A method and system for calculating driving force of lake water level

Abstract

The present invention discloses a method and system for calculating the driving force of lake water level. Firstly, lake meteorological data and hydrological data are collected and preprocessed to obtain preprocessed data. Then, a lake body mechanics model is constructed based on the preprocessed data, and the wind-driven flow and gravity-driven flow are calculated using the lake body mechanics model. The present invention realizes the function of independently analyzing wind and gravity to accurately calculate the contribution rate of wind and gravity to the lake water level in different seasons and under different meteorological conditions, and also realizes the function of detecting the water body inclination caused by wind and the change of water flow direction caused by gravity. This provides a scientific analysis tool for lake water level management and ecological balance protection, thereby helping staff to formulate more effective lake management strategies according to the specific influence of wind and gravity, which not only improves the management effect of lake hydrological dynamics, but also optimizes the regulation and protection measures of water resources, and is suitable for being widely promoted and used.

Description

Technical Field

[0001] The present invention relates to the technical field of lake ecological management calculation, and in particular to a lake water level driving force calculation method and system. Background Art

[0002] As important natural water bodies, lakes play a central role in the global water cycle and ecosystem. Changes in lake water levels directly affect lake water quality, biodiversity, and water resource management in surrounding areas.

[0003] At present, lake water level monitoring generally relies on simple hydrological measurement technology, which makes it difficult to accurately measure and quantify the contribution of various natural forces to lake water level changes. With the increasing impact of climate change, lake water levels are affected by many factors, among which wind and gravity flow in the basin are the main natural driving forces. Wind affects water levels by generating wind-generated currents, while gravity flow of water bodies in the basin is controlled by topography and hydrological conditions. However, most existing water level monitoring cannot fully integrate these factors, resulting in inaccurate predictions of lake water level changes, which cannot provide an accurate scientific basis for lake management; therefore, it is necessary to design a method and system for calculating the driving force of lake water levels. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to better and effectively solve the problem that most of the existing water level monitoring cannot fully integrate these factors, resulting in inaccurate predictions of lake water level changes, which cannot provide an accurate and scientific basis for lake management. A lake water level driving force calculation method and system are provided, which realizes the function of independently analyzing wind and gravity to accurately calculate the contribution rate of wind and gravity to the lake water level in different seasons and under different meteorological conditions, and also realizes the function of detecting the inclination of water body caused by wind and the change of water flow direction caused by gravity. This provides a scientific analysis tool for lake water level management and ecological balance protection, thereby helping staff to formulate more effective lake management strategies based on the specific influence of wind and gravity, which not only improves the management effect of lake hydrological dynamics, but also optimizes the regulation and protection measures of water resources.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for calculating the driving force of lake water level comprises the following steps:

[0007] Step A, collecting lake meteorological data and hydrological data and performing data preprocessing to obtain preprocessed data;

[0008] Step B, constructing a lake mechanics model based on the preprocessed data, and then using the lake mechanics model to calculate the wind-driven flow and gravity-driven flow;

[0009] Step C, based on the wind-driven flow and gravity-driven flow, a semi-empirical calculation model is used to calculate the parameters of the lake body mechanics model and obtain parameter calculation results according to the comprehensive influence of wind stress and bed shear stress, and then the SCE-UA algorithm is used to evaluate and adjust the parameter calculation results, so as to obtain an adjusted lake body mechanics model;

[0010] Step D, using the adjusted lake mechanics model to calculate the contribution of wind and gravity to lake water level changes, completes the lake water level driving force measurement operation.

[0011] The aforementioned method for calculating the driving force of lake water level includes step A, collecting lake meteorological data and hydrological data and performing data preprocessing to obtain preprocessed data. The specific steps are as follows:

[0012] Step A1, collecting lake meteorological data and hydrological data, wherein the lake meteorological data and hydrological data specifically include wind speed, wind direction, water level and inflow flow data, and the meteorological data and hydrological data are respectively derived from real-time recorded data of an automatic meteorological station and a hydrological station;

[0013] Step A2, preprocessing the lake meteorological data and hydrological data to obtain preprocessed data, wherein the data preprocessing specifically includes outlier removal, missing data interpolation and data standardization.

[0014] The aforementioned method for calculating the driving force of lake water level, step B, constructs a lake body mechanics model based on the preprocessed data, and then uses the lake body mechanics model to calculate the wind-driven flow and gravity-driven flow. The specific steps are as follows:

[0015] Step B1, set the horizontal x-axis and vertical y-axis and establish the wind shear stress based on the lake surface and bottom and bottom shear stress A two-dimensional elevation model for analyzing the hydrodynamic behavior of a lake under different wind and gravity forces;

[0016] Step B2, set boundary conditions and use the principles of fluid dynamics to integrate the shear stress caused by turbulence Linear expression and eddy viscosity coefficient Calculate the velocity distribution along the horizontal direction, as shown in formula (1),

[0017] (1)

[0018] in, is the velocity distribution along the x-axis, is the average depth of the lake, is the density of water, is the eddy viscosity coefficient;

[0019] Step B3, according to the velocity distribution along the x-axis Calculating wind driven flow and gravity driven flow , as shown in formula (2),

[0020] (2).

[0021] The aforementioned method for calculating the driving force of lake water level, step C, based on wind-driven flow and gravity-driven flow, uses a semi-empirical calculation model to calculate the parameters of the lake body mechanics model and obtains the parameter calculation results according to the comprehensive influence of wind stress and bed shear stress, and then uses the SCE-UA algorithm to evaluate and adjust the parameter calculation results, thereby obtaining the adjusted lake body mechanics model. The specific steps are as follows:

[0022] Step C1, based on the wind-driven flow and gravity-driven flow, the semi-empirical calculation model is used to calculate the parameters of the lake mechanics model according to the comprehensive influence of wind stress and bed shear stress, and the parameter calculation results are obtained, as shown in formula (3):

[0023] , (3)

[0024] in, is the water level change caused by wind-driven flow and throughput flow, The number of weather stations that obtain wind data for the model, U 10 is the wind speed at the ith weather station, H is the average depth of the lake, F is the wind range, A is the angle between the wind direction and the lake wind range axis, is the maximum wind speed at the ith weather station, and are all multiplication constants, , and are matrix constants, is the lake outlet flow;

[0025] Step C2, using the SCE-UA algorithm to evaluate the parameter calculation results and obtain the parameter evaluation results, specifically using the evaluation function R of the SCE-UA algorithm s Evaluate the parameter calculation results, as shown in formula (4)

[0026] (4)

[0027] in, is the model Nash efficiency coefficient, is the water level difference calculated by the model, is the measured water level difference, is the average value of the measured water level difference;

[0028] Step C3, adjust the lake body mechanics model according to the parameter evaluation results to obtain the adjusted lake body mechanics model, specifically by comparing the parameter evaluation results with the actual observation data for verification. If the parameter calculation results of the lake body mechanics model are consistent with the measured data to the set value, it means that the lake body mechanics model can reproduce the hydrodynamic process in the lake. Otherwise, the parameters of the lake body mechanics model are adjusted so that the lake body mechanics model can reproduce the hydrodynamic process in the lake.

[0029] In the aforementioned method for calculating the driving force of lake water level, step D uses the adjusted lake body mechanics model to calculate the contribution of wind and gravity to the change of lake water level, and completes the calculation of the driving force of lake water level, specifically calculating the wind shear stress. and bottom shear stress The contribution of wind and gravity to lake level change is calculated by the ratio of and bottom shear stress Ratio / When it is less than 1, the gravity flow has a greater impact on the lake level. and bottom shear stress Ratio / When it is equal to 1, the gravity flow and wind-driven flow have equal influence on the lake level. and bottom shear stress Ratio / When it is less than 1, the gravity flow has a greater impact on the lake water level.

[0030] A lake water level driving force calculation system includes a data acquisition module, a driving flow calculation module, a model adjustment module and a driving force calculation module, wherein the data acquisition module is used to collect lake meteorological data and hydrological data and perform data preprocessing to obtain preprocessed data; the driving flow calculation module is used to construct a lake body mechanics model based on the preprocessed data, and then use the lake body mechanics model to calculate the wind-driven flow and gravity-driven flow; the model adjustment module is used to calculate the lake body mechanics model parameters based on the wind-driven flow and gravity-driven flow and the comprehensive influence of wind stress and bed shear stress using a semi-empirical calculation model and obtain parameter calculation results, and then use the SCE-UA algorithm to evaluate and adjust the parameter calculation results, thereby obtaining an adjusted lake body mechanics model; the driving force calculation module is used to use the adjusted lake body mechanics model to calculate the contribution of wind and gravity to lake water level changes, and complete the lake water level driving force calculation operation.

[0031] The beneficial effects of the present invention are as follows: a lake water level driving force calculation method and system of the present invention first collects lake meteorological data and hydrological data and performs data preprocessing to obtain preprocessed data, then constructs a lake body mechanics model based on the preprocessed data, and uses the lake body mechanics model to calculate wind-driven flow and gravity-driven flow, then uses a semi-empirical calculation model to calculate the parameters of the lake body mechanics model based on the wind-driven flow and gravity-driven flow according to the comprehensive influence of wind stress and bed shear stress, and obtains parameter calculation results, then uses the SCE-UA algorithm to evaluate and adjust the parameter calculation results to obtain an adjusted lake body mechanics model, and then uses the adjusted lake body mechanics model to calculate the contribution of wind and gravity to lake water level changes, thereby completing the lake water level driving force calculation operation; effectively realizing that the driving force calculation method and system have Independent analysis of wind and gravity can accurately calculate the contribution rate of wind and gravity to the lake water level in different seasons and under different meteorological conditions. The lake mechanics model is constructed using meteorological, hydrological and topographic data to focus on the effects of the two major driving forces of wind and gravity. The direct impact of wind can be evaluated by analyzing the effect of the wind field on the lake surface and the wind-induced water surge phenomenon it produces. The impact of gravity on lake water flow and water level changes is also considered. The function of detecting water inclination caused by wind and changes in water flow direction caused by gravity is also realized. This provides a scientific analysis tool for lake water level management and ecological balance protection, which can help staff formulate more effective lake management strategies based on the specific effects of wind and gravity, which not only improves the management effect of lake hydrological dynamics, but also optimizes water resource regulation and protection measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a flow chart of a method for calculating the driving force of lake water level of the present invention;

[0033] Figure 2 is a comparison diagram of the simulated water level difference and the actual water level difference of model A in the embodiment of the present invention;

[0034] Figure 3 Schematic diagram of comparison between the simulated water level difference and the actual water level difference of model B in an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of comparison between the simulated water level difference and the actual water level difference of model C in an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of comparison between the simulated water level difference and the actual water level difference of model D in an embodiment of the present invention;

[0037] Figure 6 1 is a diagram showing the calculation results of the driving force of the lake water level in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings.

[0039] like Figure 1 As shown, a method for calculating the driving force of lake water level of the present invention comprises the following steps:

[0040] Step A, collect lake meteorological data and hydrological data and perform data preprocessing to obtain preprocessed data. The specific steps are as follows:

[0041] Step A1, collecting lake meteorological data and hydrological data, wherein the lake meteorological data and hydrological data specifically include wind speed, wind direction, water level and inflow flow data, and the meteorological data and hydrological data are respectively derived from real-time recorded data of an automatic meteorological station and a hydrological station;

[0042] Step A2, preprocessing the lake meteorological data and hydrological data to obtain preprocessed data, wherein the data preprocessing specifically includes outlier removal, missing data interpolation and data standardization.

[0043] Step B, constructing a lake mechanics model based on the preprocessed data, and then using the lake mechanics model to calculate the wind-driven flow and gravity-driven flow. The specific steps are as follows:

[0044] Step B1, set the horizontal x-axis and vertical y-axis and establish the wind shear stress based on the lake surface and bottom and bottom shear stress A two-dimensional elevation model for analyzing the hydrodynamic behavior of a lake under different wind and gravity forces;

[0045] Step B2, set boundary conditions and use the principles of fluid dynamics to integrate the shear stress caused by turbulence Linear expression and eddy viscosity coefficient Calculate the velocity distribution along the horizontal direction, as shown in formula (1),

[0046] (1)

[0047] in, is the velocity distribution along the x-axis, is the average depth of the lake, is the density of water, is the eddy viscosity coefficient;

[0048] Step B3, according to the velocity distribution along the x-axis Calculating wind driven flow and gravity driven flow , as shown in formula (2),

[0049] (2).

[0050] Step C: Based on the wind-driven flow and gravity-driven flow, the semi-empirical calculation model is used to calculate the parameters of the lake body mechanics model and obtain the parameter calculation results according to the comprehensive influence of wind stress and bed shear stress. The SCE-UA algorithm is then used to evaluate and adjust the parameter calculation results to obtain the adjusted lake body mechanics model. The specific steps are as follows:

[0051] Step C1, based on the wind-driven flow and gravity-driven flow, the semi-empirical calculation model is used to calculate the parameters of the lake mechanics model according to the comprehensive influence of wind stress and bed shear stress, and the parameter calculation results are obtained, as shown in formula (3):

[0052] , (3)

[0053] in, is the water level change caused by wind-driven flow and throughput flow, The number of weather stations that obtain wind data for the model, U 10 is the wind speed at the ith weather station, H is the average depth of the lake, F is the wind range, A is the angle between the wind direction and the lake wind range axis, is the maximum wind speed at the ith weather station, and are all multiplication constants, , and are matrix constants, is the lake outlet flow;

[0054] Step C2, using the SCE-UA algorithm to evaluate the parameter calculation results and obtain the parameter evaluation results, specifically using the evaluation function R of the SCE-UA algorithm s Evaluate the parameter calculation results, as shown in formula (4)

[0055] (4)

[0056] in, is the model Nash efficiency coefficient, is the water level difference calculated by the model, is the measured water level difference, is the average value of the measured water level difference;

[0057] Step C3, adjust the lake body mechanics model according to the parameter evaluation results to obtain the adjusted lake body mechanics model, specifically by comparing the parameter evaluation results with the actual observation data for verification. If the parameter calculation results of the lake body mechanics model are consistent with the measured data to the set value, it means that the lake body mechanics model can reproduce the hydrodynamic process in the lake. Otherwise, the parameters of the lake body mechanics model are adjusted so that the lake body mechanics model can reproduce the hydrodynamic process in the lake.

[0058] Step D, using the adjusted lake mechanics model to calculate the contribution of wind and gravity to the lake level change, complete the lake level driving force calculation operation, specifically calculate the wind shear stress and bottom shear stress The contribution of wind and gravity to lake level change is calculated by the ratio of and bottom shear stress Ratio / When it is less than 1, the gravity flow has a greater impact on the lake level. and bottom shear stress Ratio / When it is equal to 1, the gravity flow and wind-driven flow have equal influence on the lake level. and bottom shear stress Ratio / When it is less than 1, the gravity flow has a greater impact on the lake water level.

[0059] A lake water level driving force calculation system includes a data acquisition module, a driving flow calculation module, a model adjustment module and a driving force calculation module, wherein the data acquisition module is used to collect lake meteorological data and hydrological data and perform data preprocessing to obtain preprocessed data; the driving flow calculation module is used to construct a lake body mechanics model based on the preprocessed data, and then use the lake body mechanics model to calculate the wind-driven flow and gravity-driven flow; the model adjustment module is used to calculate the lake body mechanics model parameters based on the wind-driven flow and gravity-driven flow and the comprehensive influence of wind stress and bed shear stress using a semi-empirical calculation model and obtain parameter calculation results, and then use the SCE-UA algorithm to evaluate and adjust the parameter calculation results, thereby obtaining an adjusted lake body mechanics model; the driving force calculation module is used to use the adjusted lake body mechanics model to calculate the contribution of wind and gravity to lake water level changes, and complete the lake water level driving force calculation operation.

[0060] In order to better illustrate the use effect of the present invention, a specific embodiment of the method and system of the present invention is introduced below. Table 1 is a statistical table of the errors between the simulation results of model AD and the actual results. The calculation results of the lake using model AD are as follows: Figure 2-5 The final calculation results of the driving force of the lake water level are shown in Figure 6 shown.

[0061]

[0062] In summary, a lake water level driving force calculation method and system of the present invention first collects lake meteorological data and hydrological data and performs data preprocessing to obtain preprocessed data, then constructs a lake body mechanics model based on the preprocessed data, and uses the lake body mechanics model to calculate wind-driven flow and gravity-driven flow, then uses a semi-empirical calculation model to calculate the lake body mechanics model parameters based on the wind-driven flow and gravity-driven flow according to the comprehensive influence of wind stress and bed shear stress, and obtains parameter calculation results, then uses the SCE-UA algorithm to evaluate and adjust the parameter calculation results to obtain an adjusted lake body mechanics model, and then uses the adjusted lake body mechanics model to calculate the contribution of wind and gravity to lake water level changes, thereby completing the lake water level driving force calculation operation; effectively realizing that the driving force calculation method and system have the ability to calculate wind The system can independently analyze wind force and gravity to accurately calculate the contribution rate of wind force and gravity to the lake water level in different seasons and under different meteorological conditions, and construct a lake mechanics model using meteorological, hydrological and topographic data, which can focus on the effects of the two major driving forces, wind force and gravity. In this way, the direct impact of wind force can be evaluated by analyzing the effect of the wind field on the lake surface and the wind-driven water surge phenomenon it produces. At the same time, the impact of gravity on the lake flow and its water level changes is also considered, and the function of detecting the inclination of water body caused by wind and the change of water flow direction caused by gravity is realized. This provides a scientific analysis tool for lake water level management and ecological balance protection, which can help staff formulate more effective lake management strategies based on the specific impacts of wind force and gravity, which not only improves the management effect of lake hydrological dynamics, but also optimizes the regulation and protection measures of water resources.

[0063] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for calculating the driving force of lake water level, characterized in that: The following steps are included: Step A, collecting lake meteorological data and hydrological data and performing data preprocessing to obtain preprocessed data; Step B, constructing a lake mechanics model based on the preprocessed data, and then using the lake mechanics model to calculate the wind-driven flow and gravity-driven flow. The specific steps are as follows: Step B1, set the horizontal x-axis and vertical y-axis and establish the wind shear stress τ based on the lake surface and bottom w and bottom shear stress τ b A two-dimensional elevation model for analyzing the hydrodynamic behavior of a lake under different wind and gravity forces; Step B2, set boundary conditions and use the principles of fluid dynamics to integrate the turbulence-induced shear stress τ xy The linear expression and eddy viscosity coefficient K are used to calculate the velocity distribution along the horizontal direction, as shown in formula (1): Among them, V x (y) is the velocity distribution along the x-axis, H is the average depth of the lake, ρ is the density of water, and K is the eddy viscosity coefficient; Step B3, according to the velocity distribution V along the x-axis x (y) Calculate the wind-driven flow q1 and gravity-driven flow q2, as shown in formula (2), Step C: Based on the wind-driven flow and gravity-driven flow, the semi-empirical calculation model is used to calculate the parameters of the lake body mechanics model and obtain the parameter calculation results according to the comprehensive influence of wind stress and bed shear stress. The SCE-UA algorithm is then used to evaluate and adjust the parameter calculation results to obtain the adjusted lake body mechanics model. The specific steps are as follows: Step C1, based on the wind-driven flow and gravity-driven flow, the semi-empirical calculation model is used to calculate the parameters of the lake body mechanics model according to the comprehensive influence of wind stress and bed shear stress, and the parameter calculation results are obtained, as shown in formula (3): Among them, η is the water level change caused by wind-generated flow and throughput flow, n is the number of meteorological stations where the model obtains wind data, and U 10 is the wind speed at the ith weather station, H is the average depth of the lake, F is the wind distance, A is the angle between the wind direction and the lake wind distance axis, V gust,i is the maximum wind speed of the ith weather station, c and X (i) are all multiplication constants, θ (1) ,θ (2) and θ (3) are matrix constants, Q hk is the lake outlet flow; Step C2, using the SCE-UA algorithm to evaluate the parameter calculation results and obtain the parameter evaluation results, specifically using the evaluation function R of the SCE-UA algorithm s Evaluate the parameter calculation results, as shown in formula (4) Among them, E ns is the Nash efficiency coefficient of the model, η s (i) is the water level difference calculated by the model, η o (i) is the measured water level difference, is the average value of the measured water level difference; Step C3, adjusting the lake mechanics model according to the parameter evaluation results, so as to obtain the adjusted lake mechanics model, specifically by comparing the parameter evaluation results with the actual observation data for verification. If the degree of agreement between the parameter calculation results of the lake mechanics model and the measured data reaches a set value, it indicates that the lake mechanics model can reproduce the hydrodynamic process in the lake. Otherwise, the parameters of the lake mechanics model are adjusted so that the lake mechanics model can reproduce the hydrodynamic process in the lake. Step D, using the adjusted lake mechanics model to calculate the contribution of wind and gravity to lake water level changes, completes the lake water level driving force measurement operation.

2. A method for calculating lake water level driving force according to claim 1, characterized in that: Step A, collect lake meteorological data and hydrological data and perform data preprocessing to obtain preprocessed data. The specific steps are as follows: Step A1, collecting lake meteorological data and hydrological data, wherein the lake meteorological data and hydrological data specifically include wind speed, wind direction, water level and inflow flow data, and the meteorological data and hydrological data are respectively derived from real-time recorded data of an automatic meteorological station and a hydrological station; Step A2, preprocessing the lake meteorological data and hydrological data to obtain preprocessed data, wherein the data preprocessing specifically includes outlier removal, missing data interpolation and data standardization.

3. A method for calculating lake water level driving force according to claim 2, characterized in that: Step D, using the adjusted lake mechanics model to calculate the contribution of wind and gravity to the lake level change, complete the lake level driving force calculation operation, specifically calculate the wind shear stress τ w and bottom shear stress τ b The contribution of wind and gravity to lake level change is calculated by the ratio of w and bottom shear stress τ b The ratio τ w / τ b When it is less than 1, the gravity flow has a greater impact on the lake level. If the wind shear stress τ w and bottom shear stress τ b The ratio τ w / τ b When τ is equal to 1, the influence of gravity flow and wind-driven flow on lake water level is equal. w and bottom shear stress τ b The ratio τ w / τ b When it is less than 1, the gravity flow has a greater impact on the lake level.

4. A lake water level driving force calculation system, wherein the specific calculation process of the lake water level driving force calculation system is based on the lake water level driving force calculation method according to any one of claims 1 to 3, characterized in that: It includes a data acquisition module, a driving flow calculation module, a model adjustment module and a driving force measurement module. The data acquisition module is used to collect lake meteorological data and hydrological data and perform data preprocessing to obtain preprocessed data; The driving flow calculation module is used to construct a lake body mechanics model based on the preprocessed data, and then use the lake body mechanics model to calculate the wind-driven flow and gravity-driven flow; The model adjustment module is used to calculate the parameters of the lake body mechanics model based on the wind-driven flow and gravity-driven flow and the comprehensive influence of wind stress and bed shear stress using a semi-empirical calculation model and obtain parameter calculation results, and then use the SCE-UA algorithm to evaluate and adjust the parameter calculation results, so as to obtain an adjusted lake body mechanics model; The driving force calculation module is used to calculate the contribution of wind and gravity to the change of lake water level using the adjusted lake body mechanics model, and complete the lake water level driving force calculation operation.

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