from the actual numerical value, and quality control is needed for observed data. However, quality control of existing vorticity correlation technique observations is generally dependent on the wind speed in friction (u) The critical value represents the turbulence exchange intensity, which leads to the observation data not being capable of characterizing the actual situation. In addition, the forest carbon exchange flux observed by the vorticity correlation technique reflects the weighted contribution of each point in the source region to the observed carbon exchange flux. However, the vorticity correlation technique assumes that the observed underlying surface exhibits homogeneity to ensure that no horizontal exchange of CO 2 occurs within the source region, and that the values of the carbon exchange fluxes at each point within the source region exhibit uniformity due to the precondition of the homogeneity of the source region, so that the weighted value of the carbon exchange fluxes at each point of the source region to the observed carbon exchange fluxes can be reflected by the flux contribution degree of each point. However, in an actual forest environment, the values of carbon exchange fluxes at various points in a source region are different due to different topography and species compositions. It is therefore necessary to consider how to determine the carbon exchange flux at each point of the heterogeneous source region based on the forest carbon exchange flux observed by the vorticity correlation technique. Disclosure of Invention The invention provides a method, a device, equipment and a medium for observing and decomposing carbon exchange flux, which are used for solving the problems that in the prior art, the data quality control of observed data is insufficient and the carbon flux of a heterogeneous source region cannot be decomposed. In a first aspect, the present invention provides a method of observing and decomposing carbon exchange flux, the method comprising: Acquiring in-situ observation data of a source region at a plurality of moments, wherein the in-situ observation data comprise carbon exchange flux and environmental meteorological data; Determining whether the in-situ observation data at each moment meets the index requirement or not by adopting a turbulence exchange intensity index, an energy closure index and an atmosphere stability index which are determined by the in-situ observation data, and obtaining in-situ observation data at the corresponding moment meeting the index requirement; determining flux contribution degrees of all points of a source region at corresponding moments by adopting a preset flux contribution degree model based on in-situ observation data at corresponding moments meeting index requirements; Based on the flux contribution degree of each point of the source region and the source region topographic vegetation map, the flux contribution degree of each vegetation region of the source region is statistically determined; Decomposing the carbon exchange flux according to the flux contribution degree of each vegetation zone based on in-situ observation data at the corresponding moment meeting the index requirement to obtain the carbon exchange flux of each vegetation zone at the corresponding moment meeting the index requirement; And constructing a relation between the carbon exchange flux of each vegetation area and t