Lake pre-discharge opportunity determination method and system based on short-term rainfall forecast

Abstract

The invention provides a lake pre-discharge opportunity determination method and system based on short-term rainfall forecast, and relates to the technical field of urban flood control and drainage. The method comprises the following steps: acquiring short-term rainfall forecast data; calculating hourly production and confluence flow based on the short-term rainfall forecast data, and calculating the total amount of water entering the lake according to the hourly flow before a set moment; according to the designed drainage flow of the pump station, a water quantity balance equation and the total water quantity entering the lake, calculating the water quantity out of the lake, and determining the total water quantity out of the lake; the water balance equation, the total water entering the lake and the total water exiting the lake are used for combined calculation, and the starting moment of the pump station is obtained; the starting time of the pump station is used for determining the lake pre-discharge opportunity. The method can dynamically optimize the pumping and drainage mode of the pump station from time, determines the lake pre-drainage time, and improves the heavy rainfall coping capacity of a city.

Description

Technical Field

[0001] The invention relates to the technical field of urban flood control and drainage, and in particular to a method and system for determining lake pre-discharge timing based on short-term rainfall forecast. Background Art

[0002] At present, the drainage pumping stations in the middle and lower reaches of the Yangtze River are mainly operated based on fixed start-stop water level control. When heavy rain causes the lake water level to exceed the designed start water level of the pumping station, the pumping station starts the pumping mode, which has the hysteresis reaction characteristics of "heavy rain-waterlogging-pumping". On the one hand, this hysteresis increases the operating load and risk of the pumping station, and on the other hand, it also creates a huge burden on the prevention and control and reduction of urban waterlogging. Today, with the continuous improvement of the accuracy of meteorological forecasts and flood forecasts, it is urgent to take into account monitoring and forecasting information in urban waterlogging management, adopt lake pre-discharge methods in advance, and improve the resilience of urban flood control and drainage. The existing practice of lake pre-discharge is to pre-discharge to the normal water level of the lake during the flood season in advance, which is a great waste of water resources. Therefore, scientifically determining the timing of pre-discharge can take into account both flood control and drainage capabilities and increase the amount of available water resources. Summary of the invention

[0003] In order to solve the current technical problems, the main purpose of the present invention is to provide a method and system for determining the timing of lake pre-discharge based on short-term rainfall forecasts. This method can dynamically optimize the pumping and drainage mode of the pumping station in time, determine the timing of lake pre-discharge, and improve the city's ability to cope with heavy rainfall.

[0004] In order to realize the above technical features, the object of the present invention is achieved as follows: a method for determining the timing of lake pre-discharge based on short-term rainfall forecast, comprising: Get short-term rainfall forecast data; Calculating the hourly flow rate based on the short-term rainfall forecast data, and calculating the total amount of water entering the lake according to the hourly flow rate before a set time; Calculate the water outflow from the lake based on the designed drainage flow of the pump station, the water balance equation and the total water inflow, and determine the total water outflow from the lake; The water balance equation, the total amount of water entering the lake and the total amount of water leaving the lake are used for joint calculation to obtain the start time of the pump station; The pump station start-up time is used to determine the lake pre-discharge timing.

[0005] Preferably, the short-term rainfall forecast data originates from real-time short-term rainfall forecast data from a meteorological forecasting department, including short-term rainfall times and rainfall amounts at corresponding times.

[0006] Preferably, the calculation formula for the hourly flow rate is: (1); in, is the hourly flow calculated based on the forecast rainfall; is the empirical runoff coefficient, determined based on historical data; is the catchment area; To provide hourly rainfall forecasts; It is the confluence time, which is determined according to the confluence characteristics of the specific lake.

[0007] Preferably, the calculation formula for the total amount of water entering the lake is: (2); in, The total amount of water entering the lake for the future calculation period, For the deadline The number of calculation periods for the moment, It is the hourly flow calculated based on the forecast rainfall.

[0008] Preferably, the calculation of outflow from the lake is performed based on the water balance equation and the total amount of water entering the lake to determine the total amount of water leaving the lake, specifically including: The first total water volume out of the lake is calculated according to the designed drainage flow of the pump station, and the second total water volume out of the lake is determined by performing outflow calculations according to the water balance equation and the total water volume in the lake.

[0009] Preferably, the calculation formula for the first total amount of water outflow from the lake is: (3); in, The total amount of water outflow from the lake in the future calculation period is: Design the discharge flow rate for the pump station, is the start time of the pump station, and The inflow is equal to the designed discharge flow. Time less than time.

[0010] Preferably, the calculation formula for the second total water volume out of the lake is: (4); in, , The adjustable water storage capacity of the lake. To ensure the lake capacity below the water level, The lake capacity under the designed water level during the flood season is The total amount of water outflow from the lake in the future calculation period is: For the deadline The total amount of water entering the lake during the calculation period at time.

[0011] Preferably, the calculation formula for the pump station startup time is: (5); in, is the start time of the pump station, Time less than time, The total amount of water entering the lake for the future calculation period, The adjustable water storage capacity of the lake. Design the discharge flow for the pump station.

[0012] Preferably, a system for determining the timing of lake pre-discharge based on short-term rainfall forecast, the system being used to implement the method, comprises: A data acquisition unit, used to obtain short-term rainfall forecast data; A total water volume calculation unit for entering the lake, used to calculate the hourly flow rate based on the short-term rainfall forecast data, and calculate the total water volume entering the lake according to the hourly flow rate before a set time; The total water volume out of the lake is calculated by a unit for calculating the total water volume out of the lake, which is used to calculate the total water volume out of the lake according to the designed drainage flow of the pump station, the water volume balance equation and the total water volume in the lake, and determine the total water volume out of the lake; The lake pre-discharge timing determination unit is used to use the water balance equation, the total water volume entering the lake and the total water volume leaving the lake to perform a joint calculation to obtain the pump station start time; the pump station start time is used to determine the lake pre-discharge timing.

[0013] The present invention has the following beneficial effects: The method of the present invention can dynamically optimize the pumping and drainage mode of the pumping station in terms of time, determine the timing of lake pre-discharge, lower the water level of urban lakes in advance, make full use of the storage capacity of urban water bodies, scientifically and rationally respond to the risk of urban waterlogging, and enhance the city's ability to respond to heavy rainfall. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0015] Figure 1 The present invention is a flow chart of a method for determining the timing of lake pre-discharge based on short-term rainfall forecast.

[0016] Figure 2 This is a curve chart of the calculation of the pre-discharge timing in this embodiment. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1: The purpose of the present invention is to provide a method and system for determining the timing of lake pre-discharge based on short-term rainfall forecasts, which can dynamically optimize the pumping and drainage mode of pumping stations in terms of time, determine the timing of lake pre-discharge, and improve the city's ability to cope with heavy rainfall.

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1 As shown, the present invention provides a method for determining the timing of lake pre-discharge based on short-term rainfall forecast, comprising: Step 100: Obtain short-term rainfall forecast data; Step 200: Calculate the hourly flow rate based on the short-term rainfall forecast data, and calculate the total amount of water entering the lake according to the hourly flow rate before a set time; Step 300: performing outflow calculation according to the designed drainage flow of the pump station, the water balance equation and the total amount of water entering the lake, and determining the total amount of water leaving the lake; Step 400: The water balance equation, the total amount of water entering the lake and the total amount of water leaving the lake are used to perform a joint calculation to obtain a pump station start time; the pump station start time is used to determine the lake pre-discharge timing.

[0021] In this embodiment, methods such as data collection, mathematical statistics, and hydrodynamic numerical simulation are used to determine the water demand and time for pre-rain drainage according to the process of water flow from the drainage network merging into the natural water network during different heavy rainfall events, based on the lake water level storage capacity curve, port and channel flow capacity, gate flow capacity, and pumping station drainage capacity in the city's natural water system. The water level of urban lakes is lowered in advance, the storage capacity of urban water bodies is fully utilized, the risk of urban waterlogging is responded to scientifically and rationally, and the city's resilience to disaster prevention and mitigation is enhanced.

[0022] Furthermore, the calculation formula of the hourly flow rate is: ; in, is the hourly flow calculated based on the forecast rainfall; is the empirical runoff coefficient, determined based on historical data; is the catchment area; To provide hourly rainfall forecasts; It is the confluence time, which is determined according to the confluence characteristics of the specific lake.

[0023] Furthermore, the calculation formula for the total amount of water entering the lake is: ; in, The total amount of water entering the lake for the future calculation period, For the deadline The number of calculation periods for the moment, It is the hourly flow calculated based on the forecast rainfall.

[0024] Furthermore, the calculation of outflow from the lake is performed based on the water balance equation and the total amount of water entering the lake to determine the total amount of water leaving the lake, specifically including: The first total water volume out of the lake is calculated according to the designed drainage flow of the pump station, and the second total water volume out of the lake is determined by performing outflow calculations according to the water balance equation and the total water volume in the lake.

[0025] Drainage scheduling is a very complex process. The main idea is to Drain more water before the time to meet The water level at any given moment does not exceed the guaranteed water level of the lake. However, the uncertainty of rainfall forecast needs to be considered in this process. The calculation formula for the first total water volume out of the lake is: ; in, The total amount of water outflow from the lake in the future calculation period is: Design the discharge flow rate for the pump station, is the start time of the pump station, and The inflow is equal to the designed discharge flow. Time less than time.

[0026] According to the water balance equation, The water level at any given moment does not exceed the guaranteed water level of the lake. The calculation formula for the second total water outflow from the lake is: ; in, , The adjustable water storage capacity of the lake. To ensure the lake capacity below the water level, The lake capacity under the designed water level during the flood season is The total amount of water outflow from the lake in the future calculation period is: For the deadline The total amount of water entering the lake during the calculation period at time.

[0027] like Figure 2 As shown in the figure, the calculation formula of the first total water outflow from the lake and the second total water outflow from the lake can be combined to calculate the pre-discharge timing and obtain the start time of the pump station: ; in, is the start time of the pump station, Time less than time, The total amount of water entering the lake for the future calculation period, The adjustable water storage capacity of the lake. Design the discharge flow for the pump station.

[0028] Embodiment 2: The present invention provides a lake pre-discharge timing determination system based on short-term rainfall forecast, comprising: A data acquisition unit, used to obtain short-term rainfall forecast data; A total water volume calculation unit for entering the lake, used to calculate the hourly flow rate based on the short-term rainfall forecast data, and calculate the total water volume entering the lake according to the hourly flow rate before a set time; The total water volume out of the lake is calculated by a unit for calculating the total water volume out of the lake, which is used to calculate the total water volume out of the lake according to the designed drainage flow of the pump station, the water volume balance equation and the total water volume in the lake, and determine the total water volume out of the lake; The lake pre-discharge timing determination unit is used to use the water balance equation, the total water volume entering the lake and the total water volume leaving the lake to perform a joint calculation to obtain the pump station start time; the pump station start time is used to determine the lake pre-discharge timing.

[0029] The various embodiments of the present invention are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to in detail.

[0030] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for determining the timing of lake pre-discharge based on short-term rainfall forecast, characterized in that: include: Get short-term rainfall forecast data; Calculating the hourly flow rate based on the short-term rainfall forecast data, and calculating the total amount of water entering the lake according to the hourly flow rate before a set time; Calculate the water outflow from the lake based on the designed drainage flow of the pump station, the water balance equation and the total water inflow, and determine the total water outflow from the lake; The water balance equation, the total amount of water entering the lake and the total amount of water leaving the lake are used for joint calculation to obtain the start time of the pump station; The pump station start-up time is used to determine the lake pre-discharge timing.

2. A method for determining the timing of lake pre-discharge based on short-term rainfall forecast according to claim 1, characterized in that: The short-term rainfall forecast data is derived from the real-time short-term rainfall forecast data of the meteorological forecast department, including the short-term rainfall time and the rainfall at the corresponding time.

3. The method for determining the timing of lake pre-discharge based on short-term rainfall forecast according to claim 1, characterized in that: The calculation formula for the hourly flow rate is: （1）； in, is the hourly flow calculated based on the forecast rainfall; is the empirical runoff coefficient, determined based on historical data; is the catchment area; To provide hourly rainfall forecasts; It is the confluence time, which is determined according to the confluence characteristics of the specific lake.

4. The method for determining the timing of lake pre-discharge based on short-term rainfall forecast according to claim 1, characterized in that: The calculation formula for the total amount of water entering the lake is: （2）； in, The total amount of water entering the lake for the future calculation period, For the deadline The number of calculation periods for the moment, It is the hourly flow calculated based on the forecast rainfall.

5. The method for determining the timing of lake pre-discharge based on short-term rainfall forecast according to claim 1, characterized in that: The method of calculating the amount of water out of the lake based on the water balance equation and the total amount of water entering the lake to determine the total amount of water out of the lake specifically includes: The first total water volume out of the lake is calculated according to the designed drainage flow of the pump station, and the second total water volume out of the lake is determined by performing outflow calculations according to the water balance equation and the total water volume in the lake.

6. A method for determining the timing of lake pre-discharge based on short-term rainfall forecast according to claim 5, characterized in that: The calculation formula for the first total water outflow from the lake is: （3）； in, The total amount of water outflow from the lake in the future calculation period is: Design the discharge flow rate for the pump station, is the start time of the pump station, and The inflow is equal to the designed discharge flow. Time less than time.

7. A method for determining the timing of lake pre-discharge based on short-term rainfall forecast according to claim 6, characterized in that: The calculation formula for the second total water volume out of the lake is: （4）； in, , The adjustable water storage capacity of the lake. To ensure the lake capacity below the water level, The lake capacity under the designed water level during the flood season is The total amount of water outflow from the lake in the future calculation period is: For the deadline The total amount of water entering the lake during the calculation period at time.

8. The method for determining the timing of lake pre-discharge based on short-term rainfall forecast according to claim 7, characterized in that: The calculation formula for the pump station start time is: （5）； in, is the start time of the pump station, Time less than time, The total amount of water entering the lake for the future calculation period, The adjustable water storage capacity of the lake. Design the discharge flow for the pump station.

9. A system for determining the timing of lake pre-discharge based on short-term rainfall forecast, characterized in that: The system is used to implement the method according to any one of claims 1 to 8, comprising: A data acquisition unit, used to obtain short-term rainfall forecast data; A total water volume calculation unit for entering the lake, used to calculate the hourly flow rate based on the short-term rainfall forecast data, and calculate the total water volume entering the lake according to the hourly flow rate before a set time; The total water volume out of the lake is calculated by a unit for calculating the total water volume out of the lake, which is used to calculate the total water volume out of the lake according to the designed drainage flow of the pump station, the water volume balance equation and the total water volume in the lake, and determine the total water volume out of the lake; The lake pre-discharge timing determination unit is used to use the water balance equation, the total water volume entering the lake and the total water volume leaving the lake to perform a joint calculation to obtain the pump station start time; the pump station start time is used to determine the lake pre-discharge timing.

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