A mountainous river flood dynamic early warning index analysis method considering risk hidden water blockage

Abstract

This invention discloses a method for analyzing dynamic early warning indicators for floods in mountainous rivers, considering the water-blocking effect of potential risks. The method includes the following steps: Step 1, basic data preparation and identification of potential risk points; Step 2, construction of a distributed hydrological model; Step 3, construction of a hydrodynamic model; Step 4, setting warning and danger water levels along the river; Step 5, determination of initial early warning indicators; Step 6, dynamic real-time adjustment of early warning indicators and resetting across events. This invention solves the problem of false alarms or missed alarms caused by the static and fixed nature of early warning indicators in existing technologies. It considers the water-blocking effect of water-related structures in the river as dynamic risk points on the flood evolution process, and dynamically adjusts the indicators based on real-time rainfall intensity, previous accumulated rainfall, and the status of potential risk points. This achieves accurate and real-time early warning of flood risks in mountainous rivers, providing a scientific basis for disaster prevention and mitigation.

Description

Technical Field

[0001] This invention belongs to the field of flood early warning technology, and in particular relates to a method for analyzing dynamic early warning indicators of floods in mountainous rivers that takes into account potential risks and water obstruction. Background Technology

[0002] Mountainous river channels, characterized by steep terrain, rapid confluence, and concentrated rainfall, have historically been prone to flooding. Currently, flood warnings for these areas largely rely on fixed critical rainfall amounts derived from historical flood events. While this method offers advantages such as ease of operation and low implementation costs, it reveals several shortcomings in practical application. Firstly, it fails to consider the dynamic changes in hydrological factors such as soil moisture content, land use, and soil infiltration in the early stages of the watershed. These factors directly influence the entire process of rainfall-runoff-confluence. For example, even small amounts of rainfall can rapidly generate surface runoff and trigger flash floods when the soil is already highly saturated, whereas the same amount of rainfall might not generate runoff under drought conditions. Therefore, static warning indicators struggle to account for these situations, leading to false alarms or missed warnings. Secondly, existing warning systems generally fail to consider the obstructive effect of water-related structures (such as bridges and culverts) distributed along the river as dynamic risk points on the flood's progression. These structures are highly susceptible to localized blockages during heavy rainfall due to the accumulation of floating debris, silt, or garbage, leading to abnormally high water levels and flash floods. More importantly, traditional static early warning indicators remain unchanged throughout the rainfall process, unable to be dynamically adjusted based on real-time rainfall intensity, prior accumulated rainfall, and the status of risk points. With the development of remote sensing, numerical simulation, and intelligent identification technologies, we now have the capability to perform refined perception and real-time dynamic modeling of watershed hydrological conditions and the risks and hazards of water-related structures. Based on this technology, there is an urgent need to provide an analysis method for dynamic early warning indicators of mountain river floods that considers the water obstruction caused by risks, in order to improve the accuracy, adaptability, and timeliness of flood early warnings for mountain rivers. Summary of the Invention

[0003] The purpose of this invention is to provide a method for analyzing dynamic early warning indicators of floods in mountainous rivers that takes into account potential risks and water obstruction, in order to solve the above-mentioned technical problems.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] This invention discloses a method for analyzing dynamic early warning indicators of floods in mountainous rivers that considers potential risks and water obstruction. The method includes the following steps:

[0006] Step 1: Basic Data Preparation and Risk / Hazard Point Identification: Collect basic geographical, hydrological, and river channel data, as well as historical and real-time rainfall data, for the target mountainous river basin; determine the river control sections; identify, locate, and classify water-related structures along the river that affect flood flow capacity, obtaining a set of risk / hazard points; for each risk / hazard point, establish corresponding attribute information records, obtain real-time blockage status information for each risk / hazard point, and then determine the corresponding water obstruction degree parameters based on the blockage status of the risk / hazard points; construct a dynamic database of risk / hazard points based on the risk / hazard point attribute information, blockage status, and corresponding water obstruction degree parameters.

[0007] Step 2: Construct a distributed hydrological model: Based on the collected basic geographic data of the target mountain river basin, construct a distributed hydrological model; divide the target mountain river basin into several hydrological response units, and calculate the runoff generation and confluence processes in different areas based on real-time rainfall data to obtain the flow process of each control section of the river; then update the model based on changes in real-time rainfall processes, basic geographic data, and hydrological data, and calculate the flow process lines of each control section in real time;

[0008] Step 3: Construct a hydrodynamic model: Based on the constructed dynamic database of risk points, embed water-related structures into their corresponding river control sections, and set water-blocking parameters for the blockage degree of each risk point; based on the acquired river data, use the flow process of each control section calculated by the distributed hydrological model as the input of the hydrodynamic model to construct the hydrodynamic model of the target river, and obtain the real-time water level change process of each river control section through the hydrodynamic model;

[0009] Step 4: Set warning and danger water levels along the river: First, determine the outlet water level of the control section based on the established river control section. Then at the outlet water level Based on this, by reserving different levels of safety margin, two levels of early warning water levels are set along the route: warning water level and danger water level.

[0010] Warning water level : Reserve a safety margin downwards from the outlet water level. ,Right now:

[0011] (1)

[0012] Dangerous water level : Reserve a safety margin downwards from the outlet water level. ,Right now:

[0013] (2)

[0014] in, and The value is determined comprehensively based on factors such as historical flood data, river cross-sectional morphology, surrounding population density, and flood control capacity. ;

[0015] Step 5: Determining Initial Early Warning Indicators: When a rainfall event occurs in the target watershed, the start time of that rainfall event is defined as... and will Until the next warning time The period between these two points will be used as the first warning period. The warning times are determined on a rolling basis according to preset time intervals; the first warning period is used as the starting point. The newly added cumulative rainfall within the area was used as the test data to invert and trigger the warning water level. and dangerous water level The required rainfall threshold is used to obtain the initial dynamic rainfall warning index that triggers the warning water level warning within the first warning period. and initial dynamic rainfall warning indicators that trigger dangerous water level warnings During the first warning period Within that time period, the actual cumulative rainfall is obtained in real time. And compare it with the initial dynamic rainfall warning indicators, if If, then no warning will be triggered; if If so, a warning water level alert will be triggered; if This will trigger a dangerous water level warning;

[0016] Step 6: Dynamically adjust early warning indicators in real time and reset them across events: During the duration of a rainfall event, at a certain moment... hour( ),Will Until the next warning calculation time The period between these points will be used as the current warning period. The system updates the dynamic rainfall warning indicators corresponding to the current warning period. When the system detects no rainfall for a consecutive preset number of warning periods within the basin, it determines that the rainfall event has ended, terminates the dynamic warning indicator update process for this rainfall event, and archives the rainfall process, hydrological status, risk hazard point status, warning indicators, and warning results for this event. When a new rainfall event occurs, the start time of the new rainfall event is used as the starting point. The initial hydrological status of the watershed and the water-blocking status of potential risk points were re-acquired, and the initial and subsequent dynamic rainfall warning indicators were recalculated.

[0017] Furthermore, the river control sections mentioned in step 1 include the river starting and ending sections, the river sections where risk and hidden danger points are located, and the sections that need to be deployed according to the early warning response.

[0018] The risk points include bridges, culverts, flooded bridges, dams, drop structures, water pipes, and other water-related structures whose local flow capacity is reduced due to the accumulation of floating debris, silt, branches, or garbage.

[0019] The attribute information record includes the spatial location, structural parameters, and design current-carrying capacity of the risk and potential hazard points;

[0020] The blockage status information is obtained through one or more of the following methods: manual inspection records, video surveillance images, drone images, remote sensing images, river water level monitoring data, upstream and downstream water level difference monitoring data, flow velocity monitoring data, or machine vision recognition results.

[0021] The value range of the water resistance parameter is 0 to 1. 0 indicates that there is no blockage at the risk point, 1 indicates that the risk point is completely blocked, and values ​​between 0 and 1 indicate that the risk point is partially blocked to varying degrees.

[0022] The dynamic database of risk and hazard points includes the spatial location, structural parameters, design flow capacity, current blockage status, water resistance parameters, blockage status update time, and blockage status data source of the risk and hazard points.

[0023] Furthermore, the specific process of dividing the target mountain river basin into several hydrological response units as described in step 2 is as follows: based on the digital elevation data and land use classification map of the target mountain river basin, according to the slope classification standard and land use type, spatial units with the same slope level and consistent land use type are divided into the same hydrological response unit, thereby completing the division of the watershed hydrological response units.

[0024] Furthermore, the preset time interval mentioned in step 5 is set comprehensively based on the target basin confluence time, monitoring data update frequency, meteorological forecast update frequency, and early warning response lead time.

[0025] Furthermore, step 5 refers to the first warning period. The newly added cumulative rainfall within the area was used as the test data to invert and trigger the warning water level. and dangerous water level The required rainfall threshold is used to obtain the initial dynamic rainfall warning index that triggers the warning water level warning within the first warning period. and initial dynamic rainfall warning indicators that trigger dangerous water level warnings The specific process is as follows:

[0026] For dangerous water levels Let the initial trial rainfall be... The current hydrological status, calculated rainfall, and water-blocking parameters at risk points are input into a distributed hydrological model and a hydrodynamic model to simulate the water level at the early warning control section. ;

[0027] like > If the calculated rainfall is too high, it indicates that the rainfall amount needs to be reduced and recalculated; if < This indicates that the calculated rainfall is too low and needs to be increased and recalculated. The bisection method is used for k iterations, and the rainfall calculated in the kth iteration is set as... Until the rainfall amounts calculated in two consecutive trials meet the following conditions:

[0028] (3)

[0029] In the formula, For iteration The trial rainfall was calculated. For iteration The trial rainfall was calculated. The allowable rainfall amount is determined based on the accuracy of rainfall monitoring, model calculation, and early warning issuance.

[0030] It will eventually converge. Designated as the first warning period Initial dynamic rainfall warning indicators that trigger dangerous water level warnings Using the same method, the initial dynamic rainfall warning indicators that trigger the warning water level warning are then obtained. .

[0031] Furthermore, the specific process for updating the dynamic rainfall warning indicators corresponding to the current warning period as described in step 6 is as follows:

[0032] First, obtain the time from the start of rainfall. Up to the current moment The data includes measured rainfall events that have occurred during this period, river level or flow monitoring data, changes in soil moisture content, and the latest blockage status at each potential risk point; then, based on the current warning period... Using the newly added cumulative rainfall within the area as the trial calculation object, the bisection method described in step 5 is used to calculate the water level that triggers the warning level. and dangerous water level Required dynamic rainfall warning indicators and During the current warning period Within that time period, the actual cumulative rainfall is obtained in real time. And compare it with dynamic rainfall warning indicators; if If, then no warning will be triggered; if If so, a warning water level alert will be triggered; if This will trigger a dangerous water level warning;

[0033] When entering the next early warning calculation time At the same time, the rainfall process that has already occurred during the current warning period, the monitoring data of river water level or flow, and the latest status of risk points are incorporated into the real-time hydrological status of the basin. The above dynamic update process is repeated, so that the rainfall warning indicators for each warning period are adjusted in real time according to the latest rainfall, hydrological conditions and water obstruction status.

[0034] The beneficial effects of this invention are: the method described in this invention solves the problem of false alarms or missed alarms caused by the static and fixed early warning indicators in the existing technology. It takes into account the water-blocking effect of water-related structures in the river channel as dynamic risk points on the flood evolution process, and makes dynamic adjustments based on real-time rainfall intensity, previous accumulated rainfall and the status of risk points, thereby realizing accurate and real-time early warning of flood risk in mountainous river channels, and providing a scientific basis for disaster prevention and mitigation.

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the method flow described in this invention;

[0037] Figure 2 A schematic diagram showing the warning and danger water levels;

[0038] Figure 3 This is a diagram illustrating the dynamic adjustment and cross-event reset of early warning indicators. Detailed Implementation

[0039] This invention discloses a method for analyzing dynamic early warning indicators of floods in mountainous rivers that takes into account potential risks and water obstruction. Figure 1 As shown, the method includes the following steps:

[0040] Step 1: Basic Data Preparation and Risk / Hazard Identification: First, determine the scope of the study area, collect basic geographical, hydrological, and river channel data for the target mountainous river basin, and obtain historical and real-time rainfall data. Determine the river control sections, including the river's starting and ending sections, the river sections where risk / hazard points are located, and other key sections to be deployed according to early warning response requirements.

[0041] Then, water-related structures along the river that may affect flood flow capacity are identified, located, and classified to obtain a set of risk points. These risk points include bridges, culverts, floodplains, dams, drop structures, water pipes, and other water-related structures whose local flow capacity may be reduced due to the accumulation of floating debris, silt, branches, or garbage.

[0042] For each risk point, establish corresponding attribute information records, including the spatial location, structural parameters, and design flow capacity of the risk point; obtain real-time blockage status information of each risk point, which can be obtained through one or more of the following methods: manual inspection records, video surveillance images, UAV images, remote sensing images, river water level monitoring data, upstream and downstream water level difference monitoring data, flow velocity monitoring data, or machine vision recognition results.

[0043] Then, based on the blockage status of the potential risk points, determine the corresponding water resistance parameters. ,in, Indicates the first One potential risk point, The value range is 0 to 1, and it can be determined based on the proportion of the blockage to the effective water passage area of ​​the building. =0 indicates that there is no blockage at the potential risk point. =1 indicates that the risk point is completely blocked, 0 < <1 indicates that the potential risk point is partially blocked to varying degrees.

[0044] A dynamic database of risk and hazard points is constructed based on their attribute information, blockage status, and corresponding water-blocking parameters. This database includes the spatial location, structural parameters, design flow capacity, current blockage status, water-blocking parameters, blockage status update time, and data source of the blockage status. When new inspection information, monitoring information, or image recognition results are obtained, the water-blocking parameters of the corresponding risk and hazard points are updated, and these updated parameters serve as the basis for dynamic correction of hydraulic parameters of water-related structures in subsequent hydrodynamic models.

[0045] Step 2: Construct a distributed hydrological model: Based on the data collected in Step 1, construct a distributed hydrological model suitable for the target mountain river basin to simulate runoff generation and confluence processes.

[0046] First, a distributed hydrological model is constructed based on the fundamental geographic data of the target mountain river basin. This model divides the basin into several hydrological response units. Specifically, based on digital elevation data and land use classification maps of the target mountain river basin, spatial units with the same slope grade and consistent land use type are grouped into the same hydrological response unit according to slope classification standards and land use type, thus completing the division of the basin's hydrological response units. Then, runoff generation and confluence processes in different areas are calculated based on real-time rainfall data, ultimately obtaining the flow processes at each control section of the river. The model is then updated based on changes in real-time rainfall, fundamental geographic data, and hydrological data, and the flow process lines at each control section are calculated in real-time. This allows for the dynamic and real-time acquisition of the flow process lines at each control section of the river.

[0047] Step 3: Constructing a hydrodynamic model: This step is used to simulate the evolution of floods in mountainous rivers based on the flow process lines of each control section of the river obtained in Step 2, combined with the river section conditions and the real-time blockage status of risk points, and to obtain the water level process lines of each control section of the river.

[0048] First, based on the dynamic database of risk points established in Step 1, bridges, culverts, flooded bridges, river-blocking structures, or other water-related structures are embedded into their corresponding river control sections, and a water-blocking degree parameter is set for the blockage degree of each risk point. Then, based on the river data obtained in Step 1, the flow processes at each control section calculated by the distributed hydrological model are used as input to the hydrodynamic model to construct a hydrodynamic model for the target river. The hydrodynamic model further calculates the propagation process of the flow in the river or reservoir to obtain the water level changes at each control section.

[0049] Furthermore, by inputting the real-time flow process lines of each river control section, the real-time water level change process of each river control section is obtained through the hydrodynamic model.

[0050] Step 4: Set warning and danger water levels along the river: This step, based on current flood control standards and historical hydrological data, sets warning and danger water levels for each control section of the river, such as... Figure 2 As shown, the water level threshold is used for subsequent flood risk assessment and dynamic rainfall early warning index inversion.

[0051] First, based on the established river channel control sections, determine the outlet water level at each control section. The outlet water level along the river channel... This refers to the critical water level at which the water begins to overflow the main channel and submerge the beaches or dikes on both banks.

[0052] Secondly, to ensure the early warning and effectiveness of the warning, at the outlet water level... Based on this, by reserving different levels of safety margin, two levels of early warning water levels are set along the route, namely the warning water level and the danger water level.

[0053] Warning water level A large safety margin should be reserved below the outlet water level. ,Right now:

[0054] (1)

[0055] When the water level reaches the warning level This indicates that the river's water situation is becoming tense, requiring the activation of early warning response measures such as preliminary monitoring, public alerts, and flood prevention preparations.

[0056] Dangerous water level : Reserve a small safety margin below the outlet water level. ,Right now:

[0057] (2)

[0058] When the water level approaches or reaches this value, it means that the flood is about to overflow or has already posed a serious threat to water-related buildings and the banks of the river. The risk of flooding disasters has increased significantly, and a high-level emergency response, such as emergency rescue and personnel evacuation, must be initiated immediately.

[0059] in, and The value should be determined comprehensively based on factors such as historical flood data, river cross-sectional morphology, surrounding population density, and flood control capacity. .

[0060] When the simulated water level output in step 3 reaches or exceeds the corresponding warning water level, it is determined that the cross-section has reached the corresponding warning condition.

[0061] Step 5: Determining Initial Early Warning Indicators: When a rainfall event occurs in the target watershed, the start time of that rainfall event is defined as... and will Until the next warning time The period between these two points will be used as the first warning period. Each warning time is determined on a rolling basis according to a preset time interval, which is comprehensively set based on the confluence time of the target watershed, the frequency of monitoring data updates, the frequency of meteorological forecast updates, and the lead time for warning response.

[0062] exist At any given time, obtain the current hydrological status parameters of the target mountain river basin; simultaneously obtain the current water obstruction parameters of each risk and hazard point. Based on this, the effective water passage area and hydraulic parameters of water-related structures in the hydrodynamic model are corrected.

[0063] With the first warning period The newly added cumulative rainfall within the area was used as the test data to invert and trigger the warning water level. and dangerous water level Required rainfall threshold. At dangerous water levels. For example, let the initial trial rainfall be... The current hydrological status, calculated rainfall, and water-blocking parameters at risk points are input into a distributed hydrological model and a hydrodynamic model to simulate the water level at the early warning control section. .

[0064] like > This indicates that the calculated rainfall is too high, sufficient to trigger floods exceeding the danger level, and the rainfall needs to be reduced and recalculated; if < If the calculated rainfall is too low, it indicates that the rainfall is insufficient to trigger a flood exceeding the danger level, and the rainfall needs to be increased and recalculated. A bisection method is used for k iterations, with the k-th calculated rainfall being set as... Until the rainfall amounts calculated in two consecutive trials meet the following conditions:

[0065] (3)

[0066] In the formula, For iteration The trial rainfall was calculated. For iteration The trial rainfall was calculated. The allowable error rainfall is determined based on the accuracy of rainfall monitoring, model calculation, and early warning issuance.

[0067] It will eventually converge. Designated as the first warning period Initial dynamic rainfall warning indicators that trigger dangerous water level warnings Using the same method, the initial dynamic rainfall warning indicators that trigger the warning water level warning can be obtained. .

[0068] During the first warning period Within that time period, the actual cumulative rainfall is obtained in real time. And compare it with the initial dynamic rainfall warning indicators. If If, then no warning will be triggered; if If so, a warning water level alert will be triggered; if If this occurs, a dangerous water level warning will be triggered.

[0069] Step 6: Dynamically adjust early warning indicators in real time and reset them across events: During the duration of a rainfall event, at a certain moment... hour( ),Will Until the next warning calculation time The period between these points will be used as the current warning period. And update the dynamic rainfall warning indicators corresponding to that period.

[0070] First, obtain the time from the start of rainfall. Up to the current moment The data includes actual rainfall events that have occurred, river level or flow monitoring data, changes in soil moisture content, and the latest blockage status of various risk points. The rainfall data is used only to update the current hydrological information.

[0071] Then, based on the current warning period Using the newly added cumulative rainfall within the area as the trial calculation object, the bisection method described in step 5 is used to calculate the water level that triggers the warning level. and dangerous water level Required dynamic rainfall warning indicators and During the current warning period Within that time period, the actual cumulative rainfall is obtained in real time. And compare it with dynamic rainfall warning indicators. If If, then no warning will be triggered; if If so, a warning water level alert will be triggered; if If this occurs, a dangerous water level warning will be triggered.

[0072] When entering the next early warning calculation time At that time, the rainfall events that have occurred within the current warning period, river water level or flow monitoring data, and the latest status of risk points are incorporated into the real-time hydrological status of the basin. This dynamic update process is repeated, ensuring that the rainfall warning indicators for each warning period are adjusted in real time based on the latest rainfall, hydrological conditions, and water obstruction status. Figure 3 As shown.

[0073] When the system detects no rainfall for a predetermined number of consecutive warning periods within the watershed, it determines that the rainfall event has ended, terminates the dynamic warning indicator update process for this rainfall event, and archives the rainfall process, hydrological status, risk hazard point status, warning indicators, and warning results for this event. The predetermined number is determined based on historical rainfall event monitoring data to eliminate interference from short periods of no rainfall during the rainfall process in determining the event's end.

[0074] When a new rainfall event occurs, the start time of the new rainfall event is used again as the reference time. The initial hydrological status of the watershed and the water-blocking status of risk points are re-acquired, and the initial and subsequent dynamic rainfall warning indicators are recalculated according to step 5 and this step. Therefore, this method can form a closed-loop early warning process within each rainfall event, encompassing real-time monitoring, status updating, indicator inversion, early warning judgment, and rolling correction. This allows the rainfall warning indicators corresponding to warning and danger levels to dynamically change with the watershed's runoff conditions and the water-blocking status of risk points, thereby achieving dynamic flood early warning for mountain rivers that considers the water-blocking effect of risk points.

[0075] Finally, it should be noted that the above description is only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred arrangement, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for analyzing dynamic flood early warning indicators in mountainous rivers considering potential water obstruction risks, characterized in that, The method includes the following steps: Step 1: Basic Data Preparation and Risk / Hazard Point Identification: Collect basic geographical, hydrological, and river channel data, as well as historical and real-time rainfall data, for the target mountainous river basin; determine the river control sections; identify, locate, and classify water-related structures along the river that affect flood flow capacity, obtaining a set of risk / hazard points; for each risk / hazard point, establish corresponding attribute information records, obtain real-time blockage status information for each risk / hazard point, and then determine the corresponding water obstruction degree parameters based on the blockage status of the risk / hazard points; construct a dynamic database of risk / hazard points based on the risk / hazard point attribute information, blockage status, and corresponding water obstruction degree parameters. Step 2: Construct a distributed hydrological model: Based on the collected basic geographic data of the target mountain river basin, construct a distributed hydrological model; divide the target mountain river basin into several hydrological response units, and calculate the runoff generation and confluence processes in different areas based on real-time rainfall data to obtain the flow process of each control section of the river; then update the model based on changes in real-time rainfall processes, basic geographic data, and hydrological data, and calculate the flow process lines of each control section in real time; Step 3: Construct a hydrodynamic model: Based on the constructed dynamic database of risk points, embed water-related structures into their corresponding river control sections, and set water-blocking parameters for the blockage degree of each risk point; based on the acquired river data, use the flow process of each control section calculated by the distributed hydrological model as the input of the hydrodynamic model to construct the hydrodynamic model of the target river, and obtain the real-time water level change process of each river control section through the hydrodynamic model; Step 4: Set warning and danger water levels along the river: First, determine the outlet water level of the control section based on the established river control section. Then at the outlet water level Based on this, by reserving different levels of safety margin, two levels of early warning water levels are set along the route: warning water level and danger water level. Warning water level : Reserve a safety margin downwards from the outlet water level. ,Right now: （1） Dangerous water level : Reserve a safety margin downwards from the outlet water level. ,Right now: （2） in, and The value is determined comprehensively based on factors such as historical flood data, river cross-sectional morphology, surrounding population density, and flood control capacity. ; Step 5: Determining Initial Early Warning Indicators: When a rainfall event occurs in the target watershed, the start time of that rainfall event is defined as... and will Until the next warning time The period between these two points will be used as the first warning period. The warning times are determined on a rolling basis according to preset time intervals; the first warning period is used as the starting point. The newly added cumulative rainfall within the area was used as the test data to invert and trigger the warning water level. and dangerous water level The required rainfall threshold is used to obtain the initial dynamic rainfall warning index that triggers the warning water level warning within the first warning period. and initial dynamic rainfall warning indicators that trigger dangerous water level warnings During the first warning period Within that time period, the actual cumulative rainfall is obtained in real time. And compare it with the initial dynamic rainfall warning indicators, if If, then no warning will be triggered; if If so, a warning water level alert will be triggered; if This will trigger a dangerous water level warning; Step 6: Dynamically adjust early warning indicators in real time and reset them across events: During the duration of a rainfall event, at a certain moment... hour( ),Will Until the next warning calculation time The period between these points will be used as the current warning period. The system updates the dynamic rainfall warning indicators corresponding to the current warning period. When the system detects no rainfall for a consecutive preset number of warning periods within the basin, it determines that the rainfall event has ended, terminates the dynamic warning indicator update process for this rainfall event, and archives the rainfall process, hydrological status, risk hazard point status, warning indicators, and warning results for this event. When a new rainfall event occurs, the start time of the new rainfall event is used as the starting point. The initial hydrological status of the watershed and the water-blocking status of potential risk points were re-acquired, and the initial and subsequent dynamic rainfall warning indicators were recalculated.

2. The method for analyzing dynamic flood early warning indicators in mountainous rivers considering potential water obstruction risks, as described in claim 1, is characterized in that... The river control sections mentioned in step 1 include the river starting and ending sections, the river sections where risk and hidden danger points are located, and the sections that need to be deployed according to the early warning response. The risk points include bridges, culverts, flooded bridges, dams, drop structures, water pipes, and other water-related structures whose local flow capacity is reduced due to the accumulation of floating debris, silt, branches, or garbage. The attribute information record includes the spatial location, structural parameters, and design current-carrying capacity of the risk and potential hazard points; The blockage status information is obtained through one or more of the following methods: manual inspection records, video surveillance images, drone images, remote sensing images, river water level monitoring data, upstream and downstream water level difference monitoring data, flow velocity monitoring data, or machine vision recognition results. The value range of the water resistance parameter is 0 to 1. 0 indicates that there is no blockage at the risk point, 1 indicates that the risk point is completely blocked, and values ​​between 0 and 1 indicate that the risk point is partially blocked to varying degrees. The dynamic database of risk and hazard points includes the spatial location, structural parameters, design flow capacity, current blockage status, water resistance parameters, blockage status update time, and blockage status data source of the risk and hazard points.

3. The method for analyzing dynamic flood early warning indicators in mountainous rivers considering potential water obstruction risks, as described in claim 1, is characterized in that... The specific process of dividing the target mountain river basin into several hydrological response units as described in step 2 is as follows: Based on the digital elevation data and land use classification map of the target mountain river basin, according to the slope classification standard and land use type, spatial units with the same slope level and consistent land use type are divided into the same hydrological response unit, thereby completing the division of the watershed hydrological response units.

4. The method for analyzing dynamic early warning indicators of floods in mountainous rivers considering potential water obstruction risks, as described in claim 1, is characterized in that... The preset time interval mentioned in step 5 is set comprehensively based on the target watershed confluence time, monitoring data update frequency, meteorological forecast update frequency, and early warning response lead time.

5. The method for analyzing dynamic early warning indicators of floods in mountainous rivers considering potential water obstruction risks, as described in claim 1, is characterized in that... Step 5 refers to the first warning period The newly added cumulative rainfall within the area was used as the test data to invert and trigger the warning water level. and dangerous water level The required rainfall threshold is used to obtain the initial dynamic rainfall warning index that triggers the warning water level warning within the first warning period. and initial dynamic rainfall warning indicators that trigger dangerous water level warnings The specific process is as follows: For dangerous water levels Let the initial trial rainfall be... The current hydrological status, calculated rainfall, and water-blocking parameters at risk points are input into a distributed hydrological model and a hydrodynamic model to simulate the water level at the early warning control section. ; like > If the calculated rainfall is too high, it indicates that the rainfall amount needs to be reduced and recalculated; if < This indicates that the calculated rainfall is too low and needs to be increased and recalculated. The bisection method is used for k iterations, and the rainfall calculated in the kth iteration is set as... Until the rainfall amounts calculated in two consecutive trials meet the following conditions: （3） In the formula, For iteration The trial rainfall was calculated. For iteration The trial rainfall was calculated. The allowable rainfall amount is determined based on the accuracy of rainfall monitoring, model calculation, and early warning issuance. It will eventually converge. Designated as the first warning period Initial dynamic rainfall warning indicators that trigger dangerous water level warnings Using the same method, the initial dynamic rainfall warning indicators that trigger the warning water level warning are then obtained. .

6. The method for analyzing dynamic flood early warning indicators in mountainous rivers considering potential water obstruction risks, as described in claim 5, is characterized in that... The specific process for updating the dynamic rainfall warning indicators corresponding to the current warning period in step 6 is as follows: First, obtain the time from the start of rainfall. Up to the current moment The data includes measured rainfall events that have occurred during this period, river level or flow monitoring data, changes in soil moisture content, and the latest blockage status at each potential risk point; then, based on the current warning period... Using the newly added cumulative rainfall within the area as the trial calculation object, the bisection method described in step 5 is used to calculate the water level that triggers the warning level. and dangerous water level Required dynamic rainfall warning indicators and During the current warning period Within that time period, the actual cumulative rainfall is obtained in real time. And compare it with dynamic rainfall warning indicators; if If, then no warning will be triggered; if If so, a warning water level alert will be triggered; if This will trigger a dangerous water level warning; When entering the next early warning calculation time At the same time, the rainfall process that has already occurred during the current warning period, the monitoring data of river water level or flow, and the latest status of risk points are incorporated into the real-time hydrological status of the basin. The above dynamic update process is repeated, so that the rainfall warning indicators for each warning period are adjusted in real time according to the latest rainfall, hydrological conditions and water obstruction status.

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