CN-121981559-A - Rapid identification method for downstream navigation risk area of peak regulation period of large-scale cascade hydropower station

CN121981559ACN 121981559 ACN121981559 ACN 121981559ACN-121981559-A

Abstract

The application provides a rapid identification method for a downstream navigation risk area in a peak regulation period of a large-scale cascade hydropower station, which comprises the steps of collecting actual measurement basic data such as hydrology, topography and the like of a research area; the method comprises the steps of constructing a power station downstream water level amplitude risk analysis model, constructing a power station downstream water flow state risk analysis model, drawing a power station downstream navigation risk area diagram and rapidly identifying navigation risk. The application can provide an effective means for the rapid identification and evaluation of the navigation risk area at the downstream of the power station on one hand, and can provide technical support for the navigation safety guarantee at the power station on the other hand.

Inventors

XIAO XIAO
WANG ZHILI
XIANG HENG
BAO BO
ZENG YALI
ZHOU SHUAI
WANG HAN
YUAN JING
ZHU LINGLING
Dong Bingjiang
PENG CHANG
Yuan Xiongyan
LI LINJUAN
SUN SIRUI
JIN YE

Assignees

长江水利委员会水文局

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (5)

1. A rapid identification method for a downstream navigation risk area in a peak regulation period of a large-scale cascade hydropower station is characterized by comprising the following steps of: s1, collecting actual measurement basic data of hydrology and topography of a research area; S2, constructing power station downstream water level amplitude variation risk analysis; S3, constructing a power station downstream water flow state risk analysis; And S4, drawing a downstream navigation risk area diagram of the power station, and rapidly identifying navigation risks.
2. The method for quickly identifying the downstream navigation risk area in the peak regulation period of the large-scale cascade hydropower station according to claim 1, wherein S1 specifically comprises basic data of a flow discharging process under the power station, an actual measured water level of a control station under the power station, actual measured water levels of sections below a dam, a water level process of a reservoir below the dam and section data below the dam.
3. The method for quickly identifying the downstream navigation risk area in the peak shaver period of the large-scale cascade hydropower station according to claim 2, wherein the step S2 is specifically as follows: s201, through preliminary analysis, determining a variable amplitude limiting value when the water level is determined ; S202, establishing a relation between the downstream control station and the variable amplitude at the water level of each section, wherein the variable amplitude at the water level of the downstream control station is defined as based on the actual measurement basic data Downstream first The amplitude of the water level of each section becomes ( ) Through the fitting of measured data, the mapping relation is established as follows: (1); Wherein, the Formula for linear regression: In which, in the process, 、 The coefficient is obtained by a least square method; S203, determining a water level time amplitude variation reference value under a given probability, namely collecting measured water level data of a control station at the downstream of the calendar year, and calculating the water level time amplitude variation And fitting probability distribution, and setting cumulative distribution function as For a given probability Amplitude-variable reference value at corresponding water level Defined by quantiles: (2); Wherein, the Is an inverse cumulative distribution function; S204, determining the influence range of the reference value, and obtaining the water level time-varying amplitude reference value from S203 Substituting into formula (1), calculating the amplitude of each section corresponding to the frequency water level Defining a set of affected sections as: (3); set the first The distance between each section and the dam site is Length of the influence range For the furthest distance in the affected section: ; S205, determining a critical section corresponding to the limit amplitude variation, namely taking out the historical maximum water level time-varying amplitude of the downstream control station Find out to satisfy Is given the critical section number The corresponding distance is The distance from the critical position to the dam site is ; If the critical sections which are exactly equal do not exist, obtaining through interpolation; S206, dividing the water level amplitude risk area according to the length of the influence range And the distance from the critical location to the dam site Dividing the downstream river reach into two risk levels, wherein the first-level risk area is the length from the dam address to the influence range Of (1), i.e The secondary risk area is the length of the range of influence Distance to critical position to dam site Of (1), i.e 。
4. The method for quickly identifying a downstream navigation risk area in a peak shaver period of a large-scale cascade hydropower station according to claim 3, wherein the step S3 is specifically as follows: s301, establishing a two-dimensional water flow mathematical model based on data of terrain and roughness; ; Wherein: Is the depth of water; , an average flow velocity component for a vertical line; Is the river bottom elevation; , is the shear stress of the bottom bed; Gravitational acceleration; is the density of water, and any flow is obtained by numerical solution And downstream boundary water level Flow velocity field under combination Mould ; S302, calculating the spatial distribution of the flow velocity overrun, namely, mixing any flow And downstream boundary water level Discrete is typical working condition: 、 For each set of working conditions , wherein, Is the flow corresponding to the working condition, Calculating the position and flow velocity of the whole river reach by a mathematical model Defining a flow rate safety threshold Then (1) The area of the flow rate overrun under the working condition is as follows: ; S303, counting the combination of all working conditions according to the actual discharging flow of the annual power station and the water level data of the downstream reservoir Probability of occurrence For any point of downstream river The flow exceeds the flow rate safety threshold The probability of (2) is: ; S304, dividing the flow velocity risk ranges with different probabilities, namely defining distance along main body lines of downstream river channels Extracting the probability of each point Setting two probability threshold values as And Then: the flow rate exceeds a flow rate safety threshold The probability is the range of the river reach which is close to the necessary occurrence: ; determining a river reach range with occurrence probability of a medium interval: ; determining a river reach range with occurrence probability of a lower interval: ; S305, drawing a downstream navigation risk area diagram of the power station, and rapidly identifying navigation risks.
5. The method for quickly identifying the downstream navigation risk area in the peak shaver period of the large-scale cascade hydropower station according to claim 4, wherein the step S4 is specifically as follows: S401, drawing a downstream navigation risk area diagram of the power station based on the combination of the water level amplitude risk area of the S2 and the hydrodynamic risk area of the S3; S402, inquiring a downstream navigation risk area diagram of the power station through the position coordinates, and rapidly identifying the position risk.

Description

Rapid identification method for downstream navigation risk area of peak regulation period of large-scale cascade hydropower station Technical Field The invention relates to the technical field of hydraulic engineering, in particular to a rapid identification method for a downstream navigation risk area in a peak regulation period of a large-scale cascade hydropower station. Background In the process of participating in the peak shaving of a power grid, the output of the large-scale cascade hydropower station group is often required to be greatly and frequently adjusted according to load requirements in a short time, so that the downward leakage flow is severely fluctuated, and a complex unsteady flow process is formed in a river channel at the downstream of the power station. Such unsteady flow propagation may cause rapid fluctuations in the downstream channel water level and rapid changes in the flow rate, threatening the navigation safety. The main risks include 1) the steep rise and fall of the water level, which causes difficulty in mooring ships and is easy to cause drifting, stranding or collision, 2) the sudden rise of the flow velocity, which can cause difficulty in operating ships and uncontrolled heading, has particularly obvious influence on the ascending of heavy-load ships, and 3) the sudden change of the water flow condition, which can generate adverse vortex, cross flow and the like, affects the sailing stability. Therefore, the navigation risk area in the downstream channel during peak shaving operation is rapidly and accurately identified, and is very important for implementing scientific shipping scheduling and issuing navigation early warning. At present, the related risk assessment method focuses on independent analysis of single risk factors (such as the lowest navigation water level or the maximum surface flow rate), and lacks rapid identification and visual expression of risk space-time distribution characteristics under the coupling action of multiple factors such as multiple water level amplitude variation and flow state variation. The existing numerical simulation method has higher precision, but the modeling is complex, the calculation is time-consuming, and the real-time requirement of peak regulation period on rapid risk discrimination is difficult to meet. Therefore, the application provides a method capable of rapidly and intuitively identifying the downstream navigation risk area in the peak shaving period of the large-scale cascade hydropower station, so as to make up the defects of the prior art and provide technical support for the cooperative management of the peak shaving and shipping safety of the hydropower station. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a rapid identification method for a downstream navigation risk area in a peak regulation period of a large-scale cascade hydropower station, and the classification, rapid identification and visualization of the risk area are realized by coupling two key risk factors of water level amplitude and water flow state based on probability statistics and mathematical models, so that a direct basis is provided for navigation safety management. In order to achieve the above purpose, the invention adopts the following technical scheme: the invention provides a rapid identification method for a downstream navigation risk area in a peak regulation period of a large-scale cascade hydropower station, S1, collecting actual measurement basic data of hydrology and topography of a research area; S2, constructing power station downstream water level amplitude variation risk analysis; S3, constructing a power station downstream water flow state risk analysis; And S4, drawing a downstream navigation risk area diagram of the power station, and rapidly identifying navigation risks. Further, the S1 specifically comprises basic data of a current power station lower drainage flow process, a measured water level of a power station lower control station, measured water levels of various sections of a dam lower stream, a dam lower reservoir water level process and dam lower stream section data. Further, the S2 specifically is: s201, through preliminary analysis, determining a variable amplitude limiting value when the water level is determined ; S202, establishing a relation between the downstream control station and the variable amplitude at the water level of each section, wherein the variable amplitude at the water level of the downstream control station is defined as based on the actual measurement basic dataDownstream firstThe amplitude of the water level of each section becomes() Through the fitting of measured data, the mapping relation is established as follows: (1); Wherein, the Formula for linear regression: In which, in the process, 、The coefficient is obtained by a least square method; S203, determining a water level time amplitude variation reference value under a given probability, name