A method and system for determining lake pre-discharge timing based on short-term rainfall forecast

Abstract

The present invention provides a method and system for determining the timing of lake pre-discharge based on short-term rainfall forecasts, which relates to the technical field of urban flood control and drainage. The method includes: obtaining short-term rainfall forecast data; calculating hourly production and drainage flows based on the short-term rainfall forecast data, and calculating the total amount of water entering the lake based on the hourly flows before a set time; calculating the amount of water out of the lake based on 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 out of the lake; using the water balance equation, the total amount of water entering the lake, and the total amount of water out of the lake for joint calculation to obtain the pump station start-up time; the pump station start-up time is used to determine the lake pre-discharge timing. The present invention can dynamically optimize the pumping and drainage mode of the pump station in terms of time, determine the lake pre-discharge timing, and improve the city's ability to cope with heavy rainfall.

Description

Technical Field

[0001] The present 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 forecasts. Background Art

[0002] At present, the drainage pumping stations in cities in the middle and lower reaches of the Yangtze River mainly operate based on fixed start-stop water level control. When heavy rain causes the lake water level to exceed the pumping station's designed start water level, the pumping station starts the pumping mode, which has the hysteresis reaction characteristics of "heavy rain-inland waterlogging-pumping and drainage". On the one hand, this hysteresis increases the operating load and risk of the pumping station. On the other hand, it also places a huge burden on the prevention, control and reduction of urban waterlogging. Today, with the continuous improvement of the accuracy of weather forecasts and flood forecasts, it is urgent to take monitoring and forecast information into account in urban waterlogging management, and adopt lake pre-discharge methods in advance to improve the resilience of urban flood control and drainage. The existing lake pre-discharge method is to pre-discharge to the normal water level of the lake during the flood season, which is a significant 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 achieve the above technical features, the purpose 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:

[0005] Obtain short-term rainfall forecast data;

[0006] Calculating hourly flow rates based on the short-term rainfall forecast data, and calculating the total amount of water entering the lake based on the hourly flow rates before a set time;

[0007] Perform lake discharge calculations based on the designed drainage flow of the pump station, the water balance equation, and the total amount of water entering the lake to determine the total amount of water leaving the lake;

[0008] The pump station start time is obtained by performing a joint calculation using the water balance equation, the total water volume entering the lake, and the total water volume leaving the lake;

[0009] The pump station start-up time is used to determine the lake pre-discharge timing.

[0010] 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.

[0011] Preferably, the calculation formula for the hourly flow rate is:

[0012] (1);

[0013] 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.

[0014] Preferably, the calculation formula for the total amount of water entering the lake is:

[0015] (2);

[0016] in, The total amount of water entering the lake during the future calculation period, For the deadline The number of calculation periods for the moment, The hourly flow is calculated based on the forecast rainfall.

[0017] Preferably, the calculation of the 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:

[0018] The first total water outflow from the lake is calculated according to the designed drainage flow of the pump station, and the second total water outflow from the lake is determined by performing outflow calculation according to the water balance equation and the total water inflow.

[0019] Preferably, the calculation formula for the first total water volume out of the lake is:

[0020] (3);

[0021] in, The total amount of water discharged from the lake in the future calculation period is: Design the drainage flow rate for the pump station, is the pump station start time, and The inflow rate is equal to the design discharge rate. Time is less than time.

[0022] Preferably, the calculation formula for the second total water volume out of the lake is:

[0023] (4);

[0024] 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 flood season is The total amount of water discharged 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.

[0025] Preferably, the calculation formula for the pump station startup time is:

[0026] (5);

[0027] in, is the pump station start time, Time is less than time, The total amount of water entering the lake during the future calculation period, The adjustable water storage capacity of the lake, Design the discharge flow for the pump station.

[0028] Preferably, a system for determining lake pre-discharge timing based on short-term rainfall forecast, the system being used to implement the method, comprises:

[0029] A data acquisition unit for obtaining short-term rainfall forecast data;

[0030] a total water volume inflow calculation unit, configured to calculate hourly flow rates based on the short-term rainfall forecast data, and calculate the total water volume inflow into the lake based on the hourly flow rates before a set time;

[0031] a total water outflow calculation unit, configured to calculate the total water outflow 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;

[0032] The lake pre-discharge timing determination unit is used to use the water balance equation, the total water inflow and the total water outflow 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.

[0033] The present invention has the following beneficial effects:

[0034] 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 flooding, and enhance the city's ability to respond to heavy rainfall. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described below with reference to the accompanying drawings and examples.

[0036] 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.

[0037] Figure 2 This is a curve chart showing the calculation of the pre-discharge timing in this embodiment. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] Example 1:

[0040] 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.

[0041] 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.

[0042] 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:

[0043] Step 100: Obtain short-term rainfall forecast data;

[0044] Step 200: Calculating hourly flow based on the short-term rainfall forecast data, and calculating the total amount of water entering the lake based on the hourly flow before a set time;

[0045] Step 300: performing lake discharge calculation based on the designed drainage flow of the pump station, the water balance equation, and the total amount of water entering the lake to determine the total amount of water leaving the lake;

[0046] Step 400: Calculate the pump station start time using the water balance equation, the total water volume entering the lake, and the total water volume leaving the lake. The pump station start time is used to determine the lake pre-discharge timing.

[0047] In this embodiment, data collection, mathematical statistics, hydrodynamic numerical simulation and other methods are used. 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 channel flow capacity, gate flow capacity and pumping station drainage capacity in the urban natural water system, the water volume demand and time consumption for pre-rain discharge are clarified, 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 disaster prevention and mitigation resilience is enhanced.

[0048] Furthermore, the calculation formula for the hourly flow rate is:

[0049] ;

[0050] 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.

[0051] Furthermore, the calculation formula for the total amount of water entering the lake is:

[0052] ;

[0053] in, The total amount of water entering the lake during the future calculation period, For the deadline The number of calculation periods for the moment, The hourly flow is calculated based on the forecast rainfall.

[0054] Furthermore, the calculation of the 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:

[0055] The first total water outflow from the lake is calculated according to the designed drainage flow of the pump station, and the second total water outflow from the lake is determined by performing outflow calculation according to the water balance equation and the total water inflow.

[0056] 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 outflow from the lake is:

[0057] ;

[0058] in, The total amount of water discharged from the lake in the future calculation period is: Design the drainage flow rate for the pump station, is the pump station start time, and The inflow rate is equal to the design discharge rate. Time is less than time.

[0059] According to the water balance equation, we can know that The water level at any moment does not exceed the guaranteed water level of the lake. The calculation formula for the second total water outflow from the lake is:

[0060] ;

[0061] 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 flood season is The total amount of water discharged 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.

[0062] like Figure 2 As shown in the figure, the calculation formulas for the first total water outflow and the second total water outflow can be combined to calculate the pre-discharge timing and obtain the start time of the pump station:

[0063] ;

[0064] in, is the pump station start time, Time is less than time, The total amount of water entering the lake during the future calculation period, The adjustable water storage capacity of the lake, Design the discharge flow for the pump station.

[0065] Example 2:

[0066] The present invention provides a lake pre-discharge timing determination system based on short-term rainfall forecast, comprising:

[0067] A data acquisition unit for obtaining short-term rainfall forecast data;

[0068] a total water volume inflow calculation unit, configured to calculate hourly flow rates based on the short-term rainfall forecast data, and calculate the total water volume inflow into the lake based on the hourly flow rates before a set time;

[0069] a total water outflow calculation unit, configured to calculate the total water outflow 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;

[0070] The lake pre-discharge timing determination unit is used to use the water balance equation, the total water inflow and the total water outflow 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.

[0071] The various embodiments of the present invention are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to in detail.

[0072] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed 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: Obtain short-term rainfall forecast data; Calculating hourly flow rates based on the short-term rainfall forecast data, and calculating the total amount of water entering the lake based on the hourly flow rates before a set time; Perform lake discharge calculations based on the designed drainage flow of the pump station, the water balance equation, and the total amount of water entering the lake to determine the total amount of water leaving the lake; The pump station start time is obtained by performing a joint calculation using the water balance equation, the total water volume entering the lake, and the total water volume leaving the lake; The pump station start-up time is used to determine the lake pre-discharge timing; The calculation of the outflow from the lake is performed based on the designed drainage flow of the pump station, 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: Calculating a first total water outflow from the lake based on the designed drainage flow of the pump station, and performing a lake outflow calculation based on a water balance equation and the total water inflow to determine a second total water outflow from the lake; The calculation formula for the first total water outflow from the lake is: （3）； in, The total amount of water discharged from the lake in the future calculation period is: Design the drainage flow rate for the pump station, is the pump station start time, and The inflow rate is equal to the design discharge rate. Time is less than time; The calculation formula for the second total water outflow from 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 flood season is The total amount of water discharged 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 that time; The calculation formula for the pump station startup time is: （5）； in, is the pump station start time, Time is less than time, The total amount of water entering the lake during the future calculation period, The adjustable water storage capacity of the lake, Design the discharge flow for the pump station.

2. The 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 amount at the corresponding time.

3. The method for determining lake pre-discharge timing 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 lake pre-discharge timing 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 during the future calculation period, For the deadline The number of calculation periods for the moment, The hourly flow is calculated based on the forecast rainfall.

5. A lake pre-discharge timing determination system 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 4, comprising: A data acquisition unit for obtaining short-term rainfall forecast data; a total water volume inflow calculation unit, configured to calculate hourly flow rates based on the short-term rainfall forecast data, and calculate the total water volume inflow into the lake based on the hourly flow rates before a set time; a total water outflow calculation unit, configured to calculate the total water outflow 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; The lake pre-discharge timing determination unit is used to use the water balance equation, the total water inflow and the total water outflow 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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