CN-122017151-A - System and method for monitoring and evaluating carbon-nitrogen burial rate of sandy river reservoir

Abstract

The invention relates to the technical field of water ecological environment, in particular to a system and a method for monitoring and evaluating carbon and nitrogen burial rate of a sandy river reservoir, wherein the method provided by the invention is used for periodically measuring the variation of the height of a sediment layer, sampling the sediment layer at a plurality of sampling points, measuring the carbon and nitrogen content in a sediment layer sample, calculating the greenhouse gas element burial rate of each sampling point by combining the sampling period and the sediment layer updating amount, comprehensively estimating the total burial rate of the reservoir by the greenhouse gas element burial rates of a plurality of sampling points at a plurality of sampling moments, realizing the dynamic and accurate monitoring of the carbon and nitrogen burial process, and providing a reliable basis for the subsequent evaluation of the total carbon and nitrogen burial potential of the reservoir and the quantitative evaluation of the influence of the reservoir on the greenhouse gas circulation process.

Inventors

• ZHANG LING
• MA BAOQING
• ZHANG SHIAN
• SUN LONGFEI
• WANG QIANG
• LI FUJIAN
• YAN ZHENFENG
• WANG PENGYANG
• WANG YUANJIAN
• TANG FENGZHEN
• ZHANG GE
• YAN XIAOFEI
• LI DONGLIN
• LI XINJIE
• WANG XIN
• YANG FEI

Assignees

• 黄河水利委员会黄河水利科学研究院
• 黄河实验室

Dates

Publication Date

20260512

Application Date

20260317

Claims (10)

1. 1. The method for monitoring and evaluating the carbon and nitrogen burial rate of the sandy river reservoir is characterized by comprising the following steps of: Acquiring a deposit layer updating amount, wherein the deposit layer updating amount is the difference value between the deposit layer height at the current sampling moment and the deposit layer height at the last sampling moment; Acquiring sediment layer samples of a plurality of sampling points in a reservoir area, intercepting new sediment samples according to the updating amount of the sediment layer, and measuring the content of greenhouse gas elements in each new sediment sample; Calculating the greenhouse gas element burial rate of each sampling point according to the sampling period, the sediment layer update quantity of each sampling point and the greenhouse gas element content; and estimating the total greenhouse gas element burial rate of the reservoir according to the greenhouse gas element burial rates of all sampling points acquired at a plurality of sampling moments.
2. 2. The method of claim 1, wherein the deposited layer update amount is obtained by: presetting a plurality of sonar scanning paths according to the warehouse-in runoff characteristics, and acquiring deposit layer surface data at the current sampling moment by utilizing an acoustic detection means, wherein the deposit layer surface data comprises deposit layer height; And projecting the surface data of the deposit layer to a preset grid, and calculating the update quantity of the deposit layer at each preset grid node according to the surface data of the deposit layer obtained by the sampling and the surface data of the deposit layer obtained at the last sampling moment.
3. 3. The method of claim 2, wherein the location of the sampling point is determined by: and establishing a deposition rate distribution model according to the acquired update amount of the deposition layer, calculating the deposition rate at each grid node, and taking the preset grid node as a sampling point of the deposition layer when the deposition rate is greater than a deposition rate threshold value.
4. 4. The method according to claim 1, wherein the greenhouse gas element content is obtained by: drying the new sediment sample; Completely burning the dried new sediment sample to oxidize all greenhouse gas elements into oxides; And determining the content of the local greenhouse gas element in the new sediment sample through chromatographic column analysis, and obtaining the content of the greenhouse gas element in the new sediment sample according to the ratio of the mass of the new sediment sample participating in combustion to the carbon content of the local greenhouse gas element.
5. 5. The method of claim 1, wherein the greenhouse gas element burial rate is calculated by: The greenhouse gas element content in the new sediment sample of the sampling point and the dry density of the new sediment sample are multiplied by the sediment layer updating amount, and the obtained product is divided by the sampling period between adjacent sampling moments, namely the greenhouse gas element burying rate.
6. 6. The method of claim 1, wherein the overall greenhouse gas element burial rate is estimated by: Constructing a deposit layer grid model of the full reservoir area according to the sampling points, wherein each grid unit in the deposit layer grid model is a polygon taking three or four sampling points as vertexes; for each grid cell, calculating the average greenhouse gas element burial rate of the grid cell according to the greenhouse gas element burial rate of the sampling points contained in the grid cell; Adding the average greenhouse gas element burying rates of all grid cells in the deposit layer grid model to obtain the total greenhouse gas element burying rate of the whole reservoir area.
7. 7. The method of claim 1, wherein the overall greenhouse gas element burial rate is estimated by: Determining a corresponding representative region for each sampling point by using an area distribution method, and multiplying the area of the representative region by the carbon burial rate of the sampling point to obtain the average carbon burial rate of the region where the sampling point is located; the average carbon burial rates for all representative zones are summed to give a total carbon burial rate for the entire reservoir.
8. 8. A system for monitoring and evaluating carbon and nitrogen burial rate of a sandy river reservoir, comprising: The deposit layer measuring unit is used for measuring the height of the deposit layer and calculating the update quantity of the deposit layer according to the change quantity of the height of the deposit layer; the deposit layer sampling unit is used for obtaining deposit layer samples of sampling points and intercepting new deposit samples according to the update amount of the deposit layers; The element content measuring unit is used for measuring the element content of greenhouse gases in the new sediment sample; The buried rate calculation unit is used for calculating the greenhouse gas buried rate of each sampling point according to the content of the greenhouse gas elements, the updating amount of the deposit layer and the sampling period, and calculating the total greenhouse gas element buried rate of the reservoir according to the greenhouse gas buried rates of all the sampling points.
9. 9. The system of claim 8, wherein the burial rate calculation unit estimates the overall greenhouse gas element burial rate by: Constructing a deposit layer grid model of the full reservoir area according to the sampling points, wherein each grid unit in the deposit layer grid model is a polygon taking three or four sampling points as vertexes; for each grid cell, calculating the average greenhouse gas element burial rate of the grid cell according to the greenhouse gas element burial rate of the sampling points contained in the grid cell; Adding the average greenhouse gas element burying rates of all grid cells in the deposit layer grid model to obtain the total greenhouse gas element burying rate of the whole reservoir area.
10. 10. The system of claim 8, wherein the burial rate calculation unit estimates the overall greenhouse gas element burial rate by: Determining a corresponding representative region for each sampling point by using an area distribution method, and multiplying the area of the representative region by the carbon burial rate of the sampling point to obtain the average carbon burial rate of the region where the sampling point is located; the average carbon burial rates for all representative zones are summed to give a total carbon burial rate for the entire reservoir.

Description

System and method for monitoring and evaluating carbon-nitrogen burial rate of sandy river reservoir Technical Field The invention relates to the technical field of water ecological environment, in particular to a system and a method for monitoring and evaluating carbon and nitrogen burial rate of a sandy river reservoir. Background With the increase of global warming, how to control the emission of greenhouse gases is a focus of attention in the energy field, various clean energy sources have been developed rapidly, and hydropower is also expected as a clean renewable energy source. However, the construction of the reservoir is necessary to submerge the land, block water flow, intercept a large amount of sediment, and block the flow of nutrient substances by the action of the reactor in the river channel, thereby increasing the residence time of the nutrient substances in the land-ocean aquatic continuum (LOAC), inevitably changing the carbon exchange relationship between the original regional ecosystem and the atmosphere, and generating the dispute about whether the hydropower can effectively reduce the emission of greenhouse gases. Since the 90 s of the last century, studies have shown that reservoir construction may lead to an increase in the release flux of CH 4 and CO 2, and thus the process of how the reservoir affects the bio-geochemical cycle of greenhouse gases in LOAC has become an important part of hydropower construction. And the carbon and nitrogen burial in the sediment deposition process of the reservoir is taken as a key link for influencing the carbon and nitrogen circulation of the reservoir, and the accurate monitoring of the speed is important for scientifically evaluating the carbon source/sink function of the reservoir. Disclosure of Invention In order to accurately evaluate the carbon-nitrogen burial rate and the potential of a reservoir, the application provides a system and a method for monitoring and evaluating the carbon-nitrogen burial rate of a multi-sand river reservoir, wherein the method comprises the following steps: Acquiring a deposit layer updating amount, wherein the deposit layer updating amount is the difference value between the deposit layer height at the current sampling moment and the deposit layer height at the last sampling moment; Acquiring sediment layer samples of a plurality of sampling points in a reservoir area, intercepting new sediment samples according to the updating amount of the sediment layer, and measuring the content of greenhouse gas elements in each new sediment sample; Calculating the greenhouse gas element burial rate of each sampling point according to the sampling period, the sediment layer update quantity of each sampling point and the greenhouse gas element content; and estimating the total greenhouse gas element burial rate of the reservoir according to the greenhouse gas element burial rates of all sampling points acquired at a plurality of sampling moments. The system provided by the application comprises: The deposit layer measuring unit is used for measuring the height of the deposit layer and calculating the update quantity of the deposit layer according to the change quantity of the height of the deposit layer; the deposit layer sampling unit is used for obtaining deposit layer samples of sampling points and intercepting new deposit samples according to the update amount of the deposit layers; The element content measuring unit is used for measuring the element content of greenhouse gases in the new sediment sample; The buried rate calculation unit is used for calculating the greenhouse gas buried rate of each sampling point according to the content of the greenhouse gas elements, the updating amount of the deposit layer and the sampling period, and calculating the total greenhouse gas element buried rate of the reservoir according to the greenhouse gas buried rates of all the sampling points. The method has the technical effects and advantages that the change amount of the height of the sediment layer is measured regularly, the carbon and nitrogen content in the sediment layer is measured, the greenhouse gas element burial rate of each sampling point is calculated by combining the sampling period and the sediment layer updating amount, and the total burial rate of the reservoir is comprehensively estimated by the data of a plurality of sampling moments and a plurality of sampling points, so that the dynamic and accurate monitoring of the carbon and nitrogen burial process is realized. And a reliable basis is provided for subsequent evaluation of the total carbon and nitrogen burial potential of the reservoir and quantitative evaluation of the influence of the reservoir on the greenhouse gas circulation process. Drawings Fig. 1 is an overall flowchart of a method according to an embodiment of the present invention. FIG. 2 is a schematic diagram of one implementation of a sample point arrangement in an embodiment of the invention. FI