CN-121615376-B - Mountain torrent disaster bridge water-logging flooding analysis method

CN121615376BCN 121615376 BCN121615376 BCN 121615376BCN-121615376-B

Abstract

The invention discloses a mountain torrent disaster bridge water flooding analysis method, which is used for extracting a target river center line according to digital elevation model data of a river channel region to be analyzed and a target bridge position. And determining the river channel ratio drop, the water choking length and the terrain complexity index of the center line of the target river channel according to the first elevations of a plurality of preset river channel section sample points. And acquiring second elevations of three self-adaptive river section sample points of each self-adaptive river section of the center line of the target river according to a gradient attenuation model of a water choking curve and a terrain complexity index constructed by the river drop and the water choking length. And determining a third elevation of each river section target point by a terrain factor weighted inverse distance weight interpolation method according to the digital elevation model data, the second elevations and a preset comprehensive weight function. And determining a submerged range according to the preset dividing straight line of the target bridge, the preset reference directional distance and the plurality of river section target points. And obtaining a flooding analysis result according to the plurality of third elevations and the flooding range.

Inventors

LIU YEWEI
NI SHIJIE
LI GUANGJIN
YOU YUN
XU XIAOHUA
YANG PEISHENG
YANG WEIFENG
XIE XINDONG
ZHU LONGHUI
LI SIYING

Assignees

江西省水利科学院(江西省大坝安全管理中心、江西省水资源管理中心)

Dates

Publication Date: 20260508
Application Date: 20260130

Claims (9)

1. The mountain torrent disaster bridge water flooding analysis method is characterized by comprising the following steps of: extracting a target river channel center line according to digital elevation model data and a target bridge position of a river channel region to be analyzed, wherein the river channel region to be analyzed comprises a plurality of river channel section target points; determining river channel ratio drop, water choking length and terrain complexity index corresponding to the target river channel center line according to first elevations of a plurality of preset river channel section sample points corresponding to the target river channel center line; Constructing a choking curve gradient attenuation model according to the river channel specific drop and the choking length, wherein the choking curve gradient attenuation model is defined by the following expression: ; Wherein, the Gradient attenuation of a choked water curve of each preset river section sample point is represented, Representing the distance between the section of the preset river section sample point and the position of the target bridge, The river channel ratio is represented, lambda represents a correction coefficient of the choked water length, and L represents the choked water length; Acquiring second elevations of three self-adaptive river section sample points corresponding to each self-adaptive river section corresponding to the center line of the target river according to the gradient attenuation model of the choking curve and the terrain complexity index; Determining a third elevation of each river section target point through a terrain factor weighted inverse distance weight interpolation method according to the digital elevation model data, a plurality of second elevations and a preset comprehensive weight function, wherein the preset comprehensive weight function is determined according to the distance weights of the self-adaptive river section sample points and the river section target points and the terrain factor weights; Determining a submerged range according to a preset dividing straight line, a preset reference directional distance and a plurality of river section target points corresponding to the target bridge; and obtaining a flooding analysis result according to the third elevations and the flooding range.
2. The method of claim 1, wherein extracting the target river center line from the digital elevation model data of the river region to be analyzed and the target bridge position comprises: aiming at the digital elevation model data, acquiring a river network according to flow directions and converging characteristics of a plurality of river channels in the river channel region to be analyzed; determining a target river channel closest to the target bridge position in a river channel network, and extracting an initial river channel center line of the target river channel through a center axis transformation algorithm; and performing geometric smoothing on the initial river center line to obtain the target river center line.
3. The method of claim 2, wherein determining the river dip, the choked water length, and the terrain complexity index corresponding to the target river centerline according to the first elevation of the plurality of preset river section sample points corresponding to the target river centerline comprises: determining the river channel ratio drop according to a first elevation of a plurality of preset river channel section sample points and a preset river channel ratio drop calculation formula; determining the water choking length according to the river channel specific drop and a preset water choking length calculation formula; acquiring a river longitudinal slope change rate, a river plane curvature and surface roughness according to the first elevation of the plurality of preset river section sample points; and carrying out weighted summation according to the river longitudinal slope change rate, the river plane curvature and the surface roughness to determine the terrain complexity index.
4. The method of claim 3, wherein determining the channel ratio drop according to a first elevation of a plurality of preset channel section sample points and a preset channel ratio drop calculation formula comprises: Calculating the local river reach proportion drop of each preset river reach section sample point according to the first elevation of the preset river reach section sample points and the local river reach proportion drop calculation formula; And determining the river channel ratio drop according to a plurality of river channel local ratio drops and a preset river channel ratio drop calculation formula.
5. The method of claim 4, wherein the equation for the partial specific drop calculation of the river reach is defined by the expression: ; Wherein, the Represents the local drop of the river reach corresponding to the ith preset river cross section sample point, L i represents the length of the river reach corresponding to the ith preset river cross section sample point, Representing a first elevation corresponding to an ith preset river section sample point, Representing a first elevation corresponding to the (i+1) th preset river section sample point; The preset river channel ratio drop calculation formula is defined by the following expression: ; wherein n represents the total number of a plurality of preset river section sample points; The preset congestion water length calculation formula is defined by the following expression: ; where h represents the height of the target bridge.
6. The method of claim 5, wherein the obtaining the second elevation of the three adaptive channel section sample points corresponding to each adaptive channel section corresponding to the target channel centerline according to the congestion curve gradient attenuation model and the terrain complexity index comprises: Acquiring the distance between any two adjacent self-adaptive river sections in a plurality of self-adaptive river sections according to the gradient attenuation model of the water-choking curve, the terrain complexity index and a preset distance calculation formula; According to the multiple intervals, obtaining initial self-adaptive river section sample points of each self-adaptive river section through an inverse index mechanism; Determining three adaptive river section sample points corresponding to each adaptive river section according to the initial adaptive river section sample points and the adjacent initial adaptive river section sample points; Calculating the second elevation corresponding to the three self-adaptive river section sample points according to a preset elevation calculation formula; wherein the preset pitch calculation formula is defined by the following expression: ; Wherein, the Represents the interval between any two adjacent self-adaptive river sections, The minimum section spacing is indicated by the term, The maximum section spacing is indicated by the number of the sections, Representing the maximum gradient attenuation value of a choked water curve, and C represents a terrain complexity index; The preset elevation calculation formula is defined by the following expression: ; Wherein, the Representing the distance between the initial adaptive river section sample point corresponding to each adaptive river section and the target bridge position, Representing the deck elevation of the target bridge, And representing the second elevation of the three self-adaptive river section sample points corresponding to the self-adaptive river sections.
7. The method of claim 6, wherein before determining the third elevation of each river section target point by a terrain factor weighted inverse distance weight interpolation method according to the digital elevation model data, the plurality of second elevations and the preset comprehensive weight function, further comprising: acquiring initial digital elevation model data, and performing pit pretreatment on the initial digital elevation model data to obtain the digital elevation model data; carrying out terrain factor grid processing based on the digital elevation model data to obtain first terrain factor parameters corresponding to a plurality of river section target points; determining a terrain factor weight according to a first terrain factor parameter corresponding to each river section target point and a second terrain factor parameter corresponding to a plurality of self-adaptive river section sample points; determining the distance weight according to the reciprocal of the distance between each river section target point and a plurality of self-adaptive river section sample points; And carrying out product operation on the distance weight and the terrain factor weight, and determining the preset comprehensive weight function.
8. The method of claim 7, wherein determining the third elevation of each river section target point by a terrain factor weighted inverse distance weight interpolation method based on the digital elevation model data, the plurality of second elevations and a preset comprehensive weight function comprises: performing downsampling processing on the digital elevation model data; Determining initial elevations of a plurality of river section target points according to a plurality of second elevations and a preset comprehensive weight function by a terrain factor weighting inverse distance weight interpolation method aiming at the digital elevation model data after the downsampling process; And aiming at the digital elevation model data, determining a third elevation of each river section target point by a terrain factor weighted inverse distance weight interpolation method according to the initial elevations of the river section target points, the second elevations and a preset comprehensive weight function.
9. The method of claim 8, wherein determining the flooding range based on the preset dividing line, the preset reference directional distance, and the plurality of river section target points corresponding to the target bridge comprises: Constructing the preset dividing straight line according to the coordinate position set of the target bridge; calculating a preset reference directional distance between an initial adaptive river section sample point corresponding to the second adaptive river section and a preset dividing straight line; calculating the directed distance between each river section target point and a preset dividing straight line; and determining the flooding range according to the preset reference directional distance and a plurality of the directional distances.

Description

Mountain torrent disaster bridge water-logging flooding analysis method Technical Field The invention relates to the technical field of mountain torrent disaster analysis, in particular to a mountain torrent disaster bridge water-logging flooding analysis method. Background In mountain torrent disasters, the shrinkage of the bridge flow cross section can cause upstream water accumulation of a river channel, so that the submerging risk is increased. In view of this, it is important to analyze, pre-warn and forecast the flooding phenomenon of the bridge Liang Yongshui in the mountain torrent disaster. In the prior art, in the traditional mountain torrent disaster bridge water flooding assessment method, firstly, interpretation is carried out on a topographic map manually so as to extract the center line of a river channel. And then, distributing the choked water sections at fixed intervals for sampling. And finally, determining a flooding range by utilizing an interpolation algorithm based on the distance weight, so as to obtain an analysis result of the mountain torrent disaster bridge water flooding. However, in the case of using the prior art, it is difficult to accurately extract the center line of the river channel in the face of complex terrain, and variations in the complexity of the terrain are not sufficiently considered, resulting in insufficient sampling data. Meanwhile, the method ignores the influence of factors such as the slope of the terrain, the curvature, the surface roughness and the like on the water flow diffusion, so that the accuracy and the efficiency of bridge water-logging inundation analysis in mountain torrent disasters are reduced. Disclosure of Invention The invention aims to provide a mountain torrent disaster bridge water flooding analysis method which is used for solving the problems that in the prior art, when facing complex terrains, the center line of a river channel is difficult to accurately extract, and the variation of the complexity of the terrains is not fully considered, so that the defect of sampling data is caused. Meanwhile, the method ignores the influence of factors such as the slope of the terrain, the curvature, the surface roughness and the like on the water flow diffusion, so that the accuracy and the efficiency of bridge water-logging inundation analysis in mountain torrent disasters are reduced. In order to achieve the above object, in a first aspect, an embodiment of the present invention provides a method for analyzing a mountain torrent disaster bridge congestion, including: extracting a target river channel center line according to digital elevation model data and a target bridge position of a river channel region to be analyzed, wherein the river channel region to be analyzed comprises a plurality of river channel section target points; determining river channel ratio drop, water choking length and terrain complexity index corresponding to the target river channel center line according to first elevations of a plurality of preset river channel section sample points corresponding to the target river channel center line; Constructing a choking curve gradient attenuation model according to the river channel specific drop and the choking length; Acquiring second elevations of three self-adaptive river section sample points corresponding to each self-adaptive river section corresponding to the center line of the target river according to the gradient attenuation model of the choking curve and the terrain complexity index; Determining a third elevation of each river section target point through a terrain factor weighted inverse distance weight interpolation method according to the digital elevation model data, a plurality of second elevations and a preset comprehensive weight function, wherein the preset comprehensive weight function is determined according to the distance weights of the self-adaptive river section sample points and the river section target points and the terrain factor weights; Determining a submerged range according to a preset dividing straight line, a preset reference directional distance and a plurality of river section target points corresponding to the target bridge; and obtaining a flooding analysis result according to the third elevations and the flooding range. In one embodiment, the extracting the target river center line according to the digital elevation model data of the river region to be analyzed and the target bridge position includes: aiming at the digital elevation model data, acquiring a river network according to flow directions and converging characteristics of a plurality of river channels in the river channel region to be analyzed; determining a target river channel closest to the target bridge position in a river channel network, and extracting an initial river channel center line of the target river channel through a center axis transformation algorithm; and performing geometric smoothing on the initial river cente