Rapid evaluation and early warning method for stability of downstream dam bank of Yellow River

Abstract

The invention discloses a Yellow River downstream dam stability rapid evaluation and early warning method. The method comprises the following steps: S1, unmanned aerial vehicle positioning and river channel parameter identification; s2, analyzing a river surface flow field; s3, inverting and verifying the water depth of the river channel; and S4, dam bank section analysis and stability judgment. According to the method, GPS data and a river channel surface video are acquired through an unmanned aerial vehicle, a flow field is analyzed by using a PIV technology, the water depth is inverted in combination with an innovative calculation formula, a dam bank section is intercepted based on an underwater topographic map, the stability of the dam bank is judged, and early warning is issued. The method is suitable for the field of Yellow River downstream dam bank stability analysis, can efficiently and accurately evaluate the dam bank stability, and has the advantages of scientificity and practicability.

Description

Technical Field

[0001] This invention belongs to the field of water conservancy engineering technology, specifically relating to a rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River. Background Technology

[0002] Due to its complex channel morphology and flow conditions, the lower reaches of the Yellow River face severe challenges to the stability of dam banks. Traditional methods for monitoring dam bank stability mainly rely on manual measurement and fixed-point monitoring, which suffer from low efficiency, high cost, and limited coverage. Currently, there is a lack of intelligent systems capable of rapidly, comprehensively, and accurately acquiring underwater topography and flow field characteristics of the river channel and automatically analyzing dam bank stability. With the development of unmanned aerial vehicle (UAV) technology and particle image velocimetry (PIV) technology, new technical means have been provided for dam bank stability analysis. Summary of the Invention

[0003] To address the aforementioned technical problems in existing technologies, this invention provides a method for analyzing and providing early warning of dam bank stability in the lower reaches of the Yellow River based on UAV and PIV technology. Through steps such as UAV positioning, river parameter identification, flow field analysis, water depth inversion, and dam bank cross-section analysis, this method achieves efficient and accurate assessment and real-time early warning of dam bank stability.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River, comprising the following steps:

[0005] S1. UAV positioning and river parameter identification;

[0006] S2. Analysis of the surface flow field in the river channel;

[0007] S3. River depth inversion and verification;

[0008] S4. Dam bank cross-section analysis and stability assessment.

[0009] Step S1 specifically includes: using a drone to fly over the target river area, acquiring GPS data, and manually marking the ground to obtain the actual length of an object within the target area.

[0010] In step S1, the parameters of the river channel are automatically identified using image recognition technology: the river channel roughness coefficient n and the water surface gradient j. The topographic and flow characteristics of the river channel are extracted using high-definition images taken by drones.

[0011] Step S2 specifically includes: using a drone to collect orthophotos of the river surface to ensure that the video covers the entire river area; applying particle image velocimetry (PIV) technology to analyze the flow field on the river surface, and calculating the velocity distribution on the river surface by analyzing the motion trajectory of particles in the video.

[0012] Step S3 specifically includes: based on the typical characteristics of the lower Yellow River channel, using preset channel roughness coefficient n and channel slope J parameter values, based on the identified n and j parameters, using calculation formulas to invert the channel water depth, and verifying it through measured water depth points to ensure the inversion accuracy. If the accuracy is reasonable, then interpolate missing values ​​and draw an underwater topographic map.

[0013] The calculation formula is as follows:

[0014]

[0015] In the formula, V is the average flow velocity across the cross section. sf denoted as surface velocity; m is the velocity distribution index, ranging from 1 / 5 to 1 / 8, usually taken as 1 / 6; n is the channel roughness coefficient, between 0.01 and 0.04 in the lower reaches of the Yellow River, usually taken as 0.025 to 0.035; h is the water depth; J is the channel slope, between 1.9 / 10000 and 1 / 10000 below Huayuankou. For a certain section of the river, the variation is usually very small and a constant value can be taken. For the meandering section (from Huayuankou to Gaocun), 1.9 / 10000 is taken; for the transition section (from Gaocun to Aishan), 1.23 / 10000 is taken; and for the meandering section (from Luokou to Lijin), 1 / 10000 is taken.

[0016]

[0017] The roughness coefficient of the river channel, n, is approximately taken as n = 0.03.

[0018]

[0019] Substituting the slope J for each river section, we can obtain

[0020] Wandering Section:

[0021] Transition section:

[0022] Curved section:

[0023] For the lower reaches of the Yellow River as a whole,

[0024] When the calculated value of the cross-sectional water depth h deviates significantly from the measured water depth, it indicates that the roughness coefficient is not appropriate and the channel roughness coefficient n can be adjusted.

[0025] The water depth was measured at several key locations in the river channel as verification points; the accuracy of the inversion was verified by comparing the inverted water depth with the measured water depth.

[0026] If the verification accuracy is reasonable (the error is within the preset threshold), the missing water depth values ​​are interpolated using the inversion model to draw a complete underwater topographic map.

[0027] Step S4 specifically includes: based on the underwater topographic map, extracting the dam bank cross-section. Calculating the depth-to-length ratio (D / L) based on the maximum depth of the dam bank cross-section and the distance from the maximum depth to the dam head;

[0028] Based on the (D / L) ratio and the preset stability criteria, the stability of the dam bank is analyzed; when (D / L>1.0), the stability of the dam bank is poor and an early warning needs to be issued.

[0029] If the stability of the dam bank falls below a preset threshold, the system will automatically issue an early warning and notify relevant personnel to take measures.

[0030] By employing the above technical solution, this invention provides an efficient and accurate assessment and early warning method for the stability analysis of dam banks in the lower reaches of the Yellow River through the combination of unmanned aerial vehicles (UAVs) and PIV technology. Compared with traditional methods, this invention has the following advantages:

[0031] 1. High efficiency: By using drones and PIV technology, river data can be acquired quickly, reducing the workload of manual measurement.

[0032] 2. High precision: Combining innovative calculation formulas with verification by measured data ensures the accuracy of water depth inversion.

[0033] 3. Real-time capability: It can monitor the stability of the dam bank in real time, issue early warning information in a timely manner, and ensure the safety of the dam bank in the lower reaches of the Yellow River.

[0034] 4. Comprehensiveness: By using UAV orthophotos and PIV technology, the river flow field and water depth distribution are comprehensively analyzed, providing comprehensive data support for dam bank stability analysis.

[0035] In summary, this invention employs steps including UAV positioning and river parameter identification, river surface flow field analysis, river depth inversion and verification, and dam bank cross-section analysis and stability assessment. This method acquires GPS data and river surface video using UAVs, analyzes the flow field using PIV technology, inverts water depth using an innovative calculation formula, and extracts dam bank cross-sections based on underwater topographic maps to assess dam bank stability and issue early warnings. This invention is applicable to the field of dam bank stability analysis in the lower reaches of the Yellow River, enabling efficient and accurate assessment of dam bank stability, and possesses both scientific and practical advantages. Attached Figure Description

[0036] Figure 1 This is a flowchart of the steps of the present invention;

[0037] Figure 2 Velocity diagram of cross section 26 of the Yellow River Madu dangerous section;

[0038] Figure 3 This is a cross-sectional water depth diagram of the Madu dangerous section of the Yellow River, section 26. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] like Figure 1 As shown, the rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River includes the following steps:

[0041] S1. UAV positioning and river parameter identification;

[0042] S2. Analysis of the surface flow field in the river channel;

[0043] S3. River depth inversion and verification;

[0044] S4. Dam bank cross-section analysis and stability assessment.

[0045] Step S1 specifically includes: using a drone to fly over the target river area, acquiring GPS data, and manually marking the ground to obtain the actual length of an object within the target area.

[0046] In step S1, the parameters of the river channel are automatically identified using image recognition technology: the river channel roughness coefficient n and the water surface gradient j. The topographic and flow characteristics of the river channel are extracted using high-definition images taken by drones.

[0047] Step S2 specifically includes: using a drone to collect orthophotos of the river surface to ensure that the video covers the entire river area; applying particle image velocimetry (PIV) technology to analyze the flow field on the river surface, and calculating the velocity distribution on the river surface by analyzing the motion trajectory of particles in the video.

[0048] Step S3 specifically includes: based on the typical characteristics of the lower Yellow River channel, using preset channel roughness coefficient n and channel slope J parameter values, based on the identified n and j parameters, using calculation formulas to invert the channel water depth, and verifying it through measured water depth points to ensure the inversion accuracy. If the accuracy is reasonable, then interpolate missing values ​​and draw an underwater topographic map.

[0049] The calculation formula is as follows:

[0050]

[0051] In the formula, V is the average flow velocity across the cross section. sfdenoted as surface velocity; m is the velocity distribution index, ranging from 1 / 5 to 1 / 8, usually taken as 1 / 6; n is the channel roughness coefficient, between 0.01 and 0.04 in the lower reaches of the Yellow River, usually taken as 0.025 to 0.035; h is the water depth; J is the channel slope, between 1.9 / 10000 and 1 / 10000 below Huayuankou. For a certain section of the river, the variation is usually very small and a constant value can be taken. For the meandering section (from Huayuankou to Gaocun), 1.9 / 10000 is taken; for the transition section (from Gaocun to Aishan), 1.23 / 10000 is taken; and for the meandering section (from Luokou to Lijin), 1 / 10000 is taken.

[0052]

[0053] The roughness coefficient of the river channel, n, is approximately taken as n = 0.03.

[0054]

[0055] Substituting the slope J for each river section, we can obtain

[0056] Wandering Section:

[0057] Transition section:

[0058] Curved section:

[0059] For the lower reaches of the Yellow River as a whole,

[0060] When the calculated value of the cross-sectional water depth h deviates significantly from the measured water depth, it indicates that the roughness coefficient is not appropriate and the channel roughness coefficient n can be adjusted.

[0061] The water depth was measured at several key locations in the river channel as verification points; the accuracy of the inversion was verified by comparing the inverted water depth with the measured water depth.

[0062] If the verification accuracy is reasonable (error within a preset threshold), then the missing water depth values ​​are interpolated using the inversion model to draw a complete underwater topographic map. For example... Figure 2 and 3 As shown.

[0063] Step S4 specifically includes: based on the underwater topographic map, extracting the dam bank cross-section. Calculating the depth-to-length ratio (D / L) based on the maximum depth of the dam bank cross-section and the distance from the maximum depth to the dam head;

[0064] Based on the (D / L) ratio and the preset stability criteria, the stability of the dam bank is analyzed; when (D / L>1.0), the stability of the dam bank is poor and an early warning needs to be issued.

[0065] If the stability of the dam bank falls below a preset threshold, the system will automatically issue an early warning and notify relevant personnel to take measures.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River, characterized by: Includes the following steps: S1. UAV positioning and river parameter identification; S2. Analysis of the surface flow field in the river channel; S3. River depth inversion and verification; S4. Dam bank cross-section analysis and stability assessment.

2. The rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River according to claim 1, characterized in that: Step S1 specifically includes: using a drone to fly over the target river area, acquiring GPS data, and manually marking the ground to obtain the actual length of an object within the target area.

3. The rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River according to claim 2, characterized in that: In step S1, the parameters of the river channel are automatically identified using image recognition technology: the river channel roughness coefficient n and the water surface gradient j. The topographic and flow characteristics of the river channel are extracted using high-definition images taken by drones.

4. The rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River according to claim 1, characterized in that: Step S2 specifically includes: using a drone to collect orthophotos of the river surface to ensure that the video covers the entire river area; applying particle image velocimetry (PIV) technology to analyze the flow field on the river surface, and calculating the velocity distribution on the river surface by analyzing the motion trajectory of particles in the video.

5. The rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River according to claim 1, characterized in that: Step S3 specifically includes: based on the typical characteristics of the lower Yellow River channel, using preset channel roughness coefficient n and channel slope J parameter values, based on the identified n and j parameters, using calculation formulas to invert the channel water depth, and verifying it through measured water depth points to ensure the inversion accuracy. If the accuracy is reasonable, then interpolate missing values ​​and draw an underwater topographic map.

6. The rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River according to claim 5, characterized in that: The calculation formula is as follows: In the formula, V is the average flow velocity across the cross section. sf denoted as surface velocity; m is the velocity distribution index, ranging from 1 / 5 to 1 / 8, usually taken as 1 / 6; n is the channel roughness coefficient, between 0.01 and 0.04 in the lower reaches of the Yellow River, usually taken as 0.025 to 0.035; h is the water depth; J is the channel slope, between 1.9 / 10000 and 1 / 10000 below Huayuankou. For a certain section of the river, the variation is usually very small and a constant value can be taken. For the meandering section (from Huayuankou to Gaocun), 1.9 / 10000 is taken; for the transition section (from Gaocun to Aishan), 1.23 / 10000 is taken; and for the meandering section (from Luokou to Lijin), 1 / 10000 is taken. The roughness coefficient of the river channel, n, is approximately taken as n = 0.

03. Substituting the slope J for each river section, we can obtain Wandering segment: h = 2.548V sf 3 / 2 (4-1) Transition section: h = 3.530V sf 3 / 2 (4-2) Bending section: h = 4.123V sf 3 / 2 (4-3) For the lower reaches of the Yellow River as a whole, h = (2~5)V sf 3 / 2 (5) When the calculated value of the cross-sectional water depth h deviates significantly from the measured water depth, it indicates that the roughness coefficient is not appropriate and the channel roughness coefficient n can be adjusted. The water depth was measured at several key locations in the river channel as verification points; the accuracy of the inversion was verified by comparing the inverted water depth with the measured water depth. If the verification accuracy is reasonable (the error is within the preset threshold), the missing water depth values ​​are interpolated using the inversion model to draw a complete underwater topographic map.

7. The rapid assessment and early warning method for the stability of dam banks in the lower reaches of the Yellow River according to claim 1, characterized in that: Step S4 specifically includes: based on the underwater topographic map, extracting the dam bank cross-section. Calculating the depth-to-length ratio (D / L) based on the maximum depth of the dam bank cross-section and the distance from the maximum depth to the dam head; Based on the (D / L) ratio and the preset stability criteria, the stability of the dam bank is analyzed; when (D / L>1.0), the stability of the dam bank is poor and an early warning needs to be issued. If the stability of the dam bank falls below a preset threshold, the system will automatically issue an early warning and notify relevant personnel to take measures.

Images