CN-121997616-A - H-ADCP installation position optimization method based on section traversal scanning

CN121997616ACN 121997616 ACN121997616 ACN 121997616ACN-121997616-A

Abstract

The invention discloses a section traversal scanning-based H-ADCP installation position optimization method which comprises the steps of 1) selecting a section to be installed, measuring flow by using a navigation type ADCP under different water level or flow rate level water conditions, synchronously observing water level, calculating average flow rate of each measured section, 2) introducing flow rate data into a section terrain model, dividing candidate units, traversing a representative flow rate, generating a flow field and a standard differential layout, and 3) screening by combining site conditions such as flow rate standard deviation, random uncertainty and correlation coefficient multidimensional quantitative evaluation, terrain suitability, interference degree and the like, and comprehensively analyzing and determining a final position. The method has high site selection efficiency, is suitable for H-ADCP installation site selection in water areas such as rivers, lakes and the like, and is beneficial to improving the on-line monitoring precision of river flow.

Inventors

He Changfen
Miao Chuanshan
LIAO JINHUA
YANG KUNYU
YANG JIAN
HUANG YIXIN
LIU YU
CHEN YUANLI
ZHOU JIANCHAO
ZHENG WEI
Deng Rongliang
FAN HUI

Assignees

珠江水文水资源勘测中心

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (10)

1. The H-ADCP installation position optimization method based on the section traversal scanning is characterized by comprising the following steps of: Step S1, measuring section flow field data and calculating section average flow velocity, wherein the method specifically comprises the following steps: S1.1, selecting a section to be installed, meeting the flow monitoring requirement, in a target river channel, acquiring terrain data of the section of the river channel by adopting terrain measuring equipment, and establishing a section terrain model; S1.2, dividing water level levels or flow rate levels based on historical water level and flow rate data of a target river channel, carrying out flow measurement on the section to be installed by using a sailing ADCP under each water level or flow rate level, and synchronously recording real-time water level data of each measurement time through water level observation equipment to obtain sailing section flow rate data of at least 30 measurement times; Step S1.3, calculating a large cross-sectional area corresponding to the measured flow rate/the measured time according to the formula of the average flow rate of the cross section = the large cross-sectional area corresponding to the measured flow rate/the measured time according to the large cross-sectional area corresponding to the measured water level of the flow data measured by the navigation ADCP for each measured time, and obtaining the average flow rate of the cross section of each measured time; step S2, H-ADCP installation position traversal simulation analysis, which specifically comprises the following steps: s2.1, determining technical parameters of H-ADCP to be selected, wherein the technical parameters comprise a measurement range, a measurement angle and a water level elevation range to be installed; S2.2, importing the flow velocity data of each measured navigation profile obtained in the step S1.2 into the profile terrain model established in the step S1.1, and identifying the spatial distribution position of the flow velocity data of each section unit in the section by combining the real-time water level of each measured time; S2.3, dividing candidate position units according to preset intervals, adopting a traversing scanning mode to extract the navigation profile flow velocity data of each candidate position unit in all measurement times to form a profile flow field distribution map; The step S3 is preferable in mounting position, and specifically comprises the following steps: S3.1, calculating random uncertainty and correlation coefficients of the representative flow rate of each candidate position unit and the average flow rate of the corresponding measured secondary section; S3.2, screening candidate positions meeting a preset precision threshold based on the random uncertainty and the correlation coefficient; and S3.3, selecting a position with the optimal flow speed representativeness from candidate positions meeting the accuracy threshold by combining with the field actual layout conditions, and taking the position as a final installation position of the H-ADCP.
2. The method of claim 1, wherein in the step S1.2, dividing the water level or the flow rate level based on the historical hydrological data of the target river channel is specifically implemented by analyzing the flow rate change of the station and the corresponding flow rate change based on the historical hydrological data of the section of the target river channel, distinguishing different water level levels and flow rate levels, performing comparison measurement, wherein the total number of the grades is not less than 15, each water level and flow rate level is respectively subjected to 3-5 comparison measurements, and the condition is insufficient for at least 2 times; the specific parameters for carrying out flow measurement by the sailing ADCP are set according to the section condition, the possible maximum flow rate, the ship measurement power condition and the test requirement.
3. The method according to claim 2, wherein in the step S2.1, the determined technical parameters of the H-ADCP are specifically: 1) The measuring range is determined according to the width of the section to be installed, and 60% -90% of the width of the coverage section of the measuring range is met; 2) The measuring angle is the included angle between the H-ADCP probe and the water flow direction, and the value range is 80-100 degrees; 3) And determining the elevation range of the water level to be installed based on water level data of the section to be installed for approximately 5 years, and covering the section by more than 75% of the occurrence frequency of the water level.
4. The method of claim 3, wherein in the step S2.3, the predetermined interval divides the candidate location units in such a way that the interval between the candidate location units is not more than 1/2 of the H-ADCP beam resolution.
5. The method according to claim 4, wherein in the step S2.3, a specific formula for calculating the standard deviation of the flow rate of each candidate position element is: ; wherein S j is the standard deviation of the flow rate of the jth candidate position unit, n is the number of measurements, v ji is the representative flow rate of the jth candidate position unit at the ith measurement, The average value of the flow rate is represented for the candidate position element multiple times.
6. The method according to claim 5, wherein in the step S3.1, the calculating of the random uncertainty is implemented by using a class A uncertainty evaluation method, and the calculation formula is: ; Wherein U j is the standard uncertainty of the jth candidate position unit, S j is the standard deviation of the flow velocity of the jth candidate position unit, n is the number of measurements, k is the inclusion factor, and U j is the extended uncertainty of the jth candidate position unit, i.e. the final random uncertainty.
7. The method according to claim 6, wherein in the step S3.1, the correlation coefficient is calculated by using a pearson product moment correlation coefficient formula, and calculating a linear correlation coefficient r j between the representative flow velocity sequence of the candidate position unit and the section average flow velocity sequence of the corresponding measurement times, where the formula is: ; wherein r j is the correlation coefficient of the jth candidate position unit, the value range is [ -1,1], For the section average flow rate of the ith measurement, The average flow velocity is the average value of the multi-time section.
8. The method of claim 7, wherein in the step S3.2, the preset precision threshold is a random uncertainty U j % or less, a correlation coefficient r j is 0.9 or more, and candidate positions satisfying the two thresholds are positions satisfying the precision requirement.
9. The method according to claim 8, wherein in the step S3.3, the evaluation index of the on-site actual layout condition for the section of the medium-small scale river channel comprises: 1) Terrain suitability, namely the gradient of a river bed at the installation position is less than or equal to 15 degrees, and no outstanding reef or siltation pit is formed; 2) The interference degree of the water flow is that the flow velocity variation coefficient of the position is less than or equal to 10 percent, and the interference source such as return flow from a curve is more than or equal to 3 times of the section width; 3) The construction and operation convenience is that the horizontal distance between the installation position and the shore is less than or equal to 5m, the water depth is more than or equal to 1.0m, and the periphery is free from high-voltage circuits or strong electromagnetic interference sources; the evaluation indexes of the on-site actual layout conditions aiming at the ultra-wide multi-pier river cross section comprise: 1) The terrain suitability is that the transverse gradient of the river bed is less than or equal to 5 percent, the reef with the protruding height being more than 0.8m and the siltation pit with the depth being more than 1.0m are avoided, and the bearing capacity of the river bed in the installation area is more than or equal to 50kN/m < 2 >; 2) The flow interference degree is that the flow velocity variation coefficient is less than or equal to 10 percent, the distance from an interference source is more than or equal to 1 time of the distance between adjacent piers, and the H-ADCP beam angle avoids the ultrasonic reflection area of the piers; 3) The construction and operation convenience is that the installation platform anchoring system meets the requirement of impact load of water flow in 5 years, the water depth is 1.5m-5m, the data transmission signal intensity is more than or equal to-85 dBm, and the connection time with a shoreside operation and maintenance base is less than or equal to 30 minutes.
10. The method according to claim 9, wherein the step S3 further comprises a step S3.4 of verifying the installation position, wherein H-ADCP is temporarily distributed at the optimal final installation position for 72H continuous monitoring, 3 times of comparison measurement are synchronously performed by using the navigation ADCP, if the relative error of the flow rate of the comparison measurement is less than or equal to +/-3%, the position is confirmed to be the final installation position, if the relative error exceeds +/-3%, the step S2 is returned to readjust the interval of the candidate position units, and traversal scanning and optimization are performed again.

Description

H-ADCP installation position optimization method based on section traversal scanning Technical Field The invention belongs to the technical field of hydrologic monitoring, and particularly relates to an H-ADCP installation position optimization method based on section traversal scanning. Background Acoustic doppler flowmeters (Acoustic Doppler Current Profiler, ADCP) are currently the most effective instruments for measuring flow profiles, and in recent years, the use of horizontal acoustic doppler flowmeters H-ADCP in hydrographic tests in rivers, lakes, etc. has also matured. The working principle of the H-ADCP is that a Doppler flow velocity measurement sensor probe is installed at a certain water depth at the shore for use, so that an acoustic sensor on the probe is positioned on the same plane, and an ultrasonic sensor emits towards the shore at a certain angle. The ultrasonic wave is reflected by suspended matters in water, partial sound wave is reflected to the transmitting end and is received by the acoustic Doppler flow velocity measuring sensor, the frequency of the reflected sound wave changes along with the flow velocity, and the two-dimensional vector flow velocity of each point on a certain section of each layer of water flow can be calculated according to the frequency. In order to realize automatic and real-time flow measurement, the river flow on-line monitoring mainly adopts a method for indirectly measuring the average flow velocity of a section, namely an index flow velocity method. The index flow rate method is to establish a correlation between an index flow rate (i.e. H-ADCP measured flow rate) and a section average flow rate, also called a correlation analysis method or regression method, by measuring the section average flow rate by a traditional flow rate meter or a walking ADCP and then measuring a certain layer flow rate (i.e. index flow rate) of a river by the H-ADCP, thereby establishing a correlation between the two flow rates. In order to reduce flow test errors, the cross-sectional area of water passing is actually measured according to the cross-sectional water level of the basic water gauge, and the flow of each period can be calculated by the flow velocity and the area. Therefore, the selection of the H-ADCP installation position is critical to the on-line monitoring accuracy of river flow. At present, in actual work, the H-ADCP installation position is determined by combining manual test experience according to the on-site river channel condition, however, the method is too dependent on manual experience, lacks data support, is difficult to select the most suitable installation position according to the fact that site selection is not standardized, site selection quality of different personnel and sections is good, once the selected position is not good, the test precision is greatly affected, the precision requirement of relevant specifications is not met, and the continuity and consistency of hydrologic data are negatively affected. The installation position needs to be reselected, and great economic loss is caused to a constructor. Disclosure of Invention The invention aims to overcome the defects that H-ADCP installation site selection in the prior art depends on manual experience, lacks quantization standard, has insufficient data support, is difficult to ensure monitoring precision and has high construction cost, and provides an efficient, flow standardized, index quantized and reproducible H-ADCP installation site optimization method, so as to realize site selection targets with optimal flow velocity representativeness and lowest construction and operation and maintenance costs in a full hydrologic cycle. In order to solve the technical problems, the invention adopts the following technical scheme: An H-ADCP installation position optimization method based on section traversal scanning comprises the following steps: Step S1, measuring section flow field data and calculating section average flow velocity, wherein the method specifically comprises the following steps: S1.1, selecting a section to be installed, meeting flow monitoring requirements, in a target river channel, acquiring terrain data of the section of the river channel by adopting terrain measuring equipment, and establishing a section terrain model. And S1.2, dividing water levels or flow velocity levels based on historical water levels and flow velocity data of a target river channel, carrying out flow measurement on the section to be installed by using a sailing ADCP under each water level or flow velocity level, and synchronously recording real-time water level data of each measurement time through water level observation equipment to obtain sailing section flow velocity data of at least 30 measurement times. And S1.3, calculating a section average flow rate = a section average flow rate/a section large area corresponding to the measurement times according to a large section area (obtained by inquiri