CN-116821613-B - Method for preventing and controlling overgrowth of external submerged plants in river

CN116821613BCN 116821613 BCN116821613 BCN 116821613BCN-116821613-B

Abstract

The invention belongs to the technical field of ecological regulation and control of river aquatic plants, and particularly discloses a method for preventing and controlling overgrowth of external submerged plants in a river, the combination condition of the outlet flow of the upstream water reservoir and the water level fluctuation of the downstream water reservoir of the river reach is adopted for joint regulation and control, so that the aim of preventing and controlling the overgrowth of submerged plants in the river reach is fulfilled.

Inventors

SHI JIA
HE NING
LIAO MENGYU
CHEN MING

Assignees

华能(福建)能源开发有限公司清洁能源分公司

Dates

Publication Date: 20260505
Application Date: 20230529

Claims (5)

1. A method for preventing and controlling overgrowth of external submerged plants in a river is characterized in that a water flow velocity threshold value for controlling overgrowth of submerged plants is accurately calculated, and the combination condition of the outlet flow of an upstream water reservoir and the water level fluctuation of a downstream water reservoir of a river reach is adopted for joint regulation and control, so that the aim of preventing and controlling overgrowth of submerged plants in the river reach is fulfilled, and the method comprises the following steps: S1, carrying out field aquatic plant investigation in a growing vigorous period of submerged plants, shooting the spatial distribution condition of the submerged plants in a research river reach by using an unmanned aerial vehicle in the air, and simultaneously, randomly measuring the average flow of a plurality of different river sections in the research river reach by using a flow velocity and flow profiler, wherein the acquired flow data are used for a later calibration model; S2, depicting the space distribution condition of the submerged plants in the studied river reach, which are shot in the air, on an Aowei map to obtain the specific coordinates of the submerged plant sheet-shaped distribution boundary; S3, actually measuring underwater topography, and constructing a two-dimensional hydrodynamic model of the river reach according to actual measurement conditions; S4, meshing the researched river reach, and carrying out mesh local encryption treatment on a thick submerged plant growth area obtained by field aquatic weed investigation; s5, taking the average roughness of the river reach of 0.025 as an initial roughness value, researching the normal water storage level of the river reach as a boundary condition, running a hydrodynamic model, and reading water depth data of different grids; S6, according to An initial value is assumed According to the data of different grids, which are read in the step S5, the roughness value n of different grids can be calculated, and an initial roughness field is established; S7, running a hydrodynamic model in the initial rough rate field, and reading flow data of different grids of the researched river reach; s8, running a hydrodynamic model in the initial rough rate field, reading flow velocity data of different grids of the research river reach, and establishing a flow velocity field; S9, superposing the submerged plant flaky distribution boundary drawn on the austenitic map in the step S2 on a flow velocity field to obtain a flow velocity value at the submerged plant distribution boundary, and taking the maximum value as a flow velocity threshold for controlling overgrowth of the submerged plant; S10, according to the threshold value of the overgrowth flow rate of the submerged plants, which is determined in the step S9, the combined condition of the delivery flow rate of the upstream reservoir and the fluctuation of the water level of the downstream reservoir is calculated by utilizing a hydrodynamic model, and the average flow rate of the submerged plant distribution flourishing area is found by trial calculation, so that the flow rate of the threshold value of the flow rate can be reached; s11, according to the S10, the combination conditions are obtained to jointly regulate and control the outlet flow of the upstream water reservoir and the water level fluctuation of the downstream water reservoir, so that the overgrowth of submerged plants in the research river reach is prevented and controlled.
2. The method for preventing and controlling overgrowth of submerged plants outside a river according to claim 1, wherein the hydrodynamic model is ; Wherein h is the actual water depth, ζ is the water level calculated on the average lake surface, u, v are the flow velocity components along the x, y directions, g is the gravitational acceleration, ρ is the water density, and f is Ke Shili coefficients; , Is the stress component of the lake surface wind; , Is a water bottom friction component; wherein, the Kelvin coefficient: ; In the formula, Is the rotation angular velocity of the earth; The latitude of the lake; Wherein, lake surface wind stress component: , ; In the formula, Is the wind stress coefficient; Is air density; Wind speed at 10m from the lake surface; , wind speed in x and y directions respectively; Wherein, the friction force component of the water bottom: , ; In the formula, N is the roughness.
3. The method for preventing and controlling overgrowth of submerged plants outside a river according to claim 2, wherein after the hydrodynamic model is operated to read flow data, the hydrodynamic model is subjected to roughness rating by combining the measured flow data of different sections measured in the step S1, and a determination coefficient R2 and a Nash efficiency coefficient are adopted The model accuracy was checked and the expression was as follows: ; In the formula, M 3 /s for the ith measured flow; M 3 /s for the ith analog flow; for the measured average flow, m 3 /s; In order to simulate the average flow, m 3 /S, n is the number of data, if R2 is more than 0.5 and E NS is more than 0.5 and less than 1.0, the modeled roughness parameter is reasonable in value, the calculation method is correct, the influence of ecological dispatching on the river reach flow field can be inverted by using the method, otherwise, the method returns to the step S6, and is reset And (5) value until the accuracy of the model meets the requirement.
4. The method for preventing and controlling overgrowth of submerged plants outside a river according to claim 1, wherein when different grid flow data and flow rate data are read in the step S7 and the step S8, the hydrodynamic model is operated by adopting the upstream water warehouse outlet flow and the downstream water warehouse water level conditions measured by the hydrologic station on the day of the water grass survey in the step S1 as boundary conditions.
5. The method for preventing and controlling overgrowth of submerged plants outside a river according to claim 1, wherein the maximum drop of the water level of the downstream water reservoir in the step S10 is controlled to be within 0.5m of the normal water level.

Description

Method for preventing and controlling overgrowth of external submerged plants in river Technical Field The invention particularly relates to a method for preventing and controlling overgrowth of external submerged plants in a river, and belongs to the technical field of ecological regulation and control of aquatic plants in the river. Background Biosafety represented by invading plant-dominated biological invasion has posed a serious threat to environmental health and ecological safety and to sustainable development of society. Therefore, biosafety represented by invasion of living organisms dominant by invasive plants has become one of the global serious environmental ecological problems. After the exotic invasive plant invades a new habitat, the exotic invasive plant is diffused and spread in proper weather, soil, moisture and propagation conditions, competes, repels and finally replaces a local biological community to form a large-area single dominant community, and damages the local animal plant phase to cause the loss of local biological diversity. The current method for controlling overgrowth of submerged plants mainly comprises a physical method (physical interception and mechanical salvage), a chemical method (herbicide) and an ecological method (stocking herbivorous fishes), wherein the physical interception method can cause excessive accumulation of aquatic weeds, partial aquatic weeds squeeze through dirt blocking and enter a water intake trash rack to cause limited interception effect, the mechanical salvage method is also used in an urgent manner, but the problem of overgrowth of aquatic weeds is difficult to solve due to wide aquatic weeds in a reservoir area and high economic cost, the chemical method has limitation in water safety, and particularly cannot be applied to drinking water sources, and the ecological method is widely recommended, but a mode of grass disaster control by using a biological method has difficulty in duration in an implementation period, particularly during the period of fishing forbidden activities. Disclosure of Invention In order to solve the technical problems, the invention provides a method for preventing and controlling overgrowth of external submerged plants in a river, which is used for achieving the purpose of preventing and controlling overgrowth of submerged plants in the river by accurately calculating a water flow velocity threshold value for controlling overgrowth of submerged plants and adopting a combined condition of the outlet flow of an upstream water warehouse and the water level fluctuation of a downstream water warehouse of the river reach for combined regulation. The technical scheme of the invention is as follows: The invention provides a method for preventing and controlling overgrowth of external submerged plants in a river, which is characterized in that a water flow velocity threshold value for controlling overgrowth of submerged plants is accurately calculated, and the combination condition of the outlet flow of an upstream water reservoir and the water level fluctuation of a downstream water reservoir of a river is adopted for joint regulation and control, so that the aim of preventing and controlling overgrowth of submerged plants in the river is fulfilled. Preferably, the method for preventing and controlling overgrowth of the external submerged plants of the river comprises the following steps: S1, carrying out field aquatic plant investigation in a growing vigorous period of submerged plants, shooting the spatial distribution condition of the submerged plants in a research river reach by using an unmanned aerial vehicle in the air, and simultaneously, randomly measuring the average flow of a plurality of different river sections in the research river reach by using a flow velocity and flow profiler, wherein the acquired flow data are used for a later calibration model; S2, depicting the space distribution condition of the submerged plants in the studied river reach, which are shot in the air, on an Aowei map to obtain the specific coordinates of the submerged plant sheet-shaped distribution boundary; S3, actually measuring underwater topography, and constructing a two-dimensional hydrodynamic model of the river reach according to actual measurement conditions; S4, meshing the researched river reach, and carrying out mesh local encryption treatment on a thick submerged plant growth area obtained by field aquatic weed investigation; s5, taking the average roughness of the river reach of 0.025 as an initial roughness value, researching the normal water storage level of the river reach as a boundary condition, running a hydrodynamic model, and reading water depth data of different grids; S6, according to An initial value is assumedAccording to the data of different grids, which are read in the step S5, the roughness value n of different grids can be calculated, and an initial roughness field is established; S7, running a hydrodynamic mode