Calculation Method and Device for Potential Evapotranspiration Parameters in Target Area

Abstract

The present invention provides a method and device for calculating potential evapotranspiration parameters of a target area, belonging to the technical field of data processing. In order to address the bottlenecks such as low areal accuracy and spatial resolution existing in the existing measured method and model method, it includes: calculating a first estimated value and a second estimated value of the target area by using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model respectively; calculating the difference between the first estimated value and the second estimated value; establishing a multi-source potential evapotranspiration initial model according to the functional relationship between the difference and temperature and atmospheric precipitable water; performing model solution on the multi-source potential evapotranspiration initial model to obtain a multi-source potential evapotranspiration calculation model; obtaining an areal potential evapotranspiration estimation model according to the multi-source potential evapotranspiration calculation model and the first potential evapotranspiration calculation model; and estimating the potential evapotranspiration parameters of the target area by using the areal potential evapotranspiration estimation model. The present invention can more accurately evaluate the evapotranspiration situation of water in the target area.

Description

Background Art

[0002] In the broad context of hydrology and climatology, Potential Evapotranspiration (PET) is a key parameter for measuring the total evaporation from the earth's surface and the transpiration potential of plants when the soil is fully supplied with water under specific meteorological conditions. It is of indispensable significance for understanding the hydrological cycle and energy balance. It works together with precipitation to depict the humidity status of the relevant area. Especially under the trend of global warming, the increase in PET has become a significant driving factor accelerating the global drought phenomenon. The importance of PET is also reflected in its being a core component in the calculation of the standardized precipitation potential evapotranspiration index. It has been verified by research that drought indicators incorporating PET can more accurately reflect the severity of drought.

[0003] In recent years, the Global Navigation Satellite System (GNSS) has emerged as a cutting-edge technology for monitoring tropospheric water vapor content, characterized by high precision, superior spatio-temporal resolution, cost-effectiveness, and being almost unaffected by meteorological conditions. Although existing remote sensing technologies can provide large-scale PET estimations, their accuracy is still limited. As water vapor is a key factor affecting extreme weather events and regional ecological balance, its accurate measurement is particularly important. With the rapid development of GNSS technology, it has opened up new paths for accurately determining water vapor content. As a core variable in drought monitoring, climate prediction, and agricultural irrigation management, the need for accurate acquisition of PET is becoming increasingly urgent. The current challenges include: traditional PET models rely on numerous meteorological parameters that are difficult to comprehensively obtain and are limited to high-precision measurements at meteorological stations, making it difficult to meet the requirements for calculating regional drought indices. Summary of the Invention

[0004] To overcome the problems existing in related technologies, the present invention provides a method and device for calculating potential evapotranspiration parameters of a target area.

[0005] According to the first aspect of the embodiments of the present invention, there is provided a method for calculating potential evapotranspiration parameters of a target area, the method for calculating the potential evapotranspiration parameters comprising:

[0006] Calculating a first estimated value and a second estimated value of the target area by using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model respectively;

[0007] Calculating the difference between the first estimated value and the second estimated value;

[0008] Establishing a multi-source potential evapotranspiration initial model according to the functional relationship between the difference and temperature and precipitable water in the atmosphere;

[0009] Perform model calculation on the multi-source potential evapotranspiration initial model to obtain a multi-source potential evapotranspiration calculation model;

[0010] Based on the multi-source potential evapotranspiration calculation model and the first potential evapotranspiration calculation model, obtain an areal potential evapotranspiration estimation model;

[0011] Use the areal potential evapotranspiration estimation model to estimate the potential evapotranspiration parameters of the target area.

[0012] In some exemplary embodiments of the present invention, based on the foregoing solution, the calculating the first estimated value of the target area using the first potential evapotranspiration calculation model includes:

[0013] Based on the monthly average temperature of the target area, calculate the heat index of the target area;

[0014] According to the heat index, calculate the heat index coefficient;

[0015] Based on the latitude and solar declination of the target area, calculate the correction coefficient of the target area;

[0016] According to the heat index, the heat index coefficient and the correction coefficient, obtain the first potential evapotranspiration calculation model;

[0017] According to the temperature data of the target area in the current month and the first potential evapotranspiration calculation model, obtain the first estimated value.

[0018] In some exemplary embodiments of the present invention, based on the foregoing solution, obtaining the first potential evapotranspiration calculation model according to the heat index, the heat index coefficient and the correction coefficient includes:

[0019]

[0020] In the formula, PET is calculated using the first potential evapotranspiration calculation model, T is the temperature data of the current month, I is the heat index, m is the heat index coefficient, is the correction coefficient.

[0021] In some exemplary embodiments of the present invention, based on the foregoing solution, the calculating the second estimated value of the target area using the second potential evapotranspiration calculation model includes:

[0022] Taking the assumed crop canopy of the target area as the standard, considering the influence of various influencing factors on the potential evapotranspiration process, establish a second potential evapotranspiration calculation model; wherein, the various influencing factors include radiation, temperature, water vapor pressure and wind speed;

[0023] According to the air pressure in the target area, the temperature data of the current month, the temperature data of the previous month, and the second potential evapotranspiration calculation model, a second estimated value is obtained.

[0024] In some exemplary embodiments of the present invention, based on the foregoing solution, taking the assumed crop canopy in the target area as a standard and considering the influence of various influencing factors on the potential evapotranspiration process, establishing a second potential evapotranspiration calculation model includes:

[0025]

[0026] In the formula, is the net radiation at the crop surface; is the soil heat flux; is the humidity constant; and respectively represent the average air temperature and wind speed within a preset range in the target area; is the saturation water vapor pressure; is the actual water vapor pressure; is the slope of the vapor pressure curve; the constants 900 and 0.34 are the standard crop coefficient and the standard crop wind coefficient respectively.

[0027] In some exemplary embodiments of the present invention, based on the foregoing solution, according to the functional relationship between the difference and temperature and atmospheric precipitable water, establishing a multi-source potential evapotranspiration initial model includes:

[0028] According to the functional relationship between the difference and temperature and atmospheric precipitable water, piecewise function models are respectively established at multiple meteorological stations in the target area;

[0029] Fitting the coefficients of the piecewise function model to the grid points to obtain the corresponding coefficients of the grid points;

[0030] Based on the corresponding coefficients of the grid points, combining temperature data and atmospheric precipitable water data, calculating the difference data at each grid point;

[0031] According to the difference data at each grid point and the first estimated value, calculating the potential evapotranspiration at each grid point;

[0032] Based on the potential evapotranspiration at all grid points, determining the potential evapotranspiration expression;

[0033] Based on the potential evapotranspiration expression, establishing the multi-source potential evapotranspiration initial model.

[0034] In some exemplary embodiments of the present invention, based on the foregoing solution, performing model resolution on the multi-source potential evapotranspiration initial model to obtain a multi-source potential evapotranspiration calculation model includes:

[0035] Calculate the first residual between the predicted value and the actual observed value of the meteorological station, and the second residual between the predicted value and the actual observed value of the grid point;

[0036] Based on the first residual and the second residual, calculate the variance, weight, and the number of stations or grid points of the meteorological station and the grid point respectively;

[0037] According to the variance, weight, and the number of stations or grid points of the meteorological station and the grid point, calculate the combined variance of the difference in potential evapotranspiration between the meteorological station and the grid point;

[0038] Based on the combined variance, use Bartlett's test to determine the optimal weights of the meteorological station and the grid point, and obtain the final coefficients of the multi-source potential evapotranspiration calculation model;

[0039] According to the final coefficients, obtain the multi-source potential evapotranspiration calculation model.

[0040] According to the second aspect of the embodiments of the present invention, there is provided a calculation device for potential evapotranspiration parameters of a target area, including: a calculation module, where the calculation module is used to calculate a first estimated value and a second estimated value of the target area by using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model respectively; calculate the difference between the first estimated value and the second estimated value; and calculate the potential evapotranspiration parameters of the target area by using a multi-source potential evapotranspiration calculation model;

[0041] A model establishment module, where the model establishment module is used to establish a multi-source potential evapotranspiration initial model according to the functional relationship between the difference and temperature and atmospheric precipitable water; and perform model solution on the multi-source potential evapotranspiration initial model to obtain a multi-source potential evapotranspiration calculation model.

[0042] According to the third aspect of the embodiments of the present invention, there is provided an electronic device, including: a processor; and a memory, where computer-readable instructions are stored on the memory, and when the computer-readable instructions are executed by the processor, the calculation method for potential evapotranspiration parameters of the target area as described in the first aspect is implemented.

[0043] According to the fourth aspect of the embodiments of the present invention, there is provided a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the calculation method for potential evapotranspiration parameters of the target area in the first aspect is implemented.

[0044] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0045] In the embodiments of the present invention, by using two different potential evapotranspiration calculation models (the first potential evapotranspiration calculation model and the second potential evapotranspiration calculation model), the potential evapotranspiration of the target area can be estimated respectively, which helps to reduce the errors that may be brought by a single model, thereby improving the accuracy of the estimated value; by calculating the difference between the estimated values of the two models and combining the functional relationship between temperature and atmospheric precipitable water, a multi-source potential evapotranspiration initial model is established, fully considering the differences between different models and environmental factors, so that the multi-source potential evapotranspiration initial model can better adapt to the changes of potential evapotranspiration under different environmental conditions, improving the applicability and accuracy of the model; through the solution process, the model can more accurately reflect the dynamic changes of potential evapotranspiration parameters, improving the precision and practicality of the model; finally, by using the optimized multi-source potential evapotranspiration calculation model and the first potential evapotranspiration calculation model to fuse and calculate the potential evapotranspiration parameters of the target area, this means that the calculation data of the present invention is richer, so as to be able to more accurately evaluate the evaporation and transpiration of water in a specific geographical area, which is of great significance for fields such as water resource management, agricultural planning, climate research, and ecological assessment.

[0046] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. Brief Description of the Drawings

[0047] The drawings here are incorporated into the specification and form a part of the present invention, showing the embodiments in line with the present invention, and are used together with the specification to explain the principles of the present invention.

[0048] Figure 1 A schematic diagram of the system architecture showing an exemplary application environment of a calculation method and device for potential evapotranspiration parameters of a target area to which the embodiments of the present invention can be applied;

[0049] Figure 2 A schematic flowchart showing the calculation method of potential evapotranspiration parameters of a target area according to some embodiments of the present invention;

[0050] Figure 3 A schematic diagram showing the calculation device for potential evapotranspiration parameters of a target area according to some embodiments of the present invention;

[0051] Figure 4 A schematic diagram showing the structure of the computer system of an electronic device according to some embodiments of the present invention;

[0052] Figure 5 A schematic diagram showing a computer-readable storage medium according to some embodiments of the present invention. Detailed Description of the Embodiments

[0053] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0054] The terms used in the present invention are for the purpose of describing particular embodiments only and are not intended to limit the present invention. The singular forms "a", "the", and "said" used in the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0055] It should be understood that although the terms first, second, third, etc. may be used in the present invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0056] Figure 1 A schematic diagram of a system architecture of an exemplary application environment of a method and apparatus for calculating potential evapotranspiration parameters of a target area to which embodiments of the present invention can be applied is shown.

[0057] As Figure 1 shown, the system architecture 100 may include one or more of terminal devices such as a desktop computer 101, a portable computer 102, a smart phone 103, etc., a network 104, and a server 105. The network 104 is used to provide a medium for a communication link between the terminal device and the server 105. The network 104 may include various connection types, such as wired, wireless communication links, or fiber optic cables, etc. The terminal device may be various electronic devices having data processing functions, and a display screen is provided on the electronic device for presenting the calculation result of the potential evapotranspiration parameters of the target area to the user, including but not limited to the above-mentioned desktop computer, portable computer, smart phone, etc. It should be understood that Figure 1 the number of terminal devices, networks, and servers in

[0058] The calculation method of the potential evapotranspiration parameters of the target area provided by the embodiments of the present invention can generally be executed by a terminal device. Correspondingly, the calculation device of the potential evapotranspiration parameters of the target area is generally set in the terminal device. However, those skilled in the art can easily understand that the calculation method of the potential evapotranspiration parameters of the target area provided by the embodiments of the present invention can also be executed by the server 105. Correspondingly, the calculation device of the potential evapotranspiration parameters of the target area can also be set in the server 105. No special limitation is made in this exemplary embodiment.

[0059] In addition, it should be understood that the calculation method of the potential evapotranspiration parameters of the target area in the embodiments of the present invention can be configured as a software module. In some implementation scenarios, the calculation solution of the potential evapotranspiration parameters of the target area of the present invention can be deployed independently to achieve accurate calculation of the potential evapotranspiration parameters of the target area. In other implementation scenarios, the calculation solution of the potential evapotranspiration parameters of the target area of the present invention can be deployed in other software as a functional module of the software. For example, it can be deployed in the calculation and analysis software of the potential evapotranspiration parameters of the target area. The present invention does not make special restrictions on the application mode of the calculation method of the potential evapotranspiration parameters of the target area.

[0060] Next, the embodiments of the present invention will be described in detail.

[0061] As Figure 1 shown, Figure 1 is a flowchart of a calculation method of potential evapotranspiration parameters of a target area shown by the present invention according to an exemplary embodiment, including the following steps:

[0062] According to the first aspect of the embodiments of the present invention, a calculation method of potential evapotranspiration parameters of a target area is provided. The calculation method of the potential evapotranspiration parameters includes:

[0063] S201: Calculate a first estimated value and a second estimated value of the target area by using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model respectively;

[0064] S202: Calculate the difference between the first estimated value and the second estimated value;

[0065] S203: Establish a multi-source potential evapotranspiration initial model according to the functional relationship between the difference and temperature and atmospheric precipitable water;

[0066] S204: Perform model solution on the multi-source potential evapotranspiration initial model to obtain a multi-source potential evapotranspiration calculation model;

[0067] S205: Obtain an areal potential evapotranspiration estimation model according to the multi-source potential evapotranspiration calculation model and the first potential evapotranspiration calculation model;

[0068] S206: Estimate the potential evapotranspiration parameters of the target area using the areal potential evapotranspiration estimation model.

[0069] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0070] In the embodiments of the present invention, by using two different potential evapotranspiration calculation models (the first potential evapotranspiration calculation model and the second potential evapotranspiration calculation model), the potential evapotranspiration of the target area can be estimated respectively, which helps to reduce the errors that may be brought by a single model, thereby improving the accuracy of the estimated value; by calculating the difference between the estimated values of the two models and combining the functional relationship between temperature and atmospheric precipitable water to establish a multi-source potential evapotranspiration initial model, fully considering the differences between different models and environmental factors, so that the multi-source potential evapotranspiration initial model can better adapt to the changes of potential evapotranspiration under different environmental conditions, improving the applicability and accuracy of the model; through the solution process, the model can more accurately reflect the dynamic changes of potential evapotranspiration parameters, improving the precision and practicality of the model; finally, using the optimized multi-source potential evapotranspiration calculation model and the first potential evapotranspiration calculation model to fuse and calculate the potential evapotranspiration parameters of the target area, which means that the calculation data of the present invention is richer, and thus can more accurately evaluate the evaporation and transpiration of water in a specific geographical area, which is of great significance for fields such as water resource management, agricultural planning, climate research, and ecological assessment.

[0071] In S201, calculate the first estimated value and the second estimated value of the target area using the first potential evapotranspiration calculation model and the second potential evapotranspiration calculation model respectively.

[0072] The present invention does not specifically limit the first potential evapotranspiration calculation model and the second potential evapotranspiration calculation model. In some embodiments, the first potential evapotranspiration calculation model may be one of the Penman-Monteith Model, Horton Model, FAO-56 Two-Source Model, and Blaney-Criddle Model. The second potential evapotranspiration calculation model may be the same as the first potential evapotranspiration calculation model or different from the first potential evapotranspiration calculation model. Of course, in different situations, the second potential evapotranspiration calculation model may also be one of the above models. The specific choice of model depends on the availability of data, computing resources, required accuracy, and specific requirements of the application scenario. In practice, it may also be necessary to correct and validate the model according to actual monitoring data to ensure the accuracy of the prediction.

[0073] On this basis, the present invention fully considers the monthly average temperature and location of the target area to form a heat index, a heat index coefficient, and a correction coefficient, thereby determining a first potential evapotranspiration calculation model, and then obtaining a first estimated value based on the first potential evapotranspiration calculation model. Specifically, it includes:

[0074] Calculate the heat index of the target area based on the monthly average temperature of the target area;

[0075] Calculate the heat index coefficient according to the heat index;

[0076] Calculate the correction coefficient of the target area based on the latitude and solar declination of the target area;

[0077] Obtain a first potential evapotranspiration calculation model according to the heat index, the heat index coefficient, and the correction coefficient;

[0078] Obtain a first estimated value according to the temperature data of the current month of the target area and the first potential evapotranspiration calculation model.

[0079] Obviously, the first potential evapotranspiration calculation model provided by the present invention takes into account the comprehensive effects of temperature, geographical latitude, and seasonality on potential evapotranspiration in detail, so as to be able to more accurately quantify and estimate the potential evapotranspiration of the target area.

[0080] On this basis, those skilled in the art can calculate the heat index of the target area in any way based on the average temperature of the target area, and the present invention does not make specific limitations. In some embodiments, the average temperature can be made proportional to the heat index or a heat stress index can be designed, etc., to determine the calculation method of the heat index.

[0081] In some exemplary embodiments of the present invention, the heat index of the target area can be calculated by the following method:

[0082]

[0083] wherein, is the monthly average temperature of the i th month, with the unit of °C; is the heat index for 12 months.

[0084] On this basis, the heat index coefficient is calculated by the following method:

[0085]

[0086] wherein, is the heat index coefficient.

[0087] In addition, in some embodiments, the latitude of the target area and the solar declination can be directly obtained from data or calculated by some methods. On this basis, the correction coefficient of the target area can be directly calculated based on the latitude of the target area and the solar declination, or the maximum sunshine hours can be calculated based on the latitude of the target area and the solar declination, and then the correction coefficient can be calculated through the maximum sunshine hours and the number of days in a month. As an exemplary embodiment of the present invention, optionally, the correction coefficients of latitude and month are calculated by the following method:

[0088]

[0089] In the formula, represents the correction coefficient, represents the maximum sunshine hours of the target area and , represents pi, represents the angle at which the sun rises per hour and , represents the inverse cosine function, represents the tangent function, represents the latitude of the target area, represents the solar declination of the target area and , represents the sine function, represents the average Julian day in a month, represents the number of days in a month.

[0090] Based on this, according to the heat index, the heat index coefficient, and the correction coefficient, the first potential evapotranspiration calculation model can be expressed as:

[0091]

[0092] In the formula, is the potential evapotranspiration calculated using the first potential evapotranspiration calculation model (i.e., the first estimated value, PET), T is the monthly temperature data within the preset range of the target area, I is the heat index, m is the heat index coefficient, is the correction coefficient. Since the air dynamic term is ignored when calculating PET using the first potential evapotranspiration calculation model, and only the influence of heat factors on PET is considered, however, PET is determined by various meteorological factors, so the first potential evapotranspiration calculation model cannot obtain high-precision PET for the region.

[0093] Therefore, in the exemplary embodiment provided by the present invention, the second potential evapotranspiration calculation model can be established in the following manner:

[0094] That is, taking the hypothetical crop canopy in the target area as the standard, considering the influence of various influencing factors on the potential evapotranspiration process, a second potential evapotranspiration calculation model is established; among them, the various influencing factors include radiation, temperature, water vapor pressure, and wind speed.

[0095] On this basis, according to the air pressure in the target area, the temperature data of the current month, the temperature data of the previous month, and the second potential evapotranspiration calculation model, a second estimated value is obtained.

[0096] The second potential evapotranspiration calculation model takes the hypothetical crop canopy as the standard and fully considers the influence of various factors such as radiation, temperature, water vapor pressure, and wind speed on the potential evapotranspiration process. The calculation process is relatively complex. Therefore, the specific calculation formula of the second potential evapotranspiration calculation model is as follows:

[0097]

[0098] In the formula, is the potential evapotranspiration calculated using the second potential evapotranspiration calculation model (i.e., the second estimated value, PET), is the net radiation at the crop surface; is the soil heat flux; is the humidity constant; and respectively represent the monthly average temperature and wind speed within the preset range of the target area; is the saturated water vapor pressure; is the actual water vapor pressure; is the slope of the vapor pressure curve; the constants 900 and 0.34 are the standard crop coefficient and the standard crop wind coefficient respectively.

[0099] Among them, the calculation method of the saturated water vapor pressure is specifically:

[0100]

[0101] The calculation method of the actual water vapor pressure is specifically:

[0102]

[0103] and respectively represent the highest temperature and the lowest temperature; is the dew point temperature.

[0104] The humidity constant can be calculated through the air pressure The calculation formula is as follows:

[0105]

[0106] Soil heat flux It can be calculated based on the average temperatures of the target month and the previous month, and the specific calculation formula is as follows:

[0107]

[0108] and respectively refer to the monthly average temperatures of the i th month and the previous month ( i - 1).

[0109] In S202, calculate the difference between the first estimated value and the second estimated value;

[0110] That is, the difference is:

[0111]

[0112] In S203, the precipitable water vapor in the atmosphere PWV can be obtained based on experience, or calculated according to some data, or data can be obtained and inverted by using methods such as GNSS or GPS (Global Positioning System, GPS).

[0113] Temperature data can also be obtained based on experience, or collected from data, or measured. Of course, to ensure the accuracy and certainty of the data, the precipitable water vapor in the atmosphere PWV of the present invention is obtained through GNSS, and the temperature data is obtained through the collection and measurement of meteorological stations.

[0114] On this basis, further including establishing a multi-source potential evapotranspiration initial model according to the functional relationship between the difference and temperature and precipitable water vapor in the atmosphere:

[0115] According to the functional relationship between the difference and temperature and precipitable water vapor in the atmosphere, establish piecewise function models at multiple meteorological stations in the target area respectively;

[0116] Fit the coefficients of the piecewise function model to the grid points to obtain the corresponding coefficients of the grid points;

[0117] Based on the corresponding coefficients of the grid points, combine the temperature data and the precipitable water vapor data to calculate the difference data at each grid point;

[0118] According to the difference data at each grid point and the first estimated value, calculate the potential evapotranspiration at each grid point;

[0119] Based on the potential evapotranspiration at all grid points, determine the expression of potential evapotranspiration;

[0120] Based on the potential evapotranspiration expression, the multi-source potential evapotranspiration initial model is established.

[0121] By separately establishing piecewise function models based on the functional relationships between the difference and temperature and the atmospheric precipitable water at multiple meteorological stations in the target area, the variation law of potential evapotranspiration under different geographical locations and environmental conditions can be more accurately reflected, and the adaptability and estimation accuracy of the model to complex geographical and climatic characteristics are improved.

[0122] Those skilled in the art can separately establish piecewise function models at multiple meteorological stations in any way, as long as the established piecewise function models satisfy the functional relationships between the difference and temperature and the atmospheric precipitable water. In the embodiments provided by the present invention, the piecewise function model can be established as:

[0123]

[0124] In the formula, – and – are respectively and when, the coefficients of the piecewise linear model; is the atmospheric precipitable water, is the monthly temperature data within the preset range of the target area.

[0125] In addition, the present invention uses the polynomial method to fit the coefficients of the piecewise function model to the grid points to obtain the corresponding coefficients of the grid points. For the coefficients of the piecewise function model, the expression is as follows:

[0126]

[0127] In the formula, n is the number of meteorological stations, is the model coefficient of the first meteorological station, is the n th meteorological station's model coefficient; – are respectively the model coefficients of the meteorological stations - 's polynomial fitting coefficients; 、 and are respectively the longitude, latitude and elevation of the meteorological station.

[0128] 、 and - 's expressions are the same as The expressions are similar, and the present invention will not elaborate specifically herein. By calculating and solving – and – , the coefficients at the corresponding grid points can be obtained.

[0129] Substituting the coefficients at the grid points into the piecewise function model, the difference data (i.e., DPET value) at each grid point can be obtained.

[0130] After that, based on the difference data and the first estimated value at each grid point, the potential evapotranspiration at each grid point is determined:

[0131]

[0132] In the formula, is the PET calculated at the grid point.

[0133] Based on this, the expression of PET can be determined as:

[0134]

[0135] Furthermore, the multi-source potential evapotranspiration initial model is:

[0136]

[0137] In the formula, is the fusion coefficient matrix of the multi-source potential evapotranspiration initial model and , is PET the fitting coefficient of the expression, is the number of meteorological stations or grid points.

[0138] In S204, since different data sources have different precisions and information volumes, determining the optimal weight ratio of multi-source data is crucial for model solving. When integrating multiple data sources into a model, the contribution and influence of each data source need to be considered to determine the optimal data weight ratio and optimize the model performance. Therefore, the present invention obtains the multi-source potential evapotranspiration calculation model according to the solution result by performing model calculation on the multi-source potential evapotranspiration initial model.

[0139] The present invention does not specifically limit the method capable of realizing the calculation of the multi-source potential evapotranspiration initial model. In some embodiments, data fusion technology, uncertainty analysis methods, or machine learning and artificial intelligence algorithms can be used to calculate the multi-source potential evapotranspiration initial model.

[0140] However, considering the complexity of the usage environment of multi-source potential evapotranspiration and the requirements of the present invention for model accuracy and prediction accuracy. In some exemplary embodiments of the present invention, based on the foregoing solution, the multi-source potential evapotranspiration initial model is resolved to obtain a multi-source potential evapotranspiration calculation model, including:

[0141] Calculate the first residual between the predicted value and the actual observed value of the meteorological station, and the second residual between the predicted value and the actual observed value of the grid point;

[0142] Based on the first residual and the second residual, calculate the variance, weight, and the number of meteorological stations or grid points of the meteorological station and the grid point respectively;

[0143] According to the variance, weight, and the number of meteorological stations or grid points of the meteorological station and the grid point, calculate the combined variance of the potential evapotranspiration difference between the meteorological station and the grid point;

[0144] Based on the combined variance, use Bartlett's test to determine the optimal weights of the meteorological station and the grid point, and obtain the final coefficients of the multi-source potential evapotranspiration calculation model;

[0145] According to the final coefficients, obtain the multi-source potential evapotranspiration calculation model.

[0146] Quantify the model through the deviation between the predicted value and the actual observed value, and customize the contribution degree of different data sources in the model by analyzing the distribution weights of each prediction error to improve the accuracy of the model. Then, calculate the combined variance to reduce the single-point error and improve the overall adaptability of the model and the robustness of the prediction. Then, use Bartlett's test to determine the optimal weights to ensure the scientific nature of the model and the reliability of the optimization results.

[0147] Here, calculating the first residual between the predicted value and the actual observed value of the meteorological station, and the second residual between the predicted value and the actual observed value of the grid point can be calculated in the following manner:

[0148]

[0149] In the formula, and respectively refer to the first residual of the meteorological station and the second residual of the grid point, and respectively refer to the parameter input matrices of the meteorological station and the grid point, including the longitude, latitude, altitude, PWV, and T of the meteorological station and the grid point, and respectively refer to PET of the meteorological station PET and

[0150] Based on the first residual and the second residual, the variances, weights, and the number of stations or grid points of the meteorological stations and grid points can be calculated respectively in the following manner:

[0151]

[0152]

[0153] In the formula, / , / , and / are the posterior unit weight variances, weights, and the number of grid points / meteorological stations respectively, is the rank of the correlation matrix, is the inverse matrix of the N matrix, and the N matrix is and the sum of matrices, / are the adjustment criterion matrices of the grid points / meteorological stations respectively.

[0154] Based on the variances, weights, and the number of stations or grid points of the meteorological stations and grid points, the combined variance of the difference in potential evapotranspiration between the meteorological stations and the grid points can be expressed as:

[0155]

[0156] In the formula, represents the grid point when represents the meteorological station when and are the number of grid points and stations, is the combined variance of the stations and grid points.

[0157] Based on the combined variance, using Bartlett's test to determine the optimal weights of the meteorological stations and the optimal weights of the grid points, the final coefficients of the multi-source potential evapotranspiration calculation model include:

[0158] According to the chi-square test, with the significance level set to 0.1, when the degrees of freedom is 2, is 0.02; if , it is considered that the unit weight variances of the two types of data are statistically equal, and the loop is exited.

[0159]

[0160] In the formula, jis the number of iterations. Among them, according to the optimal weights of the grid points and station data determined by the present invention, the final coefficients of the MPF model can be obtained:

[0161]

[0162] In the formula, is the transpose matrix of; is and the fusion matrix of, that is ; is the fused weight and , and are the weights determined by the grid points and station data respectively; is and the combination matrix of, that is .

[0163] Substitute this coefficient into the multi-source potential evapotranspiration initial model to obtain the multi-source potential evapotranspiration calculation model.

[0164] In S205, in order to enrich the data source of the areal potential evapotranspiration estimation model and make the estimation data of the areal potential evapotranspiration estimation model more accurate, after the multi-source potential evapotranspiration calculation model MPF is established, combined with the first potential evapotranspiration calculation model, the areal potential evapotranspiration estimation model is obtained.

[0165] Here, those skilled in the art can combine the multi-source potential evapotranspiration calculation model and the first potential evapotranspiration calculation model in any way, such as in an additive manner, a multiplicative manner, or setting certain coefficients for both and then performing addition or multiplication. The present invention does not make specific limitations.

[0166] In the specific embodiments provided by the present invention, the expression of the areal potential evapotranspiration estimation model is:

[0167]

[0168] In the formula, represents the matrix composed of longitude, latitude, altitude, T, and PWV, is the PET estimated by the first potential evapotranspiration calculation model at any position.

[0169] On this basis, only by obtaining the longitude, latitude, elevation, PWV, and T of the target area can the PET of the target area be calculated.

[0170] According to the second aspect of the embodiments of the present invention, there is also provided a calculation device 300 for potential evapotranspiration parameters of a target area. Refer toFigure 3 As shown in Figure 3 , the calculation device 300 for potential evapotranspiration parameters in the target area includes:

[0171] A calculation module 310, which is configured to calculate a first estimated value and a second estimated value of the target area by using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model respectively; calculate the difference between the first estimated value and the second estimated value; and calculate the potential evapotranspiration parameters of the target area by using a multi-source potential evapotranspiration calculation model;

[0172] A model establishment module 320, which is configured to establish an initial multi-source potential evapotranspiration model according to the functional relationship between the difference and temperature and atmospheric precipitable water; and perform model solution on the initial multi-source potential evapotranspiration model to obtain a multi-source potential evapotranspiration calculation model.

[0173] In an exemplary embodiment of the present invention, based on the foregoing solution, the calculation module 310 may further include an estimation sub-module, a difference calculation sub-module, and a parameter calculation sub-module.

[0174] The estimation sub-module is configured to calculate a first estimated value and a second estimated value of the target area by using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model;

[0175] The difference calculation sub-module is configured to calculate the difference between the first estimated value and the second estimated value;

[0176] The parameter calculation sub-module is configured to calculate the potential evapotranspiration parameters of the target area by using a multi-source potential evapotranspiration calculation model.

[0177] In an exemplary embodiment of the present invention, based on the foregoing solution, the model establishment module 320 may further include an initial model establishment sub-module and a model establishment sub-module.

[0178] The initial model establishment sub-module is configured to establish an initial multi-source potential evapotranspiration model according to the functional relationship between the difference and temperature and atmospheric precipitable water;

[0179] The model establishment sub-module is configured to perform model solution on the initial multi-source potential evapotranspiration model to obtain a multi-source potential evapotranspiration calculation model.

[0180] In an exemplary embodiment of the present invention, based on the foregoing solution, the estimation sub-module may further include a first estimation unit. The first estimation unit is configured to calculate the heat index of the target area based on the monthly average temperature of the target area; calculate the heat index coefficient according to the heat index; calculate the correction coefficient of the target area based on the latitude and solar declination of the target area; obtain the first potential evapotranspiration calculation model according to the heat index, the heat index coefficient and the correction coefficient; and obtain the first estimated value according to the temperature data of the current month of the target area and the first potential evapotranspiration calculation model.

[0181] In an exemplary embodiment of the present invention, based on the foregoing solution, the estimation sub-module may further include a second estimation unit. The second estimation unit is configured to establish a second potential evapotranspiration calculation model by taking the assumed crop canopy of the target area as a standard and considering the influence of various influencing factors on the potential evapotranspiration process; wherein, the various influencing factors include radiation, temperature, water vapor pressure and wind speed; and obtain the second estimated value according to the air pressure of the target area, the temperature data of the current month, the temperature data of the previous month and the second potential evapotranspiration calculation model.

[0182] In an exemplary embodiment of the present invention, based on the foregoing solution, the initial model establishment sub-module may further include a piecewise function model establishment unit, a fitting unit, a difference data calculation unit, a potential evapotranspiration calculation unit, an expression generation unit and a model establishment unit;

[0183] Among them, the piecewise function model establishment unit is configured to establish piecewise function models at multiple meteorological stations in the target area according to the functional relationship between the difference and temperature and atmospheric precipitable water;

[0184] The fitting unit is configured to fit the piecewise function model coefficients to grid points to obtain the corresponding coefficients of the grid points;

[0185] The difference data calculation unit is configured to calculate the difference data at each grid point based on the corresponding coefficients of the grid points, in combination with temperature data and atmospheric precipitable water data;

[0186] The potential evapotranspiration calculation unit is configured to calculate the potential evapotranspiration at each grid point according to the difference data at each grid point and the first estimated value;

[0187] The expression generation unit is configured to determine the potential evapotranspiration expression based on the potential evapotranspiration at all grid points;

[0188] The model establishment unit is configured to establish the multi-source potential evapotranspiration initial model based on the potential evapotranspiration expression.

[0189] In an exemplary embodiment of the present invention, based on the foregoing solution, the model establishment sub-module may further include a residual calculation unit, a weight calculation unit, a fusion variance calculation unit, a weight calculation unit, and a model generation unit;

[0190] Among them, the residual calculation unit is used to calculate the first residual between the predicted value and the actual observed value of the meteorological station, and the second residual between the predicted value and the actual observed value of the grid point;

[0191] The weight calculation unit is used to calculate the variance, weight, and the number of meteorological stations or the number of grid points of the meteorological station and the grid point respectively based on the first residual and the second residual;

[0192] The fusion variance calculation unit is used to calculate the fusion variance of the difference in potential evapotranspiration between the meteorological station and the grid point according to the variance, weight, and the number of meteorological stations or the number of grid points of the meteorological station and the grid point;

[0193] The weight calculation unit is used to determine the optimal weight of the meteorological station and the optimal weight of the grid point based on the fusion variance by using Bartlett's test, and obtain the final coefficient of the multi-source potential evapotranspiration calculation model;

[0194] The model generation unit is used to obtain the multi-source potential evapotranspiration calculation model according to the final coefficient.

[0195] It should be noted that although several modules and sub-modules of the calculation device for potential evapotranspiration parameters in the target area are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present invention, the features and functions of two or more of the above-described modules or sub-modules can be embodied in one module or unit. Conversely, the features and functions of one module or sub-module described above can be further divided into being embodied by multiple modules or sub-modules.

[0196] In addition, in an exemplary embodiment of the present invention, an electronic device capable of implementing the above-mentioned calculation method for potential evapotranspiration parameters in the target area is also provided.

[0197] Those skilled in the art can understand that various aspects of the present invention can be implemented as a system, a method, or a program product. Therefore, various aspects of the present invention can be specifically implemented in the following forms, namely: a complete hardware embodiment, a complete software embodiment (including firmware, microcode, etc.), or an embodiment combining hardware and software aspects, which can be collectively referred to as "circuit", "module", or "system" here.

[0198] Next, refer to Figure 4 to describe the electronic device 400 according to this embodiment of the present invention. Figure 4The illustrated electronic device 400 is merely an example and shall not impose any limitation on the functions and scope of use of the embodiments of the present invention.

[0199] As Figure 4 shown, the electronic device 400 is presented in the form of a general-purpose computing device. The components of the electronic device 400 may include, but are not limited to: at least one of the above-mentioned processing units 410, at least one of the above-mentioned storage units 420, a bus 430 connecting different system components (including the storage unit 420 and the processing unit 410), and a display unit 440.

[0200] Among them, the storage unit stores program codes, and the program codes can be executed by the processing unit 410, so that the processing unit 410 executes the steps according to various exemplary embodiments of the present invention described in the "Exemplary Method" section of the present invention above. For example, the processing unit 410 may execute S201 as shown in Figure 2 to calculate a first estimated value and a second estimated value of a target area by using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model respectively; S202, calculate the difference between the first estimated value and the second estimated value; S203, establish a multi-source potential evapotranspiration initial model according to the functional relationship between the difference and temperature and atmospheric precipitable water; S204, perform model resolution on the multi-source potential evapotranspiration initial model to obtain a multi-source potential evapotranspiration calculation model; S205, obtain an areal potential evapotranspiration estimation model according to the multi-source potential evapotranspiration calculation model and the first potential evapotranspiration calculation model; S206, estimate the potential evapotranspiration parameters of the target area by using the areal potential evapotranspiration estimation model.

[0201] The storage unit 420 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) 421 and / or a cache storage unit 422, and may further include a read-only storage unit (ROM) 423.

[0202] The storage unit 420 may further include a program / utilities 424 having a set (at least one) of program modules 425. Such program modules 425 include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include the implementation of a network environment.

[0203] The bus 430 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus structures.

[0204] The electronic device 400 can also communicate with one or more external devices 470 (such as a keyboard, a pointing device, a Bluetooth device, etc.), and can also communicate with one or more devices that enable a user to interact with the electronic device 400, and / or communicate with any device that enables the electronic device 400 to communicate with one or more other computing devices (such as a router, a modem, etc.). Such communication can be carried out through the input / output (I / O) interface 450. Moreover, the electronic device 400 can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through the network adapter 460. As shown in the figure, the network adapter 460 communicates with other modules of the electronic device 400 through the bus 430. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in combination with the electronic device 400, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

[0205] Through the description of the above embodiments, those skilled in the art can easily understand that the exemplary embodiments described herein can be implemented by software or by a combination of software and necessary hardware. Therefore, the technical solution according to the embodiments of the present invention can be embodied in the form of a software product, and the software product can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the embodiments of the present invention.

[0206] In an exemplary embodiment of the present invention, there is also provided a computer-readable storage medium, on which a program product capable of implementing the above method of the present invention is stored. In some possible embodiments, various aspects of the present invention can also be implemented in the form of a program product, which includes program code. When the program product runs on a terminal device, the program code is used to enable the terminal device to execute the steps according to various exemplary embodiments of the present invention described in the above "exemplary method" part of the present invention.

[0207] Reference Figure 5 As shown, a program product 500 for implementing the calculation method of the potential evapotranspiration parameters of the above target area according to the embodiments of the present invention is described. It can be a portable compact disc read-only memory (CD-ROM) and includes program code, and can run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In the present invention, the readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, apparatus, or device.

[0208] The program product may employ any combination of one or more readable storage media. The readable storage media may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples of the readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0209] The program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and also including conventional procedural programming languages such as the "C" language or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's device, executed as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., by connecting through the Internet using an Internet service provider).

[0210] In addition, the above drawings are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present invention, and are not for limiting purposes. It is easy to understand that the processes shown in the above drawings do not indicate or limit the chronological order of these processes. Additionally, it is also easy to understand that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0211] Through the description of the above embodiments, those skilled in the art can easily understand that the exemplary embodiments described herein can be implemented by software or by a combination of software and necessary hardware. Therefore, the technical solutions according to the embodiments of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which may be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which may be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the embodiments of the present invention.

[0212] Other embodiments of the present invention will be readily apparent to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the invention following the general principles of the invention and including known or customary techniques in the art not disclosed herein. The specification and examples are only to be considered as exemplary, and the true scope and spirit of the invention are pointed out by the claims.

[0213] It should be understood that the present invention is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A method for calculating potential evapotranspiration parameters in a target area, characterized in that: The calculation method of the potential evapotranspiration parameter includes: Calculate a first estimated value and a second estimated value of the target area using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model respectively; calculating a difference between the first estimate and the second estimate; According to the functional relationship between the difference and the temperature and atmospheric precipitable water, an initial model of multi-source potential evapotranspiration is established; Solving the multi-source potential evapotranspiration initial model to obtain a multi-source potential evapotranspiration calculation model; Obtaining a planar potential evapotranspiration estimation model according to the multi-source potential evapotranspiration calculation model and the first potential evapotranspiration calculation model; Use the areal potential evapotranspiration estimation model to estimate the potential evapotranspiration parameters of the target area; The multi-source potential evapotranspiration initial model is solved to obtain a multi-source potential evapotranspiration calculation model including: Calculate the first residual between the predicted value and the actual observed value at the meteorological station, and the second residual between the predicted value and the actual observed value at the grid point; Based on the first residual and the second residual, respectively calculating the variance, weight, number of stations and number of grid points of the meteorological stations and grid points; Calculating the fused variance of the potential evapotranspiration difference between the meteorological station and the grid point according to the variance, weight, number of stations and number of grid points of the meteorological station and the grid point; Based on the fused variance, the optimal weights of the meteorological stations and the optimal weights of the grid points are determined using the Bartlett test to obtain the final coefficients of the multi-source potential evapotranspiration calculation model; According to the final coefficients, the multi-source potential evapotranspiration calculation model is obtained; According to the functional relationship between the difference and temperature and atmospheric precipitable water, the initial model of multi-source potential evapotranspiration is established, including: According to the functional relationship between the difference and the temperature and the atmospheric precipitable water, a piecewise function model is established at multiple meteorological stations in the target area; Fit the piecewise function model coefficients to the grid points to obtain the corresponding coefficients of the grid points; Based on the coefficients corresponding to the grid points, combined with the temperature data and the atmospheric precipitable water data, the difference data at each grid point is calculated; Calculating the potential evapotranspiration at each grid point according to the difference data at each grid point and the first estimated value; Based on the potential evapotranspiration at all grid points, determine the potential evapotranspiration expression; The multi-source potential evapotranspiration initial model is established based on the potential evapotranspiration expression.

2. The method for calculating the potential evapotranspiration parameters of the target area according to claim 1, characterized in that: The first estimate of the target area calculated using the first potential evapotranspiration calculation model includes: Calculating a heat index for the target area based on the monthly average temperature of the target area; Calculating a thermal index coefficient according to the thermal index; Calculating a correction factor for the target region based on the latitude of the target region and the solar declination; Obtaining a first potential evapotranspiration calculation model according to the thermal index, the thermal index coefficient and the correction coefficient; A first estimated value is obtained based on the temperature data of the target area in that month and the first potential evapotranspiration calculation model.

3. The method for calculating the potential evapotranspiration parameters of the target area according to claim 2, characterized in that: According to the thermal index, the thermal index coefficient and the correction coefficient, obtaining a first potential evapotranspiration calculation model includes: In the formula, is the PET calculated using the first potential evapotranspiration calculation model, T is the temperature data for the month, I is the heat index, m is the thermal index coefficient, is the correction factor.

4. The method for calculating the potential evapotranspiration parameters of the target area according to claim 1, characterized in that: The second estimate for the target area calculated using the second potential evapotranspiration calculation model includes: Taking the hypothetical crop canopy of the target area as a standard and considering the influence of multiple influencing factors on the potential evapotranspiration process, a second potential evapotranspiration calculation model is established; wherein the multiple influencing factors include radiation, temperature, water vapor pressure and wind speed; A second estimated value is obtained according to the air pressure of the target area, the temperature data of the current month, the temperature data of the previous month and the second potential evapotranspiration calculation model.

5. The method for calculating the potential evapotranspiration parameters of the target area according to claim 4, characterized in that: Taking the hypothetical crop canopy in the target area as the standard and considering the influence of various influencing factors on the potential evapotranspiration process, the second potential evapotranspiration calculation model is established, including: In the formula, is the net radiation on the crop surface; is the soil heat flux; is the humidity constant; and Respectively represent the average temperature and wind speed within the preset range of the target area; is the saturated water vapor pressure; is the actual water vapor pressure; is the slope of the vapor pressure curve; the constants 900 and 0.34 are the standard crop coefficient and the standard crop wind coefficient, respectively.

6. A device for calculating potential evapotranspiration parameters of a target area for implementing the method for calculating potential evapotranspiration parameters of a target area according to any one of claims 1 to 5, characterized in that: include: A calculation module, the calculation module being used to calculate a first estimated value and a second estimated value of a target area using a first potential evapotranspiration calculation model and a second potential evapotranspiration calculation model respectively; Calculating the difference between the first estimated value and the second estimated value; and calculating the potential evapotranspiration parameters of the target area using a multi-source potential evapotranspiration calculation model; A model building module is used to establish an initial model of multi-source potential evapotranspiration according to the functional relationship between the difference and the temperature and the atmospheric precipitable water; and to solve the initial model of multi-source potential evapotranspiration to obtain a multi-source potential evapotranspiration calculation model.

7. An electronic device, characterized in that: include: processor; as well as A memory having computer-readable instructions stored thereon, wherein the computer-readable instructions, when executed by the processor, implement the method for calculating the potential evapotranspiration parameter of the target area according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for calculating the potential evapotranspiration parameter of the target area according to any one of claims 1 to 5 is implemented.

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