A reservoir flood water level early warning method and system and a storage medium

Abstract

This invention provides a method, system, and storage medium for reservoir flood control water level early warning, relating to the field of flood control water level early warning technology. The invention collects rainfall intensity and flood control data for various river sections; sets rules for dam assessment; based on these rules, extracts historical dam formation data and historical dam breach data from historical data; constructs and trains a dam breach prediction model based on this data; obtains predicted dam breach data through the dam breach prediction model; acquires water level and cross-sectional data of each major tributary at the reservoir inlet; combines the current dam existence time and predicted dam breach data to determine the breach water level of each major tributary at the reservoir inlet; acquires reservoir water level data; combines the water level data of each major tributary at the reservoir inlet with the breach water level to complete the reservoir's graded flood control early warning and issue corresponding early warning signals.

Description

Technical Field

[0001] This invention relates to the field of flood control water level early warning technology, specifically to a reservoir flood control water level early warning method, system, and storage medium. Background Technology

[0002] Traditional reservoir flood control water level early warning systems typically rely on real-time monitoring of the reservoir itself and the water levels of its main tributaries, combined with historical hydrological data for trend prediction. However, these methods often overlook situations where geological disasters (such as landslides and debris flows) form temporary natural dams (i.e., intermittent upstream blockages, IBUs) on upstream tributaries. These temporary dams are difficult to detect in their early stages, but their sudden collapse can cause a sharp rise in downstream water levels, or even trigger dam breaches due to inflow into the reservoir, severely impacting reservoir operation and flood control safety. Existing early warning models are mostly based on the assumption of stable hydrology, lacking dynamic identification and risk quantification of the formation, existence, and collapse processes of temporary natural dams. This leads to delayed or missed warnings in areas with extreme weather or frequent geological activity, making it difficult to meet the precise early warning needs of reservoir flood control in complex environments.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, and storage medium for early warning of flood control water levels in reservoirs, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for early warning of flood control water levels in reservoirs, comprising the following steps: Step 1: Identify the main tributaries of the reservoir, divide each main tributary into multiple equally spaced river segments, and collect rainfall intensity and flood control data for each river segment, including water level data and flow velocity data of the upstream and downstream of the river segment; Step 2: Set the rules for judging dams, including the rules for judging the existence of temporary natural dams and the rules for judging the breach of temporary natural dams. Based on the rules, extract historical dam formation data and historical dam breach data from historical data. Dam formation data includes flood control data of the river section when the existence of temporary natural dams is first detected, as well as the average rainfall intensity during the observation period. Dam breach data includes breach time and breach water level increment. Step 3: Using historical dam formation data as input and historical dam breach data as output, construct and train a dam breach prediction model, obtain dam formation data for all river sections with temporary natural dams, and obtain predicted dam breach data through the dam breach prediction model. Step 4: Obtain water level data for each major tributary at the reservoir inlet. Based on the predicted dam breach data and the existing time of the temporary natural dam, determine the current breach risk and impact of each river section. Combine this with tributary cross-sectional data for analysis to determine the breach water level of each major tributary at the reservoir inlet. Step 5: Obtain the reservoir's water level data, combine it with the water level data of each major tributary at the reservoir's inlet and the dam breach level, to complete the reservoir's flood control graded early warning and issue corresponding early warning signals.

[0006] Furthermore, historical reservoir water level change data and simultaneously collected water level change data of each tributary at the reservoir inlet are obtained. The Pearson correlation coefficient between the water level change data of each tributary at the reservoir inlet and the reservoir water level change data is calculated. A correlation threshold is preset. Tributaries with an absolute value of Pearson correlation coefficient greater than the correlation threshold are called major tributaries, and the remaining tributaries are called non-major tributaries.

[0007] Furthermore, the end of the river section away from the reservoir along the direction of water flow is called the upstream of the river section, and the end of the river section closer to the reservoir along the direction of water flow is called the downstream of the river section; Calculate the water level difference and flow velocity difference between the upstream and downstream of the river section, and preset the water level difference range and flow velocity difference range for each major tributary; the rule for judging temporary natural dikes is: if the water level difference between the upstream and downstream of the river section is greater than the upper limit of the water level difference range of the corresponding major tributary, and the flow velocity difference between the upstream and downstream of the river section is greater than the upper limit of the flow velocity difference range of the corresponding major tributary, then it is judged that there is a temporary natural dike in the river section. For river sections with temporary natural dikes, flood control data for the upstream and downstream of the river section with temporary natural dikes are continuously acquired. The judgment rule for the breach of temporary natural dikes is as follows: if the water level difference between the upstream and downstream of the river section is less than the lower limit of the water level difference range of the corresponding main tributary, and the flow velocity difference between the upstream and downstream of the river section is less than the lower limit of the flow velocity difference range of the corresponding main tributary, then the natural dike in the river section is judged to have breached. The observation time is a time interval that starts from the moment when the existence of the temporary natural dam is first detected and traces back to the moment with a preset time length, which is the longest duration of the temporary natural dam. The breach time is the time interval between the moment when the temporary natural dike is detected to have formed and the moment when the temporary natural dike is detected to have breached. The flood level increment is the difference between the downstream water level before and after the breach of the temporary natural dike.

[0008] Furthermore, the formula for calculating the risk of levee breach is: ; in, For the j-th section of the i-th major tributary where a temporary natural dike exists, the risk of the temporary natural dike breach is as follows: For the j-th segment of the i-th major tributary where a temporary natural dike exists, the duration of the existence of the temporary natural dike is given. Let i be the time of breach of the temporary natural dam in the j-th segment of the i-th main tributary where a temporary natural dam exists; i is the index of the main tributary and j is the index of the segment where a temporary natural dam exists.

[0009] The impact of a levee breach refers to the increase in downstream water level caused by the breach. The formula for calculating the impact of a levee breach is: ; in, For the j-th section of the i-th major tributary where a temporary natural dike exists, the impact of the breach of the temporary natural dike is... For the i-th major tributary, the increase in water level downstream of the j-th section where a temporary natural dam exists.

[0010] Furthermore, the tributary cross-sectional data refers to the upstream and downstream water surface widths of each river segment. An inlet water level prediction model is constructed and trained, taking the downstream water level and corresponding downstream water surface width of each major tributary segment as input and the water level data of the major tributaries at the reservoir inlet as output. The current downstream water level and corresponding downstream water surface width of each major tributary segment are input into the inlet water level prediction model to obtain the current water level data of each major tributary at the reservoir inlet. For each major tributary segment, the sum of its current downstream water level and the impact of the levee breach is calculated as the levee breach water level. The levee breach water level and corresponding downstream water surface width of each major tributary segment are input into the inlet water level prediction model to obtain the inlet levee breach water level of each major tributary at the reservoir inlet. If there is no temporary natural levee in a river segment, the current downstream water level of this river segment is taken as the levee breach water level.

[0011] The breach water level and the downstream water width of each river section are input into the reservoir inlet water level prediction model to obtain the breach inlet water level.

[0012] Furthermore, a reservoir water level prediction model is constructed and trained, taking the water level data of each major tributary at the reservoir inlet as input and outputting the reservoir water level increment per unit time. The current water level data of each major tributary at the reservoir inlet is input into the reservoir water level prediction model to obtain the first unit time reservoir water level increment, and the inlet breach water level of each major tributary at the reservoir inlet is input into the reservoir water level prediction model to obtain the second unit time reservoir water level increment. The system presets the warning duration, calculates the product of the reservoir water level increment in the first unit time and the warning duration, and sums this product with the current reservoir water level to obtain the first reservoir water level. It also calculates the product of the reservoir water level increment in the second unit time and the warning duration, and sums this product with the current reservoir water level to obtain the second reservoir water level. The system presets a first reservoir water level threshold and a second reservoir water level threshold, with the first reservoir water level threshold being lower than the second reservoir water level threshold. Based on the first reservoir water level, the second reservoir water level, the first reservoir water level threshold, and the second reservoir water level threshold, it conducts flood prevention graded early warning for the reservoirs.

[0013] Furthermore, if the water levels of both the first and second reservoirs are lower than the threshold for the first reservoir, a Level 1 warning will be issued and a Level 1 warning signal will be sent. If the water level of the first reservoir is lower than the water level threshold of the first reservoir, and the water level of the second reservoir is greater than or equal to the water level threshold of the first reservoir but lower than the water level threshold of the second reservoir, then a level-two warning will be issued and a level-two warning signal will be sent. If the water levels of the first reservoir and the second reservoir are greater than or equal to the threshold of the first reservoir, and both are less than the threshold of the second reservoir, then a level 3 warning will be issued and a level 3 warning signal will be sent. If the water level of the first reservoir is lower than the water level threshold of the second reservoir, but greater than or equal to the water level threshold of the first reservoir; and the water level of the second reservoir is greater than or equal to the water level threshold of the second reservoir, then a Level IV warning will be issued and a Level IV warning signal will be sent. If the water levels of both the first and second reservoirs are greater than or equal to the threshold water level of the first reservoir, a Level 5 warning will be issued, and a Level 5 warning signal will be sent.

[0014] This invention also provides a reservoir flood control water level early warning system, the system being used to implement the aforementioned reservoir flood control water level early warning method, specifically including: The data acquisition module is used to determine the main tributaries of the reservoir, divide each main tributary into multiple equally spaced river segments, and collect rainfall intensity and flood control data for each river segment, including water level data and flow velocity data of the upstream and downstream of the river segment; The dam judgment module is used to set the rules for dam judgment, including the rules for judging the existence of temporary natural dams and the rules for judging the breach of temporary natural dams. Based on the rules, historical dam formation data and historical dam breach data are extracted from historical data. The dam formation data includes flood control data of the river section when the existence of temporary natural dams is first detected, as well as the average rainfall intensity during the observation period. The dam breach data includes the breach time and the increment of the breach water level. The model building module is used to build and train a dam breach prediction model with historical dam formation data as input and historical dam breach data as output. It obtains dam formation data for all river sections with temporary natural dams and obtains predicted dam breach data through the dam breach prediction model. The incremental analysis module is used to acquire water level data of each major tributary at the reservoir inlet. Based on the predicted dam breach data and the existing time of temporary natural dams, it determines the current breach risk and impact of each river section. It also combines tributary cross-sectional data for analysis to determine the breach water level of each major tributary at the reservoir inlet. The water level early warning module is used to acquire water level data of the reservoir, combine it with the water level data of each major tributary at the reservoir inlet and the dam breach water level, so as to complete the reservoir's flood control graded early warning and issue corresponding early warning signals.

[0015] The present invention also provides a computer-readable storage medium, wherein the storage medium stores a computer program that can be executed by a processor, and the computer program, when executed by the processor, can implement the reservoir flood control water level early warning method.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention effectively improves the accuracy and foresight of reservoir flood control early warning by introducing a mechanism for identifying and predicting the breach of temporary natural dams on upstream tributaries. The system can dynamically monitor and assess the formation and breach risk of temporary dams, and by combining historical data with real-time hydrological information, quantifies the impact of each tributary on the reservoir inlet water level breach, thereby achieving a graded response based on multi-level early warning logic. This method not only enhances the ability to capture sudden changes in water level under intermittent blockage conditions but also improves the timeliness and reliability of early warnings, providing more scientific decision support for reservoir flood control scheduling, and has significant application value, especially in mountainous reservoirs or areas prone to geological disasters. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall method flow of the present invention; Figure 2 This is a schematic diagram of the overall system structure of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Please see Figure 1 The present invention provides a technical solution: A method for early warning of flood control water levels in reservoirs, comprising the following steps: Step 1: Identify the main tributaries of the reservoir, divide each main tributary into multiple equally spaced river segments, and collect rainfall intensity and flood control data for each river segment, including water level data and flow velocity data of the upstream and downstream of the river segment; Furthermore, historical reservoir water level change data and simultaneously collected water level change data of each tributary at the reservoir inlet are obtained. The Pearson correlation coefficient between the water level change data of each tributary at the reservoir inlet and the reservoir water level change data is calculated. A correlation threshold is preset. Tributaries with an absolute value of Pearson correlation coefficient greater than the correlation threshold are called major tributaries, and the remaining tributaries are called non-major tributaries.

[0021] The water level changes in a reservoir are mainly affected by the inflow from its tributaries. By calculating the Pearson correlation coefficient, the degree of linear correlation between the inflow water level changes of each tributary and the reservoir water level changes can be quantified. Tributaries with high correlation (i.e., Pearson coefficient absolute values ​​greater than a threshold) indicate that their water level changes have a significant impact on the reservoir water level and should be classified as "major tributaries".

[0022] Experts in the field of hydrology were invited to investigate and demonstrate the local hydrological conditions, and to provide appropriate correlation thresholds and spacing between river segments. The river segments of each major tributary were divided at equal intervals starting from the starting point. The connection between each major tributary and the reservoir inlet was analyzed separately and not included in the river segment count.

[0023] Step 2: Set the rules for judging dams, including the rules for judging the existence of temporary natural dams and the rules for judging the breach of temporary natural dams. Based on the rules, extract historical dam formation data and historical dam breach data from historical data. Dam formation data includes flood control data of the river section when the existence of temporary natural dams is first detected, as well as the average rainfall intensity during the observation period. Dam breach data includes breach time and breach water level increment. Furthermore, the end of the river section away from the reservoir along the direction of water flow is called the upstream of the river section, and the end of the river section closer to the reservoir along the direction of water flow is called the downstream of the river section; The differences in water level and flow velocity between the upstream and downstream sections of a river segment are calculated, and the ranges for water level and flow velocity differences for each major tributary are predefined. The range of water level differences is determined by statistically analyzing historical water level data under normal, unobstructed conditions. Water level monitoring values ​​of the upstream and downstream sections of a specific river segment under long-term stable flow conditions are collected, and their water level difference sequences are calculated. Statistical methods (such as calculating the 5th to 95th percentile intervals) are used to determine the fluctuation range of water level differences under normal flow conditions. The range of flow velocity differences is determined by analyzing historical flow velocity monitoring data under normal flow conditions. Synchronous monitoring values ​​of upstream and downstream flow velocities under unobstructed conditions are collected, and their flow velocity difference sequences are calculated. The same statistical methods as for water level differences (such as the 5th to 95th percentiles) are used to determine the fluctuation range of normal flow velocity differences.

[0024] The rule for determining a temporary natural dam is as follows: if the water level difference between the upstream and downstream of a river section is greater than the upper limit of the water level difference range of the corresponding main tributary, and the velocity difference between the upstream and downstream of a river section is greater than the upper limit of the velocity difference range of the corresponding main tributary, then a temporary natural dam is determined to exist in the river section. In the absence of a temporary dam (under normal circumstances), there will be a certain difference in water level and flow velocity between the upstream and downstream sections of a river. The difference in flow velocity directly leads to the difference in flow velocity. This difference in water level and flow velocity will fluctuate within a normal range (range of water level difference and range of flow velocity difference). When a temporary dam is formed, abnormal water storage begins in the upstream section of the river, causing the water level difference to increase abnormally. After the temporary dam stabilizes, the flow velocity difference will also increase due to the increased water level difference. Therefore, the judgment rule for a temporary natural dam is met, and it can be determined that a temporary dam has been formed. For river sections with temporary natural dikes, flood control data for the upstream and downstream of the river section with temporary natural dikes are continuously acquired. The judgment rule for the breach of temporary natural dikes is as follows: if the water level difference between the upstream and downstream of the river section is less than the lower limit of the water level difference range of the corresponding main tributary, and the flow velocity difference between the upstream and downstream of the river section is less than the lower limit of the flow velocity difference range of the corresponding main tributary, then the natural dike in the river section is judged to have breached. After a dam breaks, the water stored upstream will flow rapidly downstream. Due to inertia, the water levels upstream and downstream will actually increase relative to the normal water levels. At this time, the water level difference between upstream and downstream will be less than the lower limit of the water level difference range. The flow velocity difference caused by the water level difference will also be smaller and lower than the normal range. Therefore, the breach of the natural dam in the river section can be judged by the temporary natural dam breach judgment rules.

[0025] The breach time is the time interval between the moment when the temporary natural dike is detected to have formed and the moment when the temporary natural dike is detected to have breached. The flood level increment is the difference between the downstream water level before and after the breach of the temporary natural dike.

[0026] Step 3: Using historical dam formation data as input and historical dam breach data as output, construct and train a dam breach prediction model, obtain dam formation data for all river sections with temporary natural dams, and obtain predicted dam breach data through the dam breach prediction model. Acquire dam formation data each time a dam is detected, calculate the average rainfall intensity from the start of dam formation to the time interval of the historical maximum dam breach, use the two as inputs and the corresponding historical dam breach data as outputs to construct and train a dam breach prediction model. The dataset is composed of historical dam formation data and corresponding historical dam breach data. 80% of the dataset is used as the training set and 20% as the test set. The dam breach prediction model uses a feedforward neural network, which is trained with historical dam construction data to calculate the corresponding historical dam breach data. Specifically, using historical dam formation data as input and corresponding historical dam breach data as labels, the model training employs existing technologies, including: an input layer, hidden layers, an output layer, and an activation function. The input layer receives the historical dam formation data; the hidden layer processes this data; each layer consists of multiple layers, each containing multiple time points. Each hidden layer's time point is connected to the previous layer via weights, used for feature abstraction and nonlinear transformation of the input historical dam formation data; it learns the complex mapping relationship between input and output; by using the ReLU activation function, a nonlinear relationship is introduced, enabling the model to fit complex feature relationships; an independent neuron is placed in the output layer to transform the local and high-level feature representations extracted by the hidden layer for outputting dam breach data; the root mean square error loss function is used; the input data is processed through the network once to obtain the output result; the loss function is calculated based on the predicted and true values; the gradient of the loss function with respect to each weight and bias is calculated using the chain rule; and the gradient descent algorithm is used to update the network's weights and biases to minimize the loss function.

[0027] Step 4: Obtain water level data for each major tributary at the reservoir inlet. Based on the predicted dam breach data and the existing time of the temporary natural dam, determine the current breach risk and impact of each river section. Combine this with tributary cross-sectional data for analysis to determine the breach water level of each major tributary at the reservoir inlet. Furthermore, the formula for calculating the risk of levee breach is: ; in, For the j-th section of the i-th major tributary where a temporary natural dike exists, the risk of the temporary natural dike breach is as follows: For the j-th segment of the i-th major tributary where a temporary natural dike exists, the duration of the existence of the temporary natural dike is given. Let i be the time of breach of the temporary natural dam in the j-th segment of the i-th main tributary where a temporary natural dam exists; i is the index of the main tributary and j is the index of the segment where a temporary natural dam exists.

[0028] The impact of a levee breach refers to the increase in downstream water level caused by the breach. The formula for calculating the impact of a levee breach is: ; in, For the j-th section of the i-th major tributary where a temporary natural dike exists, the impact of the breach of the temporary natural dike is... For the i-th major tributary, the increase in water level downstream of the j-th section where a temporary natural dam exists.

[0029] in, The predicted time is the downstream water level increment when the dam breaches. Typically, temporary dams will breach at the predicted time, resulting in a water level increment downstream. In this embodiment, the breach is considered a probabilistic event, with the possibility of breaches occurring earlier or later. Rainfall intensity is the main cause of the water level increment. Since the average rainfall intensity is used in the prediction, the water level increment can be considered as a process that increases equally over time. In the analysis, the breach is considered a probabilistic event. If the breach occurs at the current time, the downstream water level increment (breach impact) at the current time can be estimated by the current time and the predicted breach time.

[0030] Furthermore, the tributary cross-sectional data refers to the upstream and downstream water surface widths of each river segment. An inlet water level prediction model is constructed and trained, taking the downstream water level and corresponding downstream water surface width of each major tributary segment as input and the water level data of the major tributaries at the reservoir inlet as output. The current downstream water level and corresponding downstream water surface width of each major tributary segment are input into the inlet water level prediction model to obtain the current water level data of each major tributary at the reservoir inlet. For each major tributary segment, the sum of its current downstream water level and the impact of the levee breach is calculated as the levee breach water level. The levee breach water level and corresponding downstream water surface width of each major tributary segment are input into the inlet water level prediction model to obtain the inlet levee breach water level of each major tributary at the reservoir inlet. If there is no temporary natural levee in a river segment, the current downstream water level of this river segment is taken as the levee breach water level.

[0031] The downstream water level of each section of each major tributary, the corresponding downstream water surface width, and the reservoir water level of the major tributary are used as the reservoir inlet water level dataset. 80% of the reservoir inlet water level dataset is used as the training set and 20% as the validation set. The existing technology for constructing a reservoir inlet water level prediction model employs an additive model with a strong predictor in a gradient boosting regression tree. The specific processing flow is as follows: First, the model receives data on the downstream water levels of each major tributary segment, the corresponding downstream water surface width, and the water levels of the major tributaries at the reservoir inlet. Then, the model runs iteratively: initially, it starts with a base prediction value; in each iteration, the residuals between the current model prediction and the true value are calculated, and a new shallow decision tree is trained to specifically fit these residuals. This tree recursively finds the optimal feature splitting point to partition the data; then, the output contribution of the new tree is calculated based on the mean of the residuals in each leaf node, and this contribution is then added to the existing model with a small learning rate, thereby gradually correcting the error. Finally, the predicted output for a new sample is the sum of the initial prediction value and the output contributions of all decision trees.

[0032] Step 5: Obtain the reservoir's water level data, combine it with the water level data of each major tributary at the reservoir's inlet and the dam breach level, to complete the reservoir's flood control graded early warning and issue corresponding early warning signals.

[0033] Furthermore, a reservoir water level prediction model is constructed and trained, taking the water level data of each major tributary at the reservoir inlet as input and outputting the reservoir water level increment per unit time. The current water level data of each major tributary at the reservoir inlet is input into the reservoir water level prediction model to obtain the first unit time reservoir water level increment, and the inlet breach water level of each major tributary at the reservoir inlet is input into the reservoir water level prediction model to obtain the second unit time reservoir water level increment. The reservoir level prediction dataset is constructed by taking the water level at the inlet of each major tributary reservoir, the reservoir water level, the input time, and the reservoir water level after the input time. 80% of the reservoir level prediction dataset is used as the training set, and 20% is used as the validation set. The reservoir water level prediction model adopts a Seq2Seq with LSTM model based on an encoder-decoder architecture, which is an existing technology. Both the encoder and decoder are composed of multi-layer LSTM networks to capture long-term dependencies in the time series. Its workflow is as follows: The encoder first processes the multivariate input sequence within a past time window sequentially, updating its hidden states step by step through the gating mechanism of the LSTM, thereby compressing the information of the entire input sequence into a series of hidden state vectors. Next, the attention mechanism comes into play—at each prediction time step of the decoder, it calculates the correlation weight between the decoder's current hidden state and all the encoder's hidden states, and generates a dynamic context vector based on this. This vector focuses on the key time period information in the input sequence that is most relevant to the current prediction. Finally, the decoder LSTM combines the previous state, the current input, and this refined context vector to gradually generate the predicted water level value for the future target time.

[0034] The system presets the warning duration, calculates the product of the reservoir water level increment in the first unit time and the warning duration, and sums this product with the current reservoir water level to obtain the first reservoir water level. It also calculates the product of the reservoir water level increment in the second unit time and the warning duration, and sums this product with the current reservoir water level to obtain the second reservoir water level. The reasonable range for warning time is typically set between 2 and 4 hours. This range is determined based on a balance between emergency response efficiency and forecast reliability. A lower limit of 2 hours ensures the minimum effective action time, sufficient to complete key processes such as warning information dissemination, emergency team mobilization, decision-making consultation, and initiating downstream evacuation. An upper limit of 4 hours considers the actual capabilities of meteorological and hydrological forecasts; exceeding this timeframe significantly increases forecast uncertainty, potentially leading to false alarms and warning fatigue. This time window allows for timely response to sudden heavy rainfall or localized dam breach risks while also providing sufficient preparation time for large-scale weather events such as typhoons, making it a crucial decision parameter for effective flood prevention and disaster mitigation.

[0035] The system presets a first reservoir water level threshold and a second reservoir water level threshold, with the first reservoir water level threshold being lower than the second reservoir water level threshold. Based on the first reservoir water level, the second reservoir water level, the first reservoir water level threshold, and the second reservoir water level threshold, it conducts flood prevention graded early warning for the reservoirs.

[0036] The first reservoir water level threshold is the warning water level, and the second reservoir water level threshold is the alarm water level. The first and second reservoir water level thresholds can be obtained by inviting hydrological experts in the field to conduct argumentation and reasoning based on the specific local hydrological conditions and relevant policies, combined with historical data and literature. This is existing technology and will not be elaborated here.

[0037] Furthermore, if the water levels of both the first and second reservoirs are lower than the threshold for the first reservoir, a Level 1 warning is issued. In this case, regardless of whether the temporary dam breaches, the water level will remain within a safe range after the warning period, and there is no risk to the reservoir water level. A Level 1 warning is then issued.

[0038] If the water level of the first reservoir is lower than the first reservoir water level threshold, and the water level of the second reservoir is greater than or equal to the first reservoir water level threshold but lower than the second reservoir water level threshold, then if the temporary water level does not breach the dam, the water level after the warning time will be within a safe range. If the dam breaches, the water level after the warning time will be in a near-dangerous warning state, and a level two warning will be issued.

[0039] If the water levels of the first and second reservoirs are greater than or equal to the threshold of the first reservoir, and both are less than the threshold of the second reservoir, then regardless of whether the temporary dike breaches, the water level after the warning time will be in a near-dangerous warning state; a level three warning will be issued, and a level three warning signal will be sent.

[0040] If the water level of the first reservoir is lower than the water level threshold of the second reservoir, but greater than or equal to the water level threshold of the first reservoir; and the water level of the second reservoir is greater than or equal to the water level threshold of the second reservoir, then if the temporary water level does not breach the dam, the water level after the warning time will be in a near-dangerous warning state; if the dam breaches, the water level after the warning time will be in a dangerous alarm state, and a level four warning will be issued. If the water levels of both the first and second reservoirs are greater than or equal to the threshold water level of the first reservoir, then the water level after the warning time will be in a dangerous alarm state, and a level 5 warning will be issued.

[0041] Please see Figure 2 The present invention further provides a reservoir flood control water level early warning system, the system being used to implement the aforementioned reservoir flood control water level early warning method, specifically including: The data acquisition module is used to determine the main tributaries of the reservoir, divide each main tributary into multiple equally spaced river segments, and collect rainfall intensity and flood control data for each river segment, including water level data and flow velocity data of the upstream and downstream of the river segment; The dam judgment module is used to set the rules for dam judgment, including the rules for judging the existence of temporary natural dams and the rules for judging the breach of temporary natural dams. Based on the rules, historical dam formation data and historical dam breach data are extracted from historical data. The dam formation data includes flood control data of the river section when the existence of temporary natural dams is first detected, as well as the average rainfall intensity during the observation period. The dam breach data includes the breach time and the increment of the breach water level. The model building module is used to build and train a dam breach prediction model with historical dam formation data as input and historical dam breach data as output. It obtains dam formation data for all river sections with temporary natural dams and obtains predicted dam breach data through the dam breach prediction model. The incremental analysis module is used to acquire water level data of each major tributary at the reservoir inlet. Based on the predicted dam breach data and the existing time of temporary natural dams, it determines the current breach risk and impact of each river section. It also combines tributary cross-sectional data for analysis to determine the breach water level of each major tributary at the reservoir inlet. The water level early warning module is used to acquire water level data of the reservoir, combine it with the water level data of each major tributary at the reservoir inlet and the dam breach water level, so as to complete the reservoir's flood control graded early warning and issue corresponding early warning signals.

[0042] The present invention also provides a computer-readable storage medium, wherein the storage medium stores a computer program that can be executed by a processor, and the computer program, when executed by the processor, can implement the reservoir flood control water level early warning method.

[0043] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0044] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0045] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0046] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that cannot be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for early warning of flood control water levels in reservoirs, characterized in that, The specific steps include: Step 1: Identify the main tributaries of the reservoir, divide each main tributary into multiple equally spaced river segments, and collect rainfall intensity and flood control data for each river segment, including water level data and flow velocity data of the upstream and downstream of the river segment; Step 2: Set the rules for judging dams, including the rules for judging the existence of temporary natural dams and the rules for judging the breach of temporary natural dams. Based on the rules, extract historical dam formation data and historical dam breach data from historical data. Dam formation data includes flood control data of the river section when the existence of temporary natural dams is first detected, as well as the average rainfall intensity during the observation period. Dam breach data includes breach time and breach water level increment. Step 3: Using historical dam formation data as input and historical dam breach data as output, construct and train a dam breach prediction model, obtain dam formation data for all river sections with temporary natural dams, and obtain predicted dam breach data through the dam breach prediction model. Step 4: Obtain water level data for each major tributary at the reservoir inlet. Based on the predicted dam breach data and the existing time of the temporary natural dam, determine the current breach risk and impact of each river section. Combine this with tributary cross-sectional data for analysis to determine the breach water level of each major tributary at the reservoir inlet. Step 5: Obtain the water level data of the reservoir, combine it with the water level data of each major tributary at the reservoir inlet and the dam breach water level, to complete the reservoir's flood control graded early warning and issue corresponding early warning signals; The end of a river section that is furthest from the reservoir along the direction of water flow is called the upstream end of the river section, and the end of a river section that is closer to the reservoir along the direction of water flow is called the downstream end of the river section. Calculate the water level difference and flow velocity difference between the upstream and downstream of the river section, and preset the water level difference range and flow velocity difference range for each major tributary; the rule for judging temporary natural dikes is: if the water level difference between the upstream and downstream of the river section is greater than the upper limit of the water level difference range of the corresponding major tributary, and the flow velocity difference between the upstream and downstream of the river section is greater than the upper limit of the flow velocity difference range of the corresponding major tributary, then it is judged that there is a temporary natural dike in the river section. For river sections with temporary natural dikes, flood control data for the upstream and downstream of the river section with temporary natural dikes are continuously acquired. The judgment rule for the breach of temporary natural dikes is as follows: if the water level difference between the upstream and downstream of the river section is less than the lower limit of the water level difference range of the corresponding main tributary, and the flow velocity difference between the upstream and downstream of the river section is less than the lower limit of the flow velocity difference range of the corresponding main tributary, then the natural dike in the river section is judged to have breached. The observation time is a time interval that starts from the moment when the existence of the temporary natural dam is first detected and traces back to the moment with a preset time length, which is the longest duration of the temporary natural dam. The breach time is the time interval between the moment when the temporary natural dike is detected to have formed and the moment when the temporary natural dike is detected to have breached. The flood level increment after the breach is the difference between the downstream water level before and after the breach of the temporary natural dike. The formula for calculating the risk of a levee breach is: in, For the j-th section of the i-th major tributary where a temporary natural dike exists, the risk of the temporary natural dike breach is as follows: For the j-th segment of the i-th major tributary where a temporary natural dike exists, the duration of the existence of the temporary natural dike is given. For the j-th section of the i-th major tributary where a temporary natural dam exists, the breach time of the temporary natural dam is given; i is the index of the major tributary, and j is the index of the section where the temporary natural dam exists. The impact of a levee breach refers to the increase in downstream water level caused by the breach. The formula for calculating the impact of a levee breach is: in, For the j-th section of the i-th major tributary where a temporary natural dike exists, the impact of the breach of the temporary natural dike is... For the j-th segment of the i-th main tributary where a temporary natural dam exists, the downstream water level increment of the temporary natural dam; the tributary cross-sectional data is the downstream water surface width of each segment; A model for predicting inlet water levels is constructed and trained, taking the downstream water levels and corresponding downstream water surface widths of each major tributary segment as inputs and outputting the water level data of the major tributaries at the reservoir inlet. The current downstream water level and corresponding downstream water surface width of each major tributary segment are input into the inlet water level prediction model to obtain the current water level data of each major tributary at the reservoir inlet. For each major tributary segment, the sum of its current downstream water level and the impact of a levee breach is calculated as the levee breach level. The levee breach level and corresponding downstream water surface width of each major tributary segment are input into the inlet water level prediction model to obtain the levee breach level of each major tributary at the reservoir inlet. If a segment does not have a temporary natural levee, the current downstream water level of that segment is taken as the levee breach level.

2. The reservoir flood control water level early warning method according to claim 1, characterized in that: Historical reservoir water level change data and simultaneous data on the water level changes of each tributary at the reservoir inlet are obtained. The Pearson correlation coefficient between the water level change data of each tributary at the reservoir inlet and the reservoir water level change data is calculated. A correlation threshold is preset. Tributaries with an absolute value of Pearson correlation coefficient greater than the correlation threshold are called major tributaries, and the remaining tributaries are called non-major tributaries.

3. The reservoir flood control water level early warning method according to claim 1, characterized in that: A reservoir water level prediction model is constructed and trained, taking the water level data of each major tributary at the reservoir inlet as input and outputting the reservoir water level increment per unit time. The current water level data of each major tributary at the reservoir inlet is input into the reservoir water level prediction model to obtain the first unit time reservoir water level increment, and the inlet breach water level of each major tributary at the reservoir inlet is input into the reservoir water level prediction model to obtain the second unit time reservoir water level increment. The system presets the warning duration, calculates the product of the reservoir water level increment in the first unit time and the warning duration, and sums this product with the current reservoir water level to obtain the first reservoir water level. It also calculates the product of the reservoir water level increment in the second unit time and the warning duration, and sums this product with the current reservoir water level to obtain the second reservoir water level. The system presets a first reservoir water level threshold and a second reservoir water level threshold, with the first reservoir water level threshold being lower than the second reservoir water level threshold. Based on the first reservoir water level, the second reservoir water level, the first reservoir water level threshold, and the second reservoir water level threshold, it conducts flood prevention graded early warning for the reservoirs.

4. The reservoir flood control water level early warning method according to claim 3, characterized in that: If the water levels of both the first and second reservoirs are lower than the threshold for the first reservoir, a Level 1 warning will be issued and a Level 1 warning signal will be sent. If the water level of the first reservoir is lower than the water level threshold of the first reservoir, and the water level of the second reservoir is greater than or equal to the water level threshold of the first reservoir but lower than the water level threshold of the second reservoir, then a level-two warning will be issued and a level-two warning signal will be sent. If the water levels of the first reservoir and the second reservoir are both greater than or equal to the threshold of the first reservoir and both are less than the threshold of the second reservoir, then a level 3 warning will be issued and a level 3 warning signal will be sent. If the water level of the first reservoir is lower than the water level threshold of the second reservoir, but greater than or equal to the water level threshold of the first reservoir; and the water level of the second reservoir is greater than or equal to the water level threshold of the second reservoir, then a Level IV warning will be issued and a Level IV warning signal will be sent. If the water levels of both the first and second reservoirs are greater than or equal to the threshold water level of the first reservoir, a Level 5 warning will be issued, and a Level 5 warning signal will be sent.

5. A reservoir flood control water level early warning system, characterized in that: The system is used to implement the reservoir flood control water level early warning method according to any one of claims 1-4, specifically including: The data acquisition module is used to determine the main tributaries of the reservoir, divide each main tributary into multiple equally spaced river segments, and collect rainfall intensity and flood control data for each river segment, including water level data and flow velocity data of the upstream and downstream of the river segment; The dam judgment module is used to set the rules for dam judgment, including the rules for judging the existence of temporary natural dams and the rules for judging the breach of temporary natural dams. Based on the rules, historical dam formation data and historical dam breach data are extracted from historical data. The dam formation data includes flood control data of the river section when the existence of temporary natural dams is first detected, as well as the average rainfall intensity during the observation period. The dam breach data includes the breach time and the increment of the breach water level. The model building module is used to build and train a dam breach prediction model with historical dam formation data as input and historical dam breach data as output. It obtains dam formation data for all river sections with temporary natural dams and obtains predicted dam breach data through the dam breach prediction model. The incremental analysis module is used to acquire water level data of each major tributary at the reservoir inlet. Based on the predicted dam breach data and the existing time of temporary natural dams, it determines the current breach risk and impact of each river section. It also combines tributary cross-sectional data for analysis to determine the breach water level of each major tributary at the reservoir inlet. The water level early warning module is used to acquire water level data of the reservoir, combine it with the water level data of each major tributary at the reservoir inlet and the dam breach water level, so as to complete the reservoir's flood control graded early warning and issue corresponding early warning signals.

6. A computer-readable storage medium, characterized in that: The storage medium internally stores a computer program that can be executed by a processor. When the computer program is executed by the processor, it can implement the reservoir flood control water level early warning method according to any one of claims 1-4.

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