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CN-121994677-A - In-situ paddy field moisture infiltration rate monitoring system and monitoring method

CN121994677ACN 121994677 ACN121994677 ACN 121994677ACN-121994677-A

Abstract

The invention discloses an in-situ paddy field moisture infiltration rate monitoring system and a detection method thereof, wherein the monitoring system comprises an in-situ monitoring device and a data processing terminal, wherein the in-situ monitoring device is deployed on a paddy field; the in-situ monitoring device synchronously collects liquid level distance and meteorological parameters of the paddy field water surface according to a period, and provides the liquid level distance and the meteorological parameters for the data processing terminal after pretreatment, and the data processing terminal automatically determines the daily liquid level descending amount and the daily crop evaporation amount to obtain the daily infiltration amount and the in-situ paddy field water infiltration rate. The monitoring method comprises the steps of collecting parameters, preprocessing, obtaining an effective infiltration period list, obtaining the daily liquid level descending amount and the daily evaporation amount, determining the daily infiltration amount, and determining the in-situ paddy field water infiltration rate. The invention realizes non-contact and automatic monitoring without damaging the structure of the paddy field plough bottom layer, can effectively identify the infiltration characteristics under unsteady conditions such as dry-wet alternation period and the like, and provides low-cost and high-time-resolution data support for precise irrigation of paddy fields and prevention and control of non-point source pollution.

Inventors

  • YANG XINPING
  • LIU JIAYOU
  • ZHAO FANGJIE
  • GAO AXIANG
  • LU QINGWEI

Assignees

  • 南京农业大学

Dates

Publication Date
20260508
Application Date
20260316

Claims (14)

  1. 1. The in-situ paddy field water seepage rate monitoring system is characterized by comprising an in-situ monitoring device deployed on a paddy field site and a data processing terminal; The in-situ monitoring device comprises a non-contact distance measuring sensor and a meteorological parameter acquisition module which are vertically hung above the paddy field water surface, liquid level distance and meteorological parameters of the paddy field water surface are synchronously acquired according to the period, and are preprocessed according to the period into minute-level liquid level distance time sequence data and minute-level environment meteorological time sequence data, and the minute-level liquid level distance time sequence data and the minute-level environment meteorological time sequence data are provided for the data processing terminal; The data processing terminal automatically identifies an effective period of stable increase of the distance reading of the non-contact ranging sensor in the minute-level liquid level distance time sequence data, marks the effective period as an effective infiltration period, and determines the daily liquid level descent quantity based on the effective infiltration period; The data processing terminal automatically aggregates minute-level environmental weather time sequence data to obtain an hour-level environmental weather time sequence data average value, calculates the hour evaporation and emission quantity of the reference crop based on the hour-level environmental weather time sequence data average value, calculates the hour evaporation and emission quantity of the reference crop from hour to hour, accumulates the hour evaporation and emission quantity of the reference crop to obtain the daily evaporation and emission quantity of the reference crop, and obtains the daily evaporation and emission quantity of the crop based on the daily evaporation and emission quantity of the reference crop according to a crop coefficient method; The data processing terminal obtains daily infiltration amount based on the difference between the daily liquid level descending amount and the daily evapotranspiration of crops, and obtains in-situ paddy field water infiltration rate based on the daily infiltration amount.
  2. 2. The in-situ paddy water seepage rate monitoring system according to claim 1, wherein the in-situ monitoring device comprises a power supply unit (100), an in-situ data acquisition unit (200), a data processing unit (300) and a data storage and transmission unit (400), the power supply unit (100) is used for supplying power to the in-situ data acquisition unit (200), the data processing unit (300) and the data storage and transmission unit (400), the in-situ data acquisition unit (200) is used for synchronously acquiring the liquid level distance and the meteorological parameters of the monitoring point in real time according to the period and transmitting the liquid level distance and the meteorological parameters to the data processing unit (300), and the data processing unit (300) determines the effective period and averages and preprocesses the liquid level distance and the meteorological parameters in the effective period into minute-level liquid level distance time sequence data and minute-level environment meteorological time sequence data and provides the data to the data processing terminal through the data storage and transmission unit (400).
  3. 3. The in-situ paddy field moisture infiltration rate monitoring system according to claim 2, wherein the in-situ data acquisition unit (200) comprises a non-contact liquid level distance acquisition module, a meteorological parameter acquisition module and a time stamp module (11), the liquid level distance acquisition module is used for acquiring the liquid level distance of a monitoring point in real time according to a period and transmitting the liquid level distance to the data processing unit (300), the meteorological parameter acquisition module is used for acquiring the wind speed, the air temperature, the relative humidity and the solar radiation of the monitoring point in real time according to the period and transmitting the wind speed, the air temperature, the relative humidity and the solar radiation to the data processing unit (300), and the time stamp module (11) provides a unified time reference for the real-time data synchronously acquired by the liquid level distance acquisition module and the meteorological parameter acquisition module and supports calculation of the number of days.
  4. 4. The in-situ paddy water seepage rate monitoring system according to claim 2, wherein the in-situ data acquisition unit (200) comprises an interference monitoring module, and the interference monitoring module is used for reserving an effective seepage period with zero rainfall in the same period through time sequence matching.
  5. 5. The in-situ paddy field moisture infiltration rate monitoring system according to claim 2, wherein the power supply unit (100) comprises a solar panel (6), a lithium battery and a charging management circuit, the solar panel (6) provides 12V direct current and supplies power to the in-situ data acquisition unit (200), the data processing unit (300) and the data storage and transmission unit (400) through the depressurization module, the lithium battery is used for storing energy and supplying power at night and ensuring that the in-situ monitoring device stably operates under no illumination condition, and the solar panel (6) is connected with the lithium battery through the charging management circuit; The data processing unit (300) comprises a microcontroller (9) and an OLED display screen (13), wherein the microcontroller (9) is used for receiving the synchronously collected liquid level distance and weather parameters and preprocessing the liquid level distance and weather parameters into minute-level liquid level distance time sequence data and minute-level environment weather time sequence data, and the OLED display screen (13) is used for displaying the date, the time, the synchronously collected liquid level distance and weather parameters, the minute-level liquid level distance time sequence data obtained by preprocessing and the minute-level environment weather time sequence data; The data storage and transmission unit (400) comprises a local storage module and a remote transmission module, the local storage module is used for storing the minute-level liquid level distance time sequence data and the minute-level environment weather time sequence data which are transmitted by the data processing unit (300), the remote transmission module is used for uploading the minute-level liquid level distance time sequence data and the minute-level environment weather time sequence data which are transmitted by the data processing unit (300) to the cloud server, and the data processing terminal acquires the minute-level liquid level distance time sequence data and the minute-level environment weather time sequence data by reading the local storage module or the cloud downloading mode.
  6. 6. The in-situ paddy field moisture infiltration rate monitoring system according to any one of claims 1 to 5, wherein the in-situ monitoring device comprises a vertical rod (7), a bracket platform (4), a solar panel (6) and a sealing waterproof box (8), two bracket platforms (4) are arranged on the vertical rod (7), one bracket platform (4) is used for installing an air temperature and humidity sensor (1), a solar radiation sensor (2), a wind speed sensor (3) and the other bracket platform (4) is used for installing the solar panel (6), the air temperature and humidity sensor (1) used for collecting air temperature and relative humidity, the solar radiation sensor (2) used for collecting solar radiation and the wind speed sensor (3) used for collecting wind speed form a meteorological parameter collecting module in an in-situ data collecting unit (200), the sealing waterproof box (8) suspended above the paddy field is arranged at the lower part of the vertical rod (7), the sealing waterproof box (8) is internally provided with a micro controller (9) and an SD card module (10), a time stamp module (11), an OLED (12), an OLED sensor (4) and an ultrasonic wave display screen (13) which are respectively connected with the micro controller (9) through lines, the microcontroller (9) and the OLED display screen (13) form a data processing unit (300) in the in-situ data acquisition unit (200), the SD card module (10) and the 4G DTU module (14) form a data storage and transmission unit (400), the ultrasonic distance sensor (12) forms a liquid level distance acquisition module in the in-situ data acquisition unit (200) and is arranged at the bottom of the sealed waterproof box (8), the probe of the ultrasonic distance sensor (12) penetrates through the bottom surface of the sealed waterproof box (8) and vertically and downwards aligns to the paddy field water surface, and the distance between the probe of the ultrasonic distance sensor (12) and the paddy field water surface is preset to be 10-20cm.
  7. 7. A method for monitoring the water seepage rate of an in-situ paddy field is characterized by comprising the following steps: S1, synchronously collecting liquid level distance and meteorological parameters of the water surface of a paddy field according to the period; S2, determining an effective period, and averaging liquid level distance and meteorological parameters in the effective period to obtain minute-level liquid level distance time sequence data and minute-level environment meteorological time sequence data; S3, determining effective infiltration periods in the minute-level liquid level distance time sequence data in the step S2 by adopting a PELT change point detection algorithm or a machine learning algorithm, and forming an effective infiltration period list; s4, time weighting is carried out based on the effective infiltration period list, the average change rate of the liquid level distance is obtained, and the average change rate of the liquid level distance is multiplied by 24 hours to obtain the daily liquid level drop; s5, calling the minute-level environmental weather time sequence data provided in the step S2, and obtaining the daily evapotranspiration of crops by adopting a FAO-56 Penman-Monteth formula and a crop coefficient method; s6, a water balance calculation model based on paddy field water balance equation simplification: , the daily seepage quantity is in mm, For the daily drop in level in mm obtained in step S4, The daily evaporation quantity of the crops obtained in the step S5 is in mm; s7, obtaining the in-situ paddy field water infiltration rate based on the daily infiltration amount.
  8. 8. The method for monitoring the water seepage rate of an in-situ paddy field according to claim 7, wherein the effective period in the step S2 is that the effective sample number in the period exceeds 50% of the total sampling number, and the period is skipped when the effective sample number does not exceed 50% of the total sampling number.
  9. 9. The method for monitoring the in-situ paddy field moisture infiltration rate according to claim 7, wherein the effective infiltration period list in the step S3 is obtained by adopting a PELT change point detection algorithm, and the specific steps are as follows: S311, adopting the minute level liquid level distance time sequence data in the step S2 And carrying out smoothing treatment on the value rolling average to obtain minute-level liquid level distance time sequence data after smoothing noise reduction, wherein the calculation formula is as follows: Wherein, the To smooth and reduce noise The time liquid level distance value is in mm, For the data points in the minute-level liquid level distance time series data in step S2, The size of the window is smooth, and the window is used for eliminating high-frequency random noise interference; s312, deriving minute-level liquid level distance time sequence data after smooth noise reduction to obtain a first-order change rate The calculation formula is as follows: Wherein, the Is that The liquid level change rate at the moment (namely the instantaneous seepage rate) is expressed in mm/h, And The time sequence data of the minute-level liquid level distance after smooth noise reduction at the current moment and the last moment are respectively shown in mm, For a sampling period, in minutes, multiplier 60 is used to convert the rate units to a standard hour rate; S313, adopting a PELT change point detection algorithm to detect the first-order change rate Analyzing the time sequence data of minute liquid level distance The method is divided into a plurality of independent time periods with stable change rate, and the objective function of the PELT change point detection algorithm is as follows: Wherein, the In order to identify the set of change points, In order to change the number of points of change, For segmenting a cost function for measuring the fit residual of the segment data and the mean model, Penalty coefficients to prevent overfitting; S314, performing linear fitting on the independent time periods with the stable change rate to obtain an accurate Slope and a Duration of each independent time period; S315, screening the accurate Slope and Duration of all independent periods with stable change rate according to preset physical constraint conditions that 0 < Slope is less than or equal to 3mm/h and Duration is more than or equal to 5min, identifying the independent period with stable change rate meeting the physical constraint conditions and marking the independent period as a pending infiltration period; s316, setting a time gap threshold value of the undetermined infiltration period and calculating the time interval of the adjacent undetermined infiltration period, if the time interval of the adjacent undetermined infiltration period is not larger than the time gap threshold value, merging the adjacent undetermined infiltration periods into the same continuous period and updating the start-stop time, repeating the comparison process until the time intervals of all the adjacent periods are larger than the time gap threshold value, enabling the periods to be effective infiltration periods, and finally outputting an effective infiltration period list formed by the effective infiltration periods including the start-stop time.
  10. 10. The method for monitoring the water seepage rate of the paddy field in situ according to claim 7, wherein the effective seepage time period list in the step S3 is obtained by adopting a machine learning algorithm, and the specific steps are as follows: S321, feature engineering, namely performing feature extraction on the minute-level liquid level distance time sequence data in the step S2, and setting the size of a sliding window as For each point in time Calculating the statistical feature vector in the sliding window, namely rolling average value Extremely poor rolling Standard deviation of rolling Rolling slope reflecting instantaneous rate of change The calculation formulas are respectively as follows: Wherein, the For a distance dataset within a sliding window, The unit is mm/h obtained by calculating the change rate of the liquid level in the sliding window along with time through least square linear regression, and the local instantaneous infiltration rate is reflected; S322, model prediction and label mapping, namely inputting the feature vector extracted in the step S321 into a random forest classification model which is trained manually in advance, directly obtaining a classification result of the random forest classification model, and converting the numerical result into a text label "Rising" or "Stable" according to a label mapping table; S323, spike filtering, namely performing spike detection on all data points which are preliminarily marked as "Rising", and if the slope of the current data point exceeds a spike threshold value and the slope of the immediately following data point is fallen below a normal threshold value, judging the point as an interference signal and eliminating the interference signal; S324, merging the time periods, namely merging the data points with the residual text labels of 'Rising' after peak filtering into continuous time periods, and eliminating the time periods with the duration lower than the set time period or the time periods with the points lower than the set point number to obtain the pending infiltration time period; S325, setting a time gap threshold value of the undetermined infiltration period and calculating the time interval of the adjacent undetermined infiltration period, if the time interval of the adjacent undetermined infiltration period is not greater than the time gap threshold value, merging the adjacent undetermined infiltration periods into the same continuous period and updating the start-stop time, repeating the comparison process until the time intervals of all the adjacent periods are greater than the time gap threshold value, taking each period as an effective infiltration period, and finally outputting an effective infiltration period list formed by the effective infiltration periods including the start-stop time.
  11. 11. The method for monitoring the water seepage rate of the in-situ paddy field according to any one of claims 7, 9 and 10, wherein the effective seepage time period list needs to be further screened, the screening method comprises the steps of forming a final effective seepage time period list by matching the effective seepage time period list with time-by-time rainfall data through time sequence and only reserving the effective seepage time period with zero rainfall in the same time period, and replacing the effective seepage time period list in the step S4 with the final effective seepage time period list to carry out time weighting so as to obtain the daily liquid level drop after screening.
  12. 12. The method for monitoring the water seepage rate of an in-situ paddy field according to claim 7, wherein the time weighting method in the step S4 comprises the following specific steps: s41, counting a valid infiltration period list on the same day, and accumulating to obtain the total duration of the valid infiltration period list Total increase in liquid level distance ; S42, calculating the average change rate of the time weighted liquid level distance The calculation formula is as follows: , wherein, The average rate of change of distance in mm/h when the liquid level is weighted for time, For the total increase in liquid level distance in mm of the list of effective infiltration periods on the same day, The total duration of the list of valid infiltration periods for the day is given in h.
  13. 13. The method for monitoring the water seepage rate of an in-situ paddy field according to claim 7, wherein the daily evaporation and emission amount of the crop in the step S5 is obtained by the following steps: S51, automatically aggregating the minute-level environmental weather time sequence data provided in the step S2 according to the hour, and calculating the arithmetic average value of wind speed, air temperature, relative humidity and solar radiation in each hour to obtain the average value of the hour-level environmental weather time sequence data; s52, substituting the average value of the hour-level environmental weather time sequence data into a FAO-56 Penman-Monteth formula to calculate and obtain the hour evaporation quantity of the reference crop The FAO-56 Penman-Monteth formula is: Wherein, the For reference crop hourly evapotranspiration rate in mm/h, Is the slope of a saturated water vapor pressure curve with the unit of kPa/DEGC, The unit of the solar radiation is MJ/m2.h, which is calculated based on solar radiation, Is soil heat flux, the unit is MJ/m2.h, Is dry humidity constant in kPa/DEGC, Is the temperature of the air, the unit is the temperature, Is 2m high wind speed, the unit is m/s, And (3) with The saturated water vapor pressure and the actual water vapor pressure are calculated based on the measured air temperature and the relative humidity, and the unit is kPa; S53, the reference crop hour evapotranspiration rate Multiplying the calculated total time by the unit time to convert the calculated total time into the calculated total time of the reference crop, and accumulating the calculated total time to obtain the calculated total time of the reference crop ; S54, obtaining the daily evapotranspiration of the crops according to a crop coefficient method : Wherein, the The daily vapor emission amount of crops is in mm, For reference crop daily vapor emission quantity, the unit is mm, The crop coefficient is dynamically valued in combination with the actual growth period of the monitored rice.
  14. 14. The method for monitoring an in-situ paddy water infiltration rate according to claim 7, wherein the in-situ paddy water infiltration rate in step S7 is obtained by dividing the daily infiltration amount obtained in step S6 by 1 day and performing dimensional conversion to obtain an in-situ paddy water infiltration rate in mm/d, which is numerically equal to the daily infiltration amount.

Description

In-situ paddy field moisture infiltration rate monitoring system and monitoring method Technical Field The invention belongs to the technical field of agricultural water conservancy and environmental monitoring, and particularly relates to an in-situ paddy field water seepage rate monitoring system and method based on non-contact sensing and intelligent data processing. Background Paddy fields are the major global high water crop system. The accurate quantification of the water infiltration amount of the paddy field is a key basis for implementing accurate irrigation, improving the water resource utilization rate and controlling the non-point source pollution. In the prior art, the monitoring of the rice field infiltration mainly adopts a physical capturing method (such as a lysimeter) or a simple liquid level monitoring method. Although the physical capturing method is intuitive in principle, the original soil structure of the field needs to be destroyed, the method belongs to invasive measurement, the equipment cost is high, and low-cost deployment is difficult in a large-area farmland. Although the simple liquid level monitoring method can realize non-contact measurement, the method can only acquire the total drop of the water level of the field, and can not decouple the two key processes of water infiltration and surface evaporation, so that the monitoring data can not directly guide irrigation decision. In order to solve the decoupling problem, a water balance method can be theoretically adopted. However, the method is currently mainly used as an offline research means relying on manual participation, and an integrated automation system is lacking. More importantly, in high frequency monitoring of paddy fields in situ, the liquid level data inevitably contains severe fluctuations and noise caused by rainfall, irrigation and runoff. The prior art lacks an intelligent algorithm capable of analyzing high-time sequence data in real time and automatically identifying and calibrating effective infiltration periods, so that the water balance method cannot realize automation and precision in a complex field environment. Therefore, it is highly desirable to develop a system that can integrate non-contact sensing technology with automated data processing algorithms to achieve low cost, high time resolution hypotonic rate monitoring without damaging the in situ soil. Disclosure of Invention Aiming at the defects that the physical capturing method provided in the prior art damages an in-situ soil structure, a simple liquid level monitoring method cannot decouple evaporation and infiltration components, a traditional water balance method cannot automatically process high-frequency in-situ data interference and the like, the invention provides an in-situ paddy field water infiltration rate monitoring system and a monitoring method. The invention aims at solving the problems through the following technical scheme: an in-situ paddy field moisture infiltration rate monitoring system comprises an in-situ monitoring device deployed on a paddy field site and a data processing terminal; The in-situ monitoring device comprises a non-contact distance measuring sensor and a meteorological parameter acquisition module which are vertically hung above the paddy field water surface, liquid level distance and meteorological parameters of the paddy field water surface are synchronously acquired according to the period, and are preprocessed according to the period into minute-level liquid level distance time sequence data and minute-level environment meteorological time sequence data, and the minute-level liquid level distance time sequence data and the minute-level environment meteorological time sequence data are provided for the data processing terminal; The data processing terminal automatically identifies an effective period of stable increase of the distance reading of the non-contact ranging sensor in the minute-level liquid level distance time sequence data, marks the effective period as an effective infiltration period, and determines the daily liquid level descent quantity based on the effective infiltration period; The data processing terminal automatically aggregates minute-level environmental weather time sequence data to obtain an hour-level environmental weather time sequence data average value, calculates the hour evaporation and emission quantity of the reference crop based on the hour-level environmental weather time sequence data average value, calculates the hour evaporation and emission quantity of the reference crop from hour to hour, accumulates the hour evaporation and emission quantity of the reference crop to obtain the daily evaporation and emission quantity of the reference crop, and obtains the daily evaporation and emission quantity of the crop based on the daily evaporation and emission quantity of the reference crop according to a crop coefficient method; The data processing terminal obtains daily inf