A method and device for determining soil instantaneous evaporation ratio

Abstract

The present invention discloses a method and device for determining the soil instantaneous evaporation ratio. The method comprises: first acquiring ground data, including ground vorticity data and ground remote sensing data; then determining an initial daily soil evaporation ratio based on the ground data and a surface flux balance model; then determining the dry-side temperature of bare soil in a triangular model based on the initial daily soil evaporation ratio; then optimizing the dry-side temperature to obtain a final dry-side temperature value; and finally inputting the final dry-side temperature value into the triangular model to obtain the soil instantaneous evaporation ratio. This method reduces the error in determining the soil instantaneous evaporation ratio and improves its accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of determining soil evaporation ratio, and particularly relates to a method and device for determining soil instantaneous evaporation ratio. Background Art

[0002] The soil evaporation ratio is defined as the ratio of latent heat flux to total available energy. It is a key variable for estimating evapotranspiration. At the same time, it also serves as a diagnostic indicator for measuring energy distribution on the land surface. The soil evaporation ratio represents the distribution of available energy between latent heat flux and sensible heat flux when the surface reaches equilibrium temperature. Therefore, determining the soil evaporation ratio is of great significance for research on climate evolution, agricultural applications and water resources management.

[0003] Traditional methods for determining soil evaporation ratio are mainly based on point or field-scale observations. Since they require a series of difficult-to-obtain parameters as auxiliary and discontinuous spatial measurements, error accumulation cannot be avoided.

[0004] Therefore, how to accurately determine the instantaneous evaporation ratio of soil is a technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problem that too many parameters are required for determining the instantaneous evaporation ratio of soil in the prior art, resulting in large errors in the determination results.

[0006] To achieve the above technical objectives, the present invention provides a method for determining the instantaneous evaporation ratio of soil, the method comprising:

[0007] Acquiring ground data, wherein the ground data includes ground vorticity data and ground remote sensing data;

[0008] determining an initial daily average soil evaporation ratio based on the ground data and a surface flux balance model;

[0009] determining the dry side temperature of the bare soil in the triangle model based on the initial soil daily average evaporation ratio;

[0010] Optimizing the dry side temperature to obtain a final dry side temperature value;

[0011] The final dry side temperature value is input into the triangle model to obtain the soil instantaneous evaporation ratio.

[0012] Furthermore, the initial soil daily average evaporation ratio is specifically determined by the following formula:

[0013]

[0014] RH=e s (T d ) / e s (Ta )

[0015] Where, EF SFE is the initial soil daily average evaporation ratio, RH is the daily average relative humidity, Δ(T a ) is the daily average air temperature (T a ) is the slope of the saturated water vapor pressure curve, γ is the humidity constant, e s (T d ) is the daily average dew point temperature (T d ) under saturated water vapor pressure, e s (T a ) is the saturated water vapor pressure at the daily average air temperature.

[0016] Furthermore, the dry side temperature of the bare soil in the triangular model is specifically determined by the following formula:

[0017]

[0018] φ i =(1-TVDI i )(φ max，i -φ min，i )+φ min，i

[0019]

[0020] T smax，i =T smax +f c，i (T w -T smax )

[0021] Where, EF SFE is the initial soil daily average evaporation ratio, φ i is a dimensionless variable reflecting aerodynamic and surface impedance information, Δ(T a1 ) is the instantaneous air temperature (T a1 ), γ is the humidity constant, TVDI i is the temperature-vegetation drought index, φ max，i is a fixed value of 1.26, φ min，i is φ max，i and f c，i The product of T s，i is the weighted sum of soil temperature and vegetation temperature, T w is the wet edge temperature of bare soil, T smax，i is the dry edge temperature of the target pixel, T smax is the dry side temperature of bare soil, f c，i is the vegetation coverage of pixel i.

[0022] Furthermore, the dry edge temperature is optimized by the following formula:

[0023] T smax，new =345.05cos(0.57SZ-0.05)

[0024] Where, T smax，new is the final dry side temperature value, SZ is the solar zenith angle, wherein each coefficient is obtained by calibration of the dry side temperature and the solar zenith angle.

[0025] Furthermore, the step of inputting the final dry side temperature value into the triangle model to obtain the soil instantaneous evaporation ratio specifically includes:

[0026] The modified temperature-vegetation drought index is determined based on the bare soil temperature, wet edge temperature and final dry edge temperature values of pixel i;

[0027] The dimensionless variables reflecting aerodynamic and surface impedance information in bare land pixels are determined based on the modified temperature-vegetation drought index.

[0028] The dimensionless variable φ reflecting the aerodynamics and surface impedance information of the soil is determined based on the dimensionless variable reflecting the aerodynamics and surface impedance information in the bare ground pixel and the dimensionless variable reflecting the aerodynamics and surface impedance information in the vegetation pixel. i ;

[0029] The φ i Input into the triangle model to obtain the soil instantaneous evaporation ratio.

[0030] Furthermore, the corrected temperature-vegetation drought index is obtained by the following formula:

[0031]

[0032] Where, MTVDI i is the corrected temperature-vegetation drought index of pixel i, T soil，i is the bare soil temperature of pixel i, T w is the wet edge temperature of bare soil, T smax，new is the final dry edge temperature.

[0033] Furthermore, the dimensionless variable φ reflecting aerodynamic and surface impedance information is determined by the following formula: i :

[0034] φ i =(1-f c，i )φ soil，i +f c，i φ canopy，i

[0035] Where, fc，i is the vegetation coverage of pixel i, φ soil，i is a dimensionless variable reflecting aerodynamic and surface impedance information in bare ground pixels, φ canopy，i It is a dimensionless variable reflecting aerodynamic and surface impedance information in vegetation pixels.

[0036] On the other hand, the present invention also provides a device for determining the instantaneous evaporation ratio of soil, the device comprising:

[0037] An acquisition module, configured to acquire ground data, wherein the ground data includes ground vorticity data and ground remote sensing data;

[0038] A first determining module is configured to determine an initial daily average soil evaporation ratio based on the ground data and a surface flux balance model;

[0039] A second determining module is configured to determine the dry side temperature of the bare soil in the triangle model based on the initial daily average soil evaporation ratio;

[0040] an optimization module, configured to optimize the dry side temperature to obtain a final dry side temperature value;

[0041] The third determining module is configured to input the final dry side temperature value into the triangle model to obtain the soil instantaneous evaporation ratio.

[0042] The present invention provides a method and device for determining the soil instantaneous evaporation ratio. Compared to existing technologies, this method first acquires ground data, including ground vorticity data and ground remote sensing data; then determines an initial daily soil evaporation ratio based on this ground data and a surface flux balance model; then determines the dry-side temperature of bare soil in a triangular model based on this initial daily soil evaporation ratio; then optimizes this dry-side temperature to obtain a final dry-side temperature value; and finally, inputs this final dry-side temperature value into the triangular model to obtain the soil instantaneous evaporation ratio. This method reduces the error in determining the soil instantaneous evaporation ratio and improves its accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 1 is a flow chart of a method for determining the instantaneous evaporation ratio of soil provided in an embodiment of this specification;

[0045] Figure 2The diagram shows the structure of the device for determining the instantaneous evaporation ratio of soil provided in the embodiment of this specification.

[0046] Figure 3 Schematic diagram showing a comparison between the soil instantaneous evaporation ratio determined before the dry side temperature optimization of the triangle model in the embodiment of this specification and the observed value of the soil instantaneous evaporation ratio;

[0047] Figure 4 Schematic diagram showing a comparison between the soil instantaneous evaporation ratio determined after optimizing the dry side temperature of the triangle model in the embodiment of this specification and the observed value of the soil instantaneous evaporation ratio;

[0048] Figure 5 Schematic diagram showing a comparison between the instantaneous soil evaporation ratio determined before the dry side temperature optimization of the triangle model in the embodiment of this specification and the observed value of the daily soil evaporation ratio;

[0049] Figure 6 Schematic diagram showing a comparison between the instantaneous soil evaporation ratio determined after the dry side temperature of the triangle model is optimized and the observed value of the daily soil evaporation ratio in the embodiment of this specification;

[0050] Figure 7 It is a schematic diagram showing the various coefficients obtained by calibrating the dry edge temperature and the solar zenith angle in the embodiment of this specification. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0052] like Figure 1 The flowchart of the method for determining the instantaneous evaporation ratio of soil provided in the embodiments of this specification is shown. Although this specification provides the method operation steps or device structure shown in the following embodiments or figures, the method or device may include more or fewer operation steps or module units based on routine or no creative effort. In steps or structures that do not logically have a necessary causal relationship, the execution order of these steps or the module structure of the device is not limited to the execution order or module structure shown in the embodiments or figures of this specification. When the method or module structure is applied in actual devices, servers, or terminal products, it can be executed sequentially or in parallel according to the method or module structure shown in the embodiments or figures (for example, in a parallel processor or multi-threaded processing environment, or even in a distributed processing or server cluster implementation environment).

[0053] The method for determining the instantaneous evaporation ratio of soil provided in the embodiment of this description can be applied to terminal devices such as clients and servers, such as Figure 1 As shown, the method specifically includes the following steps:

[0054] Step S101: Acquire ground data, where the ground data includes ground vorticity data and ground remote sensing data.

[0055] Specifically, surface vorticity data were collected from 212 stations worldwide. Half-hourly observations were quality-controlled, and energy closure control and daily average data synthesis were performed on this basis. To couple the SFE method, inland sites (greater than 250 km from oceans and water bodies) were screened and then spatiotemporally matched with remote sensing products to obtain 33 valid sites. The evaporation ratio of an observation site is the ratio of latent heat flux to the sum of latent heat flux and sensible heat flux. Flux data are also used for site energy balance screening. Furthermore, MODIS products from three Terra satellites with a spatial resolution of 1 km were used. Specifically, MOD03 was used to retrieve the solar zenith angle. MOD11L2 and MOD13A2 provide surface temperature and the Normalized Difference Vegetation Index (NDVI). To ensure consistent temporal resolution, the 16-day NDVI extracted from the MOD13A2 product was interpolated to a daily scale using a locally adjusted spline interpolation function.

[0056] Step S102: determining an initial daily average soil evaporation ratio based on the ground data and a surface flux balance model.

[0057] In the embodiment of the present application, the initial soil daily average evaporation ratio is specifically determined by the following formula:

[0058]

[0059] RH=e s (T d ) / e s (T a )

[0060] Where, EF SFE is the initial soil daily average evaporation ratio, RH is the daily average relative humidity, Δ(T a ) is the daily average air temperature (T a ) is the slope of the saturated water vapor pressure curve, γ is the humidity constant, e s (T d ) is the daily average dew point temperature (T d ) under saturated water vapor pressure, e s (T a ) is the saturated water vapor pressure at the daily average air temperature.

[0061] Specifically, the above formula is also the surface flux equilibrium model (Surface Flux Equilibrium, SFE), and the initial soil daily average evaporation ratio is determined based on the surface flux equilibrium model.

[0062] Step S103: determining the dry side temperature of the bare soil in the triangle model based on the initial daily average soil evaporation ratio.

[0063] In the embodiment of the present application, the dry side temperature of the bare soil in the triangular model is specifically determined by the following formula:

[0064]

[0065] φ i =(1-TVDI i )(φ max，i -φ min，i )+φ min，i

[0066]

[0067] T smax，i =T smax +f c，i (T w -T smax )

[0068] Where, EF SFE is the initial soil daily average evaporation ratio, φ i is a dimensionless variable reflecting aerodynamic and surface impedance information, Δ(T a1 ) is the instantaneous air temperature (T a1 ), γ is the humidity constant, TVDI i is the temperature-vegetation drought index, φ max，i is a fixed value of 1.26, φ min，i is φ max，i and f c，i The product of T s，i is the weighted sum of soil temperature and vegetation temperature, T w is the wet edge temperature of bare soil, T smax，i is the dry edge temperature of the target pixel, T smax is the dry side temperature of bare soil, f c，i is the vegetation coverage of pixel i.

[0069] Specifically, the dry edge T is determined based on the daily average air temperature and the daily average dew point temperature. smaxThe SFE model and the Ts-VI triangle model are combined, where the SFE model is also the surface flux balance model, and the Ts-VI triangle model is also the triangle model mentioned above, which refers to the surface temperature-vegetation index triangle model. Based on the assumption that the EF in the Ts-VI triangle model is constant during the diurnal cycle, the daily EF retrieved under the SFE model is equal to the instantaneous EF retrieved under the Ts-VI triangle model, and the dry side in the Ts-VI triangle is then calculated.

[0070] Step S104: Optimize the dry side temperature to obtain a final dry side temperature value.

[0071] In the embodiment of the present application, the dry edge temperature is optimized specifically by the following formula:

[0072] T smax，new =345.05cos(0.57SZ-0.05)

[0073] Where, T smax，new is the final dry side temperature value, SZ is the solar zenith angle, wherein each coefficient is obtained by calibration of the dry side temperature and the solar zenith angle, such as Figure 7 The figure shows a schematic diagram of the coefficients obtained by calibrating the dry edge temperature and the solar zenith angle. The arc in the figure is the solar zenith angle.

[0074] Specifically, the numbers in the above optimization formula are determined by fitting based on historical observations, specifically based on the theoretical explanation of the maximum surface temperature. When surface conditions remain consistent and stable, its seasonal changes are mainly determined by the intensity of solar radiation, which can be approximated by the cosine function of the solar zenith angle.

[0075] Step S105: input the final dry side temperature value into the triangle model to obtain the soil instantaneous evaporation ratio.

[0076] In the embodiment of the present application, the inputting of the final dry side temperature value into the triangle model to obtain the soil instantaneous evaporation ratio specifically includes:

[0077] The modified temperature-vegetation drought index is determined based on the bare soil temperature, wet edge temperature and final dry edge temperature values of pixel i;

[0078] The dimensionless variables reflecting aerodynamic and surface impedance information in bare land pixels are determined based on the modified temperature-vegetation drought index.

[0079] The dimensionless variable φ reflecting the aerodynamics and surface impedance information of the soil is determined based on the dimensionless variable reflecting the aerodynamics and surface impedance information in the bare ground pixel and the dimensionless variable reflecting the aerodynamics and surface impedance information in the vegetation pixel. i ;

[0080] The φ i Input into the triangle model to obtain the soil instantaneous evaporation ratio.

[0081] Specifically, the T of the mixed pixel s，i is the weighted sum of soil and vegetation temperatures, while the temperature of the fully covered vegetation canopy is in equilibrium with the air temperature inside the canopy. Therefore, the soil temperature can be approximately estimated as:

[0082]

[0083] Where, T soil，i and T canopy，i represent the instantaneous surface temperature of bare soil and vegetation cover in pixel i, respectively.

[0084] In the embodiment of the present application, the corrected temperature-vegetation drought index is obtained by the following formula:

[0085]

[0086] Where, MTVDI i is the corrected temperature-vegetation drought index of pixel i, T soil，i is the bare soil temperature of pixel i, T w is the wet edge temperature of bare soil, T smax，new is the final dry edge temperature.

[0087] Among them, T w Use wet bulb temperature instead. Since we assume T canopy，i Equal to T a，i , full vegetation coverage φ canopy，i Always close to 1.26. soil，i ) is retrieved from MTVDI as follows:

[0088] φ soil，i =1.26[1-exp(MTVDI i -1)]

[0089] Determined φ soil，i and φ canopy，i , the mixed pixel φi is obtained by linear interpolation between these two components, using f c，i As a weight.

[0090] Specifically, the dimensionless variable φ reflecting aerodynamic and surface impedance information is determined by the following formula: i :

[0091] φ i =(1-f c，i )φ soil，i +f c，iφ canopy，i

[0092] Where, f c，i is the vegetation coverage of pixel i, φ soil，i is a dimensionless variable reflecting aerodynamic and surface impedance information in bare ground pixels, φ canopy，i It is a dimensionless variable reflecting aerodynamic and surface impedance information in vegetation pixels.

[0093] Then the updated φ i Substitute it into the triangle model and calculate the improved instantaneous EF, which is also the instantaneous soil evaporation ratio.

[0094] The dry side temperature in the traditional triangle model is calculated using the following formula:

[0095]

[0096] Where, α s ,σ,ε ss ,ρ,c p and c s are the bare soil surface albedo, the Stefan-Boltzmann constant, the bare soil surface emissivity, the air density, the specific heat capacity of air at constant pressure, and the ratio of the bare soil heat flux to the net surface radiation. All of the above are constants, with values of 0.15, 5.67×10-8 W / (m2·K4), 0.95, 1.29 kg / m3, 29.3 J / (mol·K), and 0.315, respectively; Sd is the downwelling shortwave radiation, estimated from the solar zenith angle extracted by MOD03; ε a is the atmospheric emissivity; r as The aerodynamic impedance of bare soil requires the introduction of an instrument to measure the average wind speed at a height of 2m; T asd Indicates air temperature during extreme drought conditions.

[0097] In addition, for comparison, the observed value of site EF needs to be calculated as follows:

[0098]

[0099] Where, EF sites is the observed value of site EF, LE is the latent heat flux, and H is the sensible heat flux.

[0100] When the instantaneous value and daily average value of LE and H are respectively brought in, EF sites The present invention uses four statistical indicators to evaluate the accuracy of EF estimation, including Pearson correlation coefficient (r), mean absolute error (MAE), root mean square error (RMSE) and bias (B), which are determined by the following formulas:

[0101]

[0102] Where n is the total number of samples, X′ i and X i are the estimated value and observed value of the i-th sample, respectively, and and are the means of the estimated and observed values, respectively.

[0103] After calculation by the above formula, if Figure 3 The figure shows a comparison diagram of the soil instantaneous evaporation ratio determined before the dry side temperature optimization of the triangle model and the observed value of the soil instantaneous evaporation ratio. Figure 4 The figure shows a comparison diagram of the soil instantaneous evaporation ratio determined after the dry side temperature of the triangle model is optimized and the observed value of the soil instantaneous evaporation ratio. Figure 5 The figure shows a comparison diagram of the soil instantaneous evaporation ratio determined before the dry side temperature optimization of the triangle model and the observed value of the soil daily evaporation ratio. Figure 6 The figure shows a comparison of the instantaneous soil evaporation ratio (IER) determined after optimizing the dry-side temperature with the observed daily IER. This comparison reveals that the traditional triangular model tends to overestimate the IER. Compared with the instantaneous EF observed at the site, the r, MAE, RMSE, and B of the optimized EF are 0.626, 0.161, 0.193, and 0.113, respectively. Compared with the daily EF observed at the site, the r, MAE, RMSE, and B of the optimized EF are 0.599, 0.152, 0.185, and 0.029, respectively. Overall, the accuracy is higher than that of existing methods.

[0104] Based on the above-mentioned method for determining the instantaneous evaporation ratio of soil, one or more embodiments of this specification also provide a platform or terminal for determining the instantaneous evaporation ratio of soil. The platform or terminal may include a device, software, module, plug-in, server, client, etc. that uses the method described in the embodiments of this specification and is combined with necessary hardware implementation devices. Based on the same innovative concept, the system in one or more embodiments provided in the embodiments of this specification is as described in the following embodiments. Since the implementation scheme and method for solving the problem of the system are similar, the implementation of the specific system in the embodiments of this specification can refer to the implementation of the aforementioned method, and the repetitions will not be repeated. The terms "unit" or "module" used below can be a combination of software and / or hardware that implements the predetermined function. Although the system described in the following embodiments is preferably implemented in software, hardware or a combination of software and hardware is also possible and conceivable.

[0105] Specifically, Figure 2 This is a schematic diagram of the module structure of an embodiment of the device for determining the instantaneous evaporation ratio of soil provided in this specification. Figure 2As shown, the device for determining the instantaneous evaporation ratio of soil provided in this specification includes:

[0106] An acquisition module 201 is used to acquire ground data, wherein the ground data includes ground vorticity data and ground remote sensing data;

[0107] A first determining module 202 is configured to determine an initial daily average soil evaporation ratio based on the ground data and a surface flux balance model;

[0108] A second determining module 203 is configured to determine the dry side temperature of the bare soil in the triangle model based on the initial daily average soil evaporation ratio;

[0109] An optimization module 204 is configured to optimize the dry side temperature to obtain a final dry side temperature value;

[0110] The third determining module 205 is configured to input the final dry side temperature value into the triangle model to obtain the soil instantaneous evaporation ratio.

[0111] It should be noted that the above-mentioned system may also include other implementation methods according to the description of the corresponding method embodiment. The specific implementation methods can refer to the description of the above-mentioned corresponding method embodiment, and will not be described one by one here.

[0112] An embodiment of the present application further provides an electronic device, including:

[0113] processor;

[0114] a memory for storing instructions executable by the processor;

[0115] The processor is configured to execute the method provided in the above embodiment.

[0116] The electronic device provided in an embodiment of the present application stores executable instructions for a processor in a memory. When the processor executes the executable instructions, it first acquires ground data, including ground vorticity data and ground remote sensing data; then determines an initial daily soil evaporation ratio based on the ground data and a surface flux balance model; then determines the dry side temperature of bare soil in a triangular model based on the initial daily soil evaporation ratio; then optimizes the dry side temperature to obtain a final dry side temperature value; and finally, inputs the final dry side temperature value into the triangular model to obtain the soil instantaneous evaporation ratio. This reduces the error in determining the soil instantaneous evaporation ratio and improves the accuracy of the soil instantaneous evaporation ratio.

[0117] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0118] The methods or devices described in the above embodiments of this specification can implement business logic through computer programs and record them on storage media. The storage media can be read and executed by a computer to achieve the effects of the solutions described in the embodiments of this specification, such as:

[0119] Acquiring ground data, wherein the ground data includes ground vorticity data and ground remote sensing data;

[0120] determining an initial daily average soil evaporation ratio based on the ground data and a surface flux balance model;

[0121] determining the dry side temperature of the bare soil in the triangle model based on the initial soil daily average evaporation ratio;

[0122] Optimizing the dry side temperature to obtain a final dry side temperature value;

[0123] The final dry side temperature value is input into the triangle model to obtain the soil instantaneous evaporation ratio.

[0124] The storage medium may include a physical device for storing information, typically digitizing the information and then storing it in a medium utilizing electrical, magnetic, or optical means. Examples of such storage media include: devices that store information electrically, such as various types of memory devices like RAM and ROM; devices that store information magnetically, such as hard disks, floppy disks, magnetic tapes, magnetic core memories, bubble memories, and USB flash drives; and devices that store information optically, such as CDs and DVDs. Of course, other types of readable storage media exist, such as quantum memories and graphene memories.

[0125] The embodiments of this specification are not limited to those that must comply with industry communication standards, standard computer resource data update and data storage rules, or the situations described in one or more embodiments of this specification. Certain industry standards or slightly modified implementation plans based on the implementation described in the embodiments using custom methods or embodiments can also achieve the same, equivalent, or similar implementation effects as the above embodiments, or the expected implementation effects after deformation. The embodiments obtained by applying these modified or deformed data acquisition, storage, judgment, processing methods, etc. can still fall within the scope of the optional implementation plans of the embodiments of this specification.

[0126] The controller can be implemented in any suitable manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel ATMEL AT91SAM, Microchip PIC18F26K20, and Silicon Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art will also appreciate that, in addition to implementing the controller in pure computer-readable program code, the controller can also be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a controller can be considered a hardware component, and the means for implementing various functions included therein can also be considered as structures within the hardware component. Alternatively, the means for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0127] The device embodiments described above are merely illustrative. For example, the division of units described is merely a logical functional division. Actual implementations may employ alternative divisions, such as combining or integrating multiple units or plug-ins into another system, or omitting or disabling certain features. Furthermore, the coupling or direct coupling or communication connection shown or discussed between devices or units may be through interfaces, or indirect coupling or communication connection between devices or units may be electrical, mechanical, or otherwise.

[0128] These computer program instructions can also be loaded onto a computer or other programmable resource data updating device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable device to implement the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0129] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referenced to the partial description of the method embodiment. In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this specification. In addition, unless there is any contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0130] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. A method for determining soil instantaneous evaporation ratio, characterized in that: The method comprises: Acquiring ground data, wherein the ground data includes ground vorticity data and ground remote sensing data; determining an initial daily average soil evaporation ratio based on the ground data and a surface flux balance model; determining the dry side temperature of the bare soil in the triangle model based on the initial soil daily average evaporation ratio; Optimizing the dry side temperature to obtain a final dry side temperature value; Inputting the final dry side temperature value into the triangle model to obtain the soil instantaneous evaporation ratio; The dry side temperature of the bare soil in the triangular model is specifically determined by the following formula: ， ， ， ， Where, is the initial soil daily average evaporation ratio, is a dimensionless variable reflecting aerodynamic and surface impedance information, is the instantaneous air temperature function, is the humidity constant, is the temperature-vegetation drought index, is a fixed value of 1.26, for and The product of is the weighted sum of soil temperature and vegetation temperature, is the wet-edge temperature of bare soil, is the dry edge temperature of the target pixel, is the dry side temperature of bare soil, For pixels vegetation coverage.

2. The method for determining the soil instantaneous evaporation ratio according to claim 1, wherein: The initial soil daily average evaporation ratio is specifically determined by the following formula: ， ， Where, is the initial soil daily average evaporation ratio, is the average daily relative humidity, is the average daily air temperature The function of is also the slope of the saturated water vapor pressure curve, is the humidity constant, The average daily dew point temperature The saturated water vapor pressure under is the saturated water vapor pressure at the average daily air temperature.

3. The method for determining the soil instantaneous evaporation ratio according to claim 1, wherein: Specifically, the dry side temperature is optimized by the following formula: ， Where, is the final dry edge temperature, is the solar zenith angle, wherein each coefficient is obtained by calibration of the dry edge temperature and the solar zenith angle.

4. The method for determining the soil instantaneous evaporation ratio according to claim 1, wherein: Inputting the final dry side temperature value into the triangle model to obtain the soil instantaneous evaporation ratio specifically includes: The modified temperature-vegetation drought index is determined based on the bare soil temperature, wet edge temperature and final dry edge temperature values of pixel i; The dimensionless variables reflecting aerodynamic and surface impedance information in bare land pixels are determined based on the modified temperature-vegetation drought index. The dimensionless variable reflecting the aerodynamics and surface impedance information of the soil is determined based on the dimensionless variable reflecting the aerodynamics and surface impedance information in the bare ground pixel and the dimensionless variable reflecting the aerodynamics and surface impedance information in the vegetation pixel. ; The Input into the triangle model to obtain the soil instantaneous evaporation ratio.

5. The method for determining the soil instantaneous evaporation ratio according to claim 4, wherein: Specifically, the corrected temperature-vegetation drought index is obtained through the following formula: ， Where, For pixels The corrected temperature-vegetation drought index, For pixels The bare soil temperature, is the wet-edge temperature of bare soil, is the final dry edge temperature.

6. The method for determining the soil instantaneous evaporation ratio according to claim 4, wherein: Specifically, the dimensionless variables reflecting aerodynamic and surface impedance information are determined by the following formula: : ， Where, For pixels The vegetation coverage, is a dimensionless variable reflecting aerodynamic and surface impedance information in bare ground pixels. It is a dimensionless variable reflecting aerodynamic and surface impedance information in vegetation pixels.

7. A device for determining soil instantaneous evaporation ratio, characterized in that: The device comprises: An acquisition module, configured to acquire ground data, wherein the ground data includes ground vorticity data and ground remote sensing data; A first determination module is configured to determine an initial daily average soil evaporation ratio based on the ground data and a surface flux balance model; A second determining module is configured to determine the dry side temperature of the bare soil in the triangle model based on the initial daily average soil evaporation ratio; an optimization module, configured to optimize the dry side temperature to obtain a final dry side temperature value; A third determining module is configured to input the final dry side temperature value into a triangle model to obtain a soil instantaneous evaporation ratio; The dry side temperature of the bare soil in the triangular model is specifically determined by the following formula: ， ， ， ， Where, is the initial soil daily average evaporation ratio, is a dimensionless variable reflecting aerodynamic and surface impedance information, is the instantaneous air temperature function, is the humidity constant, is the temperature-vegetation drought index, is a fixed value of 1.26, for and The product of is the weighted sum of soil temperature and vegetation temperature, is the wet-edge temperature of bare soil, is the dry edge temperature of the target pixel, is the dry side temperature of bare soil, For pixels vegetation coverage.

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