Method for dynamically simulating water content of sugarcane stems

Abstract

The invention provides a method for dynamically simulating the water content of sugarcane stems, and relates to the technical field of agricultural irrigation. Based on daily meteorological data, soil texture data and sugarcane variety characteristics, a soil moisture environment module and a sugarcane stem moisture characteristic module are established, and the two modules are coupled and interacted; and calculating the flow direction, size and current state of the water content of the sugarcane stems, thereby realizing real-time dynamic simulation of the water content of the sugarcane stems. According to the method, the soil water content dynamics, the meteorological data and the sugarcane phenological period sub-model are mechanically combined, and the technical problems that in the prior art, optical remote sensing is greatly influenced by weather, data processing is complex, an artificial neural network needs a large number of training data and computing resources, and a heat conduction model needs to be simplified and assumed are solved. Daily is taken as the prediction time length, the dynamic change of the water content of the sugarcane stems in the current environment is reflected, the mechanism of the calculation process is simple, and technical guidance is provided for irrigation operation.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural irrigation, in particular to a method for dynamically simulating the water content of sugarcane stems. Background Art

[0002] At present, the methods for dynamic simulation of sugarcane stem moisture content mainly include the following three methods: 1. Optical remote sensing method: Use optical sensors carried by satellites or drones to obtain spectral images of sugarcane planting areas. Sugarcane stems with different moisture contents have different reflection and absorption characteristics under specific wavelengths of light. By analyzing the spectral information of the sugarcane planting area in the spectral image, a relationship model between spectral characteristics and sugarcane stem moisture content is established. For example, the spectral information in the near-infrared band is more sensitive to moisture content, and the moisture content of sugarcane stems can be estimated by analyzing the reflectivity of the near-infrared band. Although this method can quickly and widely obtain information on the moisture content of sugarcane stems, it is easily affected by weather, light and other conditions. In cloudy, rainy and other weather conditions, the effect of optical remote sensing will be greatly reduced. Since clouds and water vapor block the propagation of light, the acquired images are unclear and information is missing. Since sugarcane is a tropical crop, it is mainly distributed in southern my country such as Guangxi and Guangzhou, and the frequency of cloudy and rainy weather is high, so the remote sensing method is subject to greater interference. At the same time, the amount of data obtained by optical remote sensing is usually very large, requiring a lot of computing resources and time to process and analyze. The processes of image preprocessing, feature extraction, classification and recognition require professional techniques and algorithms, and place high demands on operators.

[0003] 2. Artificial Neural Network (ANN) Method: By constructing a multi-layer neural network model, a large amount of sugarcane stem sample data is used as a training set and input into the network for training. The network can automatically learn the complex nonlinear relationship between the characteristics of sugarcane stems (such as growth stage, appearance characteristics, environmental parameters, etc.) and moisture content. After training, the new sugarcane stem data is input into the network to predict its moisture content. Although this method has strong adaptability and generalization capabilities and can handle complex nonlinear problems. However, artificial neural networks usually require a large amount of training data to learn and optimize the parameters of the model. If the amount of data is insufficient, the model may have an overfitting problem, that is, the model performs well on the training data but performs poorly on new data. Obtaining a large amount of high-quality labeled data often takes a lot of time and cost; training complex neural network models requires a lot of computing resources, including hardware devices such as CPU and GPU. Especially for large-scale neural networks and deep learning models, the training process may take a long time and high energy consumption.

[0004] 3. Heat conduction model method: According to the principle of heat conduction, a heat conduction equation is established. By measuring the heat conduction characteristics of the sugarcane stems and combining them with temperature change data, the moisture content of the sugarcane stems is inferred. However, this method requires an in-depth understanding of the thermophysical properties of the sugarcane stems, as well as precise temperature measurement equipment and complex calculation models that can monitor the moisture content changes of the sugarcane stems in real time and non-destructively. Moreover, for the heat conduction model, it is usually necessary to simplify and make assumptions about the actual problems, such as assuming that the material of the object is uniform and the thermal conductivity coefficient is a constant. These simplifications and assumptions may not match the actual situation, resulting in errors in the model. The boundary conditions of the heat conduction model have a great influence on the results of the model, but in practical problems, the boundary conditions are often difficult to accurately determine.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] Based on this, it is necessary to address the above problems. The purpose of the invention is to provide a method for dynamically simulating the moisture content of sugarcane stems. The preferred technical solutions among the many technical solutions provided by the present invention can produce many technical effects as described below.

[0007] To achieve the above object, the present invention provides the following technical solutions: The present invention provides a method for dynamically simulating the moisture content of sugarcane stems, comprising the following steps: S1: Establish soil water environment module; S2: driving soil water environment module; S3: Establish a sugarcane stem moisture characteristic module, couple the soil water environment module with the sugarcane stem moisture characteristic module, and realize real-time dynamic simulation of sugarcane stem moisture content.

[0008] Preferably, in S1, a correction parameter of the soil moisture surplus and deficit index is established according to the soil texture and soil organic carbon data, and then the upper and lower limits of the soil moisture surplus and deficit index corresponding to the sugarcane root system are calculated, specifically according to the following formula: (1) (2) (3) (4) (5) (6) in, is the diagonal matrix of soil texture; is the sand content ratio, unit is %; is the proportion of soil particle content, unit is %; is the clay content ratio, unit is %; is the water storage response equation of soil organic carbon under a single soil texture type; is the water storage response equation under the sand content under the international system; is the water storage response equation under soil particle content under the international system; The water storage response equation under the clay content under the international system; is the soil organic carbon content, in ‰; It is a water environment correction parameter used to correct the soil water environment profit and loss index, thereby responding to the water dynamics of sugarcane stems under current soil characteristics.

[0009] Preferably, in said S2, daily precipitation, wind speed, temperature, relative humidity and radiation data are input, the potential evapotranspiration value is corrected in combination with the sugarcane leaf area index, and the runoff synergy parameter is introduced to measure the slope for the loss rate of water in the sugarcane field, and the current soil moisture surplus and deficit index is comprehensively calculated to reflect the soil water environment state interacting with the sugarcane root system, specifically according to the following formula:

[0010] (7) (8) (9) (10) (11) in, The upper limit of soil moisture surplus and deficit index, in mm, represents the state where soil moisture reaches saturated water content; is the lower limit of soil moisture deficit index, in mm, representing the state where the soil water reaches the point where the sugarcane roots wilt; is the sugarcane leaf area index; is the evapotranspiration coefficient under the current leaf area index; is the daily precipitation, in mm; It is the Penman-Monteith calculated value, in mm; It is the runoff coordination parameter, which is determined by the slope of the sugarcane field. The value can be calculated by inputting the slope. It is the current soil moisture deficit index in mm, reflecting the soil moisture status for the sugarcane root system.

[0011] Preferably, in S3, the upper limit and lower limit of the water content of the sugarcane stem determined by the characteristics of the sugarcane variety are introduced, and the water content variation coefficient of the sugarcane stem is established as the calculation basis for the dynamic change between the water content of the sugarcane stem and the soil; according to the current soil moisture surplus and deficit index and the water content variation coefficient of the sugarcane stem provided by the soil water environment module, the water potential resistance equation of the sugarcane stem and the characteristic equation of sugarcane dehumidification are used to calculate the flow direction and size of the water content of the sugarcane stem, specifically according to the following formula:

[0012] (12) (13)

[0013] (14)

[0014] in, The upper limit of water content in sugarcane stems, expressed in %. It is the lower limit of the moisture content of sugarcane stems, in %, which is determined by the characteristics of sugarcane varieties and is the variety parameter; is the coefficient of variation of the moisture content in the cane stem, which determines the direction of the water flow. When the coefficient is positive, the flow direction is from the soil to the cane stem, and the moisture content in the cane stem increases. When the coefficient is negative, the flow direction is opposite. is the sugarcane stem water potential resistance equation, which represents the sugarcane stem water content on that day, in %, and is calculated in different ways according to the sugarcane stem water content variation coefficient value; It is the water content of sugarcane stem on the previous day, in %; is the characteristic equation of sugarcane dehumidification, which describes the characteristics of sugarcane stalk moisture reduction when the soil moisture content is low and the sugarcane stalk variation coefficient is negative. The equation is driven by the lower limit of the soil moisture surplus and deficit index and the current soil moisture surplus and deficit index.

[0015] The preferred technical solution of the present invention can at least produce the following technical effects: The present invention establishes a soil moisture environment module and a sugarcane stem moisture characteristic module based on daily meteorological data, soil texture data and sugarcane variety characteristics. The two modules are coupled and interacted to calculate the flow direction, size and current state of sugarcane stem moisture, thereby realizing real-time dynamic simulation of sugarcane stem moisture content. The present invention solves the technical problems in the prior art that optical remote sensing is greatly affected by weather, data processing is complex, artificial neural networks require a large amount of training data and computing resources, and heat conduction models need to be simplified and assumed by combining soil moisture content dynamics, meteorological data and sugarcane phenological period sub-models in a mechanistic way. The present invention uses daily as the prediction time length to reflect the dynamic changes of sugarcane stem moisture content under the current environment. The calculation process is mechanism-based and streamlined, providing technical guidance for irrigation operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic flow chart of a method for dynamically simulating the moisture content of sugarcane stems provided by the present invention; Figure 2 It is a schematic diagram of a soil water environment module and a sugarcane stem moisture characteristic module of a sugarcane stem moisture content dynamic simulation method provided by the present invention. DETAILED DESCRIPTION

[0018] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0019] like Figure 1-Figure 2 As shown, the present invention provides a method for dynamically simulating the moisture content of sugarcane stems, comprising the following steps: S1: Establish soil water environment module; S2: driving soil water environment module; S3: Establish a sugarcane stem moisture characteristic module, couple the soil water environment module with the sugarcane stem moisture characteristic module, and realize real-time dynamic simulation of sugarcane stem moisture content.

[0020] As an optional implementation, in S1, a correction parameter of the soil moisture surplus and deficit index is established according to the soil texture and soil organic carbon data, and then the upper and lower limits of the soil moisture surplus and deficit index corresponding to the sugarcane root system are calculated, specifically according to the following formula: (1) (2) (3) (4) (5) (6) in, is the diagonal matrix of soil texture; is the sand content ratio, unit is %; is the proportion of soil particle content, unit is %; is the clay content ratio, unit is %; is the water storage response equation of soil organic carbon under a single soil texture type; is the water storage response equation under the sand content under the international system; is the water storage response equation under soil particle content under the international system; The water storage response equation under the clay content under the international system; is the soil organic carbon content, in ‰; It is a water environment correction parameter used to correct the soil water environment profit and loss index, so as to respond to the water dynamics of sugarcane stems under the current soil characteristics. Among them, the soil database is deployed on the server, and the data can be input by the user or retrieved from the background to drive the model operation, so as to flexibly operate and initialize the soil water environment module.

[0021] As an optional implementation, in S2, daily precipitation data, wind speed data, temperature data, relative humidity data and radiation data are input, the potential evapotranspiration value is corrected in combination with the sugarcane leaf area index, and the runoff synergy parameter is introduced to measure the slope for the loss rate of water in the sugarcane field, and the current soil moisture surplus and deficit index is comprehensively calculated to reflect the soil water environment state interacting with the sugarcane root system, specifically according to the following formula:

[0022] (7) (8) (9) (10) (11) in, The upper limit of soil moisture surplus and deficit index, in mm, represents the state where soil moisture reaches saturated water content; is the lower limit of soil moisture deficit index, in mm, representing the state where the soil water reaches the point where the sugarcane roots wilt; is the sugarcane leaf area index; is the evapotranspiration coefficient under the current leaf area index; is the daily precipitation, in mm; It is the Penman-Monteith calculated value, in mm; It is the runoff coordination parameter, which is determined by the slope of the sugarcane field. The value can be calculated by inputting the slope. It is the current soil moisture surplus and deficit index in mm, reflecting the soil moisture status of the sugarcane root system, so as to drive the sugarcane stem moisture characteristic module for linkage simulation.

[0023] Meteorological data such as precipitation, wind speed, temperature, relative humidity and radiation are used as driving data for the soil water environment module to calculate the potential evapotranspiration value. At the same time, the sugarcane leaf area index is introduced to correct the evapotranspiration value to reflect the ability of water to lose upward in different periods. The slope loss rate of water in the sugarcane field is measured in combination with the runoff synergy parameter. The current soil moisture surplus and deficit index is comprehensively calculated to reflect the soil water environment state that interacts with the sugarcane root system, so as to calculate the direction and size of water flow in the sugarcane stem in the next step.

[0024] As an optional implementation, in S3, the upper limit and lower limit of the water content of the sugarcane stem determined by the characteristics of the sugarcane variety are introduced, and the water content variation coefficient of the sugarcane stem is established as the calculation basis for the dynamic change between the water content of the sugarcane stem and the soil; according to the current soil moisture surplus and deficit index and the water content variation coefficient of the sugarcane stem provided by the soil water environment module, the water potential resistance equation of the sugarcane stem and the characteristic equation of sugarcane dehumidification are used to calculate the flow direction and size of the water content of the sugarcane stem, specifically according to the following formula:

[0025] (12) (13)

[0026] (14)

[0027] in, The upper limit of water content in sugarcane stems, expressed in %. It is the lower limit of the moisture content of sugarcane stems, in %, which is determined by the characteristics of sugarcane varieties and is the variety parameter; is the coefficient of variation of the moisture content in the cane stem, which determines the direction of the water flow. When the coefficient is positive, the flow direction is from the soil to the cane stem, and the moisture content in the cane stem increases. When the coefficient is negative, the flow direction is opposite. is the sugarcane stem water potential resistance equation, which represents the sugarcane stem water content on that day, in %, and is calculated in different ways according to the sugarcane stem water content variation coefficient value; It is the water content of sugarcane stem on the previous day, in %; is the characteristic equation of sugarcane dehumidification, which describes the characteristics of sugarcane stalk moisture reduction when the soil moisture content is low and the sugarcane stalk variation coefficient is negative. The equation is driven by the lower limit of the soil moisture surplus and deficit index and the current soil moisture surplus and deficit index.

[0028] The sugarcane stem moisture characteristic module introduces the upper and lower limits of sugarcane stem moisture content, which is determined by the characteristics of the sugarcane variety. The sugarcane stem moisture variation coefficient is critically established as the basis for calculating the dynamic changes between the sugarcane stem and soil moisture content. The response relationship between the soil water environment and the sugarcane root moisture is measured, with the focus on quantifying the absorption capacity of soil water under different sugarcane stem moisture levels, and using the sugarcane stem moisture variation coefficient to measure this capacity. The sugarcane dehumidification characteristic equation is further established to describe the characteristic curve of sugarcane stem moisture reduction when the soil moisture content is low and the sugarcane stem variation coefficient is negative, which can increase the simulation accuracy of the sugarcane stem moisture reduction stage.

[0029] The present invention is based on soil moisture dynamics, meteorological data and sugarcane phenological period sub-models. Through the sugarcane leaf area index and soil water environment conditions during the sugarcane growth stage, the invention mechanistically calculates the transpiration loss of sugarcane stems and the water absorption capacity of the roots. The invention can simulate the water content of sugarcane stems in each phenological period. The calculation process is mechanistic and concise, with a daily prediction time length, reflecting the dynamic changes of the water content of sugarcane stems under the current environment, and providing technical guidance for irrigation operations.

[0030] It should be noted that the above data are all data and information that are easily obtained in the planting plots, and the output plan contents are all executable, clear and definite steps, which can help practitioners with certain agricultural knowledge to predict the moisture content of sugarcane stems and provide technical guidance for irrigation plans.

[0031] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0032] In the description of the present invention, it should be noted that, unless otherwise specified, the meaning of "plurality" is two or more; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "an example" etc. means 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 the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0035] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for dynamically simulating the moisture content of sugarcane stems, characterized in that: The steps include: S1: Establish soil water environment module; S2: driving soil water environment module; S3: Establish a sugarcane stem moisture characteristic module, couple the soil water environment module with the sugarcane stem moisture characteristic module, and realize real-time dynamic simulation of sugarcane stem moisture content.

2. The method for dynamic simulation of moisture content of sugarcane stems according to claim 1, characterized in that: In S1, the correction parameters of the soil moisture surplus and deficit index are established according to the soil texture and soil organic carbon data, and then the upper and lower limits of the soil moisture surplus and deficit index corresponding to the sugarcane root system are calculated, specifically according to the following formula: （1） （2） （3） （4） （5） （6） in, is the diagonal matrix of soil texture; is the sand content ratio; is the proportion of soil particles; is the clay content ratio; is the water storage response equation of soil organic carbon under a single soil texture type; is the water storage response equation under the sand content under the international system; is the water storage response equation under soil particle content under the international system; The water storage response equation under the clay content under the international system; is the soil organic carbon content; It is a water environment correction parameter used to correct the soil water environment profit and loss index, thereby responding to the water dynamics of sugarcane stems under current soil characteristics.

3. The method for dynamic simulation of moisture content of sugarcane stems according to claim 1, characterized in that: In S2, daily precipitation, wind speed, temperature, relative humidity and radiation data are input, the potential evapotranspiration value is corrected in combination with the sugarcane leaf area index, and the runoff synergy parameter is introduced to measure the slope for the loss rate of water in the sugarcane field, and the current soil moisture surplus and deficit index is comprehensively calculated to reflect the soil water environment state interacting with the sugarcane root system, specifically according to the following formula: （7） （8） （9） （10） （11） in, It is the upper limit of soil moisture surplus and deficit index, which means that soil moisture has reached the saturated moisture content state; It is the lower limit of soil moisture surplus and deficit index, which means that the soil water has reached the state where sugarcane roots wilt; is the sugarcane leaf area index; is the evapotranspiration coefficient under the current leaf area index; is the precipitation for the day; Calculated value for Penman-Monteith; It is the runoff coordination parameter, which is determined by the slope of the sugarcane field. The value can be calculated by inputting the slope. It is the current soil moisture surplus and deficit index, reflecting the soil moisture status for the sugarcane root system.

4. The method for dynamic simulation of moisture content of sugarcane stems according to claim 1, characterized in that: In the S3, the upper limit and lower limit of the water content of the sugarcane stem determined by the characteristics of the sugarcane variety are introduced, and the water content variation coefficient of the sugarcane stem is established as the calculation basis for the dynamic change between the water content of the sugarcane stem and the soil; according to the current soil moisture surplus and deficit index and the water content variation coefficient of the sugarcane stem provided by the soil water environment module, the water potential resistance equation of the sugarcane stem and the characteristic equation of sugarcane dehumidification are used to calculate the flow direction and size of the water content of the sugarcane stem, specifically according to the following formula: （12） （13） （14） in, The upper limit of water content in sugarcane stems. It is the lower limit of the moisture content of sugarcane stems, which is determined by the characteristics of sugarcane varieties, that is, the variety parameter; is the coefficient of variation of the moisture content in the cane stem, which determines the direction of the water flow. When the coefficient is positive, the flow direction is from the soil to the cane stem, and the moisture content in the cane stem increases. When the coefficient is negative, the flow direction is opposite. It is the sugarcane stem water potential resistance equation, which represents the water content of the sugarcane stem on that day, and is calculated in different ways according to the coefficient of variation of the water content of the sugarcane stem; is the water content of sugarcane stems the day before; is the characteristic equation of sugarcane dehumidification, which describes the characteristics of sugarcane stalk moisture reduction when the soil moisture content is low and the sugarcane stalk variation coefficient is negative. The equation is driven by the lower limit of the soil moisture surplus and deficit index and the current soil moisture surplus and deficit index.

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