Method for analyzing health condition of layered lake and reservoir water ecosystem

Abstract

The invention discloses a method for analyzing the health condition of a layered lake and reservoir water ecosystem, and belongs to the technical field of water ecosystem analysis. The method comprises the following steps: arranging a plurality of sampling lines in a target lake reservoir in a thermal stratification period, dividing each sampling line into a surface layer, a middle layer and a bottom layer, and collecting a water sample of each layer of each sampling line; based on the water sample of each layer of each sampling line, obtaining a water quality evaluation index and an ecological evaluation index; dividing each sampling line into a reference point and a damaged point, and screening the ecological evaluation indexes based on the reference points and the damaged points to obtain a final ecological evaluation index; and on the basis of the final ecological evaluation index, calculating to obtain a final zooplankton integrity index of each sampling line, and dividing a final zooplankton integrity grade according to the final zooplankton integrity index of each sampling line. According to the method, the health conditions of the lakes and reservoirs are analyzed through zooplanktons, meanwhile, the vertical heterogeneity of the lakes and reservoirs in the thermal stratification period is considered, and objectivity and comprehensiveness are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of water ecosystem analysis, and in particular relates to a method for analyzing the health status of a stratified lake and reservoir water ecosystem. Background Art

[0002] Zooplankton is an important component of the global biogeochemical cycle and aquatic ecosystem, and plays a key role in maintaining the function of aquatic ecosystems. The species composition, quantity changes, dominant species and pollution indicator species of zooplankton are greatly affected by the natural geographical environment of the lake, environmental factors and human activities. Most zooplankton have a short life cycle and are very sensitive to changes in climate and other environmental variables. They can respond quickly to environmental changes. Therefore, zooplankton is widely considered to be an important indicator of the ecological status of lakes.

[0003] The surface and bottom water bodies of deepwater reservoirs have different thermodynamic characteristics, and the water temperature is unevenly distributed vertically. The water body forms a variable temperature layer, a thermocline and a stagnation layer, which is the thermal stratification phenomenon. Thermal stratification is an important limnological characteristic of deepwater reservoirs and an important hydrological process. It can affect the transmission of matter and energy in the water body, resulting in uneven vertical distribution and chemical stratification. Due to the deep water body and large water level fluctuations in deepwater reservoirs, benthic animals, emergent and submerged plants are relatively scarce, and plankton has become the main component of the reservoir ecosystem. Because zooplankton is highly sensitive to changes in environmental variables, when the physical and chemical environment of the water body changes, the structure and diversity of zooplankton communities will be affected.

[0004] Existing technologies mostly use single biological indicator evaluation methods, lack the integration and application of zooplankton in comprehensive water quality biological evaluation methods in lakes and reservoirs, and ignore the vertical heterogeneity of zooplankton integrity under the influence of thermal stratification in deep-water lakes and reservoirs, resulting in the inability to fully and objectively reflect the health of stratified lake and reservoir water ecosystems. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for analyzing the health status of stratified lake and reservoir water ecosystems. The health status of lakes and reservoirs is analyzed through zooplankton, while the vertical heterogeneity of lakes and reservoirs during thermal stratification is taken into account to improve objectivity and comprehensiveness.

[0006] The present invention provides the following technical solutions:

[0007] A method for analyzing the health status of a water ecosystem of a stratified lake or reservoir comprises: arranging a number of sampling lines in a target lake or reservoir during thermal stratification, dividing each sampling line into a surface layer, a middle layer and a bottom layer, and collecting water samples of each layer of each sampling line; obtaining water quality evaluation indicators and ecological evaluation indicators based on the water samples of each layer of each sampling line; dividing each sampling line into a reference point and a damaged point according to the water quality evaluation indicators and the ecological evaluation indicators, and screening the ecological evaluation indicators based on the reference point and the damaged point to obtain a final ecological evaluation indicator; calculating a final zooplankton integrity index of each sampling line based on the final ecological evaluation indicator, and dividing the final zooplankton integrity level according to the final zooplankton integrity index of each sampling line.

[0008] As an optional technical solution of the present invention, the surface layer of the sampling line is located 0.5m below the water surface of the target lake reservoir, the middle layer of the sampling line is located at 1 / 2 of the maximum water depth of the target lake reservoir, and the bottom layer of the sampling line is located 0.5m above the sediment.

[0009] As an optional technical solution of the present invention, the water quality evaluation indicators include total nitrogen, total phosphorus, sulfate, nitrate nitrogen, ammonia nitrogen, permanganate index, chemical oxygen demand, five-day biochemical oxygen demand, sulfide, iron, manganese, copper, zinc, arsenic, chloride and fluoride; the ecological evaluation indicators include the number of zooplankton species, total zooplankton abundance, richness index, diversity index, evenness index, the number of protozoa species, the number of rotifer species, the number of cladoceran species, the number of copepod species, the percentage of protozoa abundance, the percentage of rotifer abundance, the percentage of cladoceran abundance, the percentage of copepod abundance, the total abundance of rotifers, the total abundance of non-rotifers, the abundance of the top three dominant species and the percentage of the abundance of the top three dominant species.

[0010] As an optional technical solution of the present invention, the sampling lines are divided into reference points and damaged points according to the water quality evaluation indicators and the ecological evaluation indicators, including: judging the comprehensive water quality according to the water quality evaluation indicators, dividing the sampling lines whose diversity index is greater than or equal to 2 and whose comprehensive water quality reaches Class III water standards and above into reference points, and dividing the remaining sampling lines into damaged points.

[0011] As an optional technical solution of the present invention, the screening of the ecological evaluation indicators to obtain the final ecological evaluation indicators includes: the ecological evaluation indicators are screened by distribution range screening, discrimination ability screening and correlation screening to obtain the final ecological evaluation indicators.

[0012] As an optional technical solution of the present invention, the distribution range screening includes: calculating the mean and standard deviation of the ecological evaluation index, comparing the relationship between the standard deviation and 1 / 2 of the mean, and eliminating ecological evaluation indicators with a standard deviation greater than 1 / 2 of the mean.

[0013] As an optional technical solution of the present invention, the discrimination ability screening includes: drawing a box plot of the ecological evaluation indicators that have not been eliminated by the distribution range screening based on the reference points and damaged points, and comparing the overlap of the 25%~75% quantile range of the reference points and the damaged points under the same ecological evaluation indicators; if the median line of any one of the reference point and the damaged point intersects with the box of the other, then IQ=0; if the median line of one of the reference point and the damaged point does not intersect in the other box, then IQ=1; if the boxes of the damaged point and the reference point partially overlap horizontally, but the medians of both do not intersect with each other's boxes, then IQ=2; if the boxes of the damaged point and the reference point do not overlap and the median line does not intersect with each other's boxes, then IQ=3; and eliminate ecological evaluation indicators with IQ≤1.

[0014] As an optional technical solution of the present invention, the correlation screening includes: performing normal analysis on the ecological evaluation indicators after the discrimination ability screening, if they conform to the normal distribution, using Pearson correlation analysis to obtain the correlation coefficient and significance level of any two ecological evaluation indicators; if they do not conform to the normal distribution, using Spearman correlation analysis to obtain the correlation coefficient and significance level of any two ecological evaluation indicators; if the correlation coefficient of two ecological evaluation indicators is ≥0.75, one of them is eliminated; if an ecological evaluation indicator has a correlation coefficient ≥0.75 and a significance level ≤0.01 with multiple ecological evaluation indicators at the same time, the ecological evaluation indicator is eliminated.

[0015] As an optional technical solution of the present invention, the final zooplankton integrity index of each sampling line is calculated based on the final ecological evaluation index, including:

[0016] The zooplankton integrity index of each layer of water at each sampling line was calculated by the 95% quantile method and the 5% quantile method;

[0017] The zooplankton integrity index, one of the final ecological evaluation indicators, was calculated using the 95% quantile method and is expressed as:

[0018] ;

[0019] The zooplankton integrity index, one of the final ecological evaluation indicators, was calculated using the 5% quantile method and is expressed as:

[0020] ;

[0021] in, represents the ith value of one of the final ecological evaluation indicators, It represents the 95% quantile value of the final ecological evaluation index. It represents the maximum value of the final ecological evaluation index. Indicates the value of the 5% quantile of the final ecological evaluation index;

[0022] The zooplankton integrity index of any layer of water at each sampling line is expressed as:

[0023] ;

[0024] in, , represents any layer among the surface, middle and bottom layers; n represents the nth final ecological evaluation index. For the final ecological evaluation index with a larger value as the disturbance intensity increases, the 95% quantile method is used to calculate its zooplankton integrity index; for the final ecological evaluation index with a smaller value as the disturbance intensity increases, the 5% quantile method is used to calculate its zooplankton integrity index;

[0025] The final zooplankton integrity index of each sampling line is expressed as:

[0026] ;

[0027] in, Represents the zooplankton integrity index of the surface, middle and bottom layers respectively.

[0028] As an optional technical solution of the present invention, the final zooplankton integrity level is divided according to the final zooplankton integrity index of each sampling line, including: setting a grade standard according to the final zooplankton integrity index of the reference point, and dividing the final zooplankton integrity level of each sampling line based on the grade standard; determining the health status of each sampling line according to the final zooplankton integrity level of each sampling line.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides an analysis method for the health status of stratified lake and reservoir water ecosystems, which comprehensively evaluates the health status of lake and reservoir water ecosystems through zooplankton in the lakes and reservoirs, thereby improving the scientificity and accuracy of the evaluation; at the same time, it comprehensively considers the vertical heterogeneity of zooplankton integrity under the influence of thermal stratification in deep-water lakes and reservoirs, thereby more comprehensively and objectively evaluating the health status of stratified lake and reservoir water ecosystems. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of a method for analyzing the health status of a stratified lake and reservoir water ecosystem in an embodiment of the present invention;

[0032] Figure 2 is a box plot of discrimination ability screening in an embodiment of the present invention;

[0033] Figure 3 is a correlation diagram of correlation screening in an embodiment of the present invention;

[0034] Figure 4 Schematic diagram of the redundancy analysis result of the final zooplankton integrity index in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0036] Example 1

[0037] This embodiment provides a method for analyzing the health status of a stratified lake and reservoir water ecosystem. Figure 1 As shown, the specific steps include:

[0038] Step 1: Arrange several sampling lines in the target lake or reservoir during thermal stratification, divide each sampling line into surface, middle and bottom layers, and collect water samples from each layer of each sampling line.

[0039] In this embodiment, during the thermal stratification of the target lake, a portable dissolved oxygen meter, pH meter, water temperature meter and depth sounder are used to measure the dissolved oxygen (DO), pH, water temperature (WT) and water depth (WD) at each depth in a layered manner. 16 sampling lines are arranged in the target lake, and plexiglass deep water samplers are used to achieve layered sampling. Three water quality samples of the surface, middle and bottom layers are collected and refrigerated and sent back to the laboratory.

[0040] Furthermore, the surface layer of the sampling line is located 0.5 m below the water surface of the target lake reservoir, the middle layer of the sampling line is located at 1 / 2 of the maximum water depth of the target lake reservoir, and the bottom layer of the sampling line is located 0.5 m above the sediment.

[0041] In this embodiment, after 20 L of water samples were collected by using a plexiglass deep-water sampler for protozoa and rotifers, 1.5% of the volume of the water sample was immediately added to fix the Lugo reagent. After the water samples of cladocerans and copepods were collected, they were filtered with a 25# plankton net, the filtered water was placed in a sample bottle, and the net was washed twice. The obtained water sample was placed in the above sample bottle, and 4% of the volume of the water sample was immediately added to fix the formaldehyde solution. The water samples were sent back to the laboratory for precipitation for 48 hours and concentrated to 30 mL, and then identified and counted under a microscope.

[0042] Step 2: Based on the water samples of each layer of each sampling line, water quality evaluation indicators and ecological evaluation indicators are obtained.

[0043] The water quality evaluation indicators are determined according to the "Surface Water Environmental Quality Standard" (GB 3838-2002), including total nitrogen (TN), total phosphorus (TP), sulfate (SO42-S), nitrate nitrogen (NO3--N), ammonia nitrogen (NH3-N), permanganate index ( ), chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD5), sulfide (S), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), arsenic (As), chloride (Cl-), fluoride (F-), dissolved oxygen (DO), pH, and water temperature (WT).

[0044] In this embodiment, the water quality evaluation index of a lake and the measurement results of dissolved oxygen (DO), pH, and water temperature (WT) are shown in Table 1.

[0045] Table 1 Water quality evaluation index table of a certain lake reservoir

[0046] Water quality evaluation indicators surface layer Middle level Bottom Layer WT / (℃) 21.41 20.68 15.55 pH 7.32 7.32 7.24 DO / (mg / L) 6.38 5.63 5.22 <![CDATA[COD Mn / (mg / L)]]> 3.64 3.45 3.46 COD / (mg / L) 16.50 14.94 14.75 <![CDATA[BOD5 / (mg / L)]]> 1.17 1.23 1.37 TP / (mg / L) 0.041 0.023 0.021 TN / (mg / L) 2.00 1.85 1.83 <![CDATA[SO4 2- -S / (mg / L)]]> 5.80 5.71 5.39 <![CDATA[NO3 - -N / (mg / L)]]> 0.80 0.80 0.75 <![CDATA[NH3-N / (mg / L)]]> 0.41 0.39 0.47 <![CDATA[F - / (mg / L)]]> 0.12 0.12 0.12 S / (mg / L) 0.0035 0.0035 0.0040 Fe / (mg / L) 0.070 0.071 0.150 Mn / (mg / L) 0.030 0.031 0.080 Cu / (mg / L) 0.00028 0.00027 0.00028 Zn / (mg / L) 0.0066 0.0089 0.0134 As / (mg / L) 0.00040 0.00038 0.00036 <![CDATA[Cl - / (mg / L)]]> 8.30 8.33 8.39

[0047] The ecological evaluation indicators include the number of zooplankton species, total zooplankton abundance, richness index (D), diversity index (H'), evenness index (J), the number of protozoa species, the number of rotifer species, the number of cladoceran species, the number of copepod species, the percentage of protozoa abundance, the percentage of rotifer abundance, the percentage of cladoceran abundance, the percentage of copepod abundance, the total abundance of rotifers, the total abundance of non-rotifers, the sum of the abundance of the top three dominant species, and the percentage of the abundance of the top three dominant species.

[0048] The calculation formula of richness index D is:

[0049] ;

[0050] The calculation formula of diversity index H' is:

[0051] ;

[0052] The calculation formula of uniformity index J is:

[0053] ;

[0054] The calculation formula of species dominance Y is:

[0055] ;

[0056] Among them, S represents the number of species in a certain layer of the sampling line, N represents the number of species in the lake, represents the total number of the i-th species, represents the frequency of the i-th species.

[0057] In this embodiment, the ecological evaluation index serial number table is shown in Table 2.

[0058] Table 2 Ecological evaluation index table of a lake or reservoir

[0059] Serial number Candidate ecological evaluation indicators Z1 Number of zooplankton species Z2 Number of protozoan species Z3 Number of rotifer species Z4 Number of cladoceran species Z5 Number of copepod species Z6 Total zooplankton abundance Z7 Total abundance of rotifers Z8 Total abundance of non-rotifers Z9 Richness index D Z10 Diversity index H' Z11 Uniformity index J Z12 Protozoa abundance percentage Z13 Rotifer abundance percentage Z14 Abundance percentage of cladocerans Z15 Percentage of copepod abundance Z16 The abundance of the top three dominant species and Z17 Abundance percentage of the top three dominant species

[0060] Step 3: Divide the sampling lines into reference points and damaged points according to the water quality evaluation index and the ecological evaluation index, and select the ecological evaluation index based on the reference points and the damaged points to obtain the final ecological evaluation index. Specifically including:

[0061] 3.1. The comprehensive water quality is evaluated according to the water quality evaluation index, and the sampling lines with diversity index H' greater than or equal to 2 and comprehensive water quality reaching Class III water standard or above are classified as reference points, and the remaining sampling lines are classified as damaged points.

[0062] In this embodiment, among the 16 sampling lines of a lake or reservoir, 6 meet the reference point selection criteria, and the remaining 10 are used as damaged points.

[0063] 3.2. After the ecological evaluation indicators are screened by distribution range, discrimination ability and correlation, the final ecological evaluation indicators are obtained.

[0064] The steps for screening the above 17 ecological evaluation indicators are as follows:

[0065] 3.2.1. The distribution range screening includes: calculating the mean value and standard deviation of the ecological evaluation index, as shown in Table 3.

[0066] Table 3 Distribution of ecological evaluation indicators of a lake

[0067] Ecological evaluation indicators average value Standard Deviation 25% quantile 75% quantile Z1 11.98 2.03 11.00 13.00 Z2 1.15 0.82 0.75 2.00 Z3 7.65 1.19 7.00 9.00 Z4 1.69 0.66 1.00 2.00 Z5 1.50 0.65 1.00 2.00 Z6 2015.08 622.85 1485.00 2349.25 Z7 1237.17 299.71 993.00 1456.25 Z8 777.92 502.23 450.00 914.25 Z9 2.77 0.34 2.57 2.96 Z10 2.29 0.20 2.22 2.39 Z11 0.92 0.08 0.89 0.97 Z12 0.11 0.09 0.04 0.16 Z13 0.64 0.13 0.59 0.72 Z14 0.18 0.10 0.10 0.21 Z15 0.07 0.04 0.05 0.10 Z16 827.85 341.40 564.00 985.50 Z17 0.41 0.09 0.35 0.45

[0068] Compare the relationship between the standard deviation and the 1 / 2 average value, and eliminate the ecological evaluation indicators whose standard deviation is greater than the 1 / 2 average value. In this embodiment, Z2, Z8, Z12, Z14, and Z15 are eliminated.

[0069] 3.2.2. The discrimination ability screening includes: drawing a box plot of the ecological assessment indicators that are not eliminated by the distribution range screening based on the reference points and damaged points, such as Figure 2 shown.

[0070] Compare the overlap of the 25%~75% quantile range of the reference point and the damaged point under the same ecological evaluation index: if the median line of either the reference point or the damaged point intersects with the box of the other, then IQ=0, and the discrimination ability of this index is the weakest at this time; if the median line of one of the reference point and the damaged point does not intersect in the other box, then IQ=1; if the boxes of the damaged point and the reference point partially overlap horizontally, but the medians of both do not intersect with the other box, then IQ=2; if the boxes of the damaged point and the reference point do not overlap and the medians do not intersect with the other box, then IQ=3, and the discrimination ability of this index is the strongest at this time.

[0071] Eliminate ecological evaluation indicators with IQ ≤ 1. In this embodiment, only Z3, Z4, Z13, Z16, and Z17 remain after elimination.

[0072] 3.2.3. The correlation screening includes: performing normal analysis on the ecological evaluation indicators after the discrimination ability screening. If they conform to the normal distribution, Pearson correlation analysis is used to obtain the correlation coefficient and significance level of any two ecological evaluation indicators; if they do not conform to the normal distribution, Spearman correlation analysis is used to obtain the correlation coefficient and significance level of any two ecological evaluation indicators.

[0073] If the correlation coefficient of two ecological evaluation indicators is ≥0.75, it means that the two ecological evaluation indicators have a high degree of overlap, and one of them is eliminated. If the correlation coefficient of an ecological evaluation indicator with multiple ecological evaluation indicators is ≥0.75 and the significance level is ≤0.01, it means that the indicator is not referenceable and has a lot of overlapping information, so the ecological evaluation indicator is eliminated.

[0074] like Figure 3 As shown in the figure, the "***" mark represents a significant correlation. Z16 is significantly correlated with Z4, Z13, and Z17. After excluding Z16, the remaining ones are Z3, Z4, Z13, and Z17.

[0075] Step 4: Based on the final ecological evaluation index, calculate the final zooplankton integrity index of each sampling line, and divide the final zooplankton integrity level according to the final zooplankton integrity index of each sampling line. Specifically including the following steps:

[0076] 4.1. Based on the four final ecological evaluation indicators screened, the final zooplankton integrity index of each sampling line was calculated, including:

[0077] The zooplankton integrity index of each layer of water at each sampling line was calculated by the 95% quantile method and the 5% quantile method. The interference situation, maximum value, 95% quantile and 5% quantile results of the four final ecological evaluation indicators are shown in Table 4.

[0078] Table 4 Calculation parameters of the final ecological evaluation index of a lake

[0079] Final ecological evaluation index Interference Maximum 95% quantile 5% quantile Z3 ↑ 10 9 6 Z4 ↓ 4 2.65 1 Z13 ↑ 0.92 0.84 0.40 Z17 ↑ 0.65 0.57 0.29

[0080] Among them, ↓ means that under strong interference conditions, the value of the indicator decreases; ↑ means that under strong interference conditions, the value of the indicator increases.

[0081] The zooplankton integrity index, one of the final ecological evaluation indicators, was calculated using the 95% quantile method and is expressed as:

[0082] ;

[0083] The zooplankton integrity index, one of the final ecological evaluation indicators, was calculated using the 5% quantile method and is expressed as:

[0084] ;

[0085] in, represents the ith value of one of the final ecological evaluation indicators, It represents the 95% quantile value of the final ecological evaluation index. It represents the maximum value of the final ecological evaluation index. It represents the 5% quantile value of the final ecological evaluation index.

[0086] For the final ecological evaluation index with larger values ​​as the disturbance intensity increases, the 95% quantile method is used to calculate its zooplankton integrity index; for the final ecological evaluation index with smaller values ​​as the disturbance intensity increases, the 5% quantile method is used to calculate its zooplankton integrity index. As shown in Table 4, Z4 is calculated using the 95% quantile method, and the remaining final ecological evaluation indicators are calculated using the 5% quantile method.

[0087] The zooplankton integrity index of any layer of water at each sampling line is expressed as:

[0088] ;

[0089] in, , indicating any of the surface, middle and bottom layers.

[0090] The final zooplankton integrity index of each sampling line is expressed as:

[0091] ;

[0092] in, Represents the zooplankton integrity index of the surface, middle and bottom layers respectively.

[0093] 4.2. According to the final zooplankton integrity index of the reference point, a grade standard is set, and the final zooplankton integrity grade of each sampling line is divided based on the grade standard. The health status of each sampling line is determined according to the final zooplankton integrity grade of each sampling line.

[0094] In this embodiment, the 25% quantile of the final zooplankton integrity index of the reference point is used as the dividing point, that is, the sampling line position where the index is greater than or equal to 7.45 is judged as excellent, and the grading standard is determined by the four-point method below this value, which is good, medium, general and poor. Finally, five grades of excellent, good, medium, general and poor are obtained, and the corresponding lake and reservoir grading standards are ≥7.45, 7.29 ~ 7.45, 7.18 ~ 7.29, 6.81 ~ 7.18, and <6.81.

[0095] According to this standard, the health status of each sampling line is determined, and the results are shown in Table 5.

[0096] Table 5 Final zooplankton integrity index of a lake sampling line

[0097] Sampling Line Final Zooplankton Integrity Index Analyze the results S1 7.55 excellent S2 7.80 excellent S3 8.39 excellent S4 8.79 excellent S5 5.12 Difference S6 7.44 good S7 6.87 generally S8 7.43 good S9 7.28 middle S10 7.11 generally S11 7.30 good S12 6.78 Difference S13 7.26 middle S14 6.53 Difference S15 8.34 excellent S16 7.48 excellent

[0098] Example 2

[0099] Based on Example 1, this example applies this method to analyze and obtain the driving factors that have a significant impact on the zooplankton integrity index.

[0100] In order to eliminate the impact of different water quality parameters, all water quality evaluation index data except pH were analyzed. After standardization, the first axis in the detrended correspondence analysis was 0.35 and the length gradient was < 3. Since the length gradient was < 3, redundancy analysis (RDA) was selected to analyze the driving factors that had a significant impact on the zooplankton integrity index.

[0101] like Figure 4 As shown in the figure, dissolved oxygen DO, ammonia nitrogen NH3-N and five-day biochemical oxygen demand BOD5 have the longest projection distance on the zooplankton integrity index ZIBI. Therefore, the main environmental driving factors of the zooplankton integrity index of a certain reservoir are dissolved oxygen DO, ammonia nitrogen NH3-N and five-day biochemical oxygen demand BOD5. It is necessary to strictly control the input of nutrients and organic matter and prevent and control pollution of lakes and reservoirs.

[0102] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0103] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0104] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0105] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0106] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for analyzing the health status of a stratified lake and reservoir water ecosystem, characterized in that: include: Arrange several sampling lines in the target lake during the thermal stratification period, divide each sampling line into the surface layer, the middle layer and the bottom layer, and collect water samples from each layer of each sampling line; Based on the water samples of each layer of each sampling line, water quality evaluation indicators and ecological evaluation indicators are obtained; According to the water quality evaluation index and the ecological evaluation index, each sampling line is divided into a reference point and a damaged point, and the ecological evaluation index is screened based on the reference point and the damaged point to obtain a final ecological evaluation index; Based on the final ecological evaluation index, the final zooplankton integrity index of each sampling line is calculated, and the final zooplankton integrity level is divided according to the final zooplankton integrity index of each sampling line.

2. The method for analyzing the health status of a stratified lake and reservoir water ecosystem according to claim 1, characterized in that: The surface layer of the sampling line is located 0.5 m below the water surface of the target lake reservoir, the middle layer of the sampling line is located at 1 / 2 of the maximum water depth of the target lake reservoir, and the bottom layer of the sampling line is located 0.5 m above the sediment.

3. The method for analyzing the health status of a stratified lake and reservoir water ecosystem according to claim 1 is characterized in that: The water quality evaluation indicators include total nitrogen, total phosphorus, sulfate, nitrate nitrogen, ammonia nitrogen, permanganate index, chemical oxygen demand, five-day biochemical oxygen demand, sulfide, iron, manganese, copper, zinc, arsenic, chloride and fluoride; The ecological evaluation indicators include the number of zooplankton species, total zooplankton abundance, richness index, diversity index, evenness index, the number of protozoa species, the number of rotifer species, the number of cladoceran species, the number of copepod species, the percentage of protozoa abundance, the percentage of rotifer abundance, the percentage of cladoceran abundance, the percentage of copepod abundance, the total abundance of rotifers, the total abundance of non-rotifers, the abundance of the top three dominant species and the percentage of abundance of the top three dominant species.

4. The method for analyzing the health status of a stratified lake and reservoir water ecosystem according to claim 2 is characterized in that: The method of dividing the sampling lines into reference points and damaged points according to the water quality evaluation index and the ecological evaluation index includes: The comprehensive water quality is judged according to the water quality evaluation index, and the sampling lines with diversity index greater than or equal to 2 and comprehensive water quality reaching Class III water standards and above are divided into reference points, and the remaining sampling lines are divided into damaged points.

5. The method for analyzing the health status of stratified lake and reservoir water ecosystem according to claim 1, characterized in that: The screening of the ecological evaluation indicators to obtain the final ecological evaluation indicators includes: The ecological evaluation index is obtained after distribution range screening, discrimination ability screening and correlation screening to obtain the final ecological evaluation index.

6. The method for analyzing the health status of stratified lake and reservoir water ecosystem according to claim 5, characterized in that: The distribution range screening includes: Calculate the mean and standard deviation of the ecological evaluation index, compare the relationship between the standard deviation and 1 / 2 of the mean, and eliminate the ecological evaluation index with a standard deviation greater than 1 / 2 of the mean.

7. The method for analyzing the health status of stratified lake and reservoir water ecosystem according to claim 5, characterized in that: The discrimination ability screening includes: Based on the reference points and damaged points, draw box plots of ecological assessment indicators that are not eliminated by the distribution range screening, and compare the overlap of the 25% to 75% quantile range of the reference points and damaged points under the same ecological assessment indicator; If the median line of either the reference point or the damaged point intersects the box of the other, IQ=0; if the median line of one of the reference point and the damaged point does not intersect the other box, IQ=1; if the boxes of the damaged point and the reference point partially overlap laterally, but the median lines of both do not intersect the other box, IQ=2; if the boxes of the damaged point and the reference point do not overlap and the median lines do not intersect the other box, IQ=3; Eliminate ecological evaluation indicators with IQ ≤ 1.

8. The method for analyzing the health status of stratified lake and reservoir water ecosystem according to claim 5, characterized in that: The correlation screening includes: The ecological evaluation indicators after the discrimination ability screening are subjected to normal analysis. If they conform to the normal distribution, Pearson correlation analysis is used to obtain the correlation coefficient and significance level of any two ecological evaluation indicators; if they do not conform to the normal distribution, Spearman correlation analysis is used to obtain the correlation coefficient and significance level of any two ecological evaluation indicators; If the correlation coefficient between two ecological evaluation indicators is ≥0.75, one of them will be eliminated; if the correlation coefficient of an ecological evaluation indicator with multiple ecological evaluation indicators is ≥0.75 and the significance level is ≤0.01, the ecological evaluation indicator will be eliminated.

9. The method for analyzing the health status of stratified lake and reservoir water ecosystem according to claim 1, characterized in that: The final zooplankton integrity index of each sampling line is calculated based on the final ecological evaluation index, including: The zooplankton integrity index of each layer of water at each sampling line was calculated by the 95% quantile method and the 5% quantile method; The zooplankton integrity index, one of the final ecological evaluation indicators, was calculated using the 95% quantile method and is expressed as: ； The zooplankton integrity index, one of the final ecological evaluation indicators, was calculated using the 5% quantile method and is expressed as: ； in, represents the i-th value of one of the final ecological evaluation indicators, It represents the 95% quantile value of the final ecological evaluation index. It represents the maximum value of the final ecological evaluation index. Indicates the value of the 5% quantile of the final ecological evaluation index; The zooplankton integrity index of any layer of water at each sampling line is expressed as: ； in, , represents any layer among the surface, middle and bottom layers; n represents the nth final ecological evaluation index. For the final ecological evaluation index with a larger value as the disturbance intensity increases, the 95% quantile method is used to calculate its zooplankton integrity index; for the final ecological evaluation index with a smaller value as the disturbance intensity increases, the 5% quantile method is used to calculate its zooplankton integrity index; The final zooplankton integrity index of each sampling line is expressed as: ； in, Represents the zooplankton integrity index of the surface, middle and bottom layers respectively.

10. The method for analyzing the health status of stratified lake and reservoir water ecosystem according to claim 1, characterized in that: The final zooplankton integrity level is divided according to the final zooplankton integrity index of each sampling line, including: setting a grade standard according to the final zooplankton integrity index of the reference point, and dividing the final zooplankton integrity grade of each sampling line based on the grade standard; The health status of each sampling line was determined based on the final zooplankton integrity level of each sampling line.

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