System and method for evaluating influence of lake and reservoir nitrogen element content on ecological service value

Abstract

The invention belongs to the technical field of ecological environment assessment, and particularly relates to a system and a method for assessing influence of lake and reservoir nitrogen element content on ecological service value, the system comprises a measuring assembly for measuring the nitrogen element content of a water body sample and a water body sampling head, and the water body sampling head comprises an opening at least occupying half of the width of a sampling plane of the water body sampling head; the measuring assembly comprises a sensor module positioned on a liquid path of the water body sampling head and a temperature control pipe for controlling the temperature of a water body to be measured on the liquid path; the evaluation system further comprises an evaluation module, and the evaluation module inputs the nitrogen element content into a pre-constructed quantitative evaluation model and outputs a quantitative evaluation value to represent the influence of the change of the nitrogen element content on the ecological service value. According to preposed data detected by the temperature sensor in the collection channel, water body samples at different depths can be heated and cooled for multiple times according to the data, so that the water body samples are kept at a constant temperature before measurement, and the influence of the temperature on nitrogen element measurement is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of ecological environment assessment, and specifically relates to an assessment system and method for the impact of nitrogen content in lakes and reservoirs on ecological service value. Background Art

[0002] In the field of environmental protection and water resources management, it is crucial to accurately assess the nitrogen content of lake and reservoir water and its impact on the value of ecological services. As one of the key indicators of eutrophication of water bodies, the level of nitrogen is directly related to the ecological health of the water body and the service functions it provides. However, existing technologies often face many challenges when assessing the impact of nitrogen content in lakes and reservoirs on the value of ecological services.

[0003] A notable problem is that there is a significant temperature gradient in the vertical and horizontal directions of lake water bodies. This temperature difference can lead to uneven distribution of nitrogen in the water body. Traditional assessment methods usually rely on single-point or limited-point water sampling and analyze the nitrogen content accordingly. However, due to differences in water temperature, there may be significant differences in the nitrogen content in water samples at different depths or locations, which directly leads to deviations and inaccuracies in the assessment results. In addition, the existing assessment system often lacks a set of scientific and systematic quantitative models to fully reflect the complex relationship between changes in nitrogen content and ecological service value. Most methods rely on empirical formulas or qualitative analysis, which makes it difficult to accurately quantify the comprehensive impact of changes in nitrogen content on multiple ecological service functions such as water quality, biodiversity, and water purification capacity. Summary of the invention

[0004] The purpose of the present invention is to provide a system and method for evaluating the impact of nitrogen content in lakes and reservoirs on ecological service value, so as to solve the problems raised in the background technology.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] In the first aspect, the present invention proposes an evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value, comprising a measuring component for measuring the nitrogen content of a water sample; and at least two water sampling heads forming an integral structure with the measuring component, the water sampling head comprising an opening occupying at least half the width of a sampling plane of the water sampling head, the measuring component comprising a sensor module located on a liquid path of the water sampling head and a temperature control pipe for controlling the temperature of the water to be measured on the liquid path;

[0007] The evaluation system further includes an evaluation module, which inputs the nitrogen content into a pre-built quantitative evaluation model and outputs a quantitative evaluation value to characterize the impact of changes in nitrogen content on ecological service value;

[0008] The evaluation system also includes an evaluation module, which inputs the nitrogen content into a pre-constructed quantitative evaluation model and outputs a quantitative evaluation value to characterize the impact of changes in nitrogen content on ecological service value.

[0009] Furthermore, the sensor module includes an optical nitrogen sensor and a microprocessing unit connected to the optical nitrogen sensor by signal, and the microprocessing unit is used to send the nitrogen content detected in real time by the optical nitrogen sensor to the evaluation module.

[0010] Furthermore, the water sampling head is provided with a measuring component connected to the liquid path, the sensor module is arranged inside the measuring component, and the measuring component and the water sampling head are placed at different depths of the water body to be tested through a winding member and a pull rope for sampling and detection.

[0011] Furthermore, the water sampling head includes an upper collecting tube connected to the interior of the measuring component, and a sampling end located at the lower end of the upper collecting tube, at least one opening is opened on the side wall of the sampling end, a collecting channel connected to the opening is provided inside the sampling end, and a temperature sensor is provided at the lower end of the collecting channel.

[0012] Furthermore, a flow channel for connecting the temperature control pipe and the collection channel is provided in the upper collecting tube, and an interface is provided at the lower end of the flow channel;

[0013] A solenoid valve is provided on the communication path between the opening and the collecting channel, a branch channel is provided on the path between the opening and the solenoid valve, the end of the branch channel is communicated with the side of the interface member, and a pressure regulating valve is provided at the communication point;

[0014] The pressure regulating valve is used to compare the water pressure of the water body in the branch channel with the preset sampling depth when the water sampling head is at different depths. When the water pressure meets the preset range of the corresponding sampling depth, the pressure regulating valve and the solenoid valve are opened synchronously.

[0015] Furthermore, the measuring component includes a first chamber and a second chamber, the first chamber is connected to the upper collecting cylinder, the temperature control pipe includes a U-shaped conduit arranged in the first chamber, and a temperature control component arranged thereon, the second chamber is provided with a water pump 2 connected to a port of the U-shaped conduit, the sensor module is located on the water pumping path of the water pump 2, and a temperature measuring component is also provided on the water pumping path, and the other port of the U-shaped conduit faces the upper end of the first chamber and is located at two-thirds of the liquid level in the first chamber.

[0016] Furthermore, the quantitative evaluation model includes a first function and a second function, wherein the nitrogen content is input into the first function to obtain the ecological sensitivity index ESI, and then the ecological sensitivity index ESI is input into the second function to obtain the quantitative evaluation value EVA, which is used to characterize the impact of changes in nitrogen content on ecological service value, wherein the formulas of the first function and the second function are as follows:

[0017] ESI=a*ln(N+1)+b

[0018] EVA=c*ESI d +e

[0019] Among them, a is the sensitivity coefficient of the ecosystem to changes in nitrogen, b is the baseline of the ecological sensitivity index when the nitrogen content is zero, N is the nitrogen content, c, d and e are the assessment coefficient, sensitivity index and benchmark value respectively.

[0020] In the second aspect, the present invention proposes a method for evaluating the impact of nitrogen content in lakes and reservoirs on the ecological service value, which is implemented based on the above-mentioned evaluation system and includes:

[0021] S1. Place the water sampling head at different depths of the water body to be tested through a winding piece and a pull rope for sampling and detection. When the water pressure meets the preset range of the corresponding sampling depth, the pressure regulating valve and the solenoid valve are opened synchronously;

[0022] S2, sampling the water body to be tested through the opening on at least one of the water sampling heads, so that the water body to be tested is transported to the sensor module along the liquid path;

[0023] S3, starting the sensor module to measure the nitrogen content of the water sample, and transmitting the nitrogen content to the evaluation module;

[0024] S4. The assessment module inputs the nitrogen content into a pre-constructed quantitative assessment model, and outputs a quantitative assessment value to characterize the impact of changes in nitrogen content on ecological service value.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention directly converts the nitrogen content into an ecological sensitivity index by introducing a combined model of the first function and the second function, and further quantifies it into a specific ecological service value assessment value. The model fully considers the impact of water temperature differences on nitrogen distribution, and ensures the accuracy and reliability of the assessment results through comprehensive multi-point sampling and temperature correction.

[0027] 2. The present invention collects the advance data detected by the temperature sensor in the channel, and can heat and cool water samples at different depths multiple times according to the data, so that the water samples can maintain a constant temperature before measurement, thereby avoiding the influence of temperature on nitrogen measurement.

[0028] 3. The present invention arranges a temperature control pipe in the first chamber, thereby achieving temperature control of the water body to be tested, and at the same time, the upper layer of water in the first chamber can be preferentially collected through the U-shaped conduit design, thereby ensuring that the collected water samples are purer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a framework diagram of the evaluation system in the present invention.

[0030] Figure 2 It is a structural schematic diagram of the water body sampling head in the present invention.

[0031] Figure 3 It is a structural schematic diagram of the collecting tube in the present invention.

[0032] Figure 4 It is a schematic diagram of the cross-sectional structure of the collecting tube in the present invention.

[0033] Figure 5 It is a schematic diagram of the structure of the measuring component in the present invention.

[0034] In the figure: 1. winding member; 2. pull rope; 3. measuring component; 4. water sampling head; 31. first chamber; 32. second chamber; 41. collecting tube; 42. water pump 1; 311. water inlet; 312. U-shaped guide tube; 313. temperature control component; 314. sampling port; 321. water pump 2; 322. sensor module; 323. temperature measuring component; 411. upper collecting tube; 412. sampling end; 413. flow channel; 414. opening; 415. protrusion; 416. positioning member; 417. filter screen; 418. collecting channel; 419. temperature sensor; 420. solenoid valve; 421. branch channel; 422. pressure regulating valve; 423. interface member. DETAILED DESCRIPTION

[0035] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0036] Example 1

[0037] like Figure 1-5As shown, this embodiment proposes an evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value, including a measuring component 3 for measuring the nitrogen content of water samples; and at least two water sampling heads 4 that form an integrated structure with the measuring component 3, the water sampling head 4 includes an opening 414 that occupies at least half the width of the sampling plane of the water sampling head 4, the measuring component 3 includes a sensor module 322 located on the liquid path of the water sampling head 4 and a temperature control pipe for controlling the temperature of the water to be tested on the liquid path; the evaluation system also includes an evaluation module, the evaluation module inputs the nitrogen content into a pre-constructed quantitative evaluation model, and outputs a quantitative evaluation value to characterize the impact of changes in nitrogen content on the ecological service value.

[0038] Further preferably, the water sampling head 4 is provided with a measuring component 3 connected to the liquid path, the sensor module 322 is arranged inside the measuring component 3, the measuring component 3 and the water sampling head 4 are placed at different depths of the water body to be tested through the winding member 1 and the pull rope 2 for sampling and detection, and the sampling is specifically achieved by winding and unwinding the winding member 1 and the pull rope 2.

[0039] Further preferably, in combination Figure 2 , 3 and 4, the water sampling head 4 includes an upper collecting tube 411 connected to the interior of the measuring component 3, and a sampling end 412 located at the lower end of the upper collecting tube 411, at least one opening 414 is opened on the side wall of the sampling end 412, a collecting channel 418 connected to the opening 414 is provided inside the sampling end 412, and a temperature sensor 419 is provided at the lower end of the collecting channel 418.

[0040] It can be understood that in this embodiment, the opening 414 occupies at least half of the width of the sampling plane (the outer peripheral surface of the sampling end 412) of the water sampling head 4, and the arc path in the opening 414 is oriented toward the sampling direction of the water sampling head 4. Such a half-open opening design allows water to enter the sampling head more smoothly, reducing resistance, thereby speeding up the sampling speed. The semi-open design allows water to enter the sampling head from a wider angle, which helps to reduce water vortexes and deviations during the sampling process and improve the uniformity and representativeness of the sampling.

[0041] Further preferably, a flow channel 413 for connecting the temperature control pipe and the collecting channel 418 is provided in the upper collecting tube 411, and an interface part 423 (including at least three same ports for connecting with the flow channel 413, the collecting channel 418 and the branch channel 421) is provided at the lower end of the flow channel 413; a solenoid valve 420 is provided on the communication path between the opening 414 and the collecting channel 418, and a branch channel 421 is provided on the path between the opening 414 and the solenoid valve 420, and the end of the branch channel 421 is connected to the side of the interface part 423, and a pressure regulating valve 422 is provided at the connection point; the pressure regulating valve 422 is used to compare the water pressure of the water body in the branch channel 421 with the preset sampling depth when the water sampling head 4 is at different depths. When the water pressure meets the preset range of the corresponding sampling depth, the pressure regulating valve 422 and the solenoid valve 420 are opened synchronously.

[0042] Combination Figure 4 When the pull rope 2 is lowered to different depths for water sampling, due to the setting of the collection channel 418, during the lowering process of the entire device, the water flows into the collection channel 418 from the arc path, so that a certain amount of water begins to gather at the bottom of the collection channel 418, and the temperature of the current water body is detected in real time by the temperature sensor 419. When the real-time temperatures in multiple water sampling heads 4 at different depths are inconsistent or exceed the limit value, it indicates that there is a temperature gradient in the water body in the lake reservoir area. This temperature gradient will cause uneven distribution of nitrogen in the water body. In specific implementation, the temperature sensor 419 in the collection channel 418 can be used to realize pre-temperature judgment, which provides a certain data basis for subsequent detection.

[0043] In addition, in this embodiment, the water sampling head 4 has an automatic sampling function. Specifically, the corresponding sampling depth is preset first. When the water pressure meets the preset range of the corresponding sampling depth, the pressure regulating valve 422 and the solenoid valve 420 are opened synchronously. Figure 4 , at this time, the water reaches the designated depth, and the water enters the collection channel 418 from the opening 414 for pre-temperature judgment. After the temperature judgment is completed, the water enters the flow channel 413 through the interface 423. In this process, the branch channel 421 can assist the water sampling head 4 in exhausting and promote the entry of water. While the branch channel 421 assists in exhausting, when the sampling depth has not been reached, the pressure regulating valve 422 in the channel can monitor the water pressure in real time, and judge whether the water sampling head has reached the preset depth based on the water pressure here and the preset water pressure range.

[0044] Combination Figure 5The measuring component 3 includes a first chamber 31 and a second chamber 32. The first chamber 31 is connected to the upper collecting tube 411. The temperature control pipe includes a U-shaped tube 312 arranged in the first chamber 31, and a temperature control component 313 arranged thereon (specifically an electric heating thermostat in this embodiment, which heats and cools the U-shaped tube 312). The second chamber 32 is provided with a water pump 2 321 connected to one port of the U-shaped tube 312. The sensor module 322 is located on the water pumping path of the water pump 2 321, and a temperature measuring component 323 is also provided on the water pumping path. The other port of the U-shaped tube 312 faces the upper end of the first chamber 31 and is located at two-thirds of the liquid level in the first chamber 31.

[0045] In specific implementation, the water body to be measured in the collection channel 418 is pumped from the water inlet 311 into the first chamber 31 through the water pump 1 42. After the internal water level reaches two-thirds, the water samples at different depths can be heated and cooled multiple times according to the data detected by the temperature sensor 419 in the collection channel 418, so that they can maintain a constant temperature before measurement to avoid the influence of temperature on the measurement of nitrogen element. Then, the water pump 2 321 is started to pump the water in the first chamber 31 from the U-shaped conduit 312 into the temperature measuring component 323 and the sensor module 322 in the second chamber 32. The temperature measuring component 323 is specifically another liquid temperature sensor.

[0046] It can be understood that by setting the temperature control pipe in the first chamber 31, while achieving the temperature control of the water body to be tested, the upper layer of water in the first chamber 31 can be preferably collected through the design of the U-shaped conduit 312, which can ensure that the collected water body sample is purer. Since impurities and pollutants in the water body tend to settle in the lower layer, the upper layer of water is relatively clean and more suitable as a test sample; collecting the upper layer of water can reduce interfering substances in the sample, thereby improving the accuracy of nitrogen measurement.

[0047] Further preferably, the sensor module 322 includes an optical nitrogen sensor and a microprocessing unit connected to the optical nitrogen sensor by signal, and the microprocessing unit is used to send the nitrogen content detected in real time by the optical nitrogen sensor to the evaluation module.

[0048] Further preferably, a filter screen 417 and a positioning member 416 are provided on the opening 414. The filter screen 417 is made of soft silicone material, which has good flexibility and elasticity and can adapt to the deformation requirements of the water sampling head 4 in different water depths and environments. At the same time, the soft silicone material also has excellent corrosion resistance and wear resistance, and can maintain stable performance during long-term water sampling. The positioning member 416 is used to fix the position of the filter screen 417, such as screws, detachable buckles, etc.

[0049] In this embodiment, the quantitative evaluation model includes a first function and a second function, wherein the nitrogen content is input into the first function to obtain the ecological sensitivity index ESI, and then the ecological sensitivity index ESI is input into the second function to obtain the quantitative evaluation value EVA, which is used to characterize the impact of changes in nitrogen content on the ecological service value, wherein the formulas of the first function and the second function are as follows:

[0050] ESI=a*ln(N+1)+b

[0051] EVA=c*ESI d +e

[0052] Among them, a is the sensitivity coefficient of the ecosystem to changes in nitrogen, which is determined by ecological research experiments or historical data analysis. Under different nitrogen concentration gradients, the response of key ecological indicators of the ecosystem, such as algae reproduction, water quality changes, and biodiversity, can be observed, and the relationship between nitrogen concentration and ecological response can be fitted using regression analysis and other methods to obtain the sensitivity coefficient a. b is the baseline of the ecological sensitivity index when the nitrogen content is zero. Usually, under theoretical or experimental conditions, the nitrogen content is set to an extremely low or zero value, the state of the ecosystem at this time is measured, and the baseline b is set accordingly. This can be achieved by comparing the ecological responses under different nitrogen concentration gradients and selecting the stable value at the lowest or near zero concentration as the baseline. N is the nitrogen content, c, d, and e are the evaluation coefficient, sensitivity index, and benchmark value, respectively; the evaluation coefficient c reflects the impact weight of ESI changes on EVA, which needs to be determined through multidisciplinary cross-disciplinary methods such as economics and ecology. Based on historical data, the changing trend of ecological service value under different ESIs can be analyzed, and the c value can be obtained using regression analysis and other methods; the sensitivity index d is used to adjust the weight or impact of ESI in the EVA calculation, and the specific value depends on the characteristics of the ecosystem and the evaluation objectives. Its acquisition needs to be combined with ecological expertise and determined through model simulation, expert scoring, etc. The benchmark value e represents the benchmark level of the ecological service value of lakes and reservoirs without nitrogen pollution or at a specific nitrogen concentration. This can be determined based on historical data, ecosystem service value assessment models or expert assessments.

[0053] It can be understood that the quantitative assessment model systematically and scientifically evaluates the specific impact of changes in nitrogen content in lakes and reservoirs on the ecological service value (EVA) by integrating the first function and the second function. Specifically, quantify the ecological sensitivity index (ESI): using the first function, combined with the sensitivity coefficient of the ecosystem to changes in nitrogen (a) and the baseline of the ecological sensitivity index when the nitrogen content is zero (b), accurately calculate the sensitivity of the ecosystem (ESI) at different nitrogen concentration levels. This index directly reflects the intensity of the ecosystem's response to nitrogen pollution. Calculate the quantitative assessment value of the ecological service value (EVA): through the second function, take ESI as one of the inputs, combine the assessment coefficient (c), sensitivity index (d) and baseline value (e), and comprehensively evaluate the changes in the ecological service value of lakes and reservoirs. This step not only takes into account the impact of nitrogen pollution on ecological sensitivity, but also further converts this impact into quantifiable economic value, providing an intuitive and scientific basis for decision makers.

[0054] Example 2

[0055] Based on Example 1, this example proposes a method for evaluating the impact of nitrogen content in lakes and reservoirs on ecological service value. The method is implemented based on the above evaluation system and includes:

[0056] S1, placing the water sampling head 4 at different depths of the water body to be tested through the winding member 1 and the pull rope 2 for sampling and detection. When the water pressure meets the preset range of the corresponding sampling depth, the pressure regulating valve 422 and the solenoid valve 420 are opened synchronously;

[0057] S2, sampling the water body to be tested through the opening 414 on at least one water body sampling head 4, so that the water body to be tested is transported to the sensor module 322 along the liquid path;

[0058] S3, starting the sensor module 322 to measure the nitrogen content of the water sample, and transmitting the nitrogen content to the evaluation module;

[0059] S4. The assessment module inputs the nitrogen content into a pre-built quantitative assessment model and outputs a quantitative assessment value to characterize the impact of changes in nitrogen content on the value of ecological services.

[0060] It is obvious to those skilled in the art that the embodiments of the present invention are not limited to the details of the above exemplary embodiments, and that the embodiments of the present invention can be implemented in other specific forms without departing from the spirit or basic features of the embodiments of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the embodiments of the present invention is limited by the attached claims rather than the above description, so it is intended to include all changes that fall within the meaning and scope of the equivalent elements of the claims in the embodiments of the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units, modules or devices stated in the system, device or terminal claims can also be implemented by the same unit, module or device through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0061] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value, characterized in that: The invention comprises a measuring component (3) for measuring the nitrogen content of a water sample; and at least two water sampling heads (4) forming an integral structure with the measuring component (3), the water sampling head (4) comprising an opening (414) occupying at least half the width of a sampling plane of the water sampling head (4); the measuring component (3) comprising a sensor module (322) located on a liquid path of the water sampling head (4) and a temperature control pipe for controlling the temperature of the water to be measured on the liquid path; The evaluation system also includes an evaluation module, which inputs the nitrogen content into a pre-constructed quantitative evaluation model and outputs a quantitative evaluation value to characterize the impact of changes in nitrogen content on ecological service value.

2. The evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value according to claim 1 is characterized by: The sensor module (322) comprises an optical nitrogen sensor and a microprocessing unit connected to the optical nitrogen sensor by signal, wherein the microprocessing unit is used to send the nitrogen content detected in real time by the optical nitrogen sensor to the evaluation module.

3. The evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value according to claim 1 is characterized by: The sensor module (322) is arranged inside the measuring component (3), and the measuring component (3) and the water body sampling head (4) are placed at different depths of the water body to be measured through a winding member (1) and a pull rope (2) for sampling and detection.

4. The evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value according to claim 2 is characterized by: The water sampling head (4) comprises an upper collecting tube (411) connected to the interior of the measuring component (3), and a sampling end (412) located at the lower end of the upper collecting tube (411), at least one opening (414) is opened on the side wall of the sampling end (412), a collecting channel (418) connected to the opening (414) is provided inside the sampling end (412), and a temperature sensor (419) is provided at the lower end of the collecting channel (418).

5. The evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value according to claim 4 is characterized by: The upper collecting cylinder (411) is provided with a flow channel (413) for connecting the temperature control pipe and the collecting channel (418), and the lower end of the flow channel (413) is provided with an interface member (423); A solenoid valve (420) is provided on the communication path between the opening (414) and the collecting channel (418), a branch channel (421) is provided on the path between the opening (414) and the solenoid valve (420), the end of the branch channel (421) is communicated with the side of the interface member (423), and a pressure regulating valve (422) is provided at the communication point; The pressure regulating valve (422) is used to compare the water pressure of the water body in the branch channel (421) with the preset sampling depth when the water sampling head (4) is at different depths. When the water pressure meets the preset range corresponding to the sampling depth, the pressure regulating valve (422) and the electromagnetic valve (420) are opened synchronously.

6. The evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value according to claim 4 is characterized by: The measuring component (3) comprises a first chamber (31) and a second chamber (32); the first chamber (31) is in communication with the upper collecting cylinder (411); the temperature control pipe comprises a U-shaped conduit (312) arranged in the first chamber (31) and a temperature control component (313) arranged thereon; the second chamber (32) is provided with a second water pump (321) in communication with one end of the U-shaped conduit (312); the sensor module (322) is located on a water pumping path of the second water pump (321); and a temperature measuring component (323) is also provided on the water pumping path; the other end of the U-shaped conduit (312) faces the upper end of the first chamber (31) and is located at two-thirds of the liquid level in the first chamber (31).

7. The evaluation system for the impact of nitrogen content in lakes and reservoirs on ecological service value according to claim 1 is characterized by: The quantitative evaluation model includes a first function and a second function, wherein the nitrogen content is input into the first function to obtain the ecological sensitivity index ESI, and then the ecological sensitivity index ESI is input into the second function to obtain the quantitative evaluation value EVA, which is used to characterize the impact of changes in nitrogen content on ecological service value, wherein the formulas of the first function and the second function are as follows: ESI=a*ln(N+1)+b EVA=c*ESI d +e Among them, a is the sensitivity coefficient of the ecosystem to changes in nitrogen, b is the baseline of the ecological sensitivity index when the nitrogen content is zero, N is the nitrogen content, c, d and e are the assessment coefficient, sensitivity index and benchmark value respectively.

8. A method for evaluating the impact of nitrogen content in lakes and reservoirs on ecological service value, characterized in that: Based on the implementation of the evaluation system according to any one of claims 1 to 7, the method comprises: S1. The water sampling head (4) is placed at different depths of the water body to be tested through the winding member (1) and the pull rope (2) for sampling and testing. When the water pressure meets the preset range corresponding to the sampling depth, the pressure regulating valve (422) and the electromagnetic valve (420) are opened synchronously; S2, sampling the water body to be tested through the opening (414) on at least one of the water body sampling heads (4), so that the water body to be tested is transported to the sensor module (322) along the liquid path; S3, starting the sensor module (322) to measure the nitrogen content of the water sample, and transmitting the nitrogen content to the evaluation module; S4. The assessment module inputs the nitrogen content into a pre-constructed quantitative assessment model, and outputs a quantitative assessment value to characterize the impact of changes in nitrogen content on ecological service value.

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