Plain area agricultural non-point source pollution simulation system for regulation and control of ditch-pump station

Abstract

The invention relates to the technical field of agricultural non-point source pollution load evaluation, and discloses a ditch-pump station regulation-oriented plain area agricultural non-point source pollution simulation system, which comprises a basic data collection module used for collecting boundary and basic spatial data, meteorological driving data, farming management data and synchronous hydrology and water quality data of a research area; the ditch and pump station information extraction module is used for extracting the spatial distribution, width, depth, gradient and roughness of the ditch and the operation condition, displacement and scheduling rule of the pump station; and the ditch hydrological process simulation module is used for simulating the water depth, water balance and flow velocity of the ditch. By integrating high-precision hydrological monitoring data, high-resolution remote sensing images and field survey data, a more accurate farmland ditch process module is constructed. Therefore, the system can depict pollution transmission processes of channels with different hydraulic properties in detail and influence of artificial pump station drainage on agricultural non-point source pollution load output in a river dam blocking type non-self-flow scene.

Description

Technical Field

[0001] This invention relates to the field of agricultural non-point source pollution load assessment technology, specifically to an agricultural non-point source pollution simulation system for plain areas oriented towards ditch-pump station regulation. Background Technology

[0002] In the field of agricultural non-point source pollution load assessment, existing technologies mainly focus on the underlying surface characteristics of mountainous and hilly areas, emphasizing the agricultural non-point source pollution output process dominated by natural runoff processes. These models, such as HSPF, AnnAGNPS, and SWAT models, have good simulation effects for areas with significant topographic relief and relatively small anthropogenic disturbances. However, plains, due to their flat terrain, fertile soil, convenient water sources, and easy transportation, have become important grain-producing areas and also key source areas of agricultural non-point source pollution. In these areas, intensive anthropogenic activities significantly alter the material form, transport pathways, and output intensity of agricultural non-point source pollution. In particular, the farmland irrigation system in plains, as an important corridor connecting farmland and waterways for pollutant transport, has a significant impact on the migration and transformation processes of pollutants through interception, retention, and degradation.

[0003] Furthermore, in plains areas, for flood control purposes, river embankments are typically higher than surrounding farmland, making it difficult for farmland runoff to flow into rivers naturally. Therefore, drainage pumping stations are necessary to facilitate farmland drainage. Existing models suffer from two main problems when simulating agricultural non-point source pollution in plains areas: First, they lack detailed characterization of ditch processes, often simplifying farmland runoff and pollutants as directly flowing into rivers, neglecting the interception, retention, and degradation effects of the ditch system. This leads to an underestimation of the actual amount of non-point source pollutants generated in the farmland ecosystem. Second, existing models struggle to accurately simulate pollutant transport processes under artificially regulated drainage conditions, especially in low-lying agricultural areas with flat terrain and small hydraulic gradients. Farmland drainage heavily relies on artificial control measures such as pumping stations, and traditional models fail to consider this non-natural drainage mechanism, resulting in a systematic underestimation of the agricultural non-point source pollution output load. Therefore, there is an urgent need for a simulation system capable of accurately characterizing the migration and transformation processes of pollutants under human-controlled influence, enabling precise simulation and quantitative assessment of agricultural non-point source pollution in areas with high-intensity human activity disturbance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation. This system solves the problems of insufficient characterization of ditch processes and inaccurate simulation of pollutant transport processes under artificially regulated drainage conditions in existing models for simulating agricultural non-point source pollution in plain areas.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation, comprising:

[0006] The basic data collection module is used to collect boundary data, basic spatial data, meteorological driving data, agricultural management data, and synchronous hydrological and water quality data of the study area;

[0007] The ditch and pumping station information extraction module is used to extract the spatial distribution, width, depth, slope, and roughness of ditches, as well as the operating status, drainage volume, and scheduling rules of pumping stations.

[0008] The ditch hydrological process simulation module is used to simulate the water depth, water balance, and flow velocity of ditches;

[0009] The ditch-pump station water quality process simulation module is used to simulate the attenuation coefficient, concentration, and load of pollutants in ditches, as well as the discharge load of pump stations.

[0010] The data fusion module is used to integrate the data collected and processed by the above modules to improve the accuracy of the simulation;

[0011] The model validation module is used to verify the accuracy of simulation results using actual monitoring data;

[0012] The user interface module provides a user-friendly interface for users to input data and view simulation results.

[0013] Preferably, the basic data collection module further includes:

[0014] High-resolution satellite image processing unit, used to acquire water boundaries for the study;

[0015] The DEM data processing unit is used to acquire elevation and slope information of the study area;

[0016] The meteorological data processing unit is used to collect and process meteorological data such as rainfall, temperature, wind speed, relative humidity, and solar radiation.

[0017] The agricultural management database construction unit is used to survey routine farmland management information and construct an agricultural management database.

[0018] The hydrological and water quality data processing unit is used to collect historical hydrological and water quality data from the monitoring section at the watershed outlet.

[0019] Preferably, the ditch and pumping station information extraction module further includes:

[0020] High-resolution satellite image analysis unit is used to extract spatial distribution and width data of water-holding ditches;

[0021] The UAV DSM data processing unit is used to obtain the spatial location and width of intermittent ditches;

[0022] Hydrological equivalent ditch construction unit, used to generalize a complex ditch network system into a virtual ditch;

[0023] The pump station information extraction unit is used to obtain key technical parameters such as the actual operating status of the pump station, hourly drainage volume, and pump station scheduling rules.

[0024] Preferably, the ditch hydrological process simulation module further includes:

[0025] The ditch water depth calculation unit is used to calculate the amount of water flowing from farmland into the ditch and obtain the actual water depth of the ditch.

[0026] The ditch water balance calculation unit is used to calculate ditch leakage and evaporation, as well as ditch water balance;

[0027] The ditch flow velocity calculation unit is used to calculate the ditch flow velocity using the Manning formula.

[0028] Preferably, the ditch-pump station water quality process simulation module further includes:

[0029] The pollutant attenuation coefficient measurement unit is used to describe the pollutant attenuation process using a first-order attenuation kinetic equation.

[0030] Pollutant concentration calculation unit, used to calculate pollutant concentration in ditches;

[0031] Pollutant load assessment unit is used to calculate the pollutant flux of the ditch-pump station system;

[0032] The pump station discharge load calculation unit is used to calculate the amount of pollutants output caused by the pump station's drainage.

[0033] Preferably, the data fusion module further includes:

[0034] A high-precision hydrological monitoring data fusion unit is used to integrate hydrological monitoring data;

[0035] High-resolution remote sensing image fusion unit, used to integrate remote sensing image data;

[0036] The field survey data fusion unit is used to integrate field survey data.

[0037] Preferably, the model verification module further includes:

[0038] The simulation results are compared with actual monitoring data to verify the accuracy of the simulation results;

[0039] The model accuracy evaluation unit is used to evaluate the simulation accuracy of the model.

[0040] Preferably, the user interface module further includes:

[0041] The data input interface is used for users to input basic data and ditch-pump station information;

[0042] The results display interface is used to show simulation results and model validation results;

[0043] The system settings interface is used by users to set simulation parameters and model validation parameters.

[0044] Preferably, the system is suitable for simulating agricultural non-point source pollution in low-lying agricultural areas such as the Huang-Huai-Hai Plain, and can achieve accurate simulation and quantitative assessment of agricultural non-point source pollution in areas with high-intensity human activity interference.

[0045] This invention provides a simulation system for agricultural non-point source pollution in plain areas, oriented towards ditch-pump station regulation. It has the following beneficial effects:

[0046] 1. This invention integrates high-precision hydrological monitoring data, high-resolution remote sensing imagery, and field survey data to construct a more accurate agricultural ditch process module and pump station scheduling module. This allows the system to meticulously depict the pollution transport process in ditches with different hydraulic properties, as well as the impact of anthropogenic pumping station drainage on agricultural non-point source pollution load output under non-gravity flow scenarios with river embankments. Therefore, this system significantly improves the accuracy and reliability of agricultural non-point source pollution simulation in plain areas, providing a powerful tool for the precise simulation and quantitative assessment of agricultural non-point source pollution. This not only helps to better understand and predict the dynamic changes of agricultural non-point source pollution but also provides a scientific basis for formulating effective pollution control strategies and water resource management measures, thereby achieving the dual goals of sustainable agricultural development and ecological environmental protection while ensuring food security.

[0047] 2. This invention integrates the ditch-pump station regulation process within the SWAT model framework, creating a specialized simulation tool suitable for low-lying agricultural areas such as the Huang-Huai-Hai Plain. Specifically designed for the flat terrain and significant human-induced alteration in plain areas, this system simulates the interception, retention, and degradation effects of ditch systems, as well as pollutant transport processes under artificially regulated drainage conditions. This simulation not only more realistically reflects the actual situation of agricultural non-point source pollution in plain areas but also provides customized solutions for agricultural production and water resource management in these regions. Furthermore, the application of this system reduces reliance on traditional models and minimizes prediction errors caused by model inapplicability, thereby saving costs and improving efficiency in practical operation. Attached Figure Description

[0048] Figure 1 This is a flowchart of the agricultural non-point source pollution simulation system for plain areas according to the present invention. Detailed Implementation

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Please see the appendix Figure 1 This invention provides a simulation system for agricultural non-point source pollution in plain areas, oriented towards ditch-pump station regulation, comprising:

[0051] The basic data collection module is used to collect boundary data, basic spatial data, meteorological driving data, agricultural management data, and synchronous hydrological and water quality data of the study area;

[0052] The basic data collection module further includes:

[0053] High-resolution satellite image processing unit, used to acquire water boundaries for the study;

[0054] The DEM data processing unit is used to acquire elevation and slope information of the study area;

[0055] The meteorological data processing unit is used to collect and process meteorological data such as rainfall, temperature, wind speed, relative humidity, and solar radiation.

[0056] The agricultural management database construction unit is used to survey routine farmland management information and construct an agricultural management database.

[0057] The hydrological and water quality data processing unit is used to collect historical hydrological and water quality data from the monitoring section at the watershed outlet.

[0058] Specifically, the study area boundary: Based on high-resolution satellite imagery, combined with the D8 algorithm and manual visual interpretation technology, the water boundary of the study area is obtained, including the main road network (railways, expressways, national roads and rural roads, etc.), major villages and towns, river embankments and other key water features in the plain area, to determine the boundary of the study area, river network and outlet location, etc.

[0059] Basic spatial data: Based on the research vector boundary, complete the cropping of major basic spatial data such as DEM, land use type, and soil type to obtain parameters such as elevation, slope, land use type, and soil type of the study area;

[0060] Meteorological driving data: Collect historical meteorological data of the study area, including rainfall, temperature, wind speed, relative humidity, and solar radiation data; establish a meteorological data index table file to facilitate interface with the SWAT model;

[0061] Agricultural management data: Survey routine farmland management information, including tillage methods, planting systems, crop types, irrigation systems (irrigation water sources, frequency, and water consumption), fertilization information (fertilizer types, fertilization time, and fertilization methods), autumn harvest, etc., to construct a research database on agricultural management;

[0062] Synchronous hydrological and water quality data: Historical hydrological and water quality data of the watershed outlet monitoring section are collected, including parameters such as runoff, sediment, nitrate nitrogen, ammonia nitrogen, total nitrogen, and total phosphorus. Among them, runoff is measured on a daily scale, while sediment and water quality parameters are measured on a monthly (ten-day) scale. By establishing statistical relationships between flow and water quality indicators, the output flux of agricultural non-point source pollutants under historical conditions is estimated.

[0063] The ditch and pumping station information extraction module is used to extract the spatial distribution, width, depth, slope, and roughness of ditches, as well as the operating status, drainage volume, and scheduling rules of pumping stations.

[0064] The ditch and pumping station information extraction module further includes:

[0065] High-resolution satellite image analysis unit is used to extract spatial distribution and width data of water-holding ditches;

[0066] The UAV DSM data processing unit is used to obtain the spatial location and width of intermittent ditches;

[0067] Hydrological equivalent ditch construction unit, used to generalize a complex ditch network system into a virtual ditch;

[0068] The pump station information extraction unit is used to obtain key technical parameters such as the actual operating status of the pump station, hourly drainage volume, and pump station scheduling rules.

[0069] Specifically, based on high-resolution satellite imagery (e.g., 0.30-meter resolution), a deep learning algorithm (U-NET) was used to extract the spatial distribution and width data of water-holding ditches. Combined with high-precision DSM data generated by UAVs, the spatial location and width of intermittent ditches were obtained. By integrating the above data with field survey results, information on the spatial distribution of farmland boundaries and ditches in the study area was compiled, including the spatial topological relationship between ditches and farmland (including nodes), water runoff paths, and ditches' lengths. Combined with field surveys, the geometric shape of the ditches (e.g., rectangular cross-section, trapezoidal cross-section), maximum depth, bottom width, slope coefficient, average gradient, and roughness coefficient were determined.

[0070] In real-world scenarios, each sub-basin may contain multiple ditches with varying shapes, hydraulic parameters, and hydraulic connections to the main river channel. Existing watershed models directly ignore the impact of ditches on pollutant absorption and reduction. Therefore, to reasonably quantify the impact of ditches on pollutants, it is necessary to generalize the complex ditchone network system into a virtual ditchone. This virtual ditchone should have essentially the same hydrological characteristics as the actual ditchone network, including flow velocity, depth, storage capacity, and propagation time. The specific construction methods and steps are detailed below:

[0071] Equivalent parameter selection: Different target effects will lead to different ditch parameters, including hydrological equivalence, hydrodynamic equivalence, and water environment equivalence. Generally, to characterize the ditch's effect on pollutant reduction, the ditch's water carrying capacity, maximum storage capacity, and hydraulic transmission time can be used as equivalent targets.

[0072] Equivalent ditch construction steps: Assume there are N ditches within a sub-watershed, whose length, width, depth, slope, and roughness are denoted as L. i W i D i S i and n i For the sake of simplified calculation, we assume that the cross-sectional shape of the ditch is rectangular. The general process of constructing the hydrological equivalent ditch is as follows.

[0073] Average depth calculation of ditches: The average depth of multiple ditches can be used as the depth of an equivalent ditch, as shown in the following formula.

[0074]

[0075] In the above formula, The depth of the equivalent ditch is represented by D, which is obtained by calculating the average depth of multiple ditches; i Let represent the depth of the i-th ditch; N is the total number of ditches; this formula is used to calculate the average depth of all ditches, i.e., the equivalent depth of the ditches. This average value can serve as a key parameter for evaluating the overall hydrological characteristics of the ditch system.

[0076] Calculation of average gradient: The average gradient of multiple ditches can be obtained by weighting the lengths of their gradients, as shown in the following formula:

[0077]

[0078] Calculation of average roughness: The length-weighted average of the roughness values ​​of multiple ditches can be used as the roughness of the equivalent ditch, as shown in the following formula:

[0079]

[0080] In the above formula, L represents the roughness of the equivalent ditch, which is obtained by calculating the weighted average of the roughness of multiple ditches; i n represents the length of the i-th ditch; i Let represent the roughness of the i-th ditch; N is the total number of ditches. This formula is used to calculate the weighted average of the roughness of all ditches, where the roughness of each ditch is n. i Its length L i The product of these factors is used as a weight to reflect the contribution of different ditches to the overall hydraulic characteristics, thereby obtaining the roughness of the equivalent ditch.

[0081] In the above formula, The slope of the equivalent ditch is represented by L, which is obtained by calculating the weighted average of the slopes of multiple ditches; i S represents the length of the i-th ditch; i Let S represent the slope of the i-th ditch; N is the total number of ditches. This formula is used to calculate the weighted average of the slopes of all ditches, where the slope S of each ditch is... i Its length L i The product of these factors is used as a weight to reflect the contribution of different ditches to the overall hydrological characteristics, thereby obtaining the equivalent ditch gradient.

[0082] Calculation of equivalent ditch width: First, take the equivalent water carrying capacity of the ditch as the equivalent objective, that is, the amount of water delivered to the river by the equivalent ditch per unit time is equal to the amount of water delivered by multiple ditches. According to the principle of Manning's equation, the following equation should be satisfied.

[0083]

[0084] Based on the Manning equation, this formula can be further expanded to the following formula.

[0085]

[0086] In the above formula, Q ′ Q represents the amount of water transported from the equivalent ditch to the river per unit time, i.e., the water carrying capacity of the equivalent ditch; i Let W represent the water conveyance of the i-th ditch; N is the total number of ditches; and W and N are also present. Let represent the width and average depth of the equivalent ditch, respectively; S represent the slope of the equivalent ditch; n represent the roughness of the equivalent ditch; W represent the average depth and average depth of the equivalent ditch, respectively; S represents the slope of the equivalent ditch; n represents the roughness of the equivalent ditch; W represents ...; i and D i Let represent the width and depth of the i-th ditch, respectively.

[0087] In this equation, only W is an unknown parameter, so its value can be calculated as the width of the hydrological equivalent ditch.

[0088] Calculation of equivalent ditch length: To characterize the equivalence of the equivalent ditch in terms of ditch storage capacity, the equivalent ditch length can be calculated based on its width (W) and average depth. The parameters are used to calculate the equivalent ditch length.

[0089]

[0090] In the above formula, L represents the length of the equivalent ditch, which is obtained by calculating the weighted average of the lengths of multiple ditches. i W represents the length of the i-th ditch; i and D i Let W and W represent the width and depth of the i-th ditch, respectively; Let L represent the width and average depth of the equivalent ditch, respectively; N is the total number of ditches. This formula is used to calculate the weighted average of the lengths of all ditches, where L is the length of each ditch. i Its width W i and depth D i The product of these factors is used as a weight to reflect the contribution of different ditches to the overall water storage capacity, thus obtaining the equivalent length of the ditch.

[0091] Pump station information data extraction: Based on the distribution map of water conservancy facilities, we can initially grasp the basic spatial distribution of pump stations. In conjunction with field surveys, we can obtain key technical parameters such as the actual operating status of pump stations, hourly drainage volume, and pump station scheduling rules (such as water level regulation or ditch storage regulation).

[0092] The ditch hydrological process simulation module is used to simulate the water depth, water balance, and flow velocity of ditches;

[0093] The ditch hydrological process simulation module further includes:

[0094] The ditch water depth calculation unit is used to calculate the amount of water flowing from farmland into the ditch and obtain the actual water depth of the ditch.

[0095] The ditch water balance calculation unit is used to calculate ditch leakage and evaporation, as well as ditch water balance;

[0096] The ditch flow velocity calculation unit is used to calculate the ditch flow velocity using the Manning formula.

[0097] The ditch-pump station water quality process simulation module is used to simulate the attenuation coefficient, concentration, and load of pollutants in ditches, as well as the discharge load of pump stations.

[0098] The ditch-pump station water quality process simulation module further includes:

[0099] The pollutant attenuation coefficient measurement unit is used to describe the pollutant attenuation process using a first-order attenuation kinetic equation.

[0100] Pollutant concentration calculation unit, used to calculate pollutant concentration in ditches;

[0101] Pollutant load assessment unit is used to calculate the pollutant flux of the ditch-pump station system;

[0102] The pump station discharge load calculation unit is used to calculate the amount of pollutants output caused by the pump station's drainage.

[0103] Specifically, the simulation of ditch water quality processes includes: determination of pollutant decay coefficients and assessment of pollutant concentrations and loads. The pollutant decay process is described using a first-order decay kinetic equation. The pollutant load is obtained by multiplying water quantity and water quality. The specific calculation method is shown below.

[0104] 1. Determination of Pollutant Attenuation Coefficient: Non-point source pollutants (nitrogen and phosphorus) exhibit a certain degree of attenuation in ditches due to absorption by bottom sediment, adsorption by plants, and natural degradation along the course of the pollutants. Determining the attenuation coefficient is crucial for accurately quantifying the pollutant attenuation process. The attenuation coefficient is significantly influenced by the characteristics of the underlying surface (topography, meteorology, hydrodynamics, etc.), and on-site testing is recommended. The specific formula used is as follows:

[0105]

[0106]

[0107]

[0108] In the formula, u is the average flow velocity of the ditch (m / s), x is the length of the ditch (m), c is the pollutant concentration at the ditch outlet (mg / L), c0 is the pollutant concentration at the ditch source (mg / L), and k is the pollutant attenuation coefficient (dimensionless).

[0109] 2. Pollutant Concentration Calculation and Load Assessment: In the ditch-pump station system, non-point source pollutants are affected by biological absorption, sediment adsorption, and natural sedimentation, resulting in a certain degree of attenuation in pollutant concentration. Consequently, the pollutant flux of the ditch-pump station system will also decrease due to the combined effects of water volume reduction and concentration decrease. The specific calculation process is as follows:

[0110] Concentration decay calculation: The pollutant concentration in the ditch is described by a first-order decay kinetic equation. The main parameters involve the ditch flow velocity, ditch length, initial concentration, and pollutant decay coefficient. The calculation process is shown below:

[0111]

[0112]

[0113] In the formula, P m______ represents the amount of pollutants entering the ditch, in kg; ______ represents the total volume of water entering the ditch, in m³. 3 Among them, P m and Q m Output directly from the SWAT model calculation module. Other parameters have the same meaning as above.

[0114] Pollutant load calculation: The pollutant load output value is obtained by multiplying the pollutant concentration value by the net outflow of water from the ditch. The specific calculation formula is shown below:

[0115] F = 10 -3 ×c×Q net

[0116] In the formula, F represents the pollutant load in the ditch, in kg; other parameters have the same meaning as above.

[0117] Pump station discharge load calculation: In low-lying agricultural ecosystems, pump stations are a crucial pathway for pollutant discharge and a key channel connecting ditches and external rivers. Therefore, accurately quantifying the pollutant output caused by pump station drainage is essential for a reasonable assessment of regional non-point source pollution load. It is assumed that the water quality in the ditches is uniformly mixed, neglecting spatial heterogeneity. The pollutant discharge load is equal to the fraction of the drainage volume relative to the ditches' water storage capacity multiplied by the total pollutant load in the ditches. Then, after drainage is completed, the model system automatically updates the total pollutant load in the ditches using the following formula:

[0118]

[0119] F = FF pump

[0120] In the formula, Q pump The pump station's drainage volume, in meters. 3 ;F pump The value represents the pollutant discharge from the pumping station, expressed in kg; other parameters have the same meaning as above.

[0121] The data fusion module is used to integrate the data collected and processed by the above modules to improve the accuracy of the simulation;

[0122] The data fusion module further includes:

[0123] A high-precision hydrological monitoring data fusion unit is used to integrate hydrological monitoring data;

[0124] High-resolution remote sensing image fusion unit, used to integrate remote sensing image data;

[0125] The field survey data fusion unit is used to integrate field survey data.

[0126] Specifically, the data fusion module integrates data from different sources and with varying levels of precision to improve the accuracy and reliability of simulation results. This module comprises three sub-units: First, the high-precision hydrological monitoring data fusion unit collects and integrates precise data from hydrological monitoring stations, typically including flow rate, water level, and water quality parameters, providing real-time and accurate hydrological information for the simulation. Second, the high-resolution remote sensing image fusion unit utilizes high-resolution imagery data acquired through satellite or aerial photography to extract information such as topography, land cover, and vegetation indices, crucial for understanding and simulating the distribution and transmission of agricultural non-point source pollution. Finally, the field survey data fusion unit integrates field data obtained through on-site surveys, sampling, and experiments, such as soil type, crop planting patterns, fertilization, and irrigation practices. This data provides the detailed parameters required by the model and validates the accuracy of the simulation results. Through the collaborative work of these three sub-units, the data fusion module ensures that the simulation system comprehensively considers the advantages of multi-source data, thereby improving the accuracy of simulating agricultural non-point source pollution in plain areas.

[0127] The model validation module is used to verify the accuracy of simulation results using actual monitoring data;

[0128] The model validation module further includes:

[0129] The simulation results are compared with actual monitoring data to verify the accuracy of the simulation results;

[0130] The model accuracy evaluation unit is used to evaluate the simulation accuracy of the model.

[0131] Specifically, the model validation module verifies the accuracy of the simulation by comparing the simulation results with actual monitoring data. This module comprises two key units: a simulation result vs. actual monitoring data comparison unit, responsible for collecting relevant actual monitoring data and directly comparing it with the simulation results to identify and quantify the differences between the two; and a model accuracy evaluation unit, which uses statistical methods and error analysis techniques to evaluate the overall simulation accuracy of the model, including the coefficient of determination (R²). 2 This module uses metrics such as root mean square error (RMSE) to quantify the model's predictive performance. Through this module, necessary adjustments and optimizations can be made to the model to improve its applicability and accuracy in simulating agricultural non-point source pollution in plain areas, ensuring that the model's output truly reflects the actual situation and provides a scientific basis for decision-making.

[0132] The user interface module provides a user-friendly interface for users to input data and view simulation results.

[0133] The user interface module further includes:

[0134] The data input interface is used for users to input basic data and ditch-pump station information;

[0135] The results display interface is used to show simulation results and model validation results;

[0136] The system settings interface is used by users to set simulation parameters and model validation parameters.

[0137] The system is suitable for simulating agricultural non-point source pollution in low-lying agricultural areas such as the Huang-Huai-Hai Plain, and can achieve accurate simulation and quantitative assessment of agricultural non-point source pollution in areas with high-intensity human activity interference.

[0138] Specifically, the user interface module is the part of this simulation system that provides user interaction. It includes three main interfaces: a data input interface that allows users to input the required basic data and specific information about the ditch-pump station; a results display interface that visually displays the simulation results and model validation results, helping users understand and analyze agricultural non-point source pollution; and a system settings interface that allows users to set simulation parameters and model validation parameters as needed to adapt to different simulation conditions and requirements. Furthermore, this system is particularly suitable for low-lying agricultural areas such as the Huang-Huai-Hai Plain. Due to the terrain characteristics and high-intensity human interference in these areas, the simulation and assessment of agricultural non-point source pollution have higher requirements. This system can provide accurate simulation and quantitative assessment, helping managers and researchers better understand and control agricultural non-point source pollution, thereby enabling them to take effective environmental protection measures.

[0139] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation, characterized in that, include: The basic data collection module is used to collect boundary data, basic spatial data, meteorological driving data, agricultural management data, and synchronous hydrological and water quality data of the study area; The ditch and pumping station information extraction module is used to extract the spatial distribution, width, depth, slope, and roughness of ditches, as well as the operating status, drainage volume, and scheduling rules of pumping stations. The ditch hydrological process simulation module is used to simulate the water depth, water balance, and flow velocity of ditches; The ditch-pump station water quality process simulation module is used to simulate the attenuation coefficient, concentration, and load of pollutants in ditches, as well as the discharge load of pump stations. The data fusion module is used to integrate the data collected and processed by the above modules to improve the accuracy of the simulation; The model validation module is used to verify the accuracy of simulation results using actual monitoring data; The user interface module provides a user-friendly interface for users to input data and view simulation results.

2. The simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation as described in claim 1, characterized in that, The basic data collection module further includes: High-resolution satellite image processing unit, used to acquire water boundaries for the study; The DEM data processing unit is used to acquire elevation and slope information of the study area; The meteorological data processing unit is used to collect and process meteorological data such as rainfall, temperature, wind speed, relative humidity, and solar radiation. The agricultural management database construction unit is used to survey routine farmland management information and construct an agricultural management database. The hydrological and water quality data processing unit is used to collect historical hydrological and water quality data from the monitoring section at the watershed outlet.

3. The simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation as described in claim 1, characterized in that, The ditch and pumping station information extraction module further includes: High-resolution satellite image analysis unit is used to extract spatial distribution and width data of water-holding ditches; The UAV DSM data processing unit is used to obtain the spatial location and width of intermittent ditches; Hydrological equivalent ditch construction unit, used to generalize a complex ditch network system into a virtual ditch; The pump station information extraction unit is used to obtain key technical parameters such as the actual operating status of the pump station, hourly drainage volume, and pump station scheduling rules.

4. The simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation as described in claim 1, characterized in that, The ditch hydrological process simulation module further includes: The ditch water depth calculation unit is used to calculate the amount of water flowing from farmland into the ditch and obtain the actual water depth of the ditch. The ditch water balance calculation unit is used to calculate ditch leakage and evaporation, as well as ditch water balance; The ditch flow velocity calculation unit is used to calculate the ditch flow velocity using the Manning formula.

5. The simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation as described in claim 1, characterized in that, The ditch-pump station water quality process simulation module further includes: The pollutant attenuation coefficient measurement unit is used to describe the pollutant attenuation process using a first-order attenuation kinetic equation. Pollutant concentration calculation unit, used to calculate pollutant concentration in ditches; Pollutant load assessment unit is used to calculate the pollutant flux of the ditch-pump station system; The pump station discharge load calculation unit is used to calculate the amount of pollutants output caused by the pump station's drainage.

6. The simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation as described in claim 1, characterized in that, The data fusion module further includes: A high-precision hydrological monitoring data fusion unit is used to integrate hydrological monitoring data; High-resolution remote sensing image fusion unit, used to integrate remote sensing image data; The field survey data fusion unit is used to integrate field survey data.

7. A simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation, as described in claim 1, is characterized in that, The model validation module further includes: The simulation results are compared with actual monitoring data to verify the accuracy of the simulation results; The model accuracy evaluation unit is used to evaluate the simulation accuracy of the model.

8. A simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation, as described in claim 1, is characterized in that, The user interface module further includes: The data input interface is used for users to input basic data and ditch-pump station information; The results display interface is used to show simulation results and model validation results; The system settings interface is used by users to set simulation parameters and model validation parameters.

9. A simulation system for agricultural non-point source pollution in plain areas oriented towards ditch-pump station regulation, as described in claim 1, is characterized in that, The system is applicable to the simulation of agricultural non-point source pollution in low-lying agricultural areas such as the Huang-Huai-Hai Plain, and can achieve accurate simulation and quantitative assessment of agricultural non-point source pollution in areas with high intensity of human activity interference.

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