Construction method applied to juvenile fish downward dam-passing effect evaluation model

Abstract

The invention discloses a construction method applied to a model for evaluating a downward dam-passing effect of juvenile fishes. The method comprises the following steps: step 1, performing a fish releasing test in an entrance area of a bypass channel on a dam; 2, evaluation indexes of the descending dam passing effect of the juvenile fishes are obtained; 3, constructing data file variables of the juvenile fish downward dam passing rate model; 4, building a juvenile fish downward dam passing rate model coupled with multiple factors; and step 5, evaluating the descending dam passing effect of the juvenile fish based on the model. According to the method, on the basis of a dam project with a bypass channel, an on-dam bypass channel entrance area fish releasing test is carried out, the descending effect of fish passing objects passing through the bypass channel is monitored through the radio frequency identification technology, the descending attraction rate, the descending attraction time, the descending passing rate and the descending passing time are adopted to quantify the descending dam passing efficiency of juvenile fishes, and the fish passing efficiency is improved. A juvenile fish downward dam passing rate model coupling multiple factors is constructed, an optimal model is screened out through correlation analysis and AIC criteria, and the model is used for evaluating the juvenile fish downward dam passing effect.

Description

Technical Field

[0001] The invention belongs to the technical field of ecology and fish protection, and in particular relates to a method for constructing a model for evaluating the effect of young fish passing through a dam. Background Art

[0002] After years of development, a monitoring system that integrates multiple methods has been formed in foreign countries. These methods include traditional netting and manual identification and counting, as well as modern electric fishing, video identification, hydroacoustic monitoring and radio frequency identification technology. Among them, radio frequency identification technology (RFID) has been widely used internationally due to its advantages of high efficiency, high precision and little damage to fish bodies. Radio frequency identification technology is a non-contact automatic identification technology that uses radio waves to identify objects and read data. In the monitoring of juvenile fish, radio frequency identification technology installs small electronic tags on the fish body. When the juvenile fish passes through the monitoring point equipped with a reader, the system can quickly identify and record the passage of the juvenile fish. This method not only improves the efficiency of monitoring, but also reduces interference and damage to the juvenile fish. Therefore, it shows significant advantages in the monitoring of the effect of juvenile fish passing. In addition, radio frequency identification technology also has the characteristics of strong penetration, strong anti-fouling ability, and the ability to work stably in harsh environments. These characteristics make it have broad application prospects in the field of juvenile fish monitoring. With the continuous advancement of technology and the reduction of costs, it is expected that RFID technology will play a more important role in juvenile fish monitoring and may become one of the mainstream technologies for juvenile fish monitoring in the future.

[0003] In order to ensure that juvenile fish can migrate smoothly downstream and prevent them from entering harmful channels such as turbines, a route must be provided that allows juvenile fish to actively or passively flow from the upstream of the water conservancy facility to the tailwater without causing time delays and damage. The bypass channel is a channel that collects juvenile fish near the water surface in front of the dam. From the perspective of the proportion of the number of fish to the total discharge, the bypass channel is currently the most cost-effective route. From the perspective of cost (water diversion for power generation) and benefit (the number of fish bypassing the turbine), the bypass channel is a better downstream fish passage facility. At present, the research on the descent of juvenile fish mainly focuses on describing the characteristics of the descent behavior of juvenile fish and analyzing the influence of a single variable on the descent passage rate of juvenile fish. However, indoor single-factor control variable experiments often cannot truly reflect the descent law of juvenile fish in actual field projects under the synergistic effect of multiple factors. Constructing a juvenile fish descent dam passage rate model that couples multiple factors and evaluating the juvenile fish descent dam passage effect through a mathematical model to assist the juvenile fish descent migration is an effective means to solve the above problems.

[0004] Therefore, the technical problem to be solved by the present invention is that the current evaluation method mainly relies on simple observation and statistics, lacks a quantitative analysis method that integrates multiple factors, and cannot fully reflect the effect of young fish passing the dam. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for constructing a model for evaluating the effect of juvenile fish passing through a dam, a mathematical model is used to construct a juvenile fish passing through a dam model that couples multiple factors, and the optimal model is screened, and the model is used to provide recommended reference values ​​for the evaluation of the effect of juvenile fish passing through a dam.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for constructing a model for evaluating the effect of juvenile fish passing through a dam, comprising the following steps: Step 1: Conduct a fish release test at the entrance of the bypass channel on the dam; Step 2: Establish evaluation indicators for the effect of juvenile fish passing the dam; Step 3: Construct the data file variables of the model of the rate of juvenile fish passing through the dam; Step 4: Construct a model for the passing rate of juvenile fishes going down the dam by coupling multiple factors; Step 5: Evaluate the effect of juvenile fish passing the dam based on the juvenile fish passing rate model. Preferably, the test process of step 1 is: relying on a river project with a bypass channel, first arrange induction coils at the entrance of the bypass channel on the dam and the exit below the dam, and then implant the PIT tag into the abdominal cavity of the fish-passing object; when the test officially starts, release the marked fish in the area at the entrance of the bypass channel on the dam, and when the marked fish goes down through the induction coil, the radio frequency identification monitoring system will automatically record the number of the marked fish and the time of passing.

[0007] Preferably, in step 2, the calculation method of the evaluation index of the effect of juvenile fish passing the dam is: According to the marked fish data monitored by the radio frequency identification system, the corresponding indicators for evaluating the effect of juvenile fish passing the dam are obtained. The corresponding indicators include the downward attraction rate, the downward attraction time, the downward passing rate and the downward passing time. The definitions of each evaluation indicator are as follows: (1) The formula for downward attraction rate is: ; in is the downside attraction rate; the number of tagged fish released for the area at the entrance to the bypass channel above the dam; The number of tagged fish monitored by the induction coil at the entrance of the bypass channel above the dam; (2) Downward attraction time is defined as: ; in, is the downward attraction time, in days (d); The moment when the induction coil at the entrance of the bypass channel on the dam recognizes the tagged fish; the time to release tagged fish for the area at the entrance to the bypass channel above the dam; (3) The formula for the downlink pass rate is: ; in is the downlink throughput rate, The number of tagged fish monitored by the induction coil at the entrance of the bypass channel above the dam; The number of tagged fish monitored by the induction coil at the exit of the bypass channel below the dam; (4) Downlink transit time is defined as: ; in, is the downlink transit time, in days (d), It is the moment when the induction coil at the exit of the bypass channel under the dam recognizes the tagged fish; This is the moment when the tagged fish is recognized by the induction coil at the entrance of the bypass channel on the dam.

[0008] Preferably, in step 3, the variables in the data file of the model for the rate of juvenile fish passing through the dam include biological factors and environmental factors, wherein the biological factors include fish species, body length, wet weight, fatness and total length, and the environmental factors include water temperature, day and night, water pH and flow.

[0009] Preferably, in step 4, in order to identify the key factors affecting the effect of juvenile fish passing the dam, a juvenile fish passing rate model is constructed with fish species, flow, fatness, water temperature, body length, wet weight, water pH and circadian rhythm as covariates to quantify the influence of each covariate on the juvenile fish passing rate; the formula of the juvenile fish passing rate model is as follows: ； Where: Indicates the expiration time; represents the model parameters; represents the impact factor; represents a Weibull distribution characterized by a scale parameter.

[0010] Preferably, in step 4, in order to solve the multicollinearity problem of each covariate in the model and improve the model accuracy, the Akaike information criterion is used to screen out the optimal model; the formula of the Akaike information criterion is: ; Where: are model parameters; represents the likelihood function.

[0011] Preferably, in step 5, the effect of the juvenile fish passing the dam is evaluated based on the result of the juvenile fish passing rate model, so as to effectively quantify the juvenile fish passing efficiency.

[0012] A model for evaluating the effect of juvenile fish passing a dam adopts the method for constructing a model for evaluating the effect of juvenile fish passing a dam.

[0013] The present invention can achieve the following beneficial effects: The present invention takes the demand of assisting juvenile fish to pass through the dam as the starting point, relies on the river project with a bypass channel, carries out a fish release experiment at the entrance of the bypass channel on the dam, uses radio frequency identification technology to monitor the descending efficiency of the fish objects when passing through the bypass channel, screens the data file variables of the juvenile fish passing through the dam model, constructs a juvenile fish passing through the dam model that couples multiple factors, identifies the key factors affecting the juvenile fish passing through the dam, and uses the model to provide a reference for evaluating the effect of juvenile fish passing through the dam. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a flow chart of the steps of the present invention; Figure 2 This is a schematic diagram of the river section bypass channel; Figure 3 This is the correlation analysis diagram of the dependent variable matrix of the juvenile fish downstream dam passage rate model; Figure 4 This is a curve chart of the passing rate of young fishes going down the dam at different time periods. DETAILED DESCRIPTION

[0015] The preferred solution is Figures 1 to 4 As shown, a method for constructing a model for evaluating the effect of juvenile fish passing the dam is to evaluate the effect of juvenile fish passing the dam, preliminarily determine the fish objects that need to pass the dam in the key areas of hydropower projects, and use radio frequency identification technology to mark the fish objects with PIT tags, analyze the juvenile fish's downward attraction rate, downward attraction time, downward passing rate and downward passing time, construct and screen a juvenile fish downward passing rate model that couples multiple factors, identify the key factors that affect the juvenile fish's downward passing of the dam, and use the model to provide a reference for evaluating the effect of juvenile fish passing the dam. The method for constructing a model for evaluating the effect of juvenile fish passing the dam proposed in the present invention provides technical support for evaluating the effect of juvenile fish passing the dam. The steps are: Step 1: Fish release test at the entrance of the bypass channel on the dam; Step 2: Evaluation index of the effect of juvenile fish passing the dam; Step 3: Construct the data file variables of the model of the rate of juvenile fish passing through the dam; Step 4: Construct a model for the passing rate of juvenile fishes going down the dam by coupling multiple factors; Step 5: Use the model to evaluate the effect of juvenile fish passing the dam; In step 1, the method for releasing fish in the area at the entrance of the bypass channel on the dam is as follows: relying on the river project with the bypass channel built, firstly arrange the induction coils at the entrance of the bypass channel on the dam and the exit under the dam, and then implant the PIT tag into the abdominal cavity of the fish-passing object; when the test officially starts, release the marked fish in the area at the entrance of the bypass channel on the dam, and when the marked fish goes down through the induction coil, the radio frequency identification monitoring system will automatically record the number of the marked fish and the time of passing; In step 2, the calculation method for the evaluation index of the effect of juvenile fish passing the dam is: According to the marked fish data monitored by the radio frequency identification system, the corresponding indicators for evaluating the effect of juvenile fish passing the dam are obtained. The indicators include the downward attraction rate, the downward attraction time, the downward passing rate and the downward passing time. The definitions of each evaluation indicator are as follows: (1) The formula for downward attraction rate is: ; in is the downside attraction rate; the number of tagged fish released for the area at the entrance to the bypass channel above the dam; The number of tagged fish monitored by the induction coil at the entrance of the bypass channel above the dam; (2) Downward attraction time is defined as: ; in, is the downward attraction time, in days (d); The moment when the induction coil at the entrance of the bypass channel on the dam recognizes the tagged fish; the time to release tagged fish for the area at the entrance to the bypass channel above the dam; (3) The formula for the downlink pass rate is: ; in is the downlink throughput rate, The number of tagged fish monitored by the induction coil at the entrance of the bypass channel above the dam; The number of tagged fish monitored by the induction coil at the exit of the bypass channel below the dam; (4) Downlink transit time is defined as: ; in, is the downlink transit time, in days (d), It is the moment when the induction coil at the exit of the bypass channel under the dam recognizes the tagged fish; The moment when the induction coil at the entrance of the bypass channel on the dam recognizes the tagged fish; In step 3, the variables of the model data file for the rate of juvenile fish passing the dam include biological factors and environmental factors (Table 1), where biological factors include fish species (S), body length (BL), wet weight (W), fatness (FN), total length (TL), etc., and environmental factors include water temperature (T), water pH (PH), circadian rhythm (CR), flow (Q), etc.; In step 4, in order to identify the key factors affecting the juvenile fish passing the dam, a juvenile fish passing rate model was constructed with fish species, flow, fatness, water temperature, body length, wet weight, water pH and circadian rhythm as covariates to quantify the influence of each covariate on the juvenile fish passing rate (Table 1). The formula of the juvenile fish passing rate model is as follows: ； Where: Indicates the expiration time; represents the model parameters; represents the impact factor; represents a Weibull distribution characterized by a scale parameter; In order to solve the multicollinearity problem of each covariate in the model and improve the accuracy of the model, the Akaike Information Criterion (AIC) was used to screen out the optimal model. The AIC criterion is a standard for measuring the goodness of fit of a statistical model. When selecting the best model from a set of available models, the model with the smallest AIC is usually selected. The formula for AIC is: ; Where: are model parameters; represents the likelihood function; In step 5, the effect of juvenile fish passing the dam is evaluated based on the results of the juvenile fish passing rate model, and the efficiency of juvenile fish passing the dam is effectively quantified.

[0016] Table 1 Data file variables of the model of juvenile fish passing rate Variable Name Variable meaning Assignment Description S Types of fish Categorical variables; 1-"A", 2-"B", 3-"C" Q flow Continuous variables FN Fullness Continuous variables T Water temperature Continuous variables BL Body length Continuous variables W Wet weight Continuous variables PH Water pH Continuous variables TL full length Continuous variables CR Circadian Rhythm Categorical variable; 1-"morning"; 2-"afternoon"; 3-"evening"; 0-"missing" Time Successful downlink time — Status Down state 0-"missing"; 1-"successful" Embodiment 1: After investigating several bypass channel projects that have been built in my country, it was found that most of the fish passing through are focused on the four major carps. Taking grass carp, catfish and bighead carp as examples (Table 2), a calculation example is now provided to specifically illustrate the calculation method and process involved in the present invention. The determination process is as follows: 1. Analyze the bypass channel using the tagged fish data obtained by RFID technology ( Figure 2 ) The downward attraction rate, downward attraction time, downward passage rate and downward passage time of young fish.

[0017] 2. Distinguish the fish species S (S1, S2, S3), record the physiological information factors of each marked fish (total length TL, body length BL, wet weight W) and calculate the fatness FN of each fish, the environmental factors during the test (flow rate Q, water temperature T, water pH, circadian rhythm CR), define the marked juvenile fish passing through the induction coil at the entrance but not through the induction coil at the exit as a descent failure, which is 0, and define the marked juvenile fish passing through the induction coil at the entrance and the induction coil at the exit as a descent success, which is 1.

[0018] 3. In order to identify the key factors affecting the juvenile fish passing through the dam, a juvenile fish passing through the dam model was constructed to analyze the fish passing through the bypass channel. Before constructing the model, it is necessary to conduct a correlation analysis on the dependent variables of the juvenile fish passing through the dam model and eliminate the dependent variables with high correlation ( Figure 3 The correlation between wet weight and total length was greater than 0.7, so the two factors of wet weight and total length were eliminated). Secondly, the model was screened using the AIC criterion, and the water temperature and circadian rhythm factors were retained (Table 3), and other factors were eliminated (all possible variables need to be considered and correlation analysis needs to be performed when the model is established, and then the model is screened using the AIC criterion to select the best factors for application), and the optimal model for the passing rate of juvenile fish going down the dam was obtained.

[0019] 4. As shown in Table 4, temperature (T) has no significant effect on the probability of juvenile fish passing the dam (P>0.05), while circadian rhythm (CR) has a significant effect on the probability of juvenile fish passing the dam (P<0.05). By plotting the passing rate curve of juvenile fish at different time periods, it can be seen that the probability of juvenile fish passing the dam is the highest at night, and the probability of passing the dam is the lowest in the morning ( Figure 4 ).

[0020] Table 2 Data file variables of the model of juvenile fish passing rate

[0021] Table 3 Model selection based on Akaike Information Criterion (AIC)

[0022] Note: is the model weight, is the optimal model weight.

[0023] Table 4 Evaluation of the model parameters for the juvenile fish passing rate model -2.159 3.523 -0.61 0.540 0.620 0.319 1.860 1.94 0.052 -1.447 0.186 0.235 -7.77 8.1e-15 0.112 0.116 0.97 0.334 The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for constructing a model for evaluating the effect of juvenile fish passing through a dam, characterized in that: Step 1: Conduct a fish release test at the entrance of the bypass channel on the dam; Step 2: Establish evaluation indicators for the effect of juvenile fish passing the dam; Step 3: Construct the data file variables of the model of the rate of juvenile fish passing through the dam; Step 4: Construct a model for the passing rate of juvenile fishes going down the dam by coupling multiple factors; Step 5: Evaluate the effect of juvenile fish passing the dam based on the juvenile fish passing rate model.

2. The method for constructing a model for evaluating the effect of juvenile fish passing through a dam according to claim 1, characterized in that: The test process of step 1 is as follows: relying on a river project with a bypass channel, first arrange induction coils at the entrance of the bypass channel on the dam and the exit below the dam, and then implant the PIT tag into the abdominal cavity of the fish-passing object; when the test officially starts, release the tagged fish at the entrance of the bypass channel on the dam, and when the tagged fish goes down through the induction coil, the radio frequency identification monitoring system will automatically record the number of the tagged fish and the time of passing.

3. The method for constructing a model for evaluating the effect of juvenile fish passing through a dam according to claim 1, characterized in that: In step 2, the calculation method for the evaluation index of the effect of juvenile fish passing the dam is: According to the marked fish data monitored by the radio frequency identification system, the corresponding indicators for evaluating the effect of juvenile fish passing the dam are obtained. The corresponding indicators include the downward attraction rate, the downward attraction time, the downward passing rate and the downward passing time. The definitions of each evaluation indicator are as follows: (1) The formula for downward attraction rate is: ; in is the downside attraction rate; the number of tagged fish released for the area at the entrance to the bypass channel above the dam; The number of tagged fish monitored by the induction coil at the entrance of the bypass channel above the dam; (2) Downward attraction time is defined as: ; in, To attract time for the downside; The moment when the induction coil at the entrance of the bypass channel on the dam recognizes the tagged fish; the time to release tagged fish for the area at the entrance to the bypass channel above the dam; (3) The formula for the downlink pass rate is: ; in is the downlink throughput rate, The number of tagged fish monitored by the induction coil at the entrance of the bypass channel above the dam; The number of tagged fish monitored by the induction coil at the exit of the bypass channel below the dam; (4) Downlink transit time is defined as: ; in, is the downlink transit time, It is the moment when the induction coil at the exit of the bypass channel under the dam recognizes the tagged fish; This is the moment when the tagged fish is recognized by the induction coil at the entrance of the bypass channel on the dam.

4. The method for constructing a model for evaluating the effect of juvenile fish passing through a dam according to claim 1, characterized in that: In step 3, the variables in the data file of the model of the rate of juvenile fish passing the dam include biological factors and environmental factors, where biological factors include fish species, body length, wet weight, fatness and total length, and environmental factors include water temperature, day and night, water pH and flow.

5. The method for constructing a model for evaluating the effect of juvenile fish passing through a dam according to claim 1, characterized in that: In step 4, in order to identify the key factors affecting the juvenile fish passing the dam, a juvenile fish passing rate model was constructed with fish species, flow, fatness, water temperature, body length, wet weight, water pH and circadian rhythm as covariates to quantify the influence of each covariate on the juvenile fish passing rate. The formula of the juvenile fish passing rate model is as follows: ； Where: Indicates the expiration time; represents the model parameters; represents the impact factor; represents a Weibull distribution characterized by a scale parameter.

6. The method for constructing a model for evaluating the effect of juvenile fish passing through a dam according to claim 5, characterized in that: In step 4, in order to solve the multicollinearity problem of each covariate in the model and improve the accuracy of the model, the Akaike information criterion is used to screen out the optimal model; the formula of the Akaike information criterion is: ； Where: are model parameters; represents the likelihood function.

7. The method for constructing a model for evaluating the effect of juvenile fish passing through a dam according to claim 1, characterized in that: In step 5, the effect of juvenile fish passing the dam is evaluated based on the results of the juvenile fish passing rate model, and the efficiency of juvenile fish passing the dam is effectively quantified.

8. A model for evaluating the effect of juvenile fish passing through a dam, characterized by: A method for constructing a model for evaluating the effect of juvenile fish passing through a dam according to any one of claims 1 to 7 is adopted.

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