A method and apparatus for estimating a light protection trigger threshold of vegetation

Abstract

The application discloses a vegetation light protection trigger threshold estimation method and device, the method comprising: obtaining first reflectivity data and second reflectivity data at a first time, the first time being a unit time of a preset time period in a preset area, the first reflectivity data being MODIS 11th band reflectivity data, and the second reflectivity data being MODIS 13th band reflectivity data; determining a first Rchl value according to the first reflectivity data and the second reflectivity data, the first Rchl value being the value of Rchl at the first time; obtaining solar shortwave radiation SWR data corresponding to the first Rchl value at the first time to form an Rchl-SWR corresponding relationship; determining an integrated response curve according to the Rchl-SWR corresponding relationship; and determining the light protection trigger threshold of the vegetation in the preset area according to the integrated response curve. The application can determine the light protection trigger threshold of any type of vegetation in any region in the global range, and provide scientific and technological support for crop management, climate change response and land degradation warning.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light protection trigger threshold estimation of vegetation. In particular, it relates to a method and device for estimating the light protection trigger threshold of vegetation. BACKGROUND

[0002] In many cases, vegetation cannot use all the light energy it absorbs for photosynthesis, and the excess light energy can cause serious damage to the plant's light reaction system and even lead to its death. Therefore, plants need to prevent light damage through "light protection mechanisms", such as attenuating the solar radiation received by chlorophyll through increasing light-shielding pigments such as anthocyanins, dissipating excess light energy through starting xanthophyll cycle, regulating non-photochemical quenching level, etc. The solar radiation level corresponding to the activation of the protection mechanism of vegetation is called the light protection trigger threshold. It is related to the type of vegetation and its regular growth environment, and environmental stresses such as low temperature and drought will reduce the ability of vegetation to utilize solar radiation and lower the light protection trigger threshold. Estimating the light protection trigger threshold of an ecosystem and analyzing the changes in the light protection trigger threshold under different environmental conditions will help us to better understand the suitable (dominant) conditions and the limit (critical) conditions for the survival of these vegetation, so as to better optimize crop management and support the assessment and response to climate change and land degradation.

[0003] The light protection level of vegetation is closely related to the proportion of light protection pigments in its leaves. The content of different pigments in living plants can be non-contact estimated by reflectance spectrum. However, due to the large overlap area of the spectral absorption characteristics of chlorophyll, carotenoids and anthocyanins, the existing estimation methods mostly rely on narrowband spectral indices for estimation, such as the photochemical reflectance index (PRI) for representing the proportion of carotenoids and chlorophyll, the anthocyanin reflectance index (ARI) for representing the content of anthocyanins, and the like. These indices are mainly suitable for local measurement by handheld spectrometers. The existing remote sensing systems do not have the ability to obtain related indices in a wide range and high time-frequency dynamic. The chlorophyll / carotenoid index (CCI) based on the moderate resolution imaging spectroradiometer (MODIS) on board is considered to be able to reflect the response of vegetation to environmental stress to some extent. However, this index does not consider anthocyanins, and the reflection ability of the light protection mechanism is not clear. The ratio of chlorophyll to total pigments (Rchl) can realize dynamic representation of the relative proportion of chlorophyll, carotenoids and anthocyanins independent of leaf area, but has not been used in light protection mechanism related analysis. Therefore, how to estimate the light protection trigger threshold of vegetation based on the star-based MODIS remote sensing data has become a technical problem to be solved. SUMMARY

[0004] Since the existing method has the above problems, the present application proposes a light protection trigger threshold estimation method and device for vegetation.

[0005] In a first aspect, the present application proposes a light protection trigger threshold estimation method for vegetation, comprising:

[0006] obtaining first reflectance data and second reflectance data at a first time, the first time being a unit time of a preset time period in a preset area, the first reflectance data being MODIS 11th band reflectance data, and the second reflectance data being MODIS 13th band reflectance data;

[0007] determining a first ratio of chlorophyll index (Rchl) value according to the first reflectance data and the second reflectance data, the first Rchl value being the value of Rchl at the first time;

[0008] obtain solar shortwave radiation (SWR) data corresponding to the first Rchl value at the first time, and form a Rchl-SWR correspondence relationship;

[0009] determine an integrated response curve according to the Rchl-SWR correspondence relationship;

[0010] determine a light protection triggering threshold of the vegetation in the preset area according to the integrated response curve.

[0011] In a possible implementation, the determining the first leaf chlorophyll ratio index (Rchl) value according to the first reflectivity data and the second reflectivity data comprises:

[0012] the first Rchl value = the first reflectivity data / (the first reflectivity data + the second reflectivity data).

[0013] In a possible implementation, the first Rchl value comprises a non-null value and / or a null value, and the null value comprises a first Rchl value determined when snow depth at the first time is greater than a first preset value, a first Rchl value determined when mean temperature at the first time is less than a second preset value, and / or a first Rchl value determined when normalized difference vegetation index (NDVI) at the first time is less than a third preset value.

[0014] The obtaining the solar shortwave radiation (SWR) data corresponding to the first Rchl value at the first time, and forming a Rchl-SWR correspondence relationship comprises:

[0015] obtaining first SWR data to form the Rchl-SWR correspondence relationship, wherein the first SWR data is SWR data corresponding to the non-null value in the first Rchl value at the first time.

[0016] In a possible implementation, the determining an integrated response curve according to the Rchl-SWR correspondence relationship comprises:

[0017] dividing the first SWR data into fourth preset value segments according to a dynamic range of the first SWR data;

[0018] determining a second Rchl value of each segment according to a first Rchl value corresponding to the first SWR data of each segment at the first time, wherein the second Rchl value is a mean value of the first Rchl value corresponding to the first SWR data of each segment at the first time;

[0019] determining an integrated response curve according to the second Rchl value of each segment and the first SWR data.

[0020] In a possible implementation, the method further comprises:

[0021] The Savitzky-Golay filter is used to smooth the integrated response curve with a cubic function.

[0022] The smoothed integrated response curve is interpolated by using a quadratic B-spline interpolation, and a resolution of the interpolated integrated response curve is a fifth preset value.

[0023] In a possible implementation, the method further includes determining, according to the integrated response curve, a light protection triggering threshold of vegetation in the preset area, including:

[0024] A sliding window with a sixth preset size is used to determine a maximum value of the integrated response curve in each window.

[0025] The first maximum value is removed, and the first maximum value is a maximum value of the integrated response curve at a first SWR data less than a seventh preset value.

[0026] The light protection triggering threshold of vegetation in the preset area is determined according to a second maximum value and a second Rchl value of a tail part of the integrated response curve, and the second maximum value is a maximum value among the maximum values after the first maximum value is removed.

[0027] In a possible implementation, the method further includes determining, according to the second maximum value and the second Rchl value of the tail part of the integrated response curve, the light protection triggering threshold of vegetation in the preset area, including:

[0028] If the second maximum value is greater than the second Rchl value of the tail part of the integrated response curve, a first SWR data corresponding to the second maximum value is determined as the light protection triggering threshold of vegetation in the preset area.

[0029] In a second aspect, the present application provides a device for estimating a light protection triggering threshold of vegetation, including:

[0030] The transceiver unit is configured to obtain first reflectivity data and second reflectivity data at a first time, the first time being a unit time in a preset time period in a preset area, the first reflectivity data being MODIS (Moderate Resolution Imaging Spectroradiometer) 11-band reflectivity data, and the second reflectivity data being MODIS 13-band reflectivity data.

[0031] The processing unit is configured to determine a first Rchl value according to the first reflectivity data and the second reflectivity data, the first Rchl value being a value of Rchl at the first time.

[0032] The transceiver unit is further configured to obtain solar shortwave radiation (SWR) data corresponding to the first Rchl value at the first time, to form a Rchl-SWR corresponding relationship.

[0033] The processing unit is also used to determine the integrated response curve based on the Rchl-SWR correspondence;

[0034] The processing unit is also used to determine the light protection trigger threshold of the vegetation in the preset area based on the integrated response curve.

[0035] Thirdly, this application also proposes a vegetation light protection trigger threshold estimation device, including at least one processor for executing a program stored in a memory, which, when executed, causes the device to perform the steps as described in the first aspect and various possible implementations.

[0036] Fourthly, this application also proposes a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the first aspect and various possible implementations.

[0037] As can be seen from the above technical solution, this application determines the Rchl value at a given time by acquiring the reflectance data of the 11th and 13th bands of the spaceborne MODIS within a predetermined time period in a predetermined region; it then acquires the SWR data corresponding to the aforementioned Rchl value at that time to form an Rchl-SWR correspondence; based on the Rchl-SWR correspondence, it determines the integrated response curve; and based on the integrated response curve, it can determine the light protection trigger threshold for different types of vegetation in any region globally, providing scientific and technological support for crop management, climate change response, and early warning of land degradation. Simultaneously, the light protection trigger threshold can be used to analyze the suitable climatic conditions for the survival of various types of vegetation globally and their response patterns to environmental stresses. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 A flowchart illustrating a method for estimating the light protection trigger threshold of vegetation provided in an embodiment of this application;

[0040] Figure 2 Example diagram of optical protection trigger threshold estimation provided in the embodiments of this application;

[0041] Figure 3 Example figure showing the estimation results of the global vegetation light protection triggering threshold provided in the embodiments of this application;

[0042] Figure 4 This is a schematic diagram of the structure of a vegetation light protection trigger threshold estimation device provided in an embodiment of this application. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will now be described with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0044] It should be noted that the term "and / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The terms "first," "second," and "third," etc., in the specification and claims of this application are used to distinguish different objects, not to describe a specific order of objects. For example, first preset value, second preset value, and third preset value are used to distinguish different preset values, not to describe a specific order of target objects. In the embodiments of this application, words such as "exemplary," "for example," or "e.g.," are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary," "for example," or "e.g.," in the embodiments of this application should not be construed as superior to other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "e.g.," is intended to present related concepts in a specific manner. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0045] Figure 1 A flowchart illustrating a method for estimating the light protection trigger threshold of vegetation provided in this application embodiment, the flowchart including: S101-S105, specifically including:

[0046] S101, acquire the first reflectivity data and the second reflectivity data at the first moment.

[0047] In this embodiment, remote sensing data is acquired, namely, first reflectance data and second reflectance data per unit time within a preset area and a preset time period. The first reflectance data is the reflectance data of MODIS band 11, and the second reflectance data is the reflectance data of MODIS band 13. It should be noted that the unit time within the aforementioned preset area and preset time period is referred to as the first time. It is understood that the preset time period can be at least one year, and the first time uniformly covers at least one year. For example, if the first time is one day, then the acquired first and second reflectance data are the reflectance data for each day from January 1, 2021 to December 31, 2021.

[0048] S102, determine the first Rchl value based on the first reflectivity data and the second reflectivity data.

[0049] In this embodiment, a first Rchl value can be determined based on the first reflectance data ρ1 and the second reflectance data ρ2. The first Rchl value is the Rchl value at a first time. Specifically, the first Rchl value = ρ1 / (ρ1+ρ2).

[0050] Understandably, because Rchl is sensitive to snow cover, a snow depth parameter (from the GLDAS-2.1 dataset) is used for auxiliary quality control. The first Rchl value determined when the snow depth at the first time point is greater than a first preset value is considered invalid and marked as a missing value, i.e., null. Furthermore, to further avoid photoprotective radiation response errors introduced by low temperature and bare soil, the first Rchl value determined when the average temperature at the first time point is less than a second preset value is marked as a missing value, i.e., null. Similarly, the first Rchl value determined when the normalized difference vegetation index (NDVI) at the first time point is less than a third preset value is also marked as a missing value, i.e., null. Therefore, the first Rchl value includes non-null values ​​and / or null values. In this embodiment, the first preset value is 1 cm, the second preset value is 0 °C, and the third preset value is 0.1.

[0051] S103, obtain the SWR data corresponding to the first Rchl value at the first time, and form the Rchl-SWR correspondence.

[0052] In this embodiment of the application, the SWR data corresponding to the first Rchl value at the first time is obtained to form an Rchl-SWR correspondence.

[0053] It should be noted that, in the embodiments of this application, if the first time is a day, the amount of data of the first Rchl value and the SWR data corresponding to the first time is no less than the amount of data for one year; if the first time is a month, the amount of data of the first Rchl value and the SWR data corresponding to the first time is no less than the amount of data for five years.

[0054] It is understandable that the first SWR data is extracted from the GLDAS-2.1 dataset to form an Rchl-SWR correspondence. The first SWR data is the SWR data corresponding to the non-null value in the first Rchl value at the first time.

[0055] It should be noted that, in order to mitigate the bias caused by uneven distribution of missing data and the negative impact of observation errors on the integrated response curve analysis when there is too much data, it is necessary to perform binning integration of SWR data, namely S104 and S105.

[0056] S104. Determine the integrated response curve based on the Rchl-SWR correspondence.

[0057] In this embodiment, the integrated response curve can be determined based on the Rchl-SWR correspondence. In one possible implementation, determining the integrated response curve based on the Rchl-SWR correspondence can be achieved through the following steps:

[0058] The first SWR data is binned and integrated. Specifically, it is divided into a fourth preset value segment according to the dynamic range of the first SWR data. For example, the fourth preset value is 30, meaning the first SWR data is divided into 30 segments according to its dynamic range. Based on the first Rchl value corresponding to the first SWR data of each segment at the first time, a second Rchl value is determined for each segment. The second Rchl value is the average of the first Rchl values ​​corresponding to the first SWR data of each segment at the first time. Based on the second Rchl value of each segment and the first SWR data, the integrated response curve is determined. The aforementioned steps can mitigate the bias caused by uneven distribution of missing data and the negative impact of observation errors on the integrated response curve analysis when there is too much data.

[0059] Understandably, in one possible implementation, to reduce spurious inflection points caused by non-photoprotection mechanisms, a Savitzky-Golay filter is used to smooth the integrated response curve using a cubic function. To avoid inconsistencies in the estimation accuracy of the photoprotection trigger threshold for vegetation in different regions due to binning, quadratic B-spline interpolation is used to interpolate the smoothed integrated response curve. The resolution of the interpolated integrated response curve is a fifth preset value. In this embodiment, the fifth preset value is 1 W / m². 2 .

[0060] S105. Based on the integrated response curve, determine the light protection trigger threshold for vegetation within the preset area.

[0061] In this embodiment of the application, the light protection trigger threshold of vegetation within a preset area can be determined based on the integrated response curve.

[0062] In one possible implementation, determining the light protection trigger threshold for vegetation within a preset area, based on the integrated response curve, is achieved through the following steps:

[0063] A sliding window of size six preset value is used to determine the maximum value of the integrated response curve within each window, and the maximum values ​​are then sorted. For example, the sixth preset value is 10.

[0064] Understandably, when the first SWR data is less than the light protection trigger threshold, the first Rchl value increases with the increase of the first SWR data (no light protection); when the first SWR data is greater than the light protection trigger threshold, the first Rchl value decreases with the increase of the first SWR data (light protection occurs). Since the occurrence of light protection is related to radiation intensity, light protection will not occur when the radiation intensity is lower than the seventh preset value. Therefore, the first maximum value is removed; the first maximum value is the maximum value of the integrated response curve where the first SWR data is less than the seventh preset value. For example, the seventh preset value is 100 W / m². 2 ;

[0065] Based on the second maximum value and the second Rchl value at the tail of the integrated response curve, the light protection trigger threshold for vegetation within the preset area is determined. The second maximum value is the largest maximum value among the maximum values ​​after removing the first maximum value. It can be understood that if the second maximum value is greater than the second Rchl value at the tail of the integrated response curve, then the first SWR data corresponding to the second maximum value is determined as the light protection trigger threshold for vegetation within the preset area. Figure 2 As shown. See also Figure 2 , Figure 2 Example of light protection trigger threshold estimation (RU-Cok site (latitude and longitude 70.83, 147.49), sparse shrubland (OSH)). Here, dots represent the Rchl-SWR correspondence after binning; curves represent the integrated response curves after Savitzky-Golay smoothing; and arrows represent the estimated light protection trigger threshold for vegetation at the RU-Cok site (latitude and longitude 70.83, 147.49). Otherwise, it is determined that no light protection phenomenon has occurred in the integrated response curve, and the light protection trigger threshold is unknown.

[0066] It should be noted that the estimation results of the global vegetation light protection triggering threshold obtained using the embodiments of this application are as follows: Figure 3 As shown.

[0067] This application embodiment determines the Rchl value at a given time by acquiring the reflectance data of the 11th and 13th bands of a spaceborne MODIS system within a preset time period in a preset region; it then acquires the SWR data corresponding to the aforementioned Rchl value at that time to form an Rchl-SWR correspondence; based on the Rchl-SWR correspondence, it determines an integrated response curve; and based on the integrated response curve, it can determine the light protection trigger threshold for different types of vegetation in any region globally, providing scientific and technological support for crop management, climate change response, and early warning of land degradation. Simultaneously, the light protection trigger threshold can be used to analyze the suitable climatic conditions for the survival of various types of vegetation globally and their response patterns to environmental stresses.

[0068] Figure 4 A schematic diagram of a vegetation light protection trigger threshold estimation device provided in this application, the schematic diagram including: a transceiver unit 401 and a processing unit 402;

[0069] The transceiver unit 401 is used to acquire first reflectance data and second reflectance data at a first time. The first time is a unit time of a preset time period within a preset area. The first reflectance data is the reflectance data of the MODIS band 11 of the satellite-based medium resolution imaging spectrometer, and the second reflectance data is the reflectance data of the MODIS band 13.

[0070] The processing unit 402 is used to determine the first chlorophyll ratio index Rchl value based on the first reflectance data and the second reflectance data, wherein the first Rchl value is the Rchl value at the first time.

[0071] The transceiver unit 401 is also used to acquire the solar shortwave radiation (SWR) data corresponding to the first Rchl value at the first time, and form an Rchl-SWR correspondence.

[0072] The processing unit 402 is further configured to determine the integrated response curve based on the Rchl-SWR correspondence;

[0073] The processing unit 402 is further configured to determine the light protection trigger threshold of the vegetation in the preset area based on the integrated response curve.

[0074] This application provides a vegetation light protection trigger threshold estimation device, including at least one processor. The processor is used to execute a program stored in a memory. When the program is executed, the device performs the following:

[0075] Acquire first reflectance data and second reflectance data at a first time, where the first time is a unit time within a preset time period in a preset area, the first reflectance data is the reflectance data of the MODIS band 11, and the second reflectance data is the reflectance data of the MODIS band 13.

[0076] Based on the first reflectance data and the second reflectance data, the first chlorophyll ratio index Rchl value is determined, wherein the first Rchl value is the Rchl value at the first time.

[0077] Obtain the solar shortwave radiation (SWR) data corresponding to the first Rchl value at the first time to form an Rchl-SWR correspondence.

[0078] Based on the Rchl-SWR correspondence, determine the integrated response curve;

[0079] Based on the integrated response curve, the light protection trigger threshold of the vegetation within the preset area is determined.

[0080] This application provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, performs the following steps:

[0081] Acquire first reflectance data and second reflectance data at a first time, where the first time is a unit time within a preset time period in a preset area, the first reflectance data is the reflectance data of the MODIS band 11, and the second reflectance data is the reflectance data of the MODIS band 13.

[0082] Based on the first reflectance data and the second reflectance data, the first chlorophyll ratio index Rchl value is determined, wherein the first Rchl value is the Rchl value at the first time.

[0083] Obtain the solar shortwave radiation (SWR) data corresponding to the first Rchl value at the first time to form an Rchl-SWR correspondence.

[0084] Based on the Rchl-SWR correspondence, determine the integrated response curve;

[0085] Based on the integrated response curve, the light protection trigger threshold of the vegetation within the preset area is determined.

[0086] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0087] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0088] It should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for estimating the photoprotection trigger threshold of vegetation, characterized in that, include: Acquire first reflectance data and second reflectance data at a first time, where the first time is a unit time within a preset time period in a preset area, the first reflectance data is the reflectance data of the MODIS band 11, and the second reflectance data is the reflectance data of the MODIS band 13. Based on the first reflectance data and the second reflectance data, the first chlorophyll ratio index Rchl value is determined, and the first Rchl value is the Rchl value at the first time. The first Rchl value includes: non-null values ​​and / or null values, wherein the null values ​​include: the first Rchl value determined when the snow depth at the first time is greater than a first preset value, the first Rchl value determined when the average temperature at the first time is less than a second preset value, and / or the first Rchl value determined when the normalized vegetation index (NDVI) at the first time is less than a third preset value. The process involves obtaining the solar shortwave radiation SWR data corresponding to the first Rchl value at a first time, and forming an Rchl-SWR correspondence. This includes obtaining the first SWR data and forming the Rchl-SWR correspondence, wherein the first SWR data is the SWR data corresponding to the non-empty value in the first Rchl value at the first time. The integrated response curve is determined based on the Rchl-SWR correspondence. This determination includes: dividing the first SWR data into a fourth preset value segment according to its dynamic range; determining a second Rchl value for each segment based on the first Rchl value corresponding to the first SWR data at a first time, where the second Rchl value is the average of the first Rchl values ​​corresponding to the first SWR data at a first time for each segment; and determining the integrated response curve based on the second Rchl value and the first SWR data for each segment. Based on the integrated response curve, the light protection trigger threshold of the vegetation within the preset area is determined.

2. The method according to claim 1, characterized in that, The step of determining the first chlorophyll ratio index Rchl value based on the first reflectance data and the second reflectance data includes: The first Rchl value = first reflectance data / (first reflectance data + second reflectance data).

3. The method according to any one of claims 1-2, characterized in that, The method further includes: The integrated response curve was smoothed using a Savitzky-Golay filter with a cubic function. The smoothed integrated response curve is interpolated using quadratic B-spline interpolation, and the resolution of the interpolated integrated response curve is the fifth preset value.

4. The method according to claim 1, characterized in that, Based on the integrated response curve, the light protection trigger threshold for vegetation within the preset area is determined, including: Using a sliding window with a size of the sixth preset value, the maximum value of the integrated response curve within each window is determined; Remove the first maximum value, which is the maximum value of the integrated response curve where the first SWR data is less than the seventh preset value; The light protection trigger threshold for vegetation within the preset area is determined based on the second maximum value and the second Rchl value at the tail of the integrated response curve, wherein the second maximum value is the largest maximum value among the maximum values ​​after removing the first maximum value.

5. The method according to claim 4, characterized in that, The step of determining the light protection trigger threshold for vegetation within the preset area based on the second maximum value and the second Rchl value at the tail of the integrated response curve includes: If the second maximum value is greater than the second Rchl value at the tail of the integrated response curve, then the first SWR data corresponding to the second maximum value is determined as the light protection trigger threshold for vegetation in the preset area.

6. A vegetation light protection trigger threshold estimation device, characterized in that, include: The transceiver unit is used to acquire first reflectance data and second reflectance data at a first time. The first time is a unit time of a preset time period within a preset area. The first reflectance data is the reflectance data of the MODIS band 11, and the second reflectance data is the reflectance data of the MODIS band 13. The processing unit is configured to determine a first chlorophyll ratio index Rchl value based on the first reflectance data and the second reflectance data, wherein the first Rchl value is the Rchl value at the first time. The first Rchl value includes: non-null values ​​and / or null values, wherein the null values ​​include: the first Rchl value determined when the snow depth at the first time is greater than a first preset value, the first Rchl value determined when the average temperature at the first time is less than a second preset value, and / or the first Rchl value determined when the normalized vegetation index (NDVI) at the first time is less than a third preset value. The transceiver unit is further configured to acquire solar shortwave radiation SWR data corresponding to the first Rchl value at a first time, and form an Rchl-SWR correspondence; the acquisition of solar shortwave radiation SWR data corresponding to the first Rchl value at a first time and the formation of the Rchl-SWR correspondence includes: acquiring first SWR data and forming the Rchl-SWR correspondence, wherein the first SWR data is the SWR data corresponding to the non-empty value in the first Rchl value at a first time; The processing unit is further configured to determine an integrated response curve based on the Rchl-SWR correspondence; the determination of the integrated response curve based on the Rchl-SWR correspondence includes: dividing the first SWR data into a fourth preset value segment according to the dynamic range of the first SWR data; determining a second Rchl value for each segment based on the first Rchl value corresponding to the first SWR data at a first time, wherein the second Rchl value is the average of the first Rchl values ​​corresponding to the first SWR data at a first time for each segment; and determining the integrated response curve based on the second Rchl value and the first SWR data for each segment. The processing unit is also used to determine the light protection trigger threshold of the vegetation in the preset area based on the integrated response curve.

7. A vegetation light protection trigger threshold estimation device, characterized in that, Includes at least one processor, the processor being configured to execute a program stored in memory, which, when executed, causes the device to perform: The method as described in any one of claims 1-5.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-5.

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