A method for constructing a small watershed non-point source pollution comprehensive prevention and control system

Abstract

The application discloses a method for constructing a small watershed non-point source pollution comprehensive prevention and control system, and relates to the technical field of ecological environment protection and treatment. A small watershed needing non-point source pollution treatment is selected, a pollution monitoring point scheme is determined from a preset monitoring station site library according to geographical environment data and historical water quality data, a water channel is dug, a small watershed water system is connected with the water channel, so that exogenous water can flow into the water system, and measures such as cleaning garbage floating objects, killing waterweeds, degrading and repairing bottom mud and the like are adopted to treat the small watershed water body, so that the watershed water quality is improved in a short time. Further, a suitable area around the small watershed water body is selected to construct a healthy water ecological system, an indigenous microorganism is provided with an attachment matrix and a habitat to form a biological membrane, and a proper amount of aquatic organisms is simultaneously put into the water body, so that the water body reaches a self-purification effect, and water quality is detected regularly; the monitoring data are analyzed and evaluated through a preset non-point source pollution model, so as to provide a decision basis for comprehensive treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ecological environment protection and management, in particular to a method for constructing a small watershed non-point source pollution comprehensive prevention and control system. BACKGROUND

[0002] Non-point source pollution has become the main source of water pollution in China. The main sources of non-point source pollution include soil erosion, overuse of agricultural chemicals, discharge of rural domestic sewage, livestock breeding, atmospheric deposition, etc. A small watershed refers to a relatively independent and closed natural catchment area with a catchment area of less than 50Km2, bounded by a watershed ridge and a downstream river outlet section. With the rapid development of China's economy and the continuous improvement of industrial level, the amount of sewage produced by life and production is increasing. Some of the sewage is discharged into the watershed without effective treatment, and the pollutants in the water are increasing. Due to the problem of unconnected water systems in the watershed, pollution monitoring, as an important part of environmental science and environmental management, can provide strong support for policy making. The existing non-point source pollution monitoring and evaluation method first obtains the corresponding monitoring data from fixed monitoring sites, and then processes the monitoring data according to the pollution evaluation model to obtain the non-point source pollution monitoring and evaluation result. However, the existing small watershed non-point source pollution comprehensive prevention and control system still has some problems, such as poor targeting and poor treatment effect. Therefore, we propose a method for constructing a small watershed non-point source pollution comprehensive prevention and control system. SUMMARY

[0003] The purpose of the present application is to provide a method for constructing a small watershed non-point source pollution comprehensive prevention and control system to solve the problems raised in the background.

[0004] To achieve the above purpose, the present application provides the following technical scheme:

[0005] Step one: select a small watershed for non-point source pollution control, select the area where the small watershed non-point source pollution comprehensive prevention and control system needs to be constructed, obtain the geographical environment data and historical water quality data of the target area from the database of the county, city or district of the area, and determine the pollution monitoring point scheme from the preset monitoring site library according to the geographical environment data and historical water quality data;

[0006] Step two: dig a water channel, connect the water system of the small watershed to be controlled with the water channel, so that external water sources can flow into the small watershed water body to be constructed;

[0007] Step three: treating small watershed non-point source pollution water, one: cleaning up the small watershed aquatic plants and animals residues and various kinds of household garbage floating on the water surface, and then putting the material which can improve water quality into the water source to eliminate the organic matter, ammonia nitrogen and heavy metal pollutants in the small watershed water body, and to degrade a large amount of nitrogen and phosphorus nutrients by killing algae; two: treating the water bottom and deep water area of the small watershed, using immobilized composite microorganism growth promoter, and matching with slow-release device in deep water area to degrade and repair the eutrophicated sediment;

[0008] Step four: monitoring and managing the water quality indicators of small watershed non-point source water body; monitoring the water level change of small watershed, detecting and recording the data of small watershed non-point source water before and after the rain, and setting warning signs around the small watershed non-point source water;

[0009] Step five: selecting appropriate area around the small watershed non-point source water body to construct aquatic ecosystem, providing attachment substrate and habitat for indigenous microorganisms, and putting in appropriate amount of aquatic organisms to form biofilm, so as to achieve the self-purification effect of water body, and then regularly detecting the water quality;

[0010] Step six: inputting the water quality data of small watershed non-point source water before treatment and after treatment into the water quality monitoring system;

[0011] Step seven: processing the pollution monitoring data through the preset non-point source pollution model to obtain non-point source pollution monitoring evaluation result;

[0012] Step eight: obtaining the small watershed non-point source water treatment result according to the non-point source pollution monitoring evaluation result, so as to comprehensively prevent and treat the pollution.

[0013] Further: the historical water quality data in step one includes sampling time, section, location, flow, rainfall, section catchment population, TP, NH4-N and COD; the geographical environment data includes climate data, terrain data and population data, and the climate data includes temperature, precipitation and wind speed; the terrain data includes the landform and topographic features of the region, such as mountains, rivers, lakes and elevation; the population data includes social research, urban planning and policy making.

[0014] Further: the pollution monitoring point scheme in step one includes: one: analyzing historical water quality data and geographical environment data, and then establishing water quality prediction model and geographical data model; two: inputting current water quality data into water quality prediction model, inputting geographical environment data into geographical data model, and obtaining water quality prediction data and geographical environment prediction data; three: inputting water quality prediction data and geographical environment prediction data into pollution prevention and control decision model.

[0015] Further, the pollution prevention decision model comprises a pollution prevention special database, which is established by collecting water pollution prevention big data and then analyzing water pollution prevention measures of the water pollution prevention big data.

[0016] Further, before the region is selected in step one, field positioning observation and artificial simulated rainfall are needed, that is, the runoff and sediment loss of different land use types can be analyzed, and the output rate of nitrogen, phosphorus and other non-point source pollutants can be detected, then the nitrogen and phosphorus output coefficients of each land use type in the basin are obtained by combining the output coefficient model, so that the spatial distribution and change process of non-point source pollution in the basin in the past three to five years are analyzed, and finally the contribution rate of different land use types to water and soil loss and non-point source pollution is calculated according to the area of different land use types, the migration characteristics of non-point source pollutants with water and soil loss are revealed, so as to determine whether the region meets the site selection standard.

[0017] Further, the non-point source pollution monitoring and evaluation result in step seven is that all the indexes of the sampling points and the corresponding basic index set are combined to obtain the comparison data set of the non-point source pollution index; one non-point source pollution index and the corresponding basic index set of each sampling point are a sample; the same number of samples are extracted from the comparison data set of each non-point source pollution index based on the resampling method to form a plurality of new data sets, the decision tree in the random forest model is trained by using the new data set, and the index data is obtained.

[0018] Further, the selected small watershed non-point source water body in step five comprises deep water area, shallow water area, flowing water area, slow flow area, sunny area and shady area, and the above-mentioned areas are all water bodies treated.

[0019] Further, a plurality of steel wire filter screens are arranged in the water channel in step two, and ground plugs are arranged at the bottom of both sides of the steel wire filter screen, and the mesh size of the steel wire filter screen is one centimeter.

[0020] Further, in step three, physical and chemical algae removal technologies are combined to kill and treat water algae, and the slow-release device is a water treatment agent slow-release device.

[0021] Compared with the prior art, the beneficial effects of the present application are:

[0022] The method for constructing the small watershed non-point source pollution comprehensive prevention and control system firstly collects geographical environment data and historical water quality data of a selected region, and then determines a pollution monitoring point scheme in a preset monitoring station site library, so that the region can be processed more accurately and effectively; a water channel is dug, and the small watershed water system is connected with the water channel, so that external water can flow into the water system; the small watershed water body is treated by measures such as cleaning garbage floating objects, killing waterweeds, and degrading and repairing the bottom mud, so that the watershed water quality is improved in a short time. Further, a suitable region around the small watershed water body is selected to construct a healthy water ecological system, to provide an attachment matrix and a habitat for indigenous microorganisms to form a biofilm, and a proper amount of aquatic organisms is put into the water body to achieve self-purification effect, and the water quality is detected regularly; the monitoring data are analyzed and evaluated by a preset non-point source pollution model to provide a decision basis for comprehensive management. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the steps of the present application;

[0024] Figure 2 The figure is a schematic diagram of the historical water quality data of the present application;

[0025] Figure 3 The figure is a schematic diagram of the geographical environment data of the present application. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] Embodiment 1:

[0028] Please refer to Figures 1-3 The present application provides a technical solution: a method for constructing a small watershed non-point source pollution comprehensive prevention and control system, which comprises the following steps:

[0029] Step 1: selecting a small watershed to be treated for non-point source pollution, selecting an area to be constructed for a small watershed non-point source pollution comprehensive prevention and control system, obtaining geographical environment data and historical water quality data of the target area from a database of the county, city or district of the area, and determining a pollution monitoring point scheme from a preset monitoring station site library according to the geographical environment data and the historical water quality data;

[0030] Step 2: digging a water channel, connecting the water system of the small watershed to be treated with the water channel, so that external water sources can flow into the small watershed water body to be constructed;

[0031] Step 3: Treat non-point source pollution in the small watershed. First, clean up the residue of aquatic plants and animals and various floating household waste in the small watershed. Then, add materials that can improve water quality to the water source to eliminate organic matter, ammonia nitrogen, and heavy metal pollutants in the watershed, and eliminate algae, thereby degrading large amounts of nitrogen and phosphorus nutrients. Second, treat the bottom and deep water areas of the small watershed by using immobilized composite microbial growth promoters and slow-release devices in deep water areas to degrade and remediate eutrophic bottom sediment.

[0032] Step 4: Monitoring and management of water quality indicators of non-point source water bodies in small watersheds; monitor water level changes in small watersheds, test and record various data of non-point source water bodies in small watersheds before and after rainy weather, and set up warning signs around the non-point source water bodies in small watersheds.

[0033] Step 5: Select a suitable area around the non-point source water body in the small watershed to construct an aquatic ecosystem, providing an attachment substrate and habitat for native microorganisms. At the same time, introduce an appropriate amount of aquatic organisms to form a biofilm, thereby achieving the self-purification effect of the water body. Then, conduct regular water quality testing.

[0034] Step Six: Input the water quality data of the small watershed before and after the non-point source water source treatment into the water quality monitoring system.

[0035] Step 7: Process the pollution monitoring data using a preset non-point source pollution model to obtain non-point source pollution monitoring and assessment results;

[0036] Step 8: Based on the monitoring and assessment results of non-point source pollution, the water treatment results of non-point sources in small watersheds can be obtained, thereby enabling more comprehensive pollution prevention and control.

[0037] Preferably, the historical water quality data in step one includes sampling time, cross-section, location, flow rate, rainfall, population in the cross-section catchment area, TP, NH4-N, and COD; the geographical environment data includes climate data, topographic data, and population data, and the climate data includes temperature, precipitation, and wind speed; the topographic data includes the landforms and topographic features of the region, such as mountains, rivers, lakes, and altitude; the population data includes data relevant to social research, urban planning, and policy making.

[0038] Preferably, the pollution monitoring point scheme of step one comprises: one: analyzing historical water quality data and geographical environment data, and then establishing a water quality prediction model and a geographical data model, both of which are based on LSTM neural network and Markov chain; two: inputting the current water quality data into the water quality prediction model, inputting the geographical environment data into the geographical data model, and obtaining water quality prediction data and geographical environment prediction data therefrom; three: inputting the water quality prediction data and the geographical environment prediction data into a pollution prevention and control decision model, which adopts a multi-source heterogeneous knowledge extraction and fusion algorithm model.

[0039] Preferably, the pollution prevention and control decision model comprises a pollution prevention and control special database, which is established by collecting water pollution prevention and control big data and then analyzing water pollution prevention and control measures of the water pollution prevention and control big data.

[0040] Embodiment 2:

[0041] With reference to Figure 1The embodiment is different from the first embodiment in that, in step one, before the region is selected, field positioning observation and artificial simulated rainfall are required to analyze the runoff and sediment loss of different land use types and to detect the output rate of nitrogen, phosphorus and other non-point source pollutants, and then the output coefficient model is used to obtain the nitrogen and phosphorus output coefficients of each land use type in the basin, so as to analyze the spatial distribution and change process of non-point source pollution in the basin in the past three to five years, and finally, combined with the area of different land use types, the contribution rate of different land use types to soil erosion and non-point source pollution is calculated, and the migration characteristics of non-point source pollutants with soil erosion are revealed to determine whether the region meets the site selection standard. The non-point source pollution monitoring and evaluation result in step seven is a comparison data set of the index and the corresponding basic index set of all sampling points. One non-point source pollution index and the corresponding basic index set of each sampling point are a sample. For each comparison data set of the non-point source pollution index, the same number of samples are extracted based on the resampling method to form multiple new data sets. The decision tree in the random forest model is trained using the new data set, and the index data is obtained. The selected small watershed non-point source water body in step five includes deep water area, shallow water area, flowing water area, slow flow area, sunny area and shady area. The deep water area is the deeper area near the shore in the water area. The shallow water area is the area near the shore in the water area. The flowing water area is the area with fast water flow. The slow flow area is the area with slow water flow. The sunny area is the area that can receive sunlight for a long time. The shady area is the area that cannot receive sunlight for a long time. The above-mentioned areas are all water body treated. In step two, a plurality of steel wire filter screens are arranged in the water channel, and ground plugs are arranged at the bottom of the steel wire filter screen on both sides. The mesh size of the steel wire filter screen is one centimeter. The steel wire filter screen can effectively prevent garbage and sundries in other water sources from entering the monitoring water area through the water channel, so as to avoid affecting the detection result. In step three, the physical and chemical algae removal technologies are combined to kill and treat the algae. The combination of the physical and chemical algae removal technologies can effectively and quickly treat the algae in the water body, and can also reduce the pollution to the water source and the surrounding environment. The slow-release device is a water treatment agent slow-release device. The water treatment agent slow-release device can release the water treatment material for 6-12 months. During the monitoring period, the staff only needs to replace the water treatment material regularly, so that the water source can be conveniently purified and treated.

[0042] The electrical appliances mentioned in this paper are all connected to external power supply through wires.

[0043] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A method for constructing a comprehensive prevention and control system for non-point source pollution in small watersheds, characterized in that: The method includes the following steps: Step 1: Select the small watershed that needs to be treated for non-point source pollution. Select and locate the area where a comprehensive prevention and control system for non-point source pollution needs to be built in the small watershed. Obtain the geographical environment data and historical water quality data of the target area from the database of the county, city and district of the area. Determine the pollution monitoring point plan from the pre-set monitoring station database based on the geographical environment data and historical water quality data. Step 2: Dig irrigation canals to connect the water system of the non-point source watershed that needs to be treated with the irrigation canals, so that external water sources can flow into the water body of the watershed that needs to be constructed. Step 3: Treat non-point source pollution in the small watershed. First, clean up the residue of aquatic plants and animals and various floating household waste in the small watershed. Then, add materials that can improve water quality to the water source to eliminate organic matter, ammonia nitrogen, and heavy metal pollutants in the watershed, and eliminate algae, thereby degrading large amounts of nitrogen and phosphorus nutrients. Second, treat the bottom and deep water areas of the small watershed by using immobilized composite microbial growth promoters and slow-release devices in deep water areas to degrade and remediate eutrophic bottom sediment. Step 4: Monitoring and management of water quality indicators of non-point source water bodies in small watersheds; monitor water level changes in small watersheds, test and record various data of non-point source water bodies in small watersheds before and after rainy weather, and set up warning signs around the non-point source water bodies in small watersheds. Step 5: Select a suitable area around the non-point source water body in the small watershed to construct an aquatic ecosystem, providing an attachment substrate and habitat for native microorganisms. At the same time, introduce an appropriate amount of aquatic organisms to form a biofilm, thereby achieving the self-purification effect of the water body. Then, conduct regular water quality testing. Step Six: Input the water quality data of the small watershed before and after the non-point source water source treatment into the water quality monitoring system. Step 7: Process the pollution monitoring data using a preset non-point source pollution model to obtain non-point source pollution monitoring and assessment results; Step 8: Based on the monitoring and assessment results of non-point source pollution, the water treatment results of non-point sources in small watersheds can be obtained, thereby enabling more comprehensive pollution prevention and control.

2. The method for constructing a comprehensive prevention and control system for non-point source pollution in a small watershed according to claim 1, characterized in that: The historical water quality data mentioned in Step 1 includes sampling time, cross section, location, flow rate, rainfall, population in the cross section's catchment area, TP, NH4-N, and COD; the geographical environment data includes climate data, topographic data, and population data, and the climate data includes temperature, precipitation, and wind speed; the topographic data includes the region's landforms and topographic features, such as mountains, rivers, lakes, and altitude; the population data includes data relevant to social research, urban planning, and policy making.

3. The method for constructing a comprehensive prevention and control system for non-point source pollution in a small watershed according to claim 1, characterized in that: The pollution monitoring point scheme described in step one includes:

1. Analyzing historical water quality data and geographical environment data, and then establishing a water quality prediction model and a geographical data model; 2. Inputting the current water quality data into the water quality prediction model and the geographical environment data into the geographical data model, and thereby obtaining water quality prediction data and geographical environment prediction data; 3. Inputting the water quality prediction data and geographical environment prediction data into the pollution prevention and control decision model.

4. The method for constructing a comprehensive prevention and control system for non-point source pollution in a small watershed according to claim 3, characterized in that: The pollution prevention and control decision-making model includes a pollution prevention and control themed database, which is established by collecting big data on water pollution prevention and control and then analyzing the water pollution prevention and control measures based on the big data.

5. The method for constructing a comprehensive prevention and control system for non-point source pollution in a small watershed according to claim 1, characterized in that: In step one, before selecting a region, two steps are required: field location observation and artificial rainfall simulation. First, it is possible to analyze runoff and sediment loss of different land use types and detect the output rate of non-point source pollutants such as nitrogen and phosphorus. Then, combined with the output coefficient model, the nitrogen and phosphorus output coefficients of each land use type in the watershed are obtained, thereby analyzing the spatial distribution and change process of non-point source pollution in the watershed over the past three to five years. Finally, combined with the area of ​​different land use types, the contribution rate of different land use types to soil erosion and non-point source pollution is estimated, revealing the migration characteristics of non-point source pollutants with soil erosion, thereby determining whether the region meets the site selection criteria.

6. The method for constructing a comprehensive prevention and control system for non-point source pollution in a small watershed according to claim 1, characterized in that: The non-point source pollution monitoring and assessment results described in step seven are obtained by combining the index and the corresponding basic index set of all sampling points to obtain a comparative dataset of the non-point source pollution index; each sampling point is represented by one non-point source pollution index and its corresponding basic index set as a sample; for each comparative dataset of the non-point source pollution index, the same number of samples are extracted based on the method of resampling with replacement to form multiple new datasets, and the decision tree in the random forest model is trained using the new datasets to obtain the index data.

7. The method for constructing a comprehensive prevention and control system for non-point source pollution in a small watershed according to claim 1, characterized in that: The selection of non-point source water bodies in the small watershed mentioned in step five includes deep water areas, shallow water areas, flowing water areas, slow-flowing areas, sunny areas, and shady areas, and all of the above areas have undergone water treatment.

8. The method for constructing a comprehensive prevention and control system for non-point source pollution in a small watershed according to claim 1, characterized in that: In step two, multiple sets of wire mesh filters are installed in the water channel, and ground inserts are installed on both sides of the bottom of the wire mesh filters. The mesh size of the wire mesh filters is one centimeter.

9. A method for constructing a comprehensive prevention and control system for non-point source pollution in a small watershed according to claim 1, characterized in that: In step three, a combination of physical and chemical algae removal technologies is used to eliminate algae. The slow-release device is a water treatment agent slow-release device.

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