System and method for evaluating damage level of underwater explosion to fish

Abstract

The invention provides a system and method for evaluating the damage level of underwater explosion to fishes, and the system comprises a pool for an experiment, the interior of the pool contains water for the experiment, an explosion center is selected in the pool, an explosive is arranged at the position of the explosion center, and fishes for the experiment are arranged in the pool and at different distances away from the explosion center. A sensor used for measuring shock wave pressure is arranged at the position of the fish. According to the method, the damage condition of the fish caused by explosion of different explosive equivalents at different distances can be effectively evaluated, the damage degree of the fish under the explosion load can be quickly evaluated, a basis can be provided for a safety protection scheme of the fish in underwater explosion, and damage to the ecological environment is effectively reduced; meanwhile, a basis can be provided for anti-explosion design of organisms.

Description

Technical Field

[0001] The present invention relates to the field of underwater explosion technology and fishery ecological protection, and more particularly to a system and method for evaluating the damage level of fish caused by underwater explosion. Background Art

[0002] While my country's inland waterway shipping is developing rapidly, maritime shipping is also developing rapidly. With the intensification of economic globalization and the increasing frequency of exchanges between countries around the world, maritime shipping, as a key means of international communication, has become a major project that countries are increasingly focusing on and accelerating. Ports, as transportation hubs that allow ships to safely enter, exit, berth, and resupply, serve as the nexus and hubs of water and land transportation, playing a vital role in both inland and maritime shipping. Natural harbors that meet shipping requirements are relatively rare in my country, and most ports are artificially constructed. Before construction, artificial ports often contain numerous reefs, which obstruct ship traffic and threaten vessel safety. Breaking up and excavating these reefs is a crucial task in port construction.

[0003] With the development of society, my country has attached more and more importance to the construction of ecological civilization, and has paid more and more attention to the ecological environment protection issues involved in the construction process. However, the underwater blasting charges commonly used in channel dredging, port reef clearing, ice blasting and marine engineering construction are large, which has a very large impact on the surrounding ecological environment during the blasting process. The huge shock wave energy generated in the water seriously endangers the life safety of aquatic organisms, threatens the survival of rare fish and the protection of fishery resources, and in severe cases can cause large-scale deaths of aquatic organisms. In order to evaluate this damage, a scientific and effective method is needed to quantify the degree of damage caused by underwater explosion shock waves to fish. In the existing technology, although there have been some studies on underwater explosion shock waves, most of them focus on the propagation law of shock waves, peak pressure calculation and other aspects, and the method for fish damage assessment is still imperfect. Summary of the Invention

[0004] In response to the above problems, the present invention provides a system and method for evaluating the damage level to fish caused by underwater explosions. This method can effectively evaluate the damage to fish caused by explosions of different explosive equivalents at different distances. It can not only quickly evaluate the degree of damage to fish under explosive loads, but also provide a basis for fish safety protection plans during underwater explosions, effectively reducing damage to the ecological environment; at the same time, it can provide a basis for the explosion-resistant design of organisms.

[0005] In order to achieve the above-mentioned technical features, the purpose of the present invention is achieved as follows: a system for evaluating the damage level of fish caused by underwater explosions, including a pool for experiments, the inside of the pool containing water for experiments, an explosion center selected inside the pool, explosives set at the explosion center, fish for experiments set inside the pool at different distances from the explosion center, and sensors for measuring shock wave pressure set at the positions of the fish.

[0006] Preferably, the water pool is a rectangular pool and is cast with concrete; The width and length E of the pool need to meet the requirements of being able to conduct explosion experiments with different equivalent explosives and effectively measure relevant data. The water depth F and area parameters need to be determined based on the experimental design and expected results.

[0007] Preferably, the explosion center is selected at the center of the pool.

[0008] Preferably, the explosive is fixed to the bottom of a support plate by a strap, the support plate is supported on the top of the pool, and the bottom end of the explosive is connected to a weight by a strap.

[0009] Preferably, the fish are placed inside the pool by means of a fish cage or a fixing device, which is fixed to the bottom of the support plate by means of straps, so that the fish can be affected by the explosion in a relatively natural state.

[0010] Preferably, the sensor is a high-precision, high-sensitivity pressure sensor for quickly and accurately responding to shock wave pressure changes and recording data; the placement of the sensor corresponds to the placement of the fish to analyze the relationship between shock wave pressure and fish damage at the same position.

[0011] The present invention, in another aspect, provides a method for evaluating the damage level of fish caused by underwater explosions. The method is implemented using the system for evaluating the damage level of fish caused by underwater explosions, and comprises the following steps: Step 1: Set up a pool as the blasting site and build an experimental environment inside the pool for placing explosives, fish, and sensors; Step 2: Select a series of explosives of different equivalents. The selection of explosive equivalents should cover the range that may be involved in actual underwater blasting operations, and set them step by step from small equivalents to large equivalents. Place the selected explosives at the predetermined explosion center location; Step 3: Place the experimental fish and sensors at different locations from the explosion center; Step 4: Detonate explosives of different equivalents in sequence. At the moment of explosion, the sensor begins to collect shock wave pressure data and records the complete shock wave pressure curve. Step 5: After the explosion, the fish placed in different locations are immediately recovered and processed. The survival status is first observed. Half of the fish are cultured for a period of time to observe their survival status. At the same time, half of the fish are dissected. After a period of time, the cultured fish are dissected. The damage of different parts of the fish is observed, including whether the internal organs of the fish are ruptured or bleeding, whether the bones of the fish are broken, and whether there are signs of tearing or congestion on the surface of the fish. The damage of the fish is graded according to the pre-set damage assessment criteria. Step 6: Organize and analyze the collected shock wave pressure curve data and the corresponding fish injury grade data: by establishing a mathematical model or data analysis method, find the quantitative relationship between the shock wave pressure peak value in different waters and the fish injury grade under different explosive equivalent explosion conditions; use a regression analysis method to determine the variation pattern of the fish injury grade relative to the change in the shock wave pressure peak value in water with increasing distance from the explosion center under specific explosive equivalent; Step 7: Based on the data analysis results, a curve for assessing the damage level of the underwater explosion shock wave to fish is obtained, and a diagram for assessing the damage level of the underwater explosion to fish is formed. The diagram details the relationship between the specific damage level and damage description, and the shock wave pressure and the damage level; the assessment results are used in the planning and management of underwater explosion operations.

[0012] Preferably, during the placement of the explosive in step 2, a precise positioning and fixing device is used to ensure that the position of the explosive is stable during the explosion process, thereby ensuring the accuracy and repeatability of the experiment; The fish selected in step 3 should be representative, representing fish of different species, ages, and sizes to simulate the characteristics of fish in natural waters; The shock wave pressure curve in step 4 reflects the pressure changes of the shock wave generated by the explosion at different times and locations, which is an important basis for subsequent analysis; The injury assessment criteria described in step 5 should comprehensively consider the survival status after the explosion, the activity ability of the fish one hour later, and the impact of different injury locations and degrees on the survival and physiological functions of the fish. These include: minor injuries involving only a small amount of bruising or abrasions on the body surface, while severe injuries include rupture of multiple important organs, heavy bleeding, or severe bone fractures. The injury conditions are divided into multiple levels, including: no injury, mild injury, moderate injury, severe injury, and fatal injury.

[0013] Preferably, the application of the evaluation results in step 7 to the planning and management of underwater blasting operations specifically includes: Determine the safe explosive equivalent and safe distance when conducting underwater blasting operations near fishery resource protection areas, and provide a scientific basis for formulating fishery resource protection measures to minimize the damage caused by underwater blasting to the fishery ecological environment.

[0014] Preferably, in step 7, determining the assessment curve of the damage level of the underwater explosion shock wave to the fish specifically includes: 1) During underwater blasting, high-precision, high-sensitivity pressure sensors are installed in locations with high fish density. The peak pressure of the shock wave in the water after the blast can be used to determine the level of damage to the fish and assess the ecological damage caused by the blast. (1) Where, P is the peak pressure of the shock wave in water, Pa; W is the charge mass, kg; R is the distance from the explosion center to the measuring point, m; r is the initial radius of the charge, m; 2) Before blasting, the underwater shock wave pressure at different distances from the blast source is determined using formula (1), explosive equivalent, and charge structure. The boundary of the moderate damage in the fish damage level assessment curve where the fish are not fatally injured is set as the safety boundary using the underwater explosion shock wave, and the fish within the safety boundary are driven away. 3) The fish damage level assessment curve of underwater explosion shock waves is used to determine at what peak shock wave pressure the fish are not injured and their activity is enhanced. The peak pressure in this range is used as the basis for micro-explosion to drive away fish.

[0015] The present invention has the following beneficial effects: By adopting the system and method of the present invention, it is possible to evaluate the damage caused to fish by explosions of different explosive equivalents at different distances. The damage to fish can be determined by testing the peak explosion pressure in the water after an underwater explosion, thereby providing a scientific basis for the protection of fishery resources during underwater explosion operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and examples.

[0017] Figure 1 It is the main view of the system of the present invention.

[0018] Figure 2 It is a side view of the system of the present invention.

[0019] Figure 3 It is a top view of the system of the present invention.

[0020] Figure 4 This is a diagram showing the mechanism of shock wave action on fish swim bladder.

[0021] Figure 5 To invent a diagram for evaluating damage to fish caused by underwater explosions.

[0022] In the figure, there is a pool 1, a support plate 2, water 3, a heavy object 4, explosives 5, fish 6, and a strap 7.

[0023] A, B, C, and D are the distances between the fish and the center of the explosion.

[0024] E is the length and width of the pool, and F is the water depth. DETAILED DESCRIPTION

[0025] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Example 1: This embodiment provides a system for assessing the level of damage to fish caused by underwater explosions, comprising a pool 1 for use in experiments, containing water 3 for the experiment within the pool 1, a selected explosion center within the pool 1, explosives 5 positioned at the explosion center, fish 6 for the experiment positioned within the pool 1 at varying distances from the explosion center, and sensors for measuring shock wave pressure positioned at the locations of the fish 6. The system can be used to assess the damage to fish caused by explosions of different explosive equivalents at varying distances. After an underwater explosion, the damage to the fish can be determined by measuring the peak explosion pressure in the water, thereby providing a scientific basis for protecting fishery resources during underwater explosion operations. During the specific experimental process, an experimental environment is established within the pool 1, and then explosives 5 are detonated to produce an explosion. By detecting the shock wave pressure and the degree of damage to the fish 6, a curve for assessing the level of damage to fish caused by the shock wave of the underwater explosion is constructed.

[0028] Furthermore, the water pool 1 is a rectangular pool cast with concrete. The width and length E of the water pool 1 must meet the requirements of conducting explosion experiments with different explosive yields and effectively measuring relevant data. The water depth F and area parameters must be determined based on the experimental design and expected results. The water pool 1 provides a water environment for the experiment.

[0029] Furthermore, the explosion center is selected at the center of the pool 1. By selecting the above-mentioned explosion center, the generation of boundaries and other variables is effectively reduced.

[0030] Furthermore, the explosive 5 is fixed to the bottom of the support plate 2 by a strap 7, and the support plate 2 is supported on the top of the pool 1. The bottom end of the explosive 5 is connected to the weight 4 by the strap 7. Through the above-mentioned installation and arrangement of the explosive 5, the position accuracy and stability of the explosive 5 are improved, and the accuracy and repeatability of the experiment are guaranteed.

[0031] Furthermore, the fish 6 are positioned within the pool 1 using a fish cage or fixture, which is secured to the bottom of the support plate 2 via straps 7, allowing the fish 6 to be exposed to the blast in a relatively natural state. This arrangement of the fish 6 facilitates precise positioning of the fish 6, facilitating subsequent data collection and processing to analyze the relationship between shock wave pressure and fish damage at the same location.

[0032] Furthermore, the sensor uses a high-precision, high-sensitivity pressure sensor to quickly and accurately respond to changes in shock wave pressure and record data; the placement of the sensor corresponds to the placement of the fish to analyze the relationship between shock wave pressure and fish damage at the same position.

[0033] Example 2: A method for evaluating the damage level of fish caused by underwater explosions comprises the following steps: Step 1: Set up a large pool as the blasting site and create an experimental environment for placing explosives, fish, and sensors. The pool's size should be sufficient for conducting explosion experiments with different explosive yields and effectively measuring relevant data. Parameters such as depth and area should be determined based on the experimental design and expected results. The center of the pool should be selected as the explosion center to minimize the presence of boundaries and other variables.

[0034] Step 2: Select a range of explosives of varying yields. The selection should cover the range of explosive yields encountered in actual underwater blasting operations, progressing from smaller to larger yields. The selected explosives are placed at the predetermined blast center, using precise positioning and securing devices to ensure stability during the blast, ensuring accuracy and repeatability.

[0035] Step 3: Place experimental fish and sensors at different distances from the explosion center. The fish selected should be representative, representing different species, ages, and sizes to simulate the characteristics of fish found in natural waters. The fish should be placed in a specially designed fish cage or fixture to allow them to be exposed to the blast in a relatively natural state. The sensor is used to measure the shock wave pressure curve. High-precision, high-sensitivity pressure sensors are selected, which can quickly and accurately respond to shock wave pressure changes and record data. The sensor placement should correspond to the fish placement to facilitate analysis of the relationship between shock wave pressure and fish damage at the same location.

[0036] In step 4, different explosive yields are detonated sequentially. At the moment of detonation, the sensor begins collecting shock wave pressure data, recording a complete shock wave pressure curve. This curve reflects the pressure changes of the shock wave generated by the explosion at different times and locations, and is an important basis for subsequent analysis.

[0037] Step 5: Immediately after the explosion, the fish placed in different locations are recovered and processed. Survival is first observed, and half of the fish are kept for one hour to observe their survival. Meanwhile, half of the fish are dissected, and the remaining fish are dissected one hour later. The fish's internal organs, such as the swim bladder, liver, spleen, and intestines, are observed for ruptures and bleeding, bones are broken, and surface injuries such as lacerations and congestion are observed. The fish's injuries are graded according to pre-established injury assessment criteria. These criteria comprehensively consider post-explosion survival, the fish's mobility one hour later, and the impact of different injury locations and severity on the fish's survival and physiological functions. For example, minor injuries may involve only minor congestion or abrasions, while severe injuries may include rupture of multiple vital organs, extensive bleeding, or severe bone fractures. Injury levels are categorized into several levels, such as no injury, mild injury, moderate injury, severe injury, and fatal injury.

[0038] Step 6: Organize and analyze the collected shock wave pressure curve data and the corresponding fish injury grade data. By establishing a mathematical model or data analysis method, a quantitative relationship between the peak shock wave pressure in water and the fish injury grade under different explosive equivalent explosion conditions can be found. Regression analysis or other methods can be used to determine how the change in peak shock wave pressure in water correlates with the fish injury grade as the distance from the explosion center increases, under specific explosive equivalents.

[0039] In step 7, based on the data analysis results, a curve assessing the damage level to fish caused by underwater explosion shock waves is generated, forming an underwater explosion damage level assessment chart. This chart details the specific damage level and damage description, as well as the relationship between shock wave pressure and damage level. The assessment results can be applied to the planning and management of underwater explosion operations, such as determining safe explosive equivalents and safe distances for underwater explosions near fishery resource protection areas. This provides a scientific basis for formulating fishery resource protection measures to minimize damage to the fishery ecosystem caused by underwater explosions.

[0040] Through the above steps, a damage assessment level diagram of underwater explosion shock waves on fish is obtained, which can be used to determine the damage status of fish by testing the peak explosion pressure in water after underwater explosion construction.

[0041] The working principle of the underwater explosion shock wave damage level assessment curve for fish is as follows: 1) During underwater blasting, high-precision, high-sensitivity pressure sensors can be installed in locations with high fish density. After the blast, the peak pressure of the shock wave in the water can be used to determine the level of damage to the fish and the extent of the damage, thereby assessing the ecological damage caused by the blast.

[0042] (1) Where, P is the peak pressure of the shock wave in water, Pa; W is the charge mass, kg; R is the distance from the explosion center to the measuring point, m; r is the initial radius of the charge, m; 2) Before blasting, the underwater shock wave pressure at different distances from the blast source is determined using formula (1), explosive equivalent, and charge structure. The boundary of the moderate damage in the fish damage level assessment curve where the fish are not fatally injured is set as the safety boundary using the underwater explosion shock wave, and the fish within the safety boundary are driven away. 3) The fish damage level assessment curve of underwater explosion shock waves is used to determine at what peak shock wave pressure the fish are not injured and their activity is enhanced. The peak pressure in this range is used as the basis for micro-explosion to drive away fish.

[0043] Example 3: A method for evaluating the damage level of fish caused by underwater explosions comprises the following steps: 1) Build a pool with a length, width, and height of 60 m × 60 m × 10 m to place explosives, fish, and sensors.

[0044] 2) Design the experimental plan, including the explosive equivalent, explosive location, fish location, fish species, number of fish, and sensor layout. See Table 1 for details. Figure 1 、 2 and 3 in.

[0045] Table 1 Experimental working conditions

[0046] 3) On the day of the blast, 400 crucian carp were purchased (10 per location, for a total of 360, to prevent accidents) and maintained in a bubble machine to ensure freshness and activity, minimizing non-blast injuries. Experimental fish and sensors were placed at various locations relative to the center of each blast, with the sensor placement corresponding to the fish placement to facilitate analysis of the relationship between shock wave pressure and fish injury at the same location. The fish selected were crucian carp. This study selected 30 cm crucian carp as the underwater blast model, considering its representativeness as a model organism for cyprinid fish and experimental controllability. Crucian carp share a high degree of similarity with commercial fish such as common carp and grass carp in body shape, skeletal structure, and physiological responses. They are also plentiful, easily domesticated, and can be carefully controlled for variables such as feeding and activity levels. 30 cm sexually mature individuals (approximately 750 g) were selected because their musculoskeletal mechanical properties are close to the population mean. No sex, season, or age group was distinguished, as there are no significant differences in mechanical parameters in crucian carp, allowing them to represent fish of different species, ages, and sizes, mimicking the characteristics of fish found in natural waters. The fish are placed in a special fish cage so that they can be exposed to the impact of the explosion in a relatively natural state. The sensor is used to measure the shock wave pressure curve. A high-precision, high-sensitivity pressure sensor is selected, which can quickly and accurately respond to the shock wave pressure changes and record the data. The fish and explosives are fixed with weights. For details, see Figure 1 As shown, the swim bladder was dissected before the experiment to measure its length, width, height and thickness.

[0047] 4) Explosives of different equivalents are detonated in sequence. At the moment of explosion, the sensor begins to collect shock wave pressure data and records the complete shock wave pressure curve.

[0048] 5) Immediately after the explosion, fish placed in different locations were recovered and processed. Survival was first observed, and half of the fish were kept for one hour to observe their survival. Half of the fish were dissected, and the remaining fish were dissected one hour later. Damage to various parts of the fish was observed, including whether internal organs (such as the swim bladder, liver, spleen, and intestines) were ruptured or bleeding, whether bones were broken, and whether there were any signs of lacerations or congestion on the fish's surface. The damage to the fish was graded according to pre-defined damage assessment criteria. The specific evaluation is shown in Table 2.

[0049] Table 2 Fish damage table

[0050] 6) Based on the experimental measurement results and relevant literature, use formulas (2) and (3) to calculate the shock wave pressure in the water when the swim bladder of the experimental fish critically ruptures.

[0051] The swim bladder injury model is as follows: Figure 4As shown in Figure 1, the shock wave from an underwater explosion propagates from the water to the fish, and then from the fish flesh to the swim bladder, creating a significant pressure difference between the inside and outside of the swim bladder membrane. Along the propagation direction of the water shock wave, the swim bladder membrane is compressed, causing deformation and generating tensile stress. Once the tensile stress exceeds the critical tensile stress of the swim bladder, the swim bladder will rupture. Based on the simplified elliptical shape of the swim bladder and the fish body, the formula for calculating the tensile stress of the swim bladder membrane is as follows: (2) in: σ is the critical tensile stress of the swim bladder, l is the swim bladder length, d is the width of the fish bladder, h is the swim bladder height, θ is the thickness of the fish bladder, P The pressure difference between the inside and outside of the swim bladder membrane is equal to the pressure outside the swim bladder membrane minus the pressure inside the swim bladder membrane. This data is available from measurements on experimental fish and relevant literature.

[0052] The formula for calculating the transmission ratio of water hammer wave in different medium pressures is as follows: (3) in: n is the wave impedance ratio; 、 density and wave speed on the left; 、 The density and wave speed on the right, P T is the pressure of the transmitted wave, P I is the pressure of the incident shock wave.

[0053] According to relevant literature, the impedance of the fish body material parameter calculation wave is The material parameters of the swim bladder membrane are used to calculate its wave impedance: The gas parameters in the swim bladder are used to calculate its wave impedance: The wave impedance is 1.48×10 6 kg / (m 2 ·s). According to formula (2) and the measured length, width, height and thickness of the swim bladder of the experimental fish. Therefore, according to relevant references, the ultimate tensile stress of the swim bladder rupture can be known; therefore, using formulas (2) and (3), the underwater shock wave pressure value that causes the swim bladder to rupture is calculated as P T , the calculation process is as follows: (4) Where: n1 is the ratio of the wave impedance in water to the wave impedance in fish flesh. The attenuation of the shock wave from water to fish flesh is calculated based on the wave impedance of water and fish body, and the relationship between the pressure in fish flesh and the shock wave in water is obtained.

[0054] (5) Where: n 2 is the ratio of the wave impedance of the fish flesh to the impedance of the swim bladder membrane. The attenuation of the shock wave from the fish flesh to the swim bladder membrane is calculated based on the wave impedance of the fish body and the swim bladder membrane, and the relationship between the pressure in the swim bladder membrane and the shock wave in the water is obtained.

[0055] (6) Where: n 3 is the ratio of the wave impedance of the swim bladder membrane to the wave impedance of the gas in the swim bladder membrane. The attenuation of the shock wave from the swim bladder membrane to the air in the swim bladder is calculated based on the wave impedance of the swim bladder membrane and the gas in the swim bladder membrane. The relationship between the pressure in the air in the swim bladder and the shock wave in the water is obtained. However, due to the significant difference in wave impedance between the gas in the swim bladder and the solid swim bladder membrane, P A Much smaller than P w , so it can be ignored. P w Substitute the formula to calculate the tensile stress on the swim bladder caused by the shock wave.

[0056] (7) The critical tensile stress of the swim bladder membrane under tension is known from relevant literature. Substituting it into formula (7) we can calculate the peak pressure of the shock wave in the water when the swim bladder is critically ruptured. P T : (8) Where: D is the proportional value, P is the peak pressure of the shock wave in water, P T It is the shock wave pressure value in water when the swim bladder ruptures.

[0057] 7) According to the damage level assessment in the experimental results and the calculation of the damage level at different measuring points based on the underwater shock wave and formula (8), D , and the damage level and D The relationship between the two values ​​is as follows: 0-0.2 means no damage, 0.2-0.45 means slight damage, 0.45-0.75 means moderate damage, 0.75-1 means severe damage, and >1 means extremely severe damage. The evaluation diagram of the damage caused by underwater explosion to fish is obtained. Figure 5 shown.

[0058] The above detailed description of the specific embodiment of the present invention is intended to be only one embodiment, and the present invention is not limited to the specific embodiment described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, any equivalent changes and modifications made without departing from the spirit and scope of the present invention should be included within the scope of the present invention.

Claims

1. A system for evaluating the damage level of fish caused by underwater explosions, characterized in that: The invention comprises a water pool (1) for experiment, water (3) for experiment is contained in the water pool (1), an explosion center is selected in the water pool (1), explosives (5) are arranged at the explosion center, fish (6) for experiment are arranged in the water pool (1) at different distances from the explosion center, and a sensor for measuring shock wave pressure is arranged at the position where the fish (6) is located.

2. The system for evaluating the damage level of fish caused by underwater explosions according to claim 1, characterized in that: The water pool (1) is a rectangular water pool and is cast with concrete; The width and length dimensions E of the water pool (1) need to meet the requirements of being able to conduct explosion experiments with different equivalent explosives and effectively measure relevant data. The water depth F and area parameters need to be determined based on the experimental design and expected results.

3. The system for evaluating the damage level of fish caused by underwater explosions according to claim 1, characterized in that: The explosion center is selected at the center of the pool (1).

4. The system for evaluating the damage level of fish caused by underwater explosions according to claim 1, characterized in that: The explosive (5) is fixed to the bottom of the support plate (2) via a binding strap (7), the support plate (2) is supported on the top of the pool (1), and the bottom end of the explosive (5) is connected to a weight (4) via a binding strap (7).

5. The system for evaluating the damage level of fish caused by underwater explosions according to claim 4, characterized in that: The fish (6) is placed inside the pool (1) via a fish cage or a fixing device, and the fish cage or the fixing device is fixed to the bottom of the support plate (2) via a strap (7), so that the fish (6) can be affected by the explosion in a relatively natural state.

6. The system for evaluating the damage level of fish caused by underwater explosions according to claim 1, characterized in that: The sensor is a high-precision, high-sensitivity pressure sensor used to quickly and accurately respond to changes in shock wave pressure and record data; the placement of the sensor corresponds to the placement of the fish to analyze the relationship between shock wave pressure and fish damage at the same position.

7. A method for evaluating the damage level of fish caused by underwater explosion, characterized in that: The method is implemented using the system for evaluating the damage level of fish caused by underwater explosions as described in any one of claims 1 to 6, comprising the following steps: Step 1: setting a water pool (1) as a blasting site, and constructing an experimental environment inside the water pool (1) for placing explosives (5), fish (6) and sensors; Step 2: Select a series of explosives of different equivalents. The selection of explosive equivalents should cover the range that may be involved in actual underwater blasting operations, and set them step by step from small equivalents to large equivalents. Place the selected explosives at the predetermined explosion center location; Step 3, placing experimental fish (6) and sensors at different locations away from the explosion center; Step 4: Detonate explosives of different equivalents in sequence. At the moment of explosion, the sensor begins to collect shock wave pressure data and records the complete shock wave pressure curve. Step 5: After the explosion, the fish placed in different locations are immediately recovered and processed. The survival status is first observed. Half of the fish are cultured for a period of time to observe their survival status. At the same time, half of the fish are dissected. After a period of time, the cultured fish are dissected. The damage of different parts of the fish is observed, including whether the internal organs of the fish are ruptured or bleeding, whether the bones of the fish are broken, and whether there are signs of tearing or congestion on the surface of the fish. The damage of the fish is graded according to the pre-set damage assessment criteria. Step 6: Organize and analyze the collected shock wave pressure curve data and the corresponding fish injury grade data: by establishing a mathematical model or data analysis method, find the quantitative relationship between the shock wave pressure peak value in different waters and the fish injury grade under different explosive equivalent explosion conditions; use a regression analysis method to determine the variation pattern of the fish injury grade relative to the change in the shock wave pressure peak value in water with increasing distance from the explosion center under specific explosive equivalent; Step 7: Based on the data analysis results, a curve for assessing the damage level of the underwater explosion shock wave to fish is obtained, and a diagram for assessing the damage level of the underwater explosion to fish is formed. The diagram details the relationship between the specific damage level and damage description, and the shock wave pressure and the damage level; the assessment results are used in the planning and management of underwater explosion operations.

8. The method for evaluating the damage level of fish caused by underwater explosion according to claim 7, characterized in that: During the placement of the explosives in step 2, precise positioning and fixing devices are used to ensure that the explosives are in a stable position during the explosion process, thereby ensuring the accuracy and repeatability of the experiment; The fish (6) selected in step 3 should be representative, representing fish of different species, different age stages and different sizes, so as to simulate the characteristics of fish in natural waters; The shock wave pressure curve in step 4 reflects the pressure changes of the shock wave generated by the explosion at different times and locations, which is an important basis for subsequent analysis; The injury assessment criteria described in step 5 should comprehensively consider the survival status after the explosion, the activity ability of the fish one hour later, and the impact of different injury locations and degrees on the survival and physiological functions of the fish. These include: minor injuries involving only a small amount of bruising or abrasions on the body surface, while severe injuries include rupture of multiple important organs, heavy bleeding, or severe bone fractures. The injury conditions are divided into multiple levels, including: no injury, mild injury, moderate injury, severe injury, and fatal injury.

9. The method for evaluating the damage level of fish caused by underwater explosion according to claim 7, characterized in that: The evaluation results in step 7 are applied to the planning and management of underwater blasting operations, specifically including: Determine the safe explosive equivalent and safe distance when conducting underwater blasting operations near fishery resource protection areas, and provide a scientific basis for formulating fishery resource protection measures to minimize the damage caused by underwater blasting to the fishery ecological environment.

10. The method for evaluating the damage level of fish caused by underwater explosion according to claim 7, characterized in that: The determination of the fish damage level assessment curve of the underwater explosion shock wave in step 7 specifically includes: 1) During underwater blasting, high-precision, high-sensitivity pressure sensors are installed in locations with high fish density. The peak pressure of the shock wave in the water after the blast can be used to determine the level of damage to the fish and assess the ecological damage caused by the blast. （1） Where, P is the peak pressure of the shock wave in water, Pa; W is the charge mass, kg; R is the distance from the explosion center to the measuring point, m; r is the initial radius of the charge, m; 2) Before blasting, the underwater shock wave pressure at different distances from the blast source is determined using formula (1), explosive equivalent, and charge structure. The boundary of the moderate damage in the fish damage level assessment curve where the fish are not fatally injured is set as the safety boundary using the underwater explosion shock wave, and the fish within the safety boundary are driven away. 3) The fish damage level assessment curve of underwater explosion shock waves is used to determine at what peak shock wave pressure the fish are not injured and their activity is enhanced. The peak pressure in this range is used as the basis for micro-explosion to drive away fish.

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