Precise irrigation prediction method and device for arid region crop growth period and storage medium

Abstract

The invention relates to a precise irrigation prediction method and device for the growth period of crops in an arid region and a storage medium, and is applied to the technical field of crop irrigation prediction. Then predicting the water content of the next day by using the predicted soil water content of the ashitaban, repeating the steps in sequence, simultaneously acquiring potential transpiration and actual transpiration of the crops every day in the process, judging which day is an irrigation date by using the potential transpiration and actual transpiration of the crops every day in a period of time in the future, and carrying out early warning on the irrigation date; meanwhile, if the angelica keiskei is predicted to be the irrigation date today, the irrigation volume of the angelica keiskei is obtained through the predicted soil and crop indexes related to the angelica keiskei; according to the scheme, for the prediction of the crop irrigation volume, the soil moisture condition, the weather condition and the crop generation characteristics are fully considered, the irrigation volume is predicted by integrating multi-dimensional data, and the prediction accuracy is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of crop irrigation prediction, and in particular to a method, device and storage medium for accurately predicting irrigation during the growing period of crops in arid areas. Background Art

[0002] Irrigation is a technical measure to supplement the water needed by crops. In order to ensure the normal growth of crops and obtain high and stable yields, crops must be supplied with sufficient water. Under natural conditions, the water requirements of crops cannot be met due to insufficient precipitation or uneven distribution. Therefore, artificial irrigation must be carried out to make up for the lack of natural rainfall. The irrigation principle is that the irrigation amount, frequency and time should be based on the water requirements of medicinal plants, the growth stage, climate and soil conditions. Irrigation should be timely, appropriate and reasonable. Its types mainly include irrigation before sowing, irrigation for seedling promotion, irrigation during the growth period and irrigation in winter.

[0003] Existing irrigation methods include: irrigation recommendations based on crop water demand: designing irrigation plans suitable for crop growth based on the water requirements of crops at different stages; climate-driven irrigation recommendations: considering the impact of meteorological changes on crop water requirements, combining future rainfall and water balance models to recommend irrigation strategies; sensor data-driven irrigation recommendations: real-time monitoring of soil moisture changes through sensors, and real-time adjustment of irrigation strategies based on set thresholds.

[0004] The irrigation recommendation technology based on crop water requirement takes the crop's demand for water as the starting point, which may result in the irrigation amount not being adapted to the actual soil moisture conditions, and failing to promptly detect excess or lack of soil moisture, which can easily waste water resources or affect crop growth; the climate-driven irrigation recommendation technology only considers crop water requirements based on meteorological data, without considering the impact of soil water supply on the actual water absorption of crops, and simplifies the soil moisture balance, making it impossible to obtain real-time soil moisture changes; the sensor data-driven irrigation recommendation requires a large number of soil moisture sensors to collect data in real time, which may result in higher equipment costs. The sensors may be affected by factors such as soil type, climate conditions, and installation location, resulting in data errors, thereby affecting the accuracy of the irrigation recommendation. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method, device and storage medium for accurately predicting irrigation during the growing period of crops in arid areas, so as to solve the problems in the prior art that irrigation recommendations based on crop water demand ignore soil moisture conditions, waste water resources or affect crop growth; irrigation recommendations based on climate drive do not consider the impact of soil water supply on actual crop water absorption; irrigation recommendations based on sensor data drive require a large number of soil moisture sensors to collect data in real time, resulting in higher equipment costs, and the sensors may be affected by factors such as soil type, climate conditions and installation location, resulting in data errors, thereby affecting the accuracy of irrigation recommendations.

[0006] According to a first aspect of an embodiment of the present invention, a method for predicting precise irrigation during the growing period of crops in arid areas is provided, the method comprising: Get the soil surface moisture content of the day and the moisture content in the deep soil layer on that day , get tomorrow's rainfall through the weather forecast P , predict tomorrow's leaf area index through a pre-built crop growth model LAI And the normalized root density distribution of crops ; According to the rainfall tomorrow P and tomorrow's leaf area index LAI Obtaining canopy interception I According to the canopy interception I and tomorrow's rainfall P Get surface runoff Q ; Obtain crop potential evapotranspiration through meteorological data ; Get soil texture parameters based on the soil surface moisture content on that day or the moisture content in the deep soil layer on that day , Potential transpiration of crops , soil texture parameters and normalized root density distribution of the crops Get the actual evaporation of the soil surface , Actual evaporation in deep soil and the actual evaporation from the soil surface ; The Richards equation is used to simulate the basic equation of soil moisture movement, and the soil moisture redistribution amount is obtained through the basic equation of soil moisture movement ; The moisture content of the soil surface on that day Tomorrow's rainfall P , canopy interception I , surface runoff Q , the actual evaporation of the soil surface , the actual evaporation of the soil surface and soil water redistribution Get tomorrow's soil surface moisture content ; The moisture content of the deep soil layer on that day , Actual evaporation in deep soil and soil water redistribution Get tomorrow's deep soil moisture content ; Get the soil surface moisture content every day in the first preset time period in the future , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer ; The actual transpiration of the soil surface every day in the first preset time period in the future and the actual evaporation in the deep soil layer Sum the total actual evaporation per day in the first preset time period in the future ; Obtain the soil layer involved in the crop root system, based on the daily soil surface moisture content in the future preset time period and deep soil moisture content Get the average soil moisture content of crop roots every day in the first preset time period in the future ; The total actual evaporation per day in the first preset time period in the future and crop potential evapotranspiration Determine whether crops need to be irrigated every day in the first preset time period in the future, and issue an early warning on the date when irrigation is required; If it is determined today that the crop needs to be irrigated tomorrow, then the normalized root density distribution of tomorrow , Average soil moisture content of crop roots tomorrow and soil texture parameters to obtain the total irrigation volume predicted for tomorrow .

[0007] Preferably, According to tomorrow's rainfall P , Leaf Area Index for tomorrow LAI Obtaining canopy interception I include: Get the extinction coefficient of solar radiation , according to the extinction coefficient of solar radiation and the leaf area index for tomorrow LAI Get soil coverage , set the empirical coefficient , according to the soil coverage Tomorrow's rainfall P , empirical coefficient and tomorrow's leaf area index LAI Obtaining canopy interception I .

[0008] Preferably, According to the canopy interception I and tomorrow's rainfall P Get surface runoff Q include: Get the runoff index of the soil , according to the soil runoff index Get the maximum possible infiltration S , according to the canopy interception I and tomorrow's rainfall P Get the daily rainfall after interception R , according to the maximum possible infiltration S and daily rainfall after interception R Get surface runoff Q .

[0009] Preferably, The method of obtaining crop potential transpiration through meteorological data : Obtain reference crop evapotranspiration parameters through meteorological data, and obtain reference crop evapotranspiration through the reference crop evapotranspiration parameters ; Get the target crop coefficient , based on the target crop coefficient and reference crop evapotranspiration Obtaining crop evapotranspiration ; Leaf Area Index LAI and crop evapotranspiration Obtaining soil potential evaporation ; According to the soil potential evaporation and crop evapotranspiration Obtaining crop potential transpiration .

[0010] Preferably, Obtaining the target crop coefficient include: Leaf area index LAI Minimum crop factor at zero and maximum and the maximum crop factor , through the minimum crop coefficient and the maximum crop factor Leaf Area Index LAI Curve shape shaping parameters , through the minimum crop coefficient , Maximum crop coefficient , Integer parameters Leaf area index LAI Get the target crop coefficient .

[0011] Preferably, The soil surface moisture content of each day in the future preset first time period is obtained respectively , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer include: Predict the leaf area index of the next day through the pre-built crop growth model LAI And the normalized root density distribution of crops , get the rainfall for the next day through the weather forecast P , through the soil surface moisture content tomorrow 、Tomorrow's deep soil moisture content , Leaf Area Index on the next day LAI , the normalized root density distribution of crops in the next day And the rainfall the next day P Get the soil surface moisture content on the next day , Deep soil moisture content the day after tomorrow , the potential transpiration of crops in the next day , the actual evaporation of the soil surface the day after tomorrow and the actual evaporation of the deep soil layer the day after tomorrow ; Repeat the iteration until the daily soil surface moisture content in the first preset time period in the future is obtained , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer .

[0012] Preferably, The normalized root density distribution according to tomorrow , Average soil moisture content of crop roots tomorrow and soil texture parameters to obtain the total irrigation volume predicted for tomorrow include: According to tomorrow's normalized root density distribution Get tomorrow's root depth , based on the root depth of tomorrow The soil texture parameters are used to obtain the total effective water content of the root zone soil ; Based on the average soil moisture content of tomorrow's crop roots , soil texture parameters and the root depth of tomorrow Get the actual water storage capacity of the soil ; According to the root depth of crops Get crop evapotranspiration parameters , according to the crop evapotranspiration parameters and the crop evapotranspiration Get the effective water coefficient , according to the effective water coefficient and the total available soil water content in the root zone Get the amount of water available in the root zone that is easily absorbed by the crop ; The potential transpiration of crops per day in the first preset time period in the future Get the total crop water requirement in the future preset second time period ; Obtain the total rainfall in the future preset second time period through the weather forecast , the first preset future time period is greater than the second preset future time period; According to the total effective water content of the root zone soil , the actual water storage capacity of the soil , the amount of water available in the root zone that is easily absorbed by crops , the total water demand of crops in the second preset time period in the future And the total rainfall in the second preset time period in the future Get the total irrigation volume forecast for tomorrow .

[0013] Preferably, According to the total effective water content of the root zone soil , the actual water storage capacity of the soil , the amount of water available in the root zone that is easily absorbed by crops , the total water demand of crops in the second preset time period in the future And the total rainfall in the second preset time period in the future Get the total irrigation volume forecast for tomorrow include: If the predicted soil water storage tomorrow Less than the amount of water in the root zone that is not easily absorbed by the crop, the amount of water that is not easily absorbed by the crop is the total effective water content of the soil in the root zone Subtract the amount of water available in the root zone for crop absorption ; The total irrigation volume predicted for tomorrow is The amount of water not readily available to the crop in the root zone minus tomorrow's soil water storage Plus the total water demand of crops in the second preset time period in the future , and finally subtract the total rainfall in the second preset time period in the future Get; If the predicted soil water storage tomorrow The amount of water that is greater than the root zone can easily be absorbed by the crop; The total irrigation volume predicted for tomorrow is By presetting the total water demand of crops in the second time period in the future Subtract tomorrow's soil water storage The difference between the amount of water that is not easily absorbed by the crop in the root zone and the total rainfall in the second preset time period in the future Get.

[0014] According to a second aspect of an embodiment of the present invention, a device for accurately predicting the growing period of crops in arid areas is provided, the device comprising: Data acquisition module: used to obtain the soil surface moisture content of the day and the moisture content in the deep soil layer on that day , get tomorrow's rainfall through the weather forecast P , predict tomorrow's leaf area index through a pre-built crop growth model LAI And the normalized root density distribution of crops ; Moisture content parameter acquisition module: used to obtain the water content parameter according to the rainfall tomorrow. P and tomorrow's leaf area index LAI Get canopy interception I According to the canopy interception I and tomorrow's rainfall P Get surface runoff Q ; Obtain crop potential evapotranspiration through meteorological data ; Actual transpiration acquisition module: used to obtain soil texture parameters, based on the soil surface moisture content on that day or the moisture content in the deep soil layer on that day , crop potential evapotranspiration , soil texture parameters and normalized root density distribution of the crops Get the actual evaporation of the soil surface , Actual evaporation in deep soil and the actual evaporation from the soil surface ; Water redistribution acquisition module: used to simulate the basic equation of soil moisture movement using the Richards equation, and obtain the soil moisture redistribution amount through the basic equation of soil moisture movement ; Surface moisture content acquisition module: used to obtain the moisture content of the soil surface on that day Tomorrow's rainfall P , canopy interception I , surface runoff Q , the actual evaporation of the soil surface , the actual evaporation of the soil surface and soil water redistribution Get tomorrow's soil surface moisture content ; Deep moisture content acquisition module: used to obtain the moisture content of the deep soil layer on that day , Actual evaporation in deep soil and soil water redistribution Get tomorrow's deep soil moisture content ; Future prediction module: used to obtain the soil surface moisture content every day in the first preset time period in the future , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer ; Total actual transpiration acquisition module: used to obtain the actual transpiration of the soil surface every day within the first preset time period in the future and the actual evaporation in the deep soil layer Sum the total actual evaporation per day in the first preset time period in the future ; Average soil moisture acquisition module: used to obtain the soil layer involved in the crop root system, based on the daily soil surface moisture content in the future preset time period and deep soil moisture content Get the average soil moisture content of crop roots every day in the first preset time period in the future ; Irrigation judgment module: used to determine the total actual transpiration volume per day within the first preset time period in the future and crop potential evapotranspiration Determine whether crops need to be irrigated every day in the first preset time period in the future, and issue an early warning on the date when irrigation is required; Irrigation volume prediction module: if it is determined today that crops need to be irrigated tomorrow, then the normalized root density distribution of tomorrow will be used to predict the amount of irrigation. , Average soil moisture content of crop roots tomorrow and soil texture parameters to obtain the total irrigation volume predicted for tomorrow .

[0015] According to a third aspect of an embodiment of the present invention, there is provided a storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a main controller, each step in the above method is implemented.

[0016] The technical solution provided by the embodiments of the present invention may have the following beneficial effects: The present application predicts tomorrow's soil parameters by acquiring soil parameters and weather forecasts, mainly the soil moisture content, and then uses the predicted soil parameters for tomorrow to predict the soil parameters for the day after tomorrow, and repeats this process in sequence to predict the soil parameters for each day in the future, and uses the soil parameters for each day in the future to determine which day is the irrigation date, and to issue an early warning for the irrigation date; at the same time, if it is predicted today that tomorrow is the irrigation date, the irrigation amount for tomorrow is obtained by using the predicted relevant soil parameters for tomorrow; the scheme of the present application fully considers the soil moisture conditions, weather conditions and crop production characteristics for predicting the irrigation amount of crops, and predicts the irrigation amount by integrating multi-dimensional data, and the acquisition of each parameter is mostly achieved through mathematical calculations, rather than relying on data from large-scale sensors, which saves costs, and the dynamic prediction process can also significantly improve the accuracy of the prediction.

[0017] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] Figure 1 It is a flow chart of a method for predicting precise irrigation during the growing period of crops in arid areas according to an exemplary embodiment; Figure 2 is a system schematic diagram of a device for accurately predicting the growing period of crops in arid areas according to another exemplary embodiment; In the attached figure: 1-data acquisition module, 2-water content parameter acquisition module, 3-actual transpiration acquisition module, 4-water redistribution acquisition module, 5-surface moisture content acquisition module, 6-deep moisture content acquisition module, 7-future prediction module, 8-total actual transpiration acquisition module, 9-average soil moisture content acquisition module, 10-irrigation judgment module, 11-irrigation amount prediction module. DETAILED DESCRIPTION

[0020] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0021] Embodiment 1 Figure 1 is a flow chart of a method for predicting precise irrigation during the growing period of crops in arid areas according to an exemplary embodiment. Figure 1 As shown, the method includes: S1, obtain the soil surface moisture content on that day and the moisture content in the deep soil layer on that day , get tomorrow's rainfall through the weather forecast P , predict tomorrow's leaf area index through a pre-built crop growth model LAI And the normalized root density distribution of crops ; S2, according to the rainfall tomorrow P and tomorrow's leaf area index LAI Obtaining canopy interception I According to the canopy interception I and tomorrow's rainfall P Get surface runoff Q ; Obtain crop potential evapotranspiration through meteorological data ; S3, obtaining soil texture parameters, based on the soil surface moisture content on that day or the moisture content in the deep soil layer on that day , Potential transpiration of crops , soil texture parameters and normalized root density distribution of the crops Get the actual evaporation of the soil surface , Actual evaporation in deep soil and the actual evaporation from the soil surface ; S4, using Richards equation to simulate the basic equation of soil moisture movement, and obtain soil moisture redistribution through the basic equation of soil moisture movement ; S5, the moisture content of the soil surface on that day Tomorrow's rainfall P , canopy interception I , surface runoff Q , the actual evaporation of the soil surface , the actual evaporation of the soil surface and soil water redistribution Get tomorrow's soil surface moisture content ; S6, the moisture content of the deep soil layer on that day , Actual evaporation in deep soil and soil water redistribution Get tomorrow's deep soil moisture content ; S7, respectively obtain the soil surface moisture content of each day in the first preset time period in the future , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer ; S8, calculating the actual transpiration of the soil surface layer every day in the first preset time period in the future and the actual evaporation in the deep soil layer Sum the total actual evaporation per day in the first preset time period in the future ; S9, obtaining the soil layer involved in the crop root system, and calculating the soil surface moisture content every day in the future preset time period. and deep soil moisture content Get the average soil moisture content of crop roots every day in the first preset time period in the future ; S10, the total actual transpiration amount per day in the first preset time period in the future and crop potential evapotranspiration Determine whether crops need to be irrigated every day in the first preset time period in the future, and issue an early warning on the date when irrigation is required; S11, if it is determined today that the crop needs to be irrigated tomorrow, then according to tomorrow's normalized root density distribution , Average soil moisture content of crop roots tomorrow and soil texture parameters to obtain the total irrigation volume predicted for tomorrow ; It is understood that the present application divides the soil into the surface layer ( ) and deep ( ), where the soil depth is multi-layer, and the soil surface moisture content is calculated as follows:

[0022] In the formula, It is the predicted soil surface moisture content on the next day, in cm3 cm-3; is the rainfall for the next day, obtained through the local weather forecast, in cm; is the canopy interception, in cm; is the surface runoff, in cm; The actual transpiration of the soil surface (actual absorption by the roots) is in cm. ; is the actual evaporation of the soil surface; is the water redistribution loss / increase, in cm; is the soil surface moisture content on that day, which can be obtained through sensors, z is the number of layers, is the thickness of each soil layer, in cm; The calculation formula of soil deep moisture content is as follows:

[0023] In the formula, It is the predicted soil moisture content in the deep layer on the next day, in cm3 cm-3; It is the moisture content of deep soil layer on that day, which can be obtained through sensors; The actual transpiration in the deep soil layer (actual absorption by the roots) is in cm. ; Based on the above calculation formula, Canopy interception The acquisition is as follows: Predict tomorrow's leaf area index using a pre-built crop growth model LAI , predicting tomorrow's leaf area index through crop growth model LAI As it is a mature prior art, this embodiment will not be described in detail here. If a canopy exists ( LAI >0), it will intercept the water from rainfall or irrigation, and the water that eventually flows to the soil surface should be reduced by this part, so:

[0024] In the formula, is the leaf area index; is the empirical coefficient; is the soil coverage rate. With the increase of precipitation, the intercepted rainfall gradually reaches the saturation amount. In principle, the parameter This should be determined experimentally and specified in the input file. For common crops, this example assumes ;

[0025] in, is the extinction coefficient of solar radiation, ; Surface runoff Q The acquisition is as follows: Water flowing to the soil surface will infiltrate the soil or accumulate on the soil surface, the latter of which may cause surface runoff. The runoff volume is calculated using the runoff curve formula recommended by the United States Department of Agriculture. The basic formula is as follows:

[0026]

[0027] In the formula, R To subtract the intercepted daily rainfall, tomorrow's rainfall P Subtract canopy interception , unit is cm, is the maximum possible infiltration, in cm; is the runoff index. In the standard SCS-CN method, CN The value is determined by factors such as hydrological conditions and land cover type; The actual transpiration (actual absorption by the root system) is obtained as follows: Reference crop evapotranspiration Calculated using the Penman-Monteith method:

[0028] In the formula, is the reference evapotranspiration, in cm; is the slope of the saturated vapor pressure curve, in kPa °C-1; is the net radiation on the crop surface, in MJ m-2 day-1; is the soil heat flux density, in MJ m-2 day-1; is the humidity constant, unit is kPa ℃-1; is the daily average temperature at a height of 2m, in °C; is the wind speed at a height of 2 m, in m s-1; is the saturated vapor pressure. The unit is kPa; is the actual vapor pressure, in kPa; Crop evapotranspiration ( ) is calculated by dividing the reference crop evapotranspiration ( ) multiplied by the crop factor ( ) to calculate:

[0029] in, is the crop evapotranspiration, in cm; is the crop coefficient; Using dynamic methods As a direct function of simulated LAI:

[0030] yes =0 when the minimum , is high The maximum crop coefficient at Yes and The shaping parameter of the curve shape, the reference range is 0.5-1.0, The bigger, near hour The smaller it is, the default value is set to 0.8. Take crops such as wheat and corn as an example:

[0031] Recombination Calculating soil potential evaporation and crop potential evapotranspiration :

[0032]

[0033] The normalized root density distribution of tomorrow is also predicted by the pre-built crop growth model. ; The actual evaporation is limited by the actual soil moisture content and soil texture, and the actual transpiration is limited by the actual soil moisture content, soil texture and crop root density distribution:

[0034]

[0035] In the formula, is the actual total evaporation of all soil layers, in cm. In this example, evaporation only occurs in the surface layer; is the soil moisture content at the wilting point, a soil texture parameter, in cm3; is the soil field water holding capacity, is the soil texture parameter, the unit is cm3, is the actual total evaporation of all soil layers, which is calculated from the actual evaporation of the surface layer. and actual evaporation in the deep layer The sum is obtained in cm; is the normalized root density distribution; Soil water redistribution The acquisition is as follows

[0036] In the formula, is the soil moisture content on that day, , obtained through sensors, and is the intermediate parameter, calculate; After obtaining the above parameters, the soil surface moisture content calculation formula is used to predict tomorrow's soil surface moisture content. , and use the deep soil moisture calculation formula to predict tomorrow's deep soil moisture content ; For example, if the soil depth involved by the crop root system is n, then the soil surface water content and (n-1) soil water content in the deep layer Calculate the average soil moisture content of the root system ; The potential evaporation, actual evaporation and soil moisture content of the next day are predicted from the relevant data of the day. The data of the next day can simulate the potential evaporation, actual evaporation and soil moisture content of the next day. This cycle can obtain the daily potential evaporation of the first preset time in the future (related to the number of days of weather forecast available, generally one week) , actual evaporation and soil moisture content List; When a day in the first time period in the future and When the water content of the soil is equal to that of the soil, it indicates that the soil has sufficient water supply and no irrigation is needed. Less than When the water level is 0, it indicates that the crop is under water stress and needs to be irrigated in time. At this time, an early warning of the irrigation date is required; If the irrigation date is predicted to be tomorrow, it is necessary to predict the irrigation amount for tomorrow (it is worth emphasizing that if the irrigation date is predicted to be the day after tomorrow, it is not necessary to predict the irrigation amount for the day after tomorrow. This is because the closer to the recommended irrigation date, the lower the uncertainty of various prediction results). Tomorrow's irrigation amount forecast specifically includes: If the predicted soil water storage tomorrow Less than the amount of water that is not easily absorbed by the crop (the amount of water that is not easily absorbed by the crop is equal to the total effective water content of the soil in the root zone Subtract the amount of water available in the root zone for crop absorption ), indicating that the water in the soil is not easily absorbed by crops at this time. The recommended water volume will first increase the soil water storage to the amount that is not easily absorbed by crops, plus the total water demand of crops in the future period (user input), and subtract the total rainfall in the future period. The specific calculation formula is as follows:

[0037] In the formula, is the recommended total irrigation volume in cm; The amount of water in the soil that is not easily absorbed by crops. is the total available soil water content in the root zone, in cm; It is the effective amount of water in the root zone that can be easily absorbed by crops. is the actual water storage capacity of the current soil, in cm; is the total crop water requirement in the second time period in the future, and the daily potential evaporation predicted in the second time period The sum is obtained in cm; is the total rainfall in the second time period in the future, and the daily rainfall in the second time period is obtained through weather forecast P The sum is obtained in cm. Usually, the second time period in the future is shorter than the first time period in the future. For example, if the first time period in the future is a week, then the second time period in the future is the first two or three days of the week. This is because is the daily potential evaporation predicted by the cycle The sum is usually obtained in the second time period in the future, which is no more than 1 week, otherwise the calculated irrigation amount will be too large, which may reduce the water utilization rate; If the predicted soil water storage tomorrow If the amount of water is greater than the amount that is not easily absorbed by crops, it means that a part of the water in the soil is easily absorbed by crops. The recommended amount of water will be based on the total demand minus the amount of water in the soil that is easily absorbed by crops, and minus the total rainfall in the future. The specific calculation formula is as follows:

[0038] In the above, , and The calculation is as follows:

[0039]

[0040]

[0041] In the formula, is the root depth in cm, normalized by the crop root density distribution ; is the coefficient, calculated as follows:

[0042] In the formula, The value is affected by the root depth and evaporation rate of the crop. The value generally varies between 0.3 and 0.7. The value is 0.3, which is the value of crops with deep roots and low evaporation rate. The value is 0.7. Taking corn and winter wheat as an example, the The value is 0.55; Through the above calculation, we can get the irrigation volume predicted for tomorrow. ; In the process of applying the above method, it is first necessary to determine whether the current date is the harvest date. If so, the simulation prediction will not continue. Otherwise, whether irrigation is needed at the preset time in the future is simulated according to the database prepared by the user. If irrigation is not needed at the preset time in the future, the model automatically saves today's state variables and ends today's early warning decision; if irrigation is needed at the preset time in the future, the first recommended irrigation date is saved. If the first recommended irrigation date is tomorrow, the irrigation amount is calculated and the final decision warning result is output and the today's state variable is saved, ending today's early warning decision; if the first recommended irrigation date is not tomorrow, the preliminary decision warning result is output and the today's state variable is saved, ending today's early warning decision.

[0043] Embodiment 2 Figure 2 : is a system schematic diagram of a device for accurately predicting the growth period of crops in arid areas according to another exemplary embodiment, the device comprising: Data acquisition module 1: used to obtain the soil surface moisture content of the day and the moisture content in the deep soil layer on that day , get tomorrow's rainfall through the weather forecast P, predict tomorrow's leaf area index through a pre-built crop growth model LAI And the normalized root density distribution of crops ; Water content parameter acquisition module 2: used to obtain the water content parameter according to the rainfall tomorrow. P and tomorrow's leaf area index LAI Obtaining canopy interception I According to the canopy interception I and tomorrow's rainfall P Get surface runoff Q ; Obtain crop potential evapotranspiration through meteorological data ; Actual transpiration acquisition module 3: used to obtain soil texture parameters, based on the soil surface moisture content on that day or the moisture content in the deep soil layer on that day , Potential transpiration of crops , soil texture parameters and normalized root density distribution of the crops Get the actual evaporation of the soil surface , Actual evaporation in deep soil and the actual evaporation from the soil surface ; Water redistribution acquisition module 4: used to simulate the basic equation of soil moisture movement using the Richards equation, and obtain the soil moisture redistribution amount through the basic equation of soil moisture movement ; Surface moisture content acquisition module 5: used to obtain the moisture content of the soil surface on that day Tomorrow's rainfall P , canopy interception I , surface runoff Q , the actual evaporation of the soil surface , the actual evaporation of the soil surface and soil water redistribution Get tomorrow's soil surface moisture content ; Deep moisture content acquisition module 6: used to obtain the moisture content of the deep soil layer on that day , Actual evaporation in deep soil and soil water redistribution Get tomorrow's deep soil moisture content ; Future prediction module 7: used to obtain the soil surface moisture content of each day in the first preset time period in the future , deep soil moisture content , Potential transpiration of crops , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer ; Total actual transpiration acquisition module 8: used to obtain the actual transpiration of the soil surface layer every day in the first preset time period in the future and the actual evaporation in the deep soil layer Sum the total actual evaporation per day in the first preset time period in the future ; Average soil moisture content acquisition module 9: used to obtain the soil layer involved in the crop root system, according to the daily soil surface moisture content in the future preset time period and deep soil moisture content Get the average soil moisture content of crop roots every day in the first preset time period in the future ; Irrigation judgment module 10: used to determine the total actual transpiration volume per day within the first preset time period in the future and crop potential evapotranspiration Determine whether crops need to be irrigated every day in the first preset time period in the future, and issue an early warning on the date when irrigation is required; Irrigation volume prediction module 11: if it is determined today that crops need to be irrigated tomorrow, then the normalized root density distribution of tomorrow is used to predict the amount of irrigation. , Average soil moisture content of crop roots tomorrow and soil texture parameters to obtain the total irrigation volume predicted for tomorrow .

[0044] Embodiment three: This embodiment provides a storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a main controller, each step in the above method is implemented; It is understandable that the storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0045] 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.

[0046] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0047] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0048] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0049] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0050] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0051] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0052] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" 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 invention. 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.

[0053] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for accurately predicting irrigation during the growing period of crops in arid areas, characterized in that: The method comprises: Get the soil surface moisture content of the day and the moisture content in the deep soil layer on that day , get tomorrow's rainfall through the weather forecast P , predict tomorrow's leaf area index through a pre-built crop growth model LAI And the normalized root density distribution of crops ; According to the rainfall tomorrow P and tomorrow's leaf area index LAI Get canopy interception I According to the canopy interception I and tomorrow's rainfall P Get surface runoff Q ; Obtain crop potential evapotranspiration through meteorological data ; Get soil texture parameters based on the soil surface moisture content on that day or the moisture content in the deep soil layer on that day , crop potential evapotranspiration , soil texture parameters and normalized root density distribution of the crops Get the actual evaporation of the soil surface , Actual evaporation in deep soil and the actual evaporation from the soil surface ; The Richards equation is used to simulate the basic equation of soil moisture movement, and the soil moisture redistribution amount is obtained through the basic equation of soil moisture movement ; The moisture content of the soil surface on that day Tomorrow's rainfall P , canopy interception I , surface runoff Q , the actual evaporation of the soil surface , the actual evaporation of the soil surface and soil water redistribution Get tomorrow's soil surface moisture content ; The moisture content of the deep soil layer on that day , Actual evaporation in deep soil and soil water redistribution Get tomorrow's deep soil moisture content ; Get the soil surface moisture content every day in the first preset time period in the future , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer ; The actual transpiration of the soil surface every day in the first preset time period in the future and the actual evaporation in the deep soil layer Sum the total actual evaporation per day in the first preset time period in the future ; Obtain the soil layer involved in the crop root system, and calculate the soil surface moisture content every day in the first preset time period in the future and deep soil moisture content Get the average soil moisture content of crop roots every day in the first preset time period in the future ; The total actual evaporation per day in the first preset time period in the future and crop potential evapotranspiration Determine whether crops need to be irrigated every day in the first preset time period in the future, and issue an early warning for the date when irrigation is required; If it is determined today that the crop needs to be irrigated tomorrow, then the normalized root density distribution of tomorrow , Average soil moisture content of crop roots tomorrow and soil texture parameters to obtain the total irrigation volume predicted for tomorrow .

2. The method according to claim 1, characterized in that According to tomorrow's rainfall P , tomorrow's leaf area index LAI Get canopy interception I include: Get the extinction coefficient of solar radiation , according to the extinction coefficient of solar radiation and the leaf area index for tomorrow LAI Get soil coverage , set the empirical coefficient , according to the soil coverage Tomorrow's rainfall P , empirical coefficient and tomorrow's leaf area index LAI Get canopy interception I .

3. The method according to claim 2, characterized in that According to the canopy interception I and tomorrow's rainfall P Get surface runoff Q include: Get the runoff index of the soil , according to the soil runoff index Get the maximum possible infiltration S , according to the canopy interception I and tomorrow's rainfall P Get the daily rainfall after interception R , according to the maximum possible infiltration S and daily rainfall after interception R Get surface runoff Q .

4. The method according to claim 3, characterized in that The method of obtaining crop potential transpiration through meteorological data : Obtain reference crop evapotranspiration parameters through meteorological data, and obtain reference crop evapotranspiration through the reference crop evapotranspiration parameters ; Get the target crop coefficient , based on the target crop coefficient and reference crop evapotranspiration Obtaining crop evapotranspiration ; Leaf Area Index LAI and crop evapotranspiration Obtaining soil potential evaporation ; According to the soil potential evaporation and crop evapotranspiration Obtaining crop potential transpiration .

5. The method according to claim 4, characterized in that Obtaining the target crop coefficient include: Leaf area index LAI Minimum crop factor at zero and maximum and the maximum crop factor , through the minimum crop coefficient and the maximum crop factor Leaf Area Index LAI Curve shape shaping parameters , through the minimum crop coefficient , Maximum crop coefficient , Integer parameters Leaf area index LAI Get the target crop coefficient .

6. The method according to claim 5, characterized in that The soil surface moisture content of each day in the first preset time period in the future is obtained respectively , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer include: Predict the leaf area index of the next day through the pre-built crop growth model LAI And the normalized root density distribution of crops , get the rainfall for the next day through the weather forecast P , through the soil surface moisture content tomorrow 、Tomorrow's deep soil moisture content , Leaf Area Index on the next day LAI , the normalized root density distribution of crops in the next day And the rainfall the next day P Get the soil surface moisture content on the next day , Deep soil moisture content the day after tomorrow , the potential transpiration of crops in the next day , the actual evaporation of the soil surface the day after tomorrow and the actual evaporation of the deep soil layer the day after tomorrow ; Repeat the iteration until the soil surface moisture content of each day in the first preset time period in the future is obtained , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer .

7. The method according to claim 6, characterized in that The normalized root density distribution according to tomorrow , Average soil moisture content of crop roots tomorrow and soil texture parameters to obtain the total irrigation volume predicted for tomorrow include: According to tomorrow's normalized root density distribution Get tomorrow's root depth , based on the root depth of tomorrow The soil texture parameters are used to obtain the total effective water content of the root zone soil ; Based on the average soil moisture content of tomorrow's crop roots , soil texture parameters and the root depth of tomorrow Get the actual water storage capacity of the soil ; According to the root depth of crops Get crop evapotranspiration parameters , according to the crop evapotranspiration parameters and the crop evapotranspiration Get the effective water coefficient , according to the effective water coefficient and the total available soil water content in the root zone Get the amount of water available in the root zone that is easily absorbed by the crop ; The potential transpiration of crops per day in the first preset time period in the future Get the total crop water requirement in the future preset second time period ; Obtain the total rainfall in the future preset second time period through the weather forecast , the first preset future time period is greater than the second preset future time period; According to the total effective water content of the root zone soil , the actual water storage capacity of the soil , the amount of water available in the root zone that is easily absorbed by crops , the total water demand of crops in the second preset time period in the future And the total rainfall in the second preset time period in the future Get the total irrigation volume forecast for tomorrow .

8. The method according to claim 7, characterized in that According to the total effective water content of the root zone soil , the actual water storage capacity of the soil , the amount of water available in the root zone that is easily absorbed by crops , the total water demand of crops in the second preset time period in the future And the total rainfall in the second preset time period in the future Get the total irrigation volume forecast for tomorrow include: If the predicted soil water storage tomorrow Less than the amount of water in the root zone that is not easily absorbed by the crop, the amount of water that is not easily absorbed by the crop is the total effective water content of the soil in the root zone Subtract the amount of water available in the root zone for crop absorption ; The total irrigation volume predicted for tomorrow is The amount of water not readily available to the crop in the root zone minus tomorrow's soil water storage Plus the total water demand of crops in the second preset time period in the future , and finally subtract the total rainfall in the second preset time period in the future Get; If the predicted soil water storage tomorrow The amount of water that is greater than the root zone can easily be absorbed by the crop; The total irrigation volume predicted for tomorrow is By presetting the total water demand of crops in the second time period in the future Subtract tomorrow's soil water storage The difference between the amount of water that is not easily absorbed by the crop in the root zone and the total rainfall in the second preset time period in the future Get.

9. A device for accurately predicting irrigation during the growing period of crops in arid areas, characterized in that: The device comprises: Data acquisition module: used to obtain the soil surface moisture content of the day and the moisture content in the deep soil layer on that day , get tomorrow's rainfall through the weather forecast P , predict tomorrow's leaf area index through a pre-built crop growth model LAI And the normalized root density distribution of crops ; Moisture content parameter acquisition module: used to obtain the water content parameter according to the rainfall tomorrow. P and tomorrow's leaf area index LAI Get canopy interception I According to the canopy interception I and tomorrow's rainfall P Get surface runoff Q ; Obtain crop potential evapotranspiration through meteorological data ; Actual transpiration acquisition module: used to obtain soil texture parameters, based on the soil surface moisture content on that day or the moisture content in the deep soil layer on that day , crop potential evapotranspiration , soil texture parameters and normalized root density distribution of the crops Get the actual evaporation of the soil surface , Actual evaporation in deep soil and the actual evaporation from the soil surface ; Water redistribution acquisition module: used to simulate the basic equation of soil moisture movement using the Richards equation, and obtain the soil moisture redistribution amount through the basic equation of soil moisture movement ; Surface moisture content acquisition module: used to obtain the moisture content of the soil surface on that day Tomorrow's rainfall P , canopy interception I , surface runoff Q , the actual evaporation of the soil surface , and the actual evaporation of the soil surface and soil water redistribution Get tomorrow's soil surface moisture content ; Deep moisture content acquisition module: used to obtain the moisture content of the deep soil layer on that day , Actual evaporation in deep soil and soil water redistribution Get tomorrow's deep soil moisture content ; Future prediction module: used to obtain the soil surface moisture content every day in the first preset time period in the future , deep soil moisture content , crop potential evapotranspiration , the actual evaporation of the soil surface and the actual evaporation in the deep soil layer ; Total actual transpiration acquisition module: used to obtain the actual transpiration of the soil surface every day within the first preset time period in the future and the actual evaporation in the deep soil layer Sum the total actual evaporation per day in the first preset time period in the future ; Average soil moisture content acquisition module: used to obtain the soil layer involved in the crop root system, according to the daily soil surface moisture content in the first preset time period in the future and deep soil moisture content Get the average soil moisture content of crop roots every day in the first preset time period in the future ; Irrigation judgment module: used to determine the total actual transpiration volume per day within the first preset time period in the future and crop potential evapotranspiration Determine whether crops need to be irrigated every day in the first preset time period in the future, and issue an early warning for the date when irrigation is required; Irrigation volume prediction module: if it is determined today that crops need to be irrigated tomorrow, then the normalized root density distribution of tomorrow will be used to predict the amount of irrigation. , Average soil moisture content of crop roots tomorrow and soil texture parameters to obtain the total irrigation volume predicted for tomorrow .

10. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by the main controller, each step of the method for predicting precise irrigation during the growing period of crops in arid areas as described in any one of claims 1 to 8 is implemented.

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