Alternative habitat construction methods and systems for straightening waterway curves.

Abstract

This invention proposes a method and system for constructing alternative habitats for straightening waterway bends in waterway engineering, belonging to the field of waterway engineering ecological restoration technology. The method includes: constructing artificial water flow channels and modifying the internal topography within the abandoned old waterway formed after straightening, both inside and between the old waterway and the new main waterway, to generate a water circulation system with water circulation capabilities; installing controllable gates and water disturbance devices at key nodes of the water circulation system to form a physical control system; deploying multiple sets of environmental parameter sensors to form a monitoring network; and issuing control commands to the control system based on real-time environmental parameters acquired by the monitoring network and a preset ecological control model of fish life history stages, causing the water circulation system to execute an ecological control mode adapted to the current fish life stage, such as a spawning stimulation mode. This invention achieves intelligent ecological control of abandoned old waterways, transforming them into functional alternative habitats.

Description

Technical Field

[0001] This invention relates to the field of ecological restoration technology for waterway engineering, and in particular to a method and system for constructing alternative habitats for straightening waterway curves. Background Technology

[0002] Straightening waterways in waterway engineering can effectively improve waterway efficiency, but it also creates a section of abandoned old waterway isolated from the main stream. Traditionally, this section of old waterway is either completely filled in or left to naturally silt up and degrade, leading to the complete loss or severe damage of the original aquatic ecosystem. Current technologies lack effective solutions for the systematic ecological reuse of abandoned old waterways, especially in dynamically simulating and providing the diverse and time-varying key habitat conditions found in natural rivers within limited spaces (e.g., specific flow, depth, and water quality environments required for different life stages of fish).

[0003] Therefore, there is an urgent need for an innovative method to transform abandoned old river channels into alternative habitats with ecological functions and to actively and intelligently regulate them in order to compensate for the ecological losses caused by waterway engineering. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies, the first aspect of this invention proposes a method for constructing alternative habitats for straightening waterway curves, comprising: S1: Based on the abandoned old river channel formed after the straightening construction, artificial water flow channels and internal terrain modifications are carried out within the abandoned old river channel and between it and the new main channel adjacent to the abandoned old river channel to generate a water circulation system with water circulation capabilities; wherein, S1 includes: S11: Based on the geographical locations of the two ends of the abandoned old river channel, dredging or excavation is carried out between the entrance end of the abandoned old river channel and the new main channel to create an entrance connecting channel; dredging or excavation is carried out between the exit end of the abandoned old river channel and the new main channel to create an exit connecting channel. S12: Based on the natural meandering shape of the abandoned old river channel, the riverbed of the abandoned old river channel is locally shaped to form at least one set of topographic sequences consisting of alternating shallow beach units and deep pool units within the abandoned old river channel. S13: Based on the inlet connecting channel, the abandoned old river channel where the terrain sequence is located, the outlet connecting channel and the corresponding section of the new main channel, construct a closed or semi-closed water flow path, and define the closed or semi-closed water flow path as a water flow circulation system. S2: Based on the structural characteristics of the water circulation system, a control structure group for regulating the water flow state is installed at key nodes in the main circulation path of the water circulation system, resulting in a control system physically connected to the water circulation system; wherein, S2 includes: S21: Based on the cross-sectional dimensions of the entrance connecting channel, install the first controllable gate at the intersection of the entrance connecting channel and the new main channel; S22: Based on the cross-sectional dimensions of the outlet connecting channel, a second controllable gate is installed at the intersection of the outlet connecting channel and the new main channel; S23: Based on the size of at least one deep pool unit in the terrain sequence, install a water disturbance device at the bottom of the deep pool unit; S24: Connect the electrical control lines of the first controllable gate, the second controllable gate, and the water disturbance device to the same control terminal to form a control system for coordinated control of the water circulation system; S3: Based on the spatial layout of the water circulation system, multiple sets of environmental parameter sensors are deployed inside the abandoned old river channel and near key nodes to obtain a monitoring network that continuously acquires the environmental parameters inside the abandoned old river channel. S4: Based on real-time environmental parameters obtained from the monitoring network and a pre-set ecological regulation model for fish life history stages, control commands are sent to the regulation system to enable the water circulation system to execute an ecological regulation mode adapted to the current fish life stage; wherein, the ecological regulation mode includes a spawning stimulation mode, and S4 includes: S4-1-1: Based on real-time environmental parameters obtained from the monitoring network and combined with external hydrological and meteorological data, determine whether the current period is the preset fish spawning season and whether the external hydrological conditions meet the spawning stimulation requirements. S4-1-2: When the judgment result is yes, the first set of gate control commands is generated and sent to the control system based on the preset gate cooperative opening and closing program; S4-1-3: Based on the received first set of gate control commands, the control system drives the first and second controllable gates to perform specific opening and closing actions, so that the water in the new main channel flows into and through the abandoned old river channel in a pulse manner, forming a first water flow state with directional slow flow characteristics in the abandoned old river channel.

[0005] Secondly, this invention proposes an alternative habitat construction system for straightening waterway curves in waterway engineering. The system employs the alternative habitat construction method for straightening waterway curves in waterway engineering proposed in any of the above embodiments. The system includes: The circulation system construction module is used to execute step S1: Based on the abandoned old river channel formed after the straightening construction, artificial water flow channels are constructed and internal terrain is modified within the abandoned old river channel and between it and the new main channel adjacent to the abandoned old river channel to generate a water circulation system with water circulation capabilities; wherein, S1 includes: S11: Based on the geographical locations of the two ends of the abandoned old river channel, dredging or excavation is carried out between the entrance end of the abandoned old river channel and the new main channel to create an entrance connecting channel; dredging or excavation is carried out between the exit end of the abandoned old river channel and the new main channel to create an exit connecting channel. S12: Based on the natural meandering shape of the abandoned old river channel, the riverbed of the abandoned old river channel is locally shaped to form at least one set of topographic sequences consisting of alternating shallow beach units and deep pool units within the abandoned old river channel. S13: Based on the inlet connecting channel, the abandoned old river channel where the terrain sequence is located, the outlet connecting channel and the corresponding section of the new main channel, construct a closed or semi-closed water flow path, and define the closed or semi-closed water flow path as a water flow circulation system. The control structure deployment module is used to execute step S2: Based on the structural characteristics of the water circulation system, control structure groups for regulating the water flow state are installed at key nodes in the main circulation path of the water circulation system, resulting in a control system physically connected to the water circulation system; wherein, S2 includes: S21: Based on the cross-sectional dimensions of the entrance connecting channel, install the first controllable gate at the intersection of the entrance connecting channel and the new main channel; S22: Based on the cross-sectional dimensions of the outlet connecting channel, a second controllable gate is installed at the intersection of the outlet connecting channel and the new main channel; S23: Based on the size of at least one deep pool unit in the terrain sequence, install a water disturbance device at the bottom of the deep pool unit; S24: Connect the electrical control lines of the first controllable gate, the second controllable gate, and the water disturbance device to the same control terminal to form a control system for coordinated control of the water circulation system; The monitoring network deployment module is used to perform step S3: based on the spatial layout of the water circulation system, multiple sets of environmental parameter sensors are deployed inside the abandoned old river channel and near key nodes to obtain a monitoring network that continuously acquires environmental parameters inside the abandoned old river channel. The intelligent regulation execution module is used to execute step S4: based on real-time environmental parameters obtained from the monitoring network and a preset ecological regulation model for fish life history stages, it sends control commands to the regulation system to enable the water circulation system to execute an ecological regulation mode adapted to the current fish life stage; wherein, the ecological regulation mode includes a spawning stimulation mode, and S4 includes: S4-1-1: Based on real-time environmental parameters obtained from the monitoring network and combined with external hydrological and meteorological data, determine whether the current period is the preset fish spawning season and whether the external hydrological conditions meet the spawning stimulation requirements. S4-1-2: When the judgment result is yes, the first set of gate control commands is generated and sent to the control system based on the preset gate cooperative opening and closing program; S4-1-3: Based on the received first set of gate control commands, the control system drives the first and second controllable gates to perform specific opening and closing actions, so that the water in the new main channel flows into and through the abandoned old river channel in a pulse manner, forming a first water flow state with directional slow flow characteristics in the abandoned old river channel.

[0006] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the synergistic effect of four steps, S1 to S4, the problems raised in the background technology are effectively solved. First, step S1 fundamentally transforms the abandoned old river channel. By constructing inlet and outlet connecting channels, the hydraulic connection between the abandoned old river channel and the new main channel is re-established, resolving its isolation and providing a foundation for water exchange and energy flow. Simultaneously, a topographic sequence of alternating shallow and deep pool units is created within the abandoned old river channel, directly generating diverse combinations of water depth and flow velocity, providing heterogeneous habitats for different aquatic organisms, and laying the physical foundation for alternative habitats. Second, the control system deployed in step S2 (including a first controllable gate, a second controllable gate, and water disturbance devices) endows this physical structure with "controllable" vitality, transforming it from a static topography into a dynamically adjustable system. Next, the monitoring network deployed in step S3 acts as the system's "sensors," continuously acquiring real-time environmental parameters and providing data input for intelligent decision-making. Ultimately, step S4, acting as the system's "brain," issues control commands to the regulatory system based on real-time data and pre-set ecological regulation models (such as spawning stimulation patterns). For example, by driving the first and second controllable gates to perform specific opening and closing actions, a first flow pattern with directional slow-flow characteristics can be precisely generated within the abandoned old river channel, proactively creating hydrological conditions that meet the spawning needs of fish. The entire process forms a closed loop of "perception-decision-execution," transforming the abandoned old river channel from a passive, degraded space into an intelligent alternative habitat system capable of proactively simulating key ecological processes of natural rivers and responding to biological needs, thereby effectively compensating for the ecological function losses caused by waterway engineering. Attached Figure Description

[0007] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0008] Figure 1 The diagram shown is a flowchart of an alternative habitat construction method for straightening waterway curves in an embodiment of the present invention. Figure 2 The diagram shown is a structural schematic of an alternative habitat construction system for straightening waterway curves, provided by an embodiment of the present invention. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0010] The specific embodiments of the present invention will be described below.

[0011] Example 1 like Figure 1 As shown, the first aspect of this invention proposes a method for constructing alternative habitats for straightening waterway curves, comprising: S1: Based on the abandoned old river channel formed after the straightening construction, artificial water flow channels and internal terrain modifications are carried out within the abandoned old river channel and between it and the new main channel adjacent to the abandoned old river channel to generate a water circulation system with water circulation capabilities; wherein, S1 includes: S11: Based on the geographical locations of the two ends of the abandoned old river channel, dredging or excavation is carried out between the entrance end of the abandoned old river channel and the new main channel to create an entrance connecting channel; dredging or excavation is carried out between the exit end of the abandoned old river channel and the new main channel to create an exit connecting channel. S12: Based on the natural meandering shape of the abandoned old river channel, the riverbed of the abandoned old river channel is locally shaped to form at least one set of topographic sequences consisting of alternating shallow beach units and deep pool units within the abandoned old river channel. S13: Based on the inlet connecting channel, the abandoned old river channel where the terrain sequence is located, the outlet connecting channel and the corresponding section of the new main channel, construct a closed or semi-closed water flow path, and define the closed or semi-closed water flow path as a water flow circulation system. S2: Based on the structural characteristics of the water circulation system, a control structure group for regulating the water flow state is installed at key nodes in the main circulation path of the water circulation system, resulting in a control system physically connected to the water circulation system; wherein, S2 includes: S21: Based on the cross-sectional dimensions of the entrance connecting channel, install the first controllable gate at the intersection of the entrance connecting channel and the new main channel; S22: Based on the cross-sectional dimensions of the outlet connecting channel, a second controllable gate is installed at the intersection of the outlet connecting channel and the new main channel; S23: Based on the size of at least one deep pool unit in the terrain sequence, install a water disturbance device at the bottom of the deep pool unit; S24: Connect the electrical control lines of the first controllable gate, the second controllable gate, and the water disturbance device to the same control terminal to form a control system for coordinated control of the water circulation system; S3: Based on the spatial layout of the water circulation system, multiple sets of environmental parameter sensors are deployed inside the abandoned old river channel and near key nodes to obtain a monitoring network that continuously acquires the environmental parameters inside the abandoned old river channel. S4: Based on real-time environmental parameters obtained from the monitoring network and a pre-set ecological regulation model for fish life history stages, control commands are sent to the regulation system to enable the water circulation system to execute an ecological regulation mode adapted to the current fish life stage; wherein, the ecological regulation mode includes a spawning stimulation mode, and S4 includes: S4-1-1: Based on real-time environmental parameters obtained from the monitoring network and combined with external hydrological and meteorological data, determine whether the current period is the preset fish spawning season and whether the external hydrological conditions meet the spawning stimulation requirements. S4-1-2: When the judgment result is yes, the first set of gate control commands is generated and sent to the control system based on the preset gate cooperative opening and closing program; S4-1-3: Based on the received first set of gate control commands, the control system drives the first and second controllable gates to perform specific opening and closing actions, so that the water in the new main channel flows into and through the abandoned old river channel in a pulse manner, forming a first water flow state with directional slow flow characteristics in the abandoned old river channel.

[0012] When implementing the method defined in this invention, the first challenge is dealing with the abandoned old river channel left behind after the straightening and revelation of river bends. This section of the river channel has typically lost its direct hydraulic connection to the main navigation channel due to the severance of both ends, becoming an isolated body of water with stagnant hydrological processes and severely degraded ecological functions. The purpose of step S1 is to fundamentally transform this unfavorable physical foundation, turning it into a vibrant and structurally diverse base. Specifically, the phrase "based on the geographical location of both ends of the abandoned old river channel" in step S11 means that on-site surveys are required, using measuring tools such as GPS or total stations to accurately determine the spatial coordinates of the inlet and outlet ends of the abandoned old river channel, and to analyze the shortest distance between them and the new main navigation channel shoreline, geological conditions, and potential natural barriers. Subsequently, "dredging or excavation" is a specific engineering construction process. If there are still shallows or silted soil between the old river channel outlet and the new main navigation channel, dredging equipment such as cutter suction dredgers are used to remove them; if the two are completely separated by land, excavation equipment such as excavators is needed to excavate an artificial open channel. Regardless of the method used, the final result is an inlet and outlet connecting channel with cross-sectional dimensions calculated hydraulically to ensure sufficient flow capacity. These two channels are key to revitalizing the old river channel, re-establishing the hydraulic connection between the abandoned old channel and the new main navigation channel, and providing a controllable path for water to enter and exit.

[0013] "Based on the natural meandering morphology of abandoned old river channels" means that the transformation is not about demolishing and rebuilding, but rather respecting the natural course and morphological characteristics of the original river channel. On this basis, "local topographic shaping of the riverbed" is a meticulous ecological engineering operation. In practice, equipment such as long-arm excavators or underwater bulldozers can be used to carry out operations at a series of selected points in the river channel. For example, in the convex bank area of ​​a bend where the river is wider and the flow may be slower, shallow shoal units with shallow water and coarse substrates are constructed by filling with pebbles and gravel; in the concave bank area of ​​a bend or specific sections where the river is deeper and the flow is slower, deep pool units are formed by digging downwards or clearing silt. These units do not exist in isolation, but are "alternated" along the river's course, forming at least one continuous topographic sequence. Shallow shoal units increase water turbulence, improve dissolved oxygen, and provide foraging grounds, while deep pool units provide still-water shelter, overwintering, and refuge spaces. This alternation mimics the shallow-deep sequence of natural rivers, creating diverse combinations of flow velocity, water depth, and substrate, providing a rich selection of habitats for aquatic organisms with different habits.

[0014] Step S13 integrates the aforementioned components into a systematic concept. The inlet connecting channel, the main body of the abandoned old river channel shaped by topography, the outlet connecting channel, and the section of water connecting the inlet and outlet in the new main channel are spatially connected, forming a cyclical flow loop. This loop may be completely closed (i.e., the water can circulate) or semi-closed (i.e., mainly relying on unidirectional or intermittent exchange), collectively referred to as the water circulation system. The establishment of this system means that the abandoned old river channel has transformed from an isolated "pond" into a dynamic system capable of exchanging matter and energy with the outside world, which is the physical basis for all subsequent ecological regulation.

[0015] A dynamic infrastructure alone is insufficient; it must be made "intelligent" and "controllable," which is precisely the goal of step S2. S2, based on the specific structure of the established water circulation system, installs physical control equipment at its key control nodes. In steps S21 and S22, "based on cross-sectional dimensions" refers to selecting and installing controllable gates of matching dimensions according to the actual width and depth of the previously excavated inlet and outlet connecting channels. The first controllable gate is installed at the intersection of the inlet connecting channel and the new main channel, and the second controllable gate is installed at the intersection of the outlet connecting channel and the new main channel. These gates are typically electrically or hydraulically driven gate-type or rotary gate structures, and their opening can be precisely controlled by signals, acting like "faucets" and "drain valves" installed on the system's portals, accurately regulating the flow rate and timing of incoming and outgoing water. Step S23 focuses on the microenvironmental control within the system. "Based on the dimensions of at least one deep pool unit" refers to selecting a suitably sized deep pool and installing a water disturbance device at its bottom. This device can be a low-speed submersible jet pump or a microporous aeration coil. Its function is not to violently stir, but to agitate the bottom water by gently pushing the water flow or causing bubbles to rise, preventing dissolved oxygen from becoming too low or temperature stratification from becoming too drastic. Step S24 completes the integration of the control layer by laying waterproof cables to connect the control signal lines and power lines of the first controllable gate, the second controllable gate, and the water disturbance device to a central control terminal (such as an industrial control computer or PLC cabinet) located on shore. In this way, the dispersed devices are integrated into a unified physical control system with the ability to coordinate actions.

[0016] To ensure data-driven decision-making, step S3 constructs the system's "sensory nervous system." The deployment of the monitoring network is not arbitrary but rather "based on the spatial layout of the water circulation system." This means sensors need to cover key areas of the system: typical shallow and deep sections of the topographic sequence, inlet and outlet connecting channels, and areas where old and new water bodies meet. The deployed environmental parameter sensors typically include long-term submersible sensors for water temperature, dissolved oxygen, and flow velocity. They are fixed to stakes or anchor chains, continuously converting detected physicochemical signals into electrical signals. These sensors collectively form a continuous monitoring network, capturing subtle changes within the system in real time.

[0017] The final intelligent regulation is achieved through step S4. The core of this step is "based on real-time environmental parameters acquired from the monitoring network and a pre-set ecological regulation model for fish life stages." This "ecological regulation model" is a program or algorithm stored in the control terminal, encapsulating the environmental requirements (such as water temperature, flow rate, and dissolved oxygen) of specific fish species at different life stages (e.g., spawning, foraging, and overwintering). The system continuously compares and judges the real-time data reported by the monitoring network with the conditions in the model. Taking the spawning stimulation mode in the ecological regulation model as an example, its specific operation process is as follows: In S4-1-1, the control terminal not only analyzes whether the water temperature inside the old river channel reported by the monitoring network has reached the spawning threshold of a certain fish species, but also obtains external hydrological and meteorological data through the data interface to comprehensively determine whether it is currently the breeding season of the fish species and whether there are hydrological events that may trigger natural spawning behavior, such as rainfall or increased upstream water flow. External hydrological and meteorological data include hydrological data and meteorological data. The hydrological data includes upstream inflow data (unit: cubic meters / second), water level data (unit: meters), and flow velocity data (unit: meters / second). The meteorological data includes rainfall data (unit: millimeters / hour or millimeters / day) and temperature data.

[0018] When all conditions are met and the judgment result is "yes", S4-1-2 is initiated. The control terminal then calls the "gate coordinated opening and closing program" specifically designed for spawning from a variety of stored control programs, and generates a first set of gate control commands containing specific operating parameters, which is sent to the control system through the control line. Immediately following, in S4-1-3, the gate drive unit in the control system receives the commands and precisely drives the first and second controllable gates to execute a specific, rapid-response opening and closing sequence. The design goal of this sequence is to allow the water from the new main channel to flow into the abandoned old river channel in a "pulse-like" manner. This pulse is not a simple release of water, but rather a sudden and intense water flow stimulus created by rapidly opening the gates, simulating the natural river's rising water process. As this water flow passes through the old river channel, which has been shaped by topography and has shallows and deep pools, it induces a directional, generally gentle but locally varied flow pattern throughout the entire river channel—the first flow pattern with directional slow-flow characteristics. Many fish species associate this current pattern with suitable spawning grounds (such as gravelly bottoms in shallow waters) as a signal to begin breeding.

[0019] The series of steps defined in this invention constitutes a logically rigorous and functionally complete closed-loop engineering and management system. It begins with the physical transformation of abandoned river channels, solving their isolation problem by constructing connecting channels and laying the foundation for habitat diversity by shaping the topographic sequence. Subsequently, by deploying controllable gates and water disturbance devices and centrally controlling them, the physical system is equipped with adjustable "hands and feet," transforming its state from fixed to variable. The deployment of the monitoring network acts like installing "sensors," enabling real-time perception of the system's internal environment. Finally, intelligent decision-making and execution based on real-time perception data and ecological knowledge models (such as spawning stimulation patterns) complete the closed loop from "perception" to "decision-making" to "action." The entire process transforms a stagnant, abandoned waterway into a living, intelligent alternative habitat capable of actively simulating key hydrological processes of natural rivers and responding to specific ecological needs. This not only restores the hydraulic connectivity of the waterway but, more importantly, reconstructs and finely regulates its ecological functions, directly and effectively compensating for the natural river habitat destroyed by straightening waterways.

[0020] In some implementations, S3 includes: S31: Based on the spatial distribution of the terrain sequence, water temperature sensors and dissolved oxygen sensors are fixedly installed at multiple cross-sections along the abandoned old river channel. S32: Based on the location of the inlet connecting channel and the outlet connecting channel, a flow velocity sensor is fixedly installed in the inlet connecting channel and the outlet connecting channel; S33: Connect the data output cables of the water temperature sensor, dissolved oxygen sensor, and flow velocity sensor to the data acquisition unit to form a monitoring network that continuously collects and aggregates water temperature data, dissolved oxygen data, and flow velocity data.

[0021] This embodiment provides more specific and operable limitations on the deployment of the monitoring network (step S3), ensuring the comprehensiveness, spatial representativeness, and systematic nature of data collection, which is an important prerequisite for achieving precise and intelligent control.

[0022] In practical implementation, the construction of the monitoring network must closely revolve around the core feature of the system—the topographic sequence. Step S31 requires "fixed installation of water temperature and dissolved oxygen sensors at multiple cross-sections along the abandoned old river channel, based on the spatial distribution of the topographic sequence." The selection of "multiple cross-sections" needs to be representative, typically including at least: a cross-section near the inlet connecting channel, a cross-section near the outlet connecting channel, and several cross-sections containing typical shallow and deep pool units. At each selected cross-section, "fixed installation" is crucial. This is typically achieved by setting up fixed piles on both banks of the river channel, stringing load-bearing cables between the piles, and fixing the water temperature and dissolved oxygen sensors to the cables according to different water depths (e.g., surface, middle, and bottom layers) to ensure stable positioning and continuous monitoring of the vertical water layers at that point. The purpose of this deployment is to obtain spatially gridded data. Water temperature data can reveal whether the system exhibits thermal stratification, differences in thermal characteristics between different habitat units (shallows absorb heat quickly, deep pools retain heat well), and diurnal and seasonal variation patterns. Dissolved oxygen data directly reflects the life support capacity of a water body. Shallow areas may have higher dissolved oxygen levels due to their shallow depth and rapid currents, while the bottom of deep pools may face the risk of oxygen deficiency due to the decomposition of organic matter. By simultaneously monitoring multiple cross-sections, the water temperature and dissolved oxygen fields of the entire abandoned old river channel can be mapped in two-dimensional and even three-dimensional space, providing accurate maps for assessing habitat quality and identifying potential problem areas.

[0023] Knowing only the chemical and temperature states of the water is insufficient; the direct driving force behind these state changes and influencing biological activity is water flow. Therefore, step S32 specifically monitors the "throat" of the system. "Based on the location of the inlet and outlet connecting channels," a cross-section within these two artificial channels with smooth flow and representative average velocity is selected, typically in the middle of the channel, where a flow velocity sensor is fixedly installed. This sensor is usually a probe of an acoustic Doppler current meter (ADV) or an electromagnetic current meter, which needs to be securely mounted on a base at the bottom of the channel or on a bracket on the side wall, with its sensing part aligned with the incoming flow direction. The flow velocity sensor installed in the inlet connecting channel directly reflects the velocity and flow trend of water entering the old channel from the new main channel; the sensor installed in the outlet connecting channel reflects the velocity of water exiting the old channel. These two data points are crucial, as they are the most direct basis for verifying the smoothness of the water circulation system, assessing the effectiveness of gate control (e.g., whether opening the inlet gate significantly increases the inflow velocity), and calculating the water exchange efficiency.

[0024] Data generated by numerous sensors scattered across vast bodies of water must be effectively aggregated to generate value; this is precisely the function of step S33. Implementation requires planning and laying a reliable data transmission line. Data output cables (typically specialized cables with reinforced armor and waterproof sheaths) leading from each water temperature, dissolved oxygen, and flow velocity sensor need to be laid along the riverbank or underwater, ultimately connecting to a unified data acquisition unit. This data acquisition unit can be a multi-functional data logger or remote transmission unit (RTU) installed in a waterproof box on the shore. It is responsible for periodically (e.g., every minute) sending acquisition commands to all sensors, receiving analog or digital signals from each sensor, and performing standardized format conversion, packaging, and temporary storage. Thus, a monitoring network that continuously collects and aggregates water temperature, dissolved oxygen, and flow velocity data is truly formed. It is no longer an independent measurement point, but an organic whole capable of synchronously and continuously reporting the "vital signs" of each part of the system to the control terminal.

[0025] This specific deployment scheme has yielded significant technical benefits. By installing sensors layered across multiple cross-sections along the terrain sequence, the system can capture micro-environmental differences caused by habitat heterogeneity, avoiding the risk of misjudging the overall situation due to single-point monitoring. This makes the assessment of the environmental status of different functional zones, such as shallows and deep pools, more accurate and reliable. Installing flow velocity sensors specifically in the inlet and outlet connecting channels directly monitors the "throughput" of the system's material and energy exchange with the outside world. Any changes in the hydrodynamics caused by control commands can be immediately quantified and fed back, enabling objective and real-time verification of the effectiveness of engineering measures and providing crucial data for optimizing the control model. Unifying the data lines of all sensors to a centralized data acquisition unit not only simplifies system wiring and improves reliability and maintainability, but more importantly, it enables the synchronous acquisition and standardized aggregation of multi-source, heterogeneous environmental data. This provides the control terminal with a high-quality, uniformly formatted input data stream for complex data fusion analysis (such as drawing spatial distribution maps of environmental parameters and correlating the relationship between flow velocity and dissolved oxygen). Therefore, the monitoring network construction method defined in this embodiment lays a solid and reliable information perception foundation for ensuring that the entire alternative habitat system can achieve intelligent regulation based on accurate, comprehensive, and real-time data.

[0026] In some implementations, S4-1-3 includes: S4-1-31: Based on the first set of gate control commands, open the first controllable gate to the first predetermined opening degree; S4-1-32: Simultaneously, open the second controllable gate to a second predetermined opening degree that is less than the first predetermined opening degree; S4-1-33: Maintain the first predetermined opening and the second predetermined opening for a first predetermined duration, so that the water of the new main channel is injected into the inlet connecting channel at a higher flow rate and flows out through the outlet connecting channel at a lower flow rate, so as to form a first water flow state with directional slow flow characteristics from the inlet end to the outlet end in the abandoned old river channel.

[0027] This embodiment provides a more detailed breakdown of the key execution actions (steps S4-1-3) of the spawning stimulation mode, clarifying how to precisely shape the desired water flow pattern by controlling the opening and duration of the two gates. This demonstrates the concrete transformation from "purposeful instructions" to "executable operational parameters."

[0028] In implementing this detailed plan, after the control terminal generates the "first set of gate control commands" in step S4-1-2, these commands are not simple "open" or "close" commands, but contain precise control parameters. When the control system executes this, it first performs operation S4-1-31: based on the "first predetermined opening degree" parameter specified in the command, it drives the motor or hydraulic mechanism of the first controllable gate (inlet gate) to lift or rotate the gate to a specific, larger opening position. This "first predetermined opening degree" is a relative value determined through prior hydraulic simulation and ecological demand analysis (e.g., 70% of the maximum gate opening). Its purpose is to allow sufficient volumetric flow of water to flow into the new main channel per unit time without excessively impacting the river channel, thus creating an effective "pulse" stimulus intensity.

[0029] Almost simultaneously with the inlet gate's activation or within a very short timeframe set in the command, the control system executes operation S4-1-32: based on another parameter in the command—the "second predetermined opening"—it drives the second controllable gate (outlet gate) to open. This "second predetermined opening" is set to a value "less than the first predetermined opening" (e.g., 30% of the gate's maximum opening). This setting is the ingenious aspect of the technical solution. The outlet gate is not closed, but rather maintains a small opening, serving a dual purpose: first, it allows water to flow out, maintaining the vitality and directionality of the water flow and avoiding the risk of a backlog and breach at the inlet; second, it creates a significant "throttling" effect on the water flow, limiting the outlet's discharge capacity.

[0030] Once both gates reach the specified opening degree, the system enters the holding phase S4-1-33. The control system maintains the first controllable gate at the first predetermined opening degree and the second controllable gate at the second predetermined opening degree for a set "first predetermined duration" (e.g., four hours). During this duration, the dynamic equilibrium process of the water flow is fully established and demonstrated. Due to the large inlet opening, water is injected into the abandoned old river channel with a high initial flow velocity and volume through the inlet connecting channel. This water flow brings energy, dissolved oxygen, and possible fish pheromones, simulating the initial pulse of a natural flood. However, due to the small outlet opening and limited discharge capacity, the injected water cannot be discharged in an equal amount in a timely manner, resulting in a slight rise in the water level in the abandoned old river channel and an increase in overall water pressure. Driven by a constant pressure gradient from inlet to outlet, and regulated by the channel topography (shoals increasing resistance, pools temporarily storing water), the water flow within the entire channel reaches a stable state: overall, the water flows directionally from the inlet to the outlet, with a clear direction; due to the widening of the cross-section along the channel (compared to narrow connecting channels) and the throttling at the outlet, the average velocity within the main channel is controlled within a relatively gentle range, preventing the formation of scouring rapids. Simultaneously, in the shoal units, the flow accelerates slightly due to cross-sectional contraction, while in the pool units it diffuses and slows down, creating local velocity diversity within a slow-flowing context. This flow state—constant in direction, generally gentle, and with local variations—established throughout the abandoned old channel, is the "first flow state with directional slow-flow characteristics" that the technical solution aims to achieve.

[0031] This series of precise gate control parameters has produced crucial ecological engineering effects. Opening the first controllable gate to a large, predetermined opening rapidly introduces a body of water with significant kinetic energy and flow, simulating a sudden surge in flow in a natural river caused by rainfall or snowmelt—a "hydrological pulse." This pulse is a key environmental signal that triggers physiological responses in many fish species (especially those that lay drifting eggs or require flowing water stimulation), initiating spawning migrations or directly inducing spawning behavior. The core of the regulation lies in simultaneously opening the second controllable gate to a smaller, predetermined opening. It doesn't completely close the outlet to impound water, but rather skillfully regulates the system's hydraulic response through careful "flow restriction." This differentiated opening setting of "high inlet, low outlet" utilizes fluid dynamics principles to construct a non-equilibrium but stable flow state within the system: the strong injection at the inlet provides a continuous driving force and stimulus signal, while the weak discharge at the outlet ensures that this driving force is transformed into a continuous, directional, slow flow filling the entire river channel, rather than a rapid emptying. Maintaining the predetermined duration ensures that this ideal flow pattern has sufficient duration to meet the time window required for fish to complete spawning behavior. Therefore, the detailed implementation of this embodiment ensures that the spawning stimulation mode can be transformed from a conceptual goal into a repeatable, controllable, and precisely generated automated operating procedure that generates the required hydrological conditions, greatly improving the reliability and effectiveness of ecological regulation.

[0032] In some implementations, the ecological regulation model also includes a slow-release exchange model, S4 including: S4-2-1: Based on the real-time water quality parameters inside the abandoned old river channel obtained by the monitoring network, determine whether the water body of the abandoned old river channel needs to be exchanged with the outside in order to maintain water quality; S4-2-2: When the judgment result indicates that an exchange is required, a second set of gate control commands is generated and sent to the control system based on the preset periodic micro-exchange program. S4-2-3: Based on the received second set of gate control commands, the control system drives the first and second controllable gates to perform synchronous, small-opening, and periodic opening and closing operations, so that low-velocity water exchange occurs between the new main channel and the abandoned old river channel, forming a second water flow pattern.

[0033] This embodiment supplements another routine ecological regulation mode aimed at maintaining the basic health of the system—the slow-release exchange mode. This shows that the constructed system can not only carry out "strong intervention" during specific periods (such as the spawning season), but also has the ability to "micro-adjust" on a daily basis to maintain the vitality of the water body.

[0034] In implementing this model, the triggering logic is also data-driven. In step S4-2-1, the control terminal continuously analyzes real-time parameters reflecting the water quality inside the abandoned old river channel, transmitted back from the monitoring network. The core of these parameters is dissolved oxygen concentration, and may also include pH value, ammonia nitrogen, redox potential, etc. The system pre-stores threshold ranges for various water quality parameters for the healthy survival of the target aquatic biological community (e.g., dissolved oxygen must not be continuously lower than a certain critical value). Through real-time data sequence analysis, the control terminal can not only determine whether the current instantaneous value exceeds the standard, but also identify trends, such as whether dissolved oxygen shows a continuous and slow downward trend without external interference, or whether ammonia nitrogen concentration is gradually accumulating. When the algorithm determines that the water quality of the abandoned old river channel is gradually deteriorating due to biological metabolism, organic matter decomposition, etc., and that it is difficult to maintain solely through internal ecological processes, and that it needs to exchange with the new main channel (usually with better water quality and more saturated dissolved oxygen) to replenish oxygen and dilute pollutants, it is determined that "exchange is needed".

[0035] However, the exchange principle here is quite different from the spawning stimulation mode. Spawning stimulation requires creating significant changes in water flow to transmit signals, while the core requirements of slow-release exchange are "maintaining stability" and "minimal disturbance." Therefore, in step S4-2-2, the control terminal does not invoke a strong pulse program, but a preset "periodic micro-exchange program." The design concept of this program is to achieve continuous water quality renewal with minimal hydraulic disturbance. The core characteristic parameters of the "second set of gate control instructions" generated based on this program are "small opening" and "periodicity." "Small opening" means that the instruction requires the gate to open only a very small gap (e.g., an opening of five or ten percent); "periodicity" means that this opening-closing action will be repeated in a certain rhythm (e.g., opening for ten minutes, then closing for fifty minutes).

[0036] The control system executes this set of instructions in step S4-2-3. It drives the first and second controllable gates to perform "synchronous, small-opening, periodic opening and closing operations." Specifically, in the "opening" phase of each cycle, both gates simultaneously open slightly to the same small degree; in the "closing" phase, they close simultaneously. This synchronous operation is to avoid large unidirectional water flows or violent water level fluctuations in the old channel. When the gates are slightly open, the water level difference between the new main channel and the abandoned old channel, even if it exists, is minimal due to the small opening. Therefore, the water velocity and flow rate through the connecting channel are very low. This water exchange is not a surging inflow, but a slow infiltration and seepage like a trickle. It forms a very mild hydrological state known as the "second flow regime." The main area of ​​influence of this flow regime is near the connecting channel and the edge of the old channel, minimizing disturbance to the flow field, water level, and inhabited organisms in the main channel area.

[0037] The introduction of a slow-release exchange mode significantly enhances the long-term robustness and self-sustaining potential of the entire alternative habitat system. Firstly, it embodies a preventative ecological management approach, initiating gentle interventions before problems become severe by continuously monitoring water quality trends, preventing irreversible deterioration and avoiding the need for costly remediation later. Secondly, the "synchronous, small-scale, and periodic" operation method is a sophisticated technical embodiment of the "minimal disturbance" principle. Synchronous switching avoids the scouring of the substrate and organisms by strong unidirectional flows; small-scale opening ensures extremely low exchange flow rates, preventing disruption of established habitat structures (such as benthic communities); and periodic operation allows the system to alternate between "minor renewal" and "static stability," providing both opportunities for material exchange and a calm period for the ecosystem's digestion and absorption. This low-flow, small-volume water exchange, much like the system's "autonomous breathing" or "metabolism," continuously and gently introduces dissolved oxygen from the outside while slowly removing accumulated metabolic waste without disturbing the main organisms. This effectively slows down the aging process of the water body and maintains its basic life-support functions. Therefore, the slow-release exchange mode complements strong intervention modes such as spawning stimulation, together forming a complete and multi-dimensional ecological regulation system that combines "routine health care" with "specialized care." This ensures that the constructed alternative habitat not only plays a crucial role at specific times but also survives as a healthy ecosystem in the long term.

[0038] In some implementation methods, the ecological regulation model also includes a summering and rearing model, and S4 includes: S4-3-1: Based on real-time environmental parameters obtained from the monitoring network, determine whether the current period is a preset high-temperature season or a fish juvenile stage; S4-3-2: When the judgment result is yes, the first set of equipment control commands is generated and sent to the control system based on the preset water stratification control program; S4-3-3: Based on the first set of equipment control commands received, the control system first closes the first and second controllable gates, and then controls the water disturbance device to operate intermittently in a specific mode to induce the formation of a stratified distribution structure of temperature and dissolved oxygen in the vertical direction of the water in the abandoned old river channel deep pool unit.

[0039] This embodiment introduces a third ecological regulation mode—the juvenile summering mode—which demonstrates the system's targeted protection capabilities against seasonal climate stress and vulnerable life stages of fish, further expanding the comprehensiveness of its ecological functions.

[0040] The implementation of this model begins with the accurate identification of specific environmental stresses and biological stages. In step S4-3-1, the control terminal makes logical judgments based on real-time environmental parameters acquired from the monitoring network. These judgments are primarily based on two categories: first, climatic and seasonal conditions, which involves analyzing long-term trends in water temperature sensor data (especially surface water temperature) to determine whether a sustained "high-temperature season," such as summer, has begun; second, biological stage conditions, which may be determined through externally input phenological information or by inferring from water temperature and specific fish growth models to determine whether the fish have entered the "juvenile stage" (i.e., the period when juvenile fish emerge and grow in large numbers). These two conditions are usually correlated because the high temperatures in summer are particularly stressful for juvenile fish. When either condition or both are met, the system determines that protective measures need to be initiated.

[0041] Subsequently, in step S4-3-2, the control terminal invokes a "static water stratification control program" that differs significantly from the previous approach. The goal of this program is not to promote mixing or exchange, but rather to actively create and maintain a relatively static water body structure with a gradient of physicochemical properties in the vertical direction under specific conditions. Based on this program, the "first set of equipment control instructions" are generated, covering the gate system and internal water disturbance devices, and these instructions are sent to the control system.

[0042] The control system executes this composite command in step S4-3-3. The execution process is phased and sequential. The first step is to "close the first and second controllable gates." This operation interrupts the exchange of water quality and heat between the abandoned old river channel and the new external main channel. During the high-temperature season, the water in the external main channel may have a higher overall temperature or rise faster due to its open surface and strong flow. Closing the gates is equivalent to establishing a relative "heat insulation barrier" for the abandoned old river channel, preventing the continuous inflow of high-temperature hot water from the outside, which helps to slow down the overall temperature rise rate of the internal water body and create a relatively independent and controllable thermal environment for the internal ecological processes.

[0043] After establishing a still water foundation, the second step is the precise control of the internal environment: "controlling the water disturbance device to operate intermittently in a specific mode." This "specific mode" is the key technical point. It doesn't mean continuously operating the disturbance device at the bottom of the deep pool at high intensity (which would cause complete mixing of the upper and lower water layers, disrupting stratification), nor does it mean completely shutting it off (which could lead to severe oxygen depletion at the bottom). Instead, it involves designing a low-frequency, short-duration, low-intensity intermittent operation strategy. For example, the instructions might require the disturbance device to operate for several minutes and then stop for tens of minutes, and to operate at only 20% to 30% of its rated power. This gentle, intermittent bottom disturbance aims to "induce the formation of a stratified distribution structure of temperature and dissolved oxygen." Under still water conditions and with solar radiation, the water naturally tends to form thermal stratification—the surface water absorbs heat, becomes lighter, and remains at the top, while the cooler, heavier water at the bottom remains. Complete stillness could lead to oxygen depletion at the bottom. The intermittent, low-intensity operation of the bottom disturbance device acts as a "regulated mixing" mechanism. Its slight agitation is insufficient to completely mix the surface hot water with the bottom cold water (thus disrupting thermal stratification), but it is enough to promote weak flow in the bottom water and exchange of substances with the sediment interface. This helps prevent the dissolved oxygen in the bottom from being depleted due to complete stasis, and may also make the temperature stratification interface (thermocline) more gradual and stable, rather than a thin layer with a sharp change. In this way, an ideal stratification state is "induced" in the deep pool unit: the upper layer is warmer water, suitable for the growth of food organisms and fish feeding; the lower layer is cooler water with maintained dissolved oxygen, becoming a natural "cold water sanctuary".

[0044] Therefore, the implementation of the juvenile summering model endows the alternative habitat system with a crucial climate refuge function. Through the active closure of gates for physical isolation, it effectively mitigates the impact of external high-temperature heat loads on the system's interior, providing aquatic organisms with buffer time and space to cope with high temperatures. More importantly, it actively intervenes in and optimizes the vertical structure in still water environments by precisely controlling the intermittent low-power operation of water disturbance devices. This intervention does not eliminate naturally formed stratification, but rather guides and maintains a more stable stratified structure that is more conducive to biological utilization. The resulting stratified distribution of water temperature and dissolved oxygen creates vertical habitat diversity: thermophilic organisms or those requiring high dissolved oxygen for vigorous metabolism can be active in the upper layers, while fish sensitive to high temperatures and needing to avoid heat stress (especially juvenile fish with vigorous metabolism and poor tolerance to low oxygen) can retreat to the cooler lower waters to "oversummer." This actively created stratified shelter greatly improves the survival rate of juvenile fish and aids in the replenishment process of fish populations. The model defined in this embodiment shows that the construction method not only focuses on the creation and basic maintenance of habitats, but also delves into the concern for the needs of organisms to avoid extreme environmental stresses, making the space transformed from abandoned old river channels a fully functional intelligent habitat that can cope with seasonal challenges and support fish to complete their full life cycle.

[0045] In some implementations, S4-3-3 includes: S4-3-31: When the monitoring network detects that the surface water temperature of the abandoned old river channel is higher than the preset water temperature threshold and the dissolved oxygen at the bottom layer is lower than the preset dissolved oxygen threshold, the water disturbance device is activated. S4-3-32: Control the water disturbance device to operate at a low power level below its rated power for a second predetermined period of time, and then shut it off; S4-3-33: Repeat S4-3-31 to S4-3-32 to maintain a stratified state in the deep pool unit of the abandoned old river channel, where the upper water is warm, the lower water is cool, and the dissolved oxygen in the bottom layer is stable.

[0046] This embodiment further defines step S4-3-3, providing a clear, executable, and real-time feedback-based specific control logic for the fundamental operation of "intermittent operation of the water disturbance device in a specific mode." This limitation transforms the process of maintaining the layered distribution structure from open-loop control to closed-loop adaptive adjustment.

[0047] In implementing this scheme, the water disturbance devices installed at the bottom of the deep pool unit, such as low-speed submersible pumps or microporous aeration discs, no longer rely solely on a preset schedule for operation, but rather closely depend on the real-time monitoring results of key environmental parameters by the monitoring network. Step S4-3-31 defines the dual triggering conditions for starting the device. The control terminal continuously receives and analyzes data from sensors at different depths within the designated deep pool unit. It needs to simultaneously determine two independent but related conditions: First, whether the "surface water temperature" of the deep pool unit exceeds the "preset water temperature threshold." This threshold is set based on the ecological characteristics of the target protected fish (especially juvenile fish), for example, it could be the upper limit of the optimal growth temperature range for the juvenile fish, or the critical temperature at which heat stress begins to appear. Second, whether the "bottom dissolved oxygen" of the same deep pool unit is lower than the "preset dissolved oxygen threshold." This threshold is a safe concentration lower limit set to maintain a basic aerobic environment at the bottom and prevent the production of toxic substances such as hydrogen sulfide during anaerobic processes. The control terminal only recognizes a potential risk in the current water stratification state when the monitoring data simultaneously meet both conditions: "surface water temperature is above the threshold" and "bottom dissolved oxygen is below the threshold." Overheating at the surface may drive away or threaten fish, while oxygen deficiency at the bottom threatens benthic organisms and could lead to water quality deterioration. At this point, the system determines that intervention is necessary and thus "activates the water disturbance device."

[0048] Once the startup conditions are met, the system immediately executes step S4-3-32. The core control concept of this step is "gentle disturbance" and "time-limited action." The control terminal sends a command to the water disturbance device, instructing it to "operate at a low power level below its rated power." This means that even if the equipment itself is capable of strong stirring or aeration, it is only allowed to operate at partial load in this mode, for example, only 30% of its rated power. The purpose of this is to generate a gentle water flow or a small number of bubbles sufficient to break the absolute stillness of the bottom water and promote weak material exchange between water layers, but not enough energy to trigger violent turbulent mixing, thus avoiding disruption of the precious temperature gradient (i.e., thermal stratification) between the upper warm water and the lower cold water. Simultaneously, this low-power operation lasts only for a pre-set "second predetermined duration," which is usually short, such as five to fifteen minutes. Its design intent is to perform a brief, pulsed fine-tuning, rather than continuous stirring. After the second predetermined duration ends, the control terminal instructs the water disturbance device to shut down, allowing the deep pool unit to return to a quiescent state.

[0049] A single, short-term disturbance is often insufficient to offset continuous environmental changes, as solar radiation constantly heats the surface, and biological respiration and the decomposition of organic matter continuously deplete dissolved oxygen in the bottom layer. Therefore, the system needs to establish a dynamic adjustment cycle, as defined in step S4-3-33: "repeatedly executing S4-3-31 to S4-3-32." After shutting down the disturbance device, the system returns to monitoring mode. After a period of settling, the surface water temperature may rise again due to sunlight, and the dissolved oxygen in the bottom layer may decrease again due to depletion. Once the monitoring data triggers both conditions simultaneously again, the entire "judgment-start-low-power operation-shutdown" process automatically repeats. This cycle repeats continuously, forming a periodic micro-adjustment loop based on environmental feedback.

[0050] By implementing a sophisticated control logic based on clear environmental threshold judgments and periodic low-power disturbances, the system can achieve intelligent and adaptive maintenance management of the stratified state of deep pool units. First, the dual triggering conditions ensure the accuracy and necessity of intervention; the device only activates when monitoring data clearly indicates the simultaneous presence of "surface overheating stress" and "bottom hypoxia risk," effectively avoiding energy waste and unnecessary disturbance to the aquatic environment. Second, operating at "low power below rated power" is a sophisticated balancing strategy that achieves key control objectives with minimal energy input: gentle bottom disturbances are sufficient to promote weak exchange between the bottom water and sediment interface, helping to prevent dissolved oxygen depletion and mitigate the accumulation of harmful substances; simultaneously, due to its strictly limited intensity, this disturbance does not massively mix the warm surface water with the cool bottom water, thus completely preserving the vertical temperature gradient that forms the basis of the "cold refuge." Furthermore, the periodic pattern of "shutting down after the second predetermined duration" and "repeating the execution" simulates the intermittent and slight disturbance characteristics of wind and other factors on the stratified structure in natural water bodies. This allows the system to find a dynamic and sustainable balance between the sometimes contradictory goals of "actively improving the hypoxia in the bottom layer" and "passively maintaining the thermal stratification of the upper layer to store cold water resources." Ultimately, through this intelligent intermittent fine-tuning, the system can maintain a stratified state of "warm upper water, cool lower water, and stable dissolved oxygen in the bottom layer" in the deep pool units of abandoned old river channels throughout the high-temperature season or during the fish larval stage. This carefully maintained stratified structure creates valuable vertical ecological niche selection for aquatic organisms: fish and prey organisms can feed and grow efficiently in the warm upper water, while when the surface temperature is too high and poses a threat, they can readily dive into the cooler lower water with guaranteed dissolved oxygen, thus significantly improving the survival rate and growth efficiency of vulnerable groups such as juvenile fish, ensuring that the alternative habitat can still play a crucial conservation and sheltering role under climate pressure.

[0051] In some implementation methods, the ecological regulation model also includes a wintering shelter model, S4 including: S4-4-1: Based on water level data obtained from seasonal climate forecasting and monitoring networks, determine whether the cold season is approaching; S4-4-2: When the judgment result is yes, based on the preset water storage and heat preservation program, the third set of gate control commands is generated and sent to the control system; S4-4-3: Based on the received third set of gate control commands, the control system first opens the first controllable gate to fill the abandoned old river channel with water to the preset water level, then closes all the first and second controllable gates, and stops all water disturbance devices, so that the abandoned old river channel remains in a stagnant water state, forming a wintering site.

[0052] This embodiment adds a fourth ecological regulation mode—the overwintering shelter mode. This mode shifts the system's regulation objective from responding to high-temperature stress to ensuring that organisms safely survive the low-temperature season, reflecting comprehensive support for the critical overwintering stage in the complete annual life cycle of fish, and enabling the function of alternative habitats to cover the whole year.

[0053] The activation of the winter shelter mode relies on a combined analysis of early predictions of seasonal climate change and internal conditions. In step S4-4-1, the control terminal needs to integrate two types of information for decision-making. One type is "seasonal climate prediction," which typically obtains medium- to long-term weather forecasts through data interfaces or statistical analysis models based on historical climate data to predict whether and when severe cold or freezing weather will arrive. The other type is "water level data acquired by the monitoring network," which is a real-time indicator reflecting the water storage status within abandoned old river channels. Combining external climate predictions with actual internal water levels is crucial, enabling the system to determine the optimal timing for operation. For example, if a forecast indicates a strong cold front will cause temperatures to drop below freezing in a week, and monitoring data shows that the water level in the abandoned old river channel is low due to evaporation and seepage, then pre-emptive water storage becomes an urgent and necessary measure.

[0054] When the assessment confirms that the cold season is approaching, the system enters step S4-4-2. At this time, the control terminal invokes a pre-set "water storage and insulation program." The program's logical objective is very clear: before the onset of severe cold, fully utilize the water source of the new main channel to store as much water as possible in the abandoned old river channel, and by converting it to a stagnant state, utilize the water's high heat capacity and the insulating effect of the ice layer to maintain a relatively stable underwater environment with a temperature above freezing point during winter, providing a safe overwintering place for fish. Based on this program, the control terminal generates a set of explicit "third set of gate control commands" and sends them to the control system.

[0055] The control system executes these instructions sequentially in step S4-4-3. The first step is to "open the first controllable gate to fill the abandoned old river channel to the preset water level." In this step, only the first controllable gate located at the inlet connecting channel is opened, while the second controllable gate at the outlet remains closed. Under the influence of gravity or water level difference, the water from the new main channel flows unidirectionally into the abandoned old river channel through the inlet connecting channel, causing its internal water level to gradually rise. The "preset water level" here is a value set after engineering calculations and hydraulic safety assessments. It is usually lower than the flood control crest elevation on both banks of the river. Its purpose is to accumulate the maximum possible water volume to increase the total heat capacity, while reserving a safe space for winter water surface freezing and its potential volume expansion, and ensuring bank stability. When the water level sensors in the monitoring network indicate that the water level has reached the preset water level, the control terminal executes the second step: "Then close all the first and second controllable gates." At this point, both the inlet and outlet are cut off, and the abandoned old river channel is completely transformed into a closed water unit isolated from the external main channel water. The third step is to "stop all water disturbance devices." After the gates are closed, the system further instructs all water disturbance devices installed at the bottom of the deep pool unit to completely cease operation, eliminating any internal disturbance sources that could cause internal convection or mixing of the water. The ultimate goal of this series of operations is to keep the abandoned old river channel "in a stagnant state." In frigid climates, this stagnant state, free from external inflow and internal disturbance, is most conducive to the rapid heat dissipation and freezing of surface water. Once the ice layer forms, it becomes a highly efficient thermal insulation barrier, greatly reducing heat exchange between the water and the cold air, allowing the water temperature below the ice layer to remain stable within a relatively low range above zero degrees Celsius with minimal fluctuations.

[0056] The establishment of the overwintering shelter model endows the entire alternative habitat system with an indispensable seasonal survival guarantee function. By proactively integrating external climate forecasting with real-time internal water level monitoring, it achieves predictive intelligent control of overwintering preparations, enabling the system to operate within the optimal window before the arrival of cold waves, avoiding insufficient water storage or hasty responses due to delayed reactions. During the water storage and insulation procedure, the inlet gate is first opened to unidirectionally store water to the preset level. This direct and effective operation maximizes the water storage and total heat capacity of the abandoned old river channel before the arrival of low temperatures. This is equivalent to storing more "thermal inertia" for the entire water body, slowing down the rate of temperature drop when encountering cold, and buying time for biological adaptation. Subsequently, closing all gates and stopping all disturbance devices are key measures to create a stable overwintering physical environment. The completely closed state completely blocks heat and mass exchange with potentially colder and more fluid water bodies outside; while stopping internal disturbances causes the water body to quickly return to calm, minimizing heat loss due to water flow and accelerating the surface freezing process. The resulting stagnant water state, along with the overlying ice cap, creates an extremely stable underwater microclimate. The water beneath the ice cap remains cold but not frozen, providing ideal conditions for many temperate fish to overwinter: the low temperature significantly reduces their metabolic rate and energy consumption, allowing them to survive the food-scarce winter with their limited energy reserves; the exceptionally stable water temperature avoids physiological stress caused by temperature fluctuations; and the sufficient depth of the water beneath the ice and the ice cap itself provide a solid physical barrier, protecting fish from the direct impact of wind chill, surface fluctuations, predators, and drastic temperature changes. Therefore, the overwintering shelter model defined in this embodiment enables the modified abandoned river channel to become a reliable and safe winter refuge, ensuring that the fish populations inhabiting it can successfully overwinter, thereby guaranteeing the integrity, continuity, and reliability of the ecological function of this alternative habitat on a year-round timescale.

[0057] In some implementations, after S3 and before S4, the following are also included: Sa: Based on the water area of ​​the abandoned old river channel, an underwater acoustic signal receiving array is deployed to continuously receive signals emitted by target fish with acoustic tags to obtain fish activity location data; Sb: The real-time environmental parameters obtained from the monitoring network are spatiotemporally correlated and fused with fish activity location data to generate an enhanced ecological dataset containing environmental and biological behavior information; In S4, control commands are sent to the control system based on the enhanced ecological dataset and the preset ecological regulation model of fish life history stages.

[0058] This embodiment incorporates two new steps (Sa and Sb) between steps S3 and S4. These two steps expand the system's monitoring dimensions from purely abiotic environmental parameters to the behavior and distribution of biological individuals, and use data fusion technology to spatially and temporally link environmental and biological information. This expansion signifies a qualitative leap in the system's intelligence level, moving from "responding to environmental changes" to "responding to ecological processes and biological feedback."

[0059] In practical implementation, after the environmental monitoring network (S3) has been deployed, a biological behavior monitoring system needs to be constructed in parallel, i.e., the Sa step needs to be executed. The Sa step requires "deploying an underwater acoustic signal receiving array based on the water area of ​​the abandoned old river channel". The "underwater acoustic signal receiving array" here usually consists of multiple hydrophones fixed underwater according to a certain spatial geometry (e.g., grid-like deployment or linear deployment along key sections of the river channel). These hydrophones are connected to the signal receiving and processing unit on shore via waterproof cables. Its working principle is based on acoustic telemetry technology: miniature acoustic transmitters (acoustic tags) are implanted or attached externally to the target fish individuals being studied or needing protection. Each transmitter periodically emits ultrasonic signals with a unique identification code. The hydrophone array deployed in the abandoned old river channel can continuously "listen" to the underwater acoustic environment and "continuously receive" these signals emitted by the "target fish with acoustic tags". The multiple hydrophones in the array receive the same signal at slightly different times. The signal processing unit uses this time difference to calculate, through acoustic localization algorithms (such as time difference localization), the real-time "fish activity location data" of the tagged fish individual in three-dimensional space. This data is a sequence containing timestamps and spatial coordinates, which can accurately reflect when the target fish appeared in the specific location of the abandoned old river channel, and even its movement trajectory and speed.

[0060] Simply acquiring fish location data and environmental monitoring data is insufficient; these two types of information, occurring synchronously in time and space, must be integrated and correlated to reveal the underlying ecological connections. This is precisely the task of the Sb step. The core of the Sb step is "spatiotemporal correlation and fusion processing." The control terminal or a dedicated data fusion server establishes a unified spatiotemporal framework. It matches and correlates the "fish activity location data" generated in the Sa step (each data point includes time, fish ID, X coordinate, and Y coordinate) with the "real-time environmental parameters acquired by the monitoring network" in the S3 step (each data point includes time, sensor location, water temperature, dissolved oxygen, flow rate, etc.). For example, the system might analyze: at a specific moment, a fish with the ID "Fish_001" is located at coordinates (X1, Y1). At the same moment, what is the temperature recorded by the nearest water temperature sensor to that coordinate? What is the dissolved oxygen level in that area? By continuously correlating, overlaying, and analyzing large amounts of such data, the system can "generate" a completely new "enhanced ecological dataset containing environmental and biological behavior information." This dataset not only records "what the environment is like", but also records "what the organisms do under these conditions", directly linking environmental parameters with the spatial behavioral responses of organisms.

[0061] In step S4, the decision-making and execution phase of ecological regulation, the basis for decision-making has been fundamentally enhanced. The original S4 was based on "real-time environmental parameters obtained from the monitoring network and a pre-defined ecological regulation model of fish life history stages" to make judgments and issue commands. However, with the addition of steps Sa and Sb, the decision-making basis of S4 has shifted to "based on an enhanced ecological dataset and a pre-defined ecological regulation model of fish life history stages." This means that the information input into the regulation model includes not only real-time environmental parameters but also the fused enhanced ecological dataset. For example, when determining whether to activate the "spawning stimulation mode," the model analyzes not only whether the water temperature has reached the spawning threshold and whether the season is suitable, but also simultaneously analyzes whether the marked, sexually mature parent fish in the enhanced ecological dataset have begun to gather at their historically preferred spawning grounds (such as a specific shallow water unit), and whether their activity patterns exhibit pre-spawning cruising or exploratory behaviors. This decision-making logic, which combines direct biological behavioral evidence, is far more accurate and reliable than indirect inferences based solely on environmental parameters.

[0062] The introduction of fish activity monitoring and multi-level data fusion significantly enhances the accuracy, foresight, and ecological relevance of the entire system's ecological regulation. By deploying an underwater acoustic signal receiving array, the system has, for the first time, obtained direct, objective, and quantitative behavioral data on organisms' habitat utilization. This overcomes the limitations of indirectly inferring biological states solely through environmental parameters such as water temperature and dissolved oxygen, enabling managers to truly "perceive" where fish are, how they move, and how they respond to the environment. Rigorous spatiotemporal correlation and fusion of fish activity location data with environmental parameters is crucial for uncovering the causal or correlational relationships between environmental factors and biological behavior. This allows the system to begin understanding ecological questions such as "under what combination of water temperature and flow rate will fish prefer to congregate in deep pool units" or "what quantifiable changes occur in the distribution and movement trajectories of fish after a pulsed water flow." The resulting enhanced ecological dataset is a comprehensive data treasure trove with richer information dimensions and clearer ecological significance, establishing an initial empirical link between environmental drivers and biological responses. Using this enhanced dataset as a basis for regulatory decisions means the system can move towards "adaptive regulation based on ecological feedback," rather than simply "programmed regulation based on fixed environmental thresholds." The system can validate and optimize regulatory strategies based on actual fish behavior feedback. For example, if data shows that parent fish are not attracted to the target shallows after the spawning stimulation mode is activated, the system can adjust gate control parameters or investigate other limiting factors in conjunction with environmental data. Therefore, this supplement to the embodiment transforms the alternative habitat construction system from an automated environmental regulation system into an intelligent ecological engineering system capable of sensing biological feedback, understanding ecological interactions, and optimizing management measures accordingly. Each regulatory action is more likely to produce the expected and verifiable ecological benefits, ultimately achieving a profound shift from "artificially constructing a habitat" to "intelligently operating and maintaining a habitat effectively utilized by organisms."

[0063] In some implementations, Sb includes: Sb1: Based on fish activity location data, the main aggregation areas and activity intensity of target fish in abandoned old river channels at different times were analyzed; Sb2: Match and overlay the information on the main aggregation areas and activity intensity with the water temperature data, dissolved oxygen data and flow velocity data obtained by the monitoring network at the same time and spatial location; Sb3: Stores the completed matching and overlay datasets as an enhanced ecological dataset that is updated over time.

[0064] This embodiment provides a more detailed description and definition of the specific data processing flow for step Sb, namely, generating the enhanced ecological dataset. It breaks down the relatively abstract concept of data fusion into a series of operable and achievable steps, clarifying the transformation path from raw environmental data and fish location data to high-value ecological information products.

[0065] When implementing step Sb, the data processing system (which can be a module built into the control terminal or a standalone server) first needs to perform in-depth analysis and feature extraction on the raw "fish activity location data" from the underwater acoustic array. Step Sb1 requires "analyzing the main aggregation areas and activity intensity information of target fish in abandoned old river channels based on the fish activity location data." This "analysis" involves spatial statistics and time series analysis. Identification of "main aggregation areas" is typically accomplished using spatial clustering algorithms (such as kernel density estimation). The system spatially overlays the location points of all marked fish individuals over a period of time (e.g., the past 24 hours or the entire spawning season), and by calculating the spatial point density, identifies "hotspot" areas where the frequency of fish occurrence is significantly higher than the background value. These areas are defined as "main aggregation areas," which may correspond to feeding grounds, spawning grounds, or resting areas. The extraction of "activity intensity information at different times" is achieved through time series statistical analysis. The system can segment data by hour, day / night, or other ecologically relevant time periods (such as dawn and dusk), and count the number of valid location points recorded in each time period, the average movement speed of fish, or the total movement distance. High location point update rates and high movement speeds generally indicate that fish are active (e.g., foraging), while low update rates and low speeds may indicate a resting state. Through this analysis, the system can quantify the activity rhythms of fish within a day or a specific period.

[0066] Having obtained these biologically significant characteristics, the next step is to precisely align them with the corresponding environmental context. Step Sb2 explicitly requires "matching and overlaying the information on major aggregation areas and activity intensity with water temperature, dissolved oxygen, and flow velocity data acquired by monitoring networks at the same time and spatial location." The key here lies in strict "spatiotemporal alignment." "Same time period" means that for the analyzed information of "high activity intensity at dusk," the system needs to match all water temperature, dissolved oxygen, and flow velocity data recorded by the monitoring network during "dusk hours." "Same spatial location" means that for an identified "major aggregation area" (e.g., a polygonal area), the system needs to find data from several environmental monitoring sensors located within or closest to that area and treat these data as environmental characteristics of that area. This matching is not a simple one-to-one correspondence, but a complex data association operation based on spatiotemporal grid or buffer analysis, designed to attach detailed environmental condition labels to each identified biological behavior pattern (where they aggregate and when they are active), answering the question, "In this environment, fish exhibit this behavior."

[0067] After completing the complex matching and overlay process described above, the data has achieved initial fusion. However, to ensure that the subsequent ecological regulation model can efficiently and conveniently access this information, systematic data organization and storage are required, namely the Sb3 step. The Sb3 step specifies that "the dataset that has completed matching and overlay should be stored as an enhanced ecological dataset that updates over time." This means that the fused data is not used to generate a static report, but is persistently stored in the form of a structured database table or time-series file. Each record may contain the following fields: timestamp, spatial region identifier (or coordinates), average water temperature, average dissolved oxygen, average current velocity, fish aggregation intensity index, and a list of major active fish species IDs for that region at that time. This dataset is a "live" database; it automatically updates and expands as new data is continuously input from the monitoring network and underwater acoustic array, maintaining its timeliness and continuity, forming a constantly growing ecological information repository that combines historical and real-time data.

[0068] By implementing this standardized and streamlined data processing procedure, the value, reliability, and usability of the generated enhanced ecological dataset are fundamentally improved. Deep analysis of raw fish activity location data to extract "major aggregation areas" and "activity intensity information" is a crucial first step in transforming massive, fragmented location data into ecologically significant knowledge about biological distribution patterns and behavioral rhythms. This enables the system to go beyond simply "seeing where the fish are" and further "understanding the distribution patterns and activity patterns of fish schools." Matching and overlaying these extracted biological pattern information with environmental monitoring data that strictly correspond in time and space is the core step in constructing an "environment-behavior" response relationship database. It systematically establishes the correlation between environmental variables and the spatial distribution and temporal activity of organisms, providing a solid empirical data foundation for quantitatively understanding fish's selective use of habitats and their behavioral responses to environmental changes. Finally, the fused data is stored in a structured, time-series format, forming a dynamically updated, standardized ecological information product. This provides a rich and uniformly formatted input interface for pre-defined ecological regulation models. The model can not only query current fused data to support real-time decision-making, but also retrieve historical data to analyze how fish responded under similar environmental conditions in the past, thus providing historical patterns and optimization basis for current control strategies. Therefore, the detailed data processing method in this embodiment ensures that the raw information collected from steps Sa and Sb can be efficiently, accurately, and systematically transformed into high-quality "data fuel" to drive the intelligent control model, greatly enhancing the system's ability and potential to continuously self-optimize through data accumulation and machine learning, and achieve more precise ecological management.

[0069] Example 2 like Figure 2 As shown, in a second aspect, the present invention proposes an alternative habitat construction system for straightening waterway curves in waterway engineering. The system employs the alternative habitat construction method for straightening waterway curves in waterway engineering proposed in any of the above embodiments. The system includes: The circulation system construction module is used to execute step S1: Based on the abandoned old river channel formed after the straightening construction, artificial water flow channels are constructed and internal terrain is modified within the abandoned old river channel and between it and the new main channel adjacent to the abandoned old river channel to generate a water circulation system with water circulation capabilities; wherein, S1 includes: S11: Based on the geographical locations of the two ends of the abandoned old river channel, dredging or excavation is carried out between the entrance end of the abandoned old river channel and the new main channel to create an entrance connecting channel; dredging or excavation is carried out between the exit end of the abandoned old river channel and the new main channel to create an exit connecting channel. S12: Based on the natural meandering shape of the abandoned old river channel, the riverbed of the abandoned old river channel is locally shaped to form at least one set of topographic sequences consisting of alternating shallow beach units and deep pool units within the abandoned old river channel. S13: Based on the inlet connecting channel, the abandoned old river channel where the terrain sequence is located, the outlet connecting channel and the corresponding section of the new main channel, construct a closed or semi-closed water flow path, and define the closed or semi-closed water flow path as a water flow circulation system. The control structure deployment module is used to execute step S2: Based on the structural characteristics of the water circulation system, control structure groups for regulating the water flow state are installed at key nodes in the main circulation path of the water circulation system, resulting in a control system physically connected to the water circulation system; wherein, S2 includes: S21: Based on the cross-sectional dimensions of the entrance connecting channel, install the first controllable gate at the intersection of the entrance connecting channel and the new main channel; S22: Based on the cross-sectional dimensions of the outlet connecting channel, a second controllable gate is installed at the intersection of the outlet connecting channel and the new main channel; S23: Based on the size of at least one deep pool unit in the terrain sequence, install a water disturbance device at the bottom of the deep pool unit; S24: Connect the electrical control lines of the first controllable gate, the second controllable gate, and the water disturbance device to the same control terminal to form a control system for coordinated control of the water circulation system; The monitoring network deployment module is used to perform step S3: based on the spatial layout of the water circulation system, multiple sets of environmental parameter sensors are deployed inside the abandoned old river channel and near key nodes to obtain a monitoring network that continuously acquires environmental parameters inside the abandoned old river channel. The intelligent regulation execution module is used to execute step S4: based on real-time environmental parameters obtained from the monitoring network and a preset ecological regulation model for fish life history stages, it sends control commands to the regulation system to enable the water circulation system to execute an ecological regulation mode adapted to the current fish life stage; wherein, the ecological regulation mode includes a spawning stimulation mode, and S4 includes: S4-1-1: Based on real-time environmental parameters obtained from the monitoring network and combined with external hydrological and meteorological data, determine whether the current period is the preset fish spawning season and whether the external hydrological conditions meet the spawning stimulation requirements. S4-1-2: When the judgment result is yes, the first set of gate control commands is generated and sent to the control system based on the preset gate cooperative opening and closing program; S4-1-3: Based on the received first set of gate control commands, the control system drives the first and second controllable gates to perform specific opening and closing actions, so that the water in the new main channel flows into and through the abandoned old river channel in a pulse manner, forming a first water flow state with directional slow flow characteristics in the abandoned old river channel.

[0070] This system corresponds to the method proposed in Example 1, and will not be described in detail here.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing alternative habitats for straightening waterway curves, characterized in that, include: S1: Based on the abandoned old river channel formed after the straightening construction, artificial water flow channels and internal terrain modifications are carried out within the abandoned old river channel and between it and the new main channel adjacent to the abandoned old river channel to generate a water circulation system with water circulation capabilities; wherein, S1 includes: S11: Based on the geographical locations of the two ends of the abandoned old river channel, dredging or excavation is carried out between the entrance end of the abandoned old river channel and the new main channel to create an entrance connecting channel; dredging or excavation is carried out between the exit end of the abandoned old river channel and the new main channel to create an exit connecting channel. S12: Based on the natural meandering shape of the abandoned old river channel, the riverbed of the abandoned old river channel is locally shaped to form at least one set of topographic sequences consisting of alternating shallow beach units and deep pool units within the abandoned old river channel. S13: Based on the inlet connecting channel, the abandoned old river channel where the terrain sequence is located, the outlet connecting channel and the corresponding section of the new main channel, construct a closed or semi-closed water flow path, and define the closed or semi-closed water flow path as a water flow circulation system. S2: Based on the structural characteristics of the water circulation system, a control structure group for regulating the water flow state is installed at key nodes in the main circulation path of the water circulation system, resulting in a control system physically connected to the water circulation system; wherein, S2 includes: S21: Based on the cross-sectional dimensions of the entrance connecting channel, install the first controllable gate at the intersection of the entrance connecting channel and the new main channel; S22: Based on the cross-sectional dimensions of the outlet connecting channel, a second controllable gate is installed at the intersection of the outlet connecting channel and the new main channel; S23: Based on the size of at least one deep pool unit in the terrain sequence, install a water disturbance device at the bottom of the deep pool unit; S24: Connect the electrical control lines of the first controllable gate, the second controllable gate, and the water disturbance device to the same control terminal to form a control system for coordinated control of the water circulation system; S3: Based on the spatial layout of the water circulation system, multiple sets of environmental parameter sensors are deployed inside the abandoned old river channel and near key nodes to obtain a monitoring network that continuously acquires the environmental parameters inside the abandoned old river channel. S4: Based on real-time environmental parameters obtained from the monitoring network and a pre-set ecological regulation model for fish life history stages, control commands are sent to the regulation system to enable the water circulation system to execute an ecological regulation mode adapted to the current fish life stage; wherein, the ecological regulation mode includes a spawning stimulation mode, and S4 includes: S4-1-1: Based on real-time environmental parameters obtained from the monitoring network and combined with external hydrological and meteorological data, determine whether the current period is the preset fish spawning season and whether the external hydrological conditions meet the spawning stimulation requirements. S4-1-2: When the judgment result is yes, the first set of gate control commands is generated and sent to the control system based on the preset gate cooperative opening and closing program; S4-1-3: Based on the received first set of gate control commands, the control system drives the first and second controllable gates to perform specific opening and closing actions, so that the water in the new main channel flows into and through the abandoned old river channel in a pulse manner, forming a first water flow state with directional slow flow characteristics in the abandoned old river channel.

2. The alternative habitat construction method for straightening waterway curves according to claim 1, characterized in that, S3 include: S31: Based on the spatial distribution of the terrain sequence, water temperature sensors and dissolved oxygen sensors are fixedly installed at multiple cross-sections along the abandoned old river channel. S32: Based on the location of the inlet connecting channel and the outlet connecting channel, a flow velocity sensor is fixedly installed in the inlet connecting channel and the outlet connecting channel; S33: Connect the data output cables of the water temperature sensor, dissolved oxygen sensor, and flow velocity sensor to the data acquisition unit to form a monitoring network that continuously collects and aggregates water temperature data, dissolved oxygen data, and flow velocity data.

3. The method for constructing alternative habitats for straightening waterway curves according to claim 1, characterized in that, S4-1-3 includes: S4-1-31: Based on the first set of gate control commands, open the first controllable gate to the first predetermined opening degree; S4-1-32: Simultaneously, open the second controllable gate to a second predetermined opening degree that is less than the first predetermined opening degree; S4-1-33: Maintain the first predetermined opening and the second predetermined opening for a first predetermined duration, so that the water of the new main channel is injected into the inlet connecting channel at a higher flow rate and flows out through the outlet connecting channel at a lower flow rate, so as to form a first water flow state with directional slow flow characteristics from the inlet end to the outlet end in the abandoned old river channel.

4. The method for constructing alternative habitats for straightening waterway curves according to claim 1, characterized in that, Ecological regulation models also include slow-release exchange models, S4 includes: S4-2-1: Based on the real-time water quality parameters inside the abandoned old river channel obtained by the monitoring network, determine whether the water body of the abandoned old river channel needs to be exchanged with the outside in order to maintain water quality; S4-2-2: When the judgment result indicates that an exchange is required, a second set of gate control commands is generated and sent to the control system based on the preset periodic micro-exchange program. S4-2-3: Based on the received second set of gate control commands, the control system drives the first and second controllable gates to perform synchronous, small-opening, and periodic opening and closing operations, so that low-velocity water exchange occurs between the new main channel and the abandoned old river channel, forming a second water flow pattern.

5. The method for constructing alternative habitats for straightening waterway curves according to claim 1, characterized in that, Ecological regulation models also include the summering and rearing model, S4 includes: S4-3-1: Based on real-time environmental parameters obtained from the monitoring network, determine whether the current period is a preset high-temperature season or a fish juvenile stage; S4-3-2: When the judgment result is yes, based on the preset still water stratification control program, the first set of equipment control commands is generated and sent to the control system; S4-3-3: Based on the first set of equipment control commands received, the control system first closes the first and second controllable gates, and then controls the water disturbance device to operate intermittently in a specific mode to induce the formation of a stratified distribution structure of temperature and dissolved oxygen in the vertical direction of the water in the abandoned old river channel deep pool unit.

6. The method for constructing alternative habitats for straightening waterway curves according to claim 5, characterized in that, S4-3-3 includes: S4-3-31: When the monitoring network detects that the surface water temperature of the abandoned old river channel is higher than the preset water temperature threshold and the dissolved oxygen at the bottom layer is lower than the preset dissolved oxygen threshold, the water disturbance device is activated. S4-3-32: Control the water disturbance device to operate at a low power level below its rated power for a second predetermined period of time, and then shut it off; S4-3-33: Repeat S4-3-31 to S4-3-32 to maintain a stratified state in the deep pool unit of the abandoned old river channel, where the upper water is warm, the lower water is cool, and the dissolved oxygen in the bottom layer is stable.

7. The method for constructing alternative habitats for straightening waterway curves according to claim 1, characterized in that, Ecological regulation models also include overwintering shelter models, S4 includes: S4-4-1: Based on water level data obtained from seasonal climate forecasting and monitoring networks, determine whether the cold season is approaching; S4-4-2: When the judgment result is yes, based on the preset water storage and heat preservation program, the third set of gate control commands is generated and sent to the control system; S4-4-3: Based on the received third set of gate control commands, the control system first opens the first controllable gate to fill the abandoned old river channel with water to the preset water level, then closes all the first and second controllable gates, and stops all water disturbance devices, so that the abandoned old river channel remains in a stagnant water state, forming a wintering site.

8. The method for constructing alternative habitats for straightening waterway curves according to claim 1, characterized in that, The section between S3 and S4 also includes: Sa: Based on the water area of ​​the abandoned old river channel, an underwater acoustic signal receiving array is deployed to continuously receive signals emitted by target fish with acoustic tags to obtain fish activity location data; Sb: The real-time environmental parameters obtained from the monitoring network are spatiotemporally correlated and fused with fish activity location data to generate an enhanced ecological dataset containing environmental and biological behavior information; In S4, control commands are sent to the control system based on the enhanced ecological dataset and the preset ecological regulation model of fish life history stages.

9. The method for constructing alternative habitats for straightening waterway curves according to claim 8, characterized in that, Sb includes: Sb1: Based on fish activity location data, the main aggregation areas and activity intensity of target fish in abandoned old river channels at different times were analyzed; Sb2: Match and overlay the information on the main aggregation areas and activity intensity with the water temperature data, dissolved oxygen data and flow velocity data obtained by the monitoring network at the same time and spatial location; Sb3: Stores the completed matching and overlay datasets as an enhanced ecological dataset that is updated over time.

10. An alternative habitat construction system for straightening waterway curves, characterized in that, The system employs the alternative habitat construction method for straightening waterway curves as described in any one of claims 1 to 9, and the system comprises: The circulation system construction module is used to execute step S1: Based on the abandoned old river channel formed after the straightening construction, artificial water flow channels are constructed and internal terrain is modified within the abandoned old river channel and between it and the new main channel adjacent to the abandoned old river channel to generate a water circulation system with water circulation capabilities; wherein, S1 includes: S11: Based on the geographical locations of the two ends of the abandoned old river channel, dredging or excavation is carried out between the entrance end of the abandoned old river channel and the new main channel to create an entrance connecting channel; dredging or excavation is carried out between the exit end of the abandoned old river channel and the new main channel to create an exit connecting channel. S12: Based on the natural meandering shape of the abandoned old river channel, the riverbed of the abandoned old river channel is locally shaped to form at least one set of topographic sequences consisting of alternating shallow beach units and deep pool units within the abandoned old river channel. S13: Based on the inlet connecting channel, the abandoned old river channel where the terrain sequence is located, the outlet connecting channel and the corresponding section of the new main channel, construct a closed or semi-closed water flow path, and define the closed or semi-closed water flow path as a water flow circulation system. The control structure deployment module is used to execute step S2: Based on the structural characteristics of the water circulation system, control structure groups for regulating the water flow state are installed at key nodes in the main circulation path of the water circulation system, resulting in a control system physically connected to the water circulation system; wherein, S2 includes: S21: Based on the cross-sectional dimensions of the entrance connecting channel, install the first controllable gate at the intersection of the entrance connecting channel and the new main channel; S22: Based on the cross-sectional dimensions of the outlet connecting channel, a second controllable gate is installed at the intersection of the outlet connecting channel and the new main channel; S23: Based on the size of at least one deep pool unit in the terrain sequence, install a water disturbance device at the bottom of the deep pool unit; S24: Connect the electrical control lines of the first controllable gate, the second controllable gate, and the water disturbance device to the same control terminal to form a control system for coordinated control of the water circulation system; The monitoring network deployment module is used to perform step S3: based on the spatial layout of the water circulation system, multiple sets of environmental parameter sensors are deployed inside the abandoned old river channel and near key nodes to obtain a monitoring network that continuously acquires environmental parameters inside the abandoned old river channel. The intelligent regulation execution module is used to execute step S4: based on real-time environmental parameters obtained from the monitoring network and a preset ecological regulation model for fish life history stages, it sends control commands to the regulation system to enable the water circulation system to execute an ecological regulation mode adapted to the current fish life stage; wherein, the ecological regulation mode includes a spawning stimulation mode, and S4 includes: S4-1-1: Based on real-time environmental parameters obtained from the monitoring network and combined with external hydrological and meteorological data, determine whether the current period is the preset fish spawning season and whether the external hydrological conditions meet the spawning stimulation requirements. S4-1-2: When the judgment result is yes, the first set of gate control commands is generated and sent to the control system based on the preset gate cooperative opening and closing program; S4-1-3: Based on the received first set of gate control commands, the control system drives the first and second controllable gates to perform specific opening and closing actions, so that the water in the new main channel flows into and through the abandoned old river channel in a pulse manner, forming a first water flow state with directional slow flow characteristics in the abandoned old river channel.

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