Method, system, device and medium for evaluating nitrogen sink potential of wetland in river basin

Abstract

The method, system, device and medium for evaluating the nitrogen sink potential of a wetland in a river basin first acquire natural geographical data, agricultural production activity data and wetland distribution data of the river basin, then determine the nitrogen input of each wetland in the river basin based on the natural geographical data and the agricultural production activity data, determine the nitrogen reduction rate of each wetland in the river basin based on the natural geographical data and the wetland distribution data, and finally determine the nitrogen sink potential of the wetland in the river basin based on the nitrogen input of the wetland and the nitrogen reduction rate of the wetland. The nitrogen reduction capacity of the wetland in the river basin is systematically evaluated, and the nitrogen sink potential of the wetland is determined.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ecological environment evaluation, and particularly relates to a method, system, device and medium for evaluating nitrogen sink potential of a wetland in a river basin. BACKGROUND

[0002] Excessive anthropogenic nitrogen input has been widely recognized as one of the main causes of water eutrophication, especially in areas with high human activity. Wetland ecosystems, as an integral part of the river basin landscape, play a key role in water purification. Wetlands not only serve as important nitrogen sinks, but also effectively reduce nitrogen concentration in water bodies, preventing excessive nitrogen from entering downstream water bodies and thus inhibiting the occurrence of eutrophication. Therefore, systematically evaluating the nitrogen sink potential of wetlands is of great practical significance for developing scientific and targeted wetland protection and management measures and improving the nitrogen removal efficiency of wetlands. This process can effectively reduce the risk of nitrogen pollution and promote the overall environmental health and sustainable development of the river basin.

[0003] However, existing research on wetland nitrogen reduction and nitrogen sink mostly focuses on the analysis of individual wetlands, lacking systematic evaluation of wetland nitrogen sink capacity at the regional scale. The lack of regional research limits the understanding of wetland nitrogen sink capacity, which hinders the development of effective wetland management strategies at the river basin scale. Therefore, it is necessary to establish a scientific and reasonable regional evaluation method to systematically study wetland nitrogen reduction and nitrogen sink capacity, and to make up for the shortcomings of existing research. SUMMARY

[0004] The present application aims to solve the above-mentioned problems existing in the prior art, and provides a method, system, device and medium for evaluating nitrogen sink potential of a wetland in a river basin.

[0005] To achieve the above-mentioned purposes, the technical solutions of the present application are as follows:

[0006] In a first aspect, the present application provides a method for evaluating nitrogen sink potential of a wetland in a river basin, comprising:

[0007] S1, obtaining natural geographical data, agricultural production activity data and wetland distribution data of the river basin;

[0008] S2, determining nitrogen input of each wetland in the river basin based on the natural geographical data and the agricultural production activity data; and determining nitrogen reduction rate of each wetland in the river basin based on the natural geographical data and the wetland distribution data;

[0009] S3, determining nitrogen sink potential of the wetlands in the river basin based on the nitrogen input and the nitrogen reduction rate of each wetland.

[0010] In the S2, the nitrogen input of each wetland in the river basin is calculated according to the following formula:

[0011] Nin，i = f x N sur x A wetland，i x 8.2

[0012] In the above formula, N in，i is the nitrogen input of the i-th wetland, f is the attenuation factor, N sur is the nitrogen surplus of the watershed, A wetland，i is the area of the i-th wetland;

[0013] The nitrogen reduction rate of each wetland in the watershed is calculated according to the following formula:

[0014]

[0015] In the above formula, R i is the nitrogen reduction rate of the i-th wetland, k i is the first-order kinetic decay constant of the i-th wetland, t i is the hydraulic retention time of the i-th wetland;

[0016] In the S3, the potential of wetland nitrogen sink in the watershed is calculated according to the following formula:

[0017]

[0018] In the above formula, N is the number of wetlands in the watershed.

[0019] The N sur is calculated according to the following formula:

[0020]

[0021] N crop = N fer + N manure + N dep + N fix + N straw - N utake

[0022] In the above formula, A crop , A non-crop are the cultivated land area and non-cultivated land area in the watershed, N crop is the nitrogen surplus of the cultivated land, N dep is the atmospheric nitrogen deposition rate in the watershed, A watershed is the watershed area, N fer is the nitrogen fertilizer input intensity of the cultivated land, N manure is the amount of nitrogen in livestock manure returned to the field per unit area, N fix is the amount of biological nitrogen fixation per unit area, N straw is the amount of nitrogen in straw returned to the field per unit area, N uptake is the amount of nitrogen absorbed by crops per unit area.

[0023] The k i According to the following formula:

[0024] ln(k i )=-1.07×ln(t i )-0.029×T i -1.08

[0025]

[0026] In the above formula, T i is the average annual temperature of the i-th wetland.

[0027] In a second aspect, the present application provides a watershed wetland nitrogen sink potential evaluation system, comprising a data acquisition module, a nitrogen input determination module, a nitrogen reduction rate determination module, and a wetland nitrogen sink potential determination module;

[0028] The data acquisition module is configured to acquire natural geographical data, agricultural production activity data, and wetland distribution data of the watershed.

[0029] The nitrogen input determination module is configured to determine the nitrogen input of the wetland based on the natural geographical data and the agricultural production activity data.

[0030] The nitrogen reduction rate determination module is configured to determine the nitrogen reduction rate of the wetland based on the natural geographical data and the wetland distribution data.

[0031] The wetland nitrogen sink potential determination module is configured to determine the wetland nitrogen sink potential in the watershed based on the nitrogen input of the wetland and the nitrogen reduction rate of the wetland.

[0032] The nitrogen input determination module calculates the nitrogen input of each wetland in the watershed according to the following formula:

[0033] N in，i =f×N sur ×A wetland，i ×8.2

[0034] In the above formula, N in，i is the nitrogen input of the i-th wetland, f is the attenuation factor, N sur is the nitrogen surplus of the watershed, A wetland，i is the area of the i-th wetland.

[0035] The nitrogen reduction rate determination module calculates the nitrogen reduction rate of each wetland in the watershed according to the following formula:

[0036]

[0037] In the above formula, R i is the nitrogen reduction rate of the i-th wetland, k iis the first-order kinetic decay constant of the ith wetland, t i is the hydraulic retention time of the ith wetland.

[0038] The wetland nitrogen sink potential determination module calculates the wetland nitrogen sink potential Sink in the basin according to the following formula:

[0039]

[0040] In the above formula, N is the number of wetlands in the basin.

[0041] The N sur is calculated according to the following formula:

[0042]

[0043] N crop = N fer +N manure +N dep +N fix +N straw -N uptake

[0044] In the above formula, A crop , A non-crop are the cultivated land area and non-cultivated land area in the basin, N crop is the nitrogen surplus of cultivated land, N dep is the atmospheric nitrogen deposition rate in the basin, A watershed is the basin area, N fer is the nitrogen fertilizer input intensity of cultivated land, N manure is the amount of nitrogen in livestock and poultry manure returned to the field per unit area, N fix is the amount of biological nitrogen fixation per unit area, N straw is the amount of nitrogen in straw returned to the field per unit area, and N uptake is the amount of nitrogen absorbed by crops per unit area.

[0045] The k i is calculated according to the following formula:

[0046] ln(k i ) = -1.07 x ln(t i ) - 0.029 x T i - 1.08

[0047]

[0048] In the above formula, T i is the average annual temperature of the ith wetland.

[0049] In a third aspect, the present application provides a basin wetland nitrogen sink potential evaluation device, comprising a memory and a processor.

[0050] The memory is used to store computer program code and transmit the computer program code to the processor;

[0051] The processor is used to execute the foregoing method according to instructions in the computer program code.

[0052] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the foregoing method.

[0053] Compared with the prior art, the present application has the following beneficial effects:

[0054] The method for evaluating the nitrogen sink potential of a basin wetland first acquires natural geographical data, agricultural production activity data and wetland distribution data of the basin, then determines nitrogen input of each wetland in the basin based on the natural geographical data and the agricultural production activity data, determines a nitrogen reduction rate of each wetland in the basin based on the natural geographical data and the wetland distribution data, and finally determines the nitrogen sink potential of the wetland in the basin based on the nitrogen input of the wetland and the nitrogen reduction rate of the wetland. The method systematically evaluates the nitrogen reduction capacity of the wetland in the basin and clearly defines the nitrogen sink potential of the wetland. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 A flow chart of the method described in Example 1.

[0056] Figure 2 A schematic diagram of the nitrogen surplus of the Yangtze River Basin in 2015 in Example 1.

[0057] Figure 3 A schematic diagram of the nitrogen sink potential of different basins in the Yangtze River Basin in 2015 in Example 1.

[0058] Figure 4 A structure diagram of the system described in Example 2.

[0059] Figure 5 A structure diagram of the device described in Example 3. DETAILED DESCRIPTION

[0060] The present application will be further described in detail in combination with the description of the accompanying drawings and specific embodiments.

[0061] Example 1:

[0062] This example takes the Yangtze River Basin as an example to implement the method for evaluating the nitrogen sink potential of a basin wetland described in the present application, as shown in the following specific steps: Figure 1

[0063] 1. Determine the range and boundary of the Yangtze River Basin.

[0064] ​The Yangtze River Basin has diverse topography, including mountains, plateaus, basins, hills and plains, and runs through the Qinghai-Tibet Plateau, Hengduan Mountains, Yunnan-Guizhou Plateau, Sichuan Basin, Jiangnan Hills and the middle and lower reaches of the Yangtze River. Most of the Yangtze River Basin belongs to a typical subtropical monsoon climate, but the climate characteristics of different regions in the Yangtze River Basin are obviously different, and there is also a part of plateau climate. The average annual temperature in the basin is about 13°C, and the average annual precipitation is about 1067mm. According to the water system and topography of the Yangtze River Basin, the Yangtze River Basin is divided into 45 small basins.

[0065] 2. Obtain the natural geographical data, agricultural production activity data and wetland distribution data of the Yangtze River Basin.

[0066] (1) Natural geographical data: The data includes the temperature data, cultivated land area, construction land area, forest and grassland area and atmospheric nitrogen deposition rate of the Yangtze River Basin in 2015; the temperature data is from the national temperature grid data of the Resource and Environment Science and Data Center of the Chinese Academy of Sciences (https: / / www.resdc.cn / ), with a spatial resolution of 1km; the cultivated land area, construction land area and forest and grassland area are from the China Statistical Yearbook and the statistical yearbooks of the provinces and cities involved in the Yangtze River Basin; the atmospheric nitrogen deposition rate is from the unit area atmospheric deposition monitored in different regions of the Yangtze River Basin in the literature.

[0067] (2) Agricultural production activity data: The data includes the fertilizer nitrogen input (including nitrogen fertilizer and compound fertilizer), different crop yields, livestock and poultry breeding scale, straw returning rate and empirical parameter data of the Yangtze River Basin in 2015; the fertilizer nitrogen input, crop yield and livestock and poultry breeding scale are from the China Statistical Yearbook and the statistical yearbooks of the provinces and cities involved in the Yangtze River Basin; the straw returning rate data is from the straw returning rate reported in different regions in the literature; the empirical parameter data includes the seed nitrogen content, straw nitrogen content, straw to grain ratio and biological nitrogen fixation rate of different crops, which are from the results reported in the literature.

[0068] (3) Wetland distribution data: The data includes the wetland area, longitude and latitude of the Yangtze River Basin in 2015; the wetland distribution data is from the China Multi-period Land Use Remote Sensing Monitoring Dataset.

[0069] 3. Determine the nitrogen input of each wetland in the basin based on the natural geographical data and agricultural production activity data:

[0070] N in，i = f x N sur x A wetland，i x 8.2

[0071]

[0072] N crop= N fer + N manure + N dep + N fix + N straw - N uptake

[0073] In the above formula, N in，i is the nitrogen input of the i-th wetland (kg), f is the attenuation factor (dimensionless), ranging from 0.3 to 0.5, which represents the proportion of the nitrogen surplus in the basin potentially entering the wetland, and is calculated according to the proportion of land use types (farmland, construction land and forest and grassland) in the basin and the nitrogen loss coefficients of different land use types. The nitrogen loss coefficients of different land use types are reported in the literature. N sur is the nitrogen surplus in the basin (kg / ha), A wetland，i is the area of the i-th wetland (ha), A crop and A non-crop are the farmland area (ha) and non-farmland area (ha) in the basin, respectively, N crop is the nitrogen surplus in farmland (kg / ha), N dep is the atmospheric nitrogen deposition rate in the basin (kg / ha), A watershed is the basin area (ha), N fer is the nitrogen fertilizer input intensity of farmland (kg / ha), N manure is the amount of nitrogen in livestock and poultry manure returned to the field per unit area (kg / ha), N fix is the amount of nitrogen fixed by biological fixation per unit area (kg / ha), N straw is the amount of nitrogen in straw returned to the field per unit area (kg / ha), N uptake is the amount of nitrogen absorbed by crops per unit area (kg / ha).

[0074] In the above formula, the nitrogen surplus in the Yangtze River Basin in 2015 is shown in Table 1. Figure 2

[0075] N fer is calculated by the formula:

[0076] N fer = (Fer N + 0.3 x Fer com ) / A crop

[0077] In the above formula, Fer N is the amount of nitrogen fertilizer input (kg), and Fer com is the amount of compound fertilizer input (kg).

[0078] N manure is calculated by the formula:

[0079] ​

[0080] In the above formula, M i is the national scale livestock manure application amount (kg) of large livestock, pigs, cattle and poultry, θ i is the proportion of regional livestock breeding scale to the national scale (dimensionless decimal) ;

[0081] N fix When calculating, crops are divided into legumes, paddy fields and upland fields, and the calculation formula is:

[0082] N fix = (Crop leg × 0.6 + A paddy × f paddy + A upland × f upland ) / A crop

[0083] In the above formula, Crop leg is the nitrogen content of legumes (including seeds and straw, calculation method see crop absorption) (kg), A paddy , A upland are the areas of paddy fields and upland fields (ha), f paddy , f upland are the nitrogen fixation coefficients of paddy fields and upland fields per unit area (kg / ha) ;

[0084] N straw The calculation formula is:

[0085] N straw = (Straw × R str ) / A crop

[0086] In the above formula, Straw is the total amount of straw resources (kg), R str is the straw application rate (dimensionless decimal) ;

[0087] N uptake According to the yield, seed nitrogen content, straw nitrogen content and grass-grain ratio of different crops, when calculating, crops are divided into wheat, corn, rice, other grains, fruits, oil crops, sugar crops, tuber crops, vegetables, legumes and other crops, and the calculation formula of N

[0088]

[0089] In the above formula, Yield i is the yield of the i-th crop (kg), c seed，i is the seed nitrogen content of the i-th crop (dimensionless decimal), c str，iLet μ be the nitrogen content (dimensionless decimal) of the i-th crop straw. i Let be the ratio of grass to grain for the i-th crop (dimensionless decimal).

[0090] 4. Determine the nitrogen reduction rate of each wetland within the watershed based on natural geographic data and wetland distribution data:

[0091]

[0092] ln(k i )=-1.07×ln(t i -0.029×T i -1.08

[0093]

[0094] In the above formula, R i Let k be the nitrogen reduction rate (%) of the i-th wetland. i Let d be the first-order kinetic attenuation constant of the i-th wetland. -1 ), t i Let T be the hydraulic residence time (d) of the i-th wetland. i Let A be the average annual temperature (°C) of the i-th wetland. wetand，i Let be the area (ha) of the i-th wetland.

[0095] 5. Determine the nitrogen sink potential of wetlands within the watershed based on nitrogen input and nitrogen reduction rates of each wetland:

[0096]

[0097] In the above formula, Sink is the wetland nitrogen sink potential (kg) in the watershed, and N is the number of wetlands in the watershed.

[0098] This embodiment calculates the nitrogen sequestration potential of wetlands in the Yangtze River Basin in 2015 to be 256,000 tons. The nitrogen sequestration potential of wetlands in 45 smaller watersheds within the Yangtze River Basin is as follows: Figure 3 As shown.

[0099] Example 2:

[0100] Watershed wetland nitrogen sequestration potential assessment system, such as Figure 4 As shown, it includes a data acquisition module, a nitrogen input determination module, a nitrogen reduction rate determination module, and a wetland nitrogen sink potential determination module.

[0101] The data acquisition module is configured to acquire natural geographical data, agricultural production activity data and wetland distribution data of the basin, wherein the natural geographical data comprises air temperature data, cultivated land area, construction land area, forest and grassland area and atmospheric nitrogen deposition rate of the basin; the agricultural production activity data comprises fertilizer nitrogen input (including nitrogen fertilizer and compound fertilizer), different crop yield, livestock and poultry breeding scale, straw returning rate and experience parameter data of the basin; and the wetland distribution data comprises wetland area, longitude and latitude of the basin.

[0102] The nitrogen input determination module is configured to determine wetland nitrogen input based on the natural geographical data and the agricultural production activity data.

[0103] N in，i = f x N sur x A wetland，i x 8.2

[0104]

[0105] N crop = N fer + N manure + N dep + N fix + N straw - N uptake

[0106] In the above formula, N in，i represents nitrogen input of the i-th wetland, f represents an attenuation factor, the range of which is 0.3-0.5, the attenuation factor representing the proportion of nitrogen surplus in the basin potentially entering the wetland, which is calculated according to the proportion of land use types (cultivated land, construction land and forest and grassland) in the basin and nitrogen loss coefficients of different land use types, N sur represents nitrogen surplus in the basin, A wetland，i represents the area of the i-th wetland, A crop and A non-crop respectively represent the area of cultivated land and non-cultivated land in the basin, N crop represents nitrogen surplus of the cultivated land, N dep represents atmospheric nitrogen deposition rate in the basin, A watershed represents the area of the basin, N fer represents nitrogen fertilizer input intensity of the cultivated land, N manure represents the amount of nitrogen in livestock and poultry manure returned to the field per unit area, N fix represents the amount of nitrogen fixed by organisms per unit area, N straw represents the amount of nitrogen in straw returned to the field per unit area, and N uptake represents the amount of nitrogen absorbed by crops per unit area.

[0107] N fer is calculated according to the following formula:

[0108] N fer = (Fer N + 0.3 x Fer com ) / A crop

[0109] In the above formula, Fer N is the nitrogen fertilizer input (kg), and Fer com is the compound fertilizer input (kg);

[0110] N manure The calculation formula is:

[0111]

[0112] In the above formula, M i is the national scale livestock manure application amount (kg) of large livestock, pigs, cattle and poultry, and θ i is the proportion of regional livestock breeding scale to the national scale (dimensionless decimal);

[0113] N fix When calculating, crops are divided into legumes, paddy fields and upland fields, and the calculation formula is:

[0114] N fix = (Crop leg x 0.6 + A paddy x f paddy + A upland x f upland ) / A crop

[0115] In the above formula, Crop leg is the nitrogen content of legumes (including seeds and straw, calculation method see crop absorption) (kg), A paddy and A upland are the areas of paddy fields and upland fields (ha), and f paddy and f upland are the nitrogen fixation coefficients of paddy fields and upland fields (kg / ha);

[0116] N straw The calculation formula is:

[0117] N straw = (Straw x R str ) / A crop

[0118] In the above formula, Straw is the total amount of straw resources (kg), and R str is the straw application rate (dimensionless decimal);

[0119] N uptakeAccording to the yield, seed nitrogen content, straw nitrogen content and grass-grain ratio of different crops, the crops are divided into wheat, corn, rice, other grains, fruits, oil crops, sugar crops, tuber crops, vegetables, legumes and other crops, and the calculation formula is:

[0120]

[0121] In the above formula, Yield i is the yield of the i-th crop (kg), c seed，i is the seed nitrogen content of the i-th crop (dimensionless decimal), c str，i is the straw nitrogen content of the i-th crop (dimensionless decimal), μ i is the grass-grain ratio of the i-th crop (dimensionless decimal).

[0122] The nitrogen reduction rate determination module is configured to determine the nitrogen reduction rate of the wetland based on the natural geographical data and the wetland distribution data:

[0123]

[0124] ln(k i ) = -1.07 × ln(t i ) - 0.029 × T i - 1.08

[0125]

[0126] In the above formula, R i is the nitrogen reduction rate of the i-th wetland, k i is the first-order kinetic decay constant of the i-th wetland, t i is the hydraulic retention time of the i-th wetland, T i is the average annual temperature of the i-th wetland.

[0127] The wetland nitrogen sink potential determination module is configured to determine the wetland nitrogen sink potential Sink in the basin based on the wetland nitrogen input and the nitrogen reduction rate of the wetland:

[0128]

[0129] In the above formula, N is the number of wetlands in the basin.

[0130] Embodiment 3:

[0131] The wetland nitrogen sink potential evaluation device, as shown in Figure 5 , comprises a memory and a processor.

[0132] The memory is configured to store computer program code and transmit the computer program code to the processor.

[0133] The processor is configured to execute the method according to any one of the preceding embodiments based on instructions in the computer program code.

[0134] Embodiment 4:

[0135] A computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method according to any one of the preceding embodiments.

Claims

1. A method for assessing nitrogen sink potential of wetlands in a river basin, characterized in that, the method comprises: S1, obtaining natural geographical data, agricultural production activity data and wetland distribution data of the river basin; S2, determining nitrogen input of each wetland in the river basin based on the natural geographical data and the agricultural production activity data, and determining nitrogen reduction rate of each wetland in the river basin based on the natural geographical data and the wetland distribution data; the nitrogen input of each wetland in the river basin is calculated according to the following formula: ； in the above formula, Ninj is the nitrogen input for the ith wetland, D is the decay factor, Nsurplus is the nitrogen surplus of the catchment, Aij is the area of the ith wetland; the nitrogen reduction rate of each wetland in the river basin is calculated according to the following formula: ； In the above formula, is the reduction rate of nitrogen for the i-th wetland, is the first-order kinetic decay constant for the i-th wetland, is the hydraulic retention time for the i-th wetland; S3. Determine the potential of wetland nitrogen sink in the basin based on the nitrogen input and reduction rate of each wetland : ； In the above formula, is the number of wetlands in the watershed. 2.The method for assessing nitrogen sink potential of wetlands in a river basin according to claim 1, characterized in that, The The result is calculated according to the following formula: ； ； In the above formula, , are the cultivated land area and non-cultivated land area in the basin, respectively, is the nitrogen surplus of cultivated land, is the atmospheric nitrogen deposition rate in the basin, is the basin area, is the nitrogen fertilizer input intensity of cultivated land, is the amount of nitrogen in livestock and poultry manure returned to the field per unit area, is the amount of biological nitrogen fixation per unit area, is the amount of nitrogen in straw returned to the field per unit area, is the amount of nitrogen absorbed by crops per unit area. 3.The method for assessing nitrogen sink potential of wetlands in a river basin according to claim 1, characterized in that, The The result is calculated according to the following formula: ； ； In the above formula, T is the average annual temperature of the ith wetland. 4.A system for assessing nitrogen sink potential of wetlands in a river basin, characterized in that, the system comprises a data acquisition module, a nitrogen input determination module, a nitrogen reduction rate determination module and a wetland nitrogen sink potential determination module; the data acquisition module is used for obtaining natural geographical data, agricultural production activity data and wetland distribution data of the river basin; the nitrogen input determination module is used for calculating nitrogen input of each wetland in the river basin based on the natural geographical data and the agricultural production activity data according to the following formula: ； in the above formula, Ninj is the nitrogen input for the ith wetland, D is the decay factor, Nsurplus is the nitrogen surplus of the catchment, Ainj is the area of the ith wetland; the nitrogen reduction rate determination module is used for calculating nitrogen reduction rate of each wetland in the river basin based on the natural geographical data and the wetland distribution data according to the following formula: ； In the above formula, is the reduction rate of nitrogen by the i-th wetland, is the first-order kinetic decay constant of the i-th wetland, is the hydraulic retention time of the i-th wetland; The wetland nitrogen sink potential determination module is configured to determine the wetland nitrogen sink potential in the basin based on the wetland nitrogen input and the reduction rate of nitrogen by the wetland : ； In the above formula, is the number of wetlands within the watershed. 5.The system for assessing nitrogen sink potential of wetlands in a river basin according to claim 4, characterized in that, The The result is calculated according to the following formula: ； ； In the above formula, , are the cultivated land area and non-cultivated land area in the basin, respectively, is the nitrogen surplus of cultivated land, is the atmospheric nitrogen deposition rate in the basin, is the basin area, is the nitrogen fertilizer input intensity of cultivated land, is the amount of nitrogen in livestock and poultry manure returned to the field per unit area, is the amount of biological nitrogen fixation per unit area, is the amount of nitrogen in straw returned to the field per unit area, is the amount of nitrogen absorbed by crops per unit area. 6.The system for assessing nitrogen sink potential of wetlands in a river basin according to claim 4, characterized in that, The The result is calculated according to the following formula: ； ； In the above formula, T is the average annual temperature of the ith wetland. 7.An apparatus for assessing nitrogen sink potential of wetlands in a river basin, characterized in that: the apparatus comprises a memory and a processor; the memory is used for storing computer program code and transmitting the computer program code to the processor; the processor is used for executing the method according to any one of claims 1-3 according to instructions in the computer program code.

8. A computer-readable storage medium, characterized in that: The computer program is stored on the computer readable storage medium, and the computer program is executed by the processor to realize the method according to any one of claims 1-3.

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