A method for constructing a network based on contour lines of river characteristics

Abstract

The present invention provides a method for constructing contour lines based on the characteristic morphology of rivers. The method determines characteristic lines such as the water surface lines and the thalassemia lines of the left and right banks of the river through measured data, fits and encrypts characteristic curves, and optimizes and determines the contour lines of the river by combining the encrypted characteristic curves with the measured points for modeling. The method also linearly interpolates underwater contour lines using the planned survey lines and points. The method also uses the characteristic lines of the encrypted interpolation points such as the water surface lines and the thalassemia lines of the left and right banks for joint optimization modeling with the measured points on land to generate the contour lines on land. After the optimized modeling, the underwater contour lines truly express the river morphology, the onshore contour lines do not cross characteristic lines, and the contour lines are smoother and conform to the actual terrain. The automatically generated contour lines are close to the actual surface morphology, have good smoothness, and are highly automated. The present invention has good economic and social benefits and is suitable for promotion and use.

Description

Technical Field

[0001] The present invention relates to the technical field of river surveying, and in particular to a method for constructing a network based on contour lines of river characteristic morphology. Background Art

[0002] River morphology is relatively complex, and river topography is measured by laying out planned survey lines at certain intervals. When contour lines are automatically generated, if the network construction is unreasonable, the following problems may occur: ① River contour lines form multiple closed contour lines, the contour lines cannot be generated along the river channel, and the automatically generated contour lines cannot represent the actual terrain; ② Using traditional triangulated network modeling, underwater contour lines generate redundant nodes, the contour lines are not smooth, and cannot represent the actual river morphology; ③ Contour lines frequently cross the water surface line and the thalassemia line, which cannot represent the actual terrain and requires a lot of manual intervention. To overcome the above problems, underwater contour lines use linear interpolation contour lines for planned survey lines; onshore contour lines are determined by combining the characteristic lines of the water surface lines and the thalassemia lines on the left and right banks with the onshore measured points for optimized modeling. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies of the above-mentioned existing technologies and provide a method for constructing a network of contour lines based on the characteristic morphology of rivers. The method uses the linear interpolation of underwater contour lines, left and right bank water surface lines, deep-sea lines and other characteristic lines of encrypted interpolation points along the planned survey lines and points, and the onshore measured points to jointly optimize the modeling to generate onshore contour lines.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a method for constructing a network based on the contour lines of river characteristic morphology, including extracting river morphological characteristic lines, fitting characteristic lines, and encrypting and interpolating characteristic lines;

[0006] The river morphological characteristic line includes a water surface line, which is composed of two lines, the left bank and the right bank. The water surface line is fitted by water surface feature points. The data set of the water surface line is expressed as:

[0007] A={A 左 ,A 右};

[0008] Among them, A 左 A is the water surface curve dataset of the left bank of the river; 右 This is the water surface curve dataset of the right bank of the river;

[0009] A 左 ={(X 左1 , Y 左1 , Z 左1 ),(X 左2 , Y 左2 , Z 左2 ),…,(X左n , Y 左n , Z 左n )};

[0010] A 右 ={(X 右1 , Y 右1 , Z 右1 ),(X 右2 , Y 右2 , Z 右2 ),…,(X 右n , Y 右n , Z 右n )};

[0011] Among them, n is the total number of water surface line points; X 左n , Y 左n , Z 左n are the three-dimensional coordinates of the nth feature point of the left bank water surface line; X 右n , Y 右n , Z 右n are the three-dimensional coordinates of the nth feature point of the right bank water surface line.

[0012] Furthermore, the river morphological characteristic line also includes the river channel deep line, specifically:

[0013] S201. When measuring underwater topography of a river channel, plan survey lines are laid out perpendicular to the contour lines. The line connecting the deepest points of each plan survey line is the abyssal line. Suppose the data set of the plan survey line is:

[0014] B={B1,B2,…,B m};

[0015] Where B is the data set of the planned survey line; m is the total number of survey lines; B m is the mth planned survey line;

[0016] S202, the data set of the mth planned survey line is:

[0017]

[0018] in, is the coordinate of the left endpoint of the planned survey line; is the coordinate of the right endpoint of the planned survey line;

[0019] S203, the data set of each sounding point of the mth planned survey line is:

[0020] C m ={(X C1 ,Y C1 ,Z C1 ),(X C2 ,Y C2 ,Z C2),…,(X Ci ,Y Ci ,Z Ci )};

[0021] Where i is the total number of water depth measurement points; X Ci ,Y Ci ,Z Ci is the three-dimensional coordinate of the i-th sounding point;

[0022] S204, the deep point of the mth planned survey line is:

[0023] D m =min(Z C1 ,Z C2 ,…,Z Cj ,,Z Ci );

[0024] Among them, D m is the deepest point on the mth survey line; j is the number of the deepest point, and the corresponding three-dimensional coordinates are X Cj ,Y Cj ,Z Cj ;

[0025] S205, then the deep-sea line dataset is:

[0026] E={(X 1j ,Y 1j ,Z 1j ),(X 2j ,Y 2j ,Z 2j ),…,(X mj ,Y mj ,Z mj )};

[0027] Among them, E is the deep line data set; X 1j ,Y 1j ,Z 1j is the three-dimensional coordinate of the deepest point on the first survey line; X mj ,Y mj ,Z mj is the three-dimensional coordinate of the deepest point on the mth survey line.

[0028] Furthermore, the water surface line and the river channel depth line are fitted with a cubic spline curve, specifically:

[0029] The mathematical expression of plane fitting is:

[0030]

[0031] Among them, Y k is the ordinate corresponding to the kth segment characteristic line; X kis the horizontal coordinate corresponding to the kth segment characteristic line; a0, a1, a2, a3 are the coefficients to be determined in the expression;

[0032] Solve for the coefficients using the least squares method:

[0033]

[0034] Where u is the number of fitting points.

[0035] Furthermore, the fitting characteristic line function is used to encrypt the points on the interpolated characteristic line and calculate the three-dimensional coordinates of the points, specifically:

[0036] Function interpolation is performed with the rate of change of the first-order derivative of the curve not exceeding 0.2 as the increment interval;

[0037]

[0038] Among them, X l ,Y l is the horizontal coordinate of the lth point; l is calculated from the starting point of the piecewise function to the end point;

[0039] Calculate the plane coordinates of the interpolation point as:

[0040]

[0041] Among them, X l ,Y l is the plane coordinate of the interpolation point;

[0042] Elevation is done via linear interpolation:

[0043]

[0044] Among them, Z p 、Z p-1 are the starting and ending elevations of the interpolation points respectively; Z l is the elevation of the interpolation point; X p ,Y p 、X p-1 ,Y p-1 X is the plane coordinate of the starting and ending points of the curve; l ,Y l are the plane coordinates of the interpolation point.

[0045] Furthermore, the interpolation points of the water surface line and the abyssal line as well as the measured points are used to construct a network to generate contour lines, specifically:

[0046] S301, underwater contour lines are generated by interpolation of underwater measured points and abyssal lines, and the contour line points between the two sides are calculated using the elevations of the measured points on the planned survey line;

[0047] The calculation method for the interpolation contour points of the f-1th and fth sounding points on the mth planned survey line is:

[0048]

[0049] Among them, max cf The f-1th and fth measuring points have the largest elevation; min cf The point with smaller elevation between the f-1th and fth measuring points;

[0050] Calculate the multiples of the contour line between two points and round them up:

[0051]

[0052] Among them, F is the contour line spacing; [] is the rounding function; G and H represent the contour line multiples between high and low points respectively;

[0053] Contour line interpolation: F×G and F×H are the maximum and minimum values of the corresponding contour line between the two points, respectively. The corresponding contour line points between the two points are interpolated according to the multiples of the contour interval. The contour line points with the same multiples are connected in sequence to determine the underwater contour line;

[0054] S302: Establish an irregular triangulated network using the measuring points closest to the water surface lines on the left and right banks, the water surface lines on the left and right banks, and the measuring points on the shore, and determine the contour lines based on the irregular triangulated network through triangulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 The water surface line of the river of the present invention;

[0056] Figure 2 Planning survey lines and deep-sea lines for the rivers of the present invention;

[0057] Figure 3 The nodes of the deep-sea line and the interpolation points thereof of the present invention;

[0058] Figure 4 The underwater contour interpolation of the present invention;

[0059] Figure 5 This is a model diagram of sediment particle size and river channel mileage in the rapid sediment refinement area of the present invention;

[0060] Figure 6 Automatically generate contour lines using traditional methods;

[0061] Figure 7 The method of the present invention is used to automatically generate contour lines. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0063] Example 1

[0064] A method for constructing a network based on the contour lines of river morphology, including extracting river morphology characteristic lines, fitting characteristic lines, and encrypting and interpolating characteristic lines;

[0065] The river morphological characteristic line includes a water surface line, which is composed of two lines, the left bank and the right bank. The water surface line is fitted by water surface feature points, such as Figure 1 As shown, the two lines are the left bank and right bank water surface lines, and the values are the water surface line data points. Each water surface line data point constitutes the water surface line dataset:

[0066]

[0067] The river morphological characteristic line also includes the river channel deep line, specifically:

[0068] S201. When measuring underwater topography of a river channel, plan survey lines are laid out perpendicular to the contour lines. The line connecting the deepest points of each plan survey line is the abyssal line. Suppose the data set of the plan survey line is:

[0069] B={B1,B2,…,B m};

[0070] Where B is the data set of the planned survey line; m is the total number of survey lines; B m is the mth planned survey line;

[0071] S202, the data set of the mth planned survey line is:

[0072]

[0073] in, is the coordinate of the left endpoint of the planned survey line; is the coordinate of the right endpoint of the planned survey line;

[0074] S203, the data set of each sounding point of the mth planned survey line is:

[0075] C m ={(X C1 ,Y C1 ,Z C1 ),(X C2 ,Y C2 ,Z C2 ),…,(X Ci ,Y Ci ,Z Ci)};

[0076] Where i is the total number of water depth measurement points; X Ci ,Y Ci ,Z Ci is the three-dimensional coordinate of the i-th sounding point;

[0077] S204, the deep point of the mth planned survey line is:

[0078] D m =min(Z C1 ,Z C2 ,…,Z Cj ,,Z Ci );

[0079] Among them, D m is the deepest point on the mth survey line; j is the number of the deepest point, and the corresponding three-dimensional coordinates are X Cj ,Y Cj ,Z Cj ;

[0080] S205, then the deep-sea line dataset is:

[0081] E={(X 1j ,Y 1j ,Z 1j ),(X 2j ,Y 2j ,Z 2j ),…,(X mj ,Y mj ,Z mj )};

[0082] Among them, E is the deep line data set; X 1j ,Y 1j ,Z 1j is the three-dimensional coordinate of the deepest point on the first survey line; X mj ,Y mj ,Z mj is the three-dimensional coordinate of the deepest point on the mth survey line.

[0083] River surface line, planned survey line, sounding point, sinking line, etc. Figure 2 As shown in the figure, the corresponding deep-sea line dataset is:

[0084]

[0085] The water surface line and the river channel depth line are fitted with a cubic spline curve, specifically:

[0086] The mathematical expression of plane fitting is:

[0087]

[0088] Among them, Y k is the ordinate corresponding to the kth segment characteristic line; X k is the horizontal coordinate corresponding to the kth segment characteristic line; a0, a1, a2, a3 are the coefficients to be determined in the expression;

[0089] Solve for the coefficients using the least squares method:

[0090]

[0091] Where u is the number of fitting points.

[0092] The fitting formulas of the water surface line and the deep channel line on the left and right banks are:

[0093]

[0094] Using the fitting characteristic line function, the points on the interpolated characteristic line are encrypted and the three-dimensional coordinates of the points are calculated. Specifically:

[0095] Function interpolation is performed with the rate of change of the first-order derivative of the curve not exceeding 0.2 as the increment interval;

[0096]

[0097] Among them, X l ,Y l is the horizontal coordinate of the lth point; l is calculated from the starting point of the piecewise function to the end point;

[0098] Calculate the plane coordinates of the interpolation point as:

[0099]

[0100] Among them, X l ,Y l is the plane coordinate of the interpolation point;

[0101] Figure 3 It is the difference point between the nodes of the deep line and the nodes;

[0102] Elevation is done via linear interpolation:

[0103]

[0104] Among them, Z p 、Z p-1 are the starting and ending elevations of the interpolation points respectively; Z l is the elevation of the interpolation point; X p ,Y p 、X p-1 ,Y p-1 X is the plane coordinate of the starting and ending points of the curve; l ,Y lare the plane coordinates of the interpolation point.

[0105] Using the water surface line, the abyssal line interpolation points and the measured points, a network is constructed to generate contour lines, specifically:

[0106] S301, underwater contour lines are generated by interpolation of underwater measured points and abyssal lines, and the contour line points between the two sides are calculated using the elevations of the measured points on the planned survey line;

[0107] The calculation method for the interpolation contour points of the f-1th and fth sounding points on the mth planned survey line is:

[0108]

[0109] Among them, max cf The f-1th and fth measuring points have the largest elevation; min cf The point with smaller elevation between the f-1th and fth measuring points;

[0110] Calculate the multiples of the contour line between two points and round them up:

[0111]

[0112] Among them, F is the contour line spacing; [] is the rounding function; G and H represent the contour line multiples between high and low points respectively;

[0113] Contour line interpolation: F×G and F×H are the maximum and minimum values of the corresponding contour line between the two points, respectively. The corresponding contour line points between the two points are interpolated according to the multiples of the contour interval. The contour line points with the same multiples are connected in sequence to determine the underwater contour line;

[0114] like Figure 4 As shown in the figure, the schematic diagram of the interpolation of the underwater contour lines of 160m and 165m isolines is performed based on the underwater measuring points and the abyssal line.

[0115] S302: Establish an irregular triangulated network using the measuring points closest to the water surface lines on the left and right banks, the water surface lines on the left and right banks, and the measuring points on the shore, and determine the contour lines based on the irregular triangulated network through triangulation.

[0116] like Figure 5 As shown in the figure, a triangulated network diagram is constructed based on water surface lines and measured land points.

[0117] The traditional method is used to automatically generate contour lines, such as Figure 6 As shown, the method of the present invention is used to automatically generate contour lines, such as Figure 7 shown.

[0118] The above-described embodiments merely illustrate the implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for constructing a network based on contour lines of river characteristic morphology, characterized by: Including extracting river morphological characteristic lines, fitting characteristic lines, and encrypting interpolation characteristic lines; The river morphological characteristic line includes a water surface line, which is composed of two lines, the left bank and the right bank. The water surface line is fitted by water surface feature points. The data set of the water surface line is expressed as: A={A 左 ,A 右 }; Among them, A 左 A is the water surface curve dataset of the left bank of the river; 右 This is the water surface curve dataset of the right bank of the river; A 左 ={(X 左1 ,Y 左1 ,Z 左1 ),(X 左2 ,Y 左2 ,Z 左2 ),…,(X 左n ,Y 左n ,Z 左n )}; A 右 ={(X 右1 ,Y 右1 ,Z 右1 ),(X 右2 ,Y 右2 ,Z 右2 ),…,(X 右n ,Y 右n ,Z 右n )}; Among them, n is the total number of water surface line points; X 左n , Y 左n , Z 左n are the three-dimensional coordinates of the nth feature point of the left bank water surface line; X 右n , Y 右n , Z 右n are the three-dimensional coordinates of the nth feature point of the right bank water surface line; The river morphological characteristic line also includes the river channel deep line, specifically: S201. When measuring underwater topography of a river channel, plan survey lines are laid out perpendicular to the contour lines. The line connecting the deepest points of each plan survey line is the abyssal line. Suppose the data set of the plan survey line is: B={B1,B2,…,B m }; Where B is the data set of the planned survey line; m is the total number of survey lines; B m is the mth planned survey line; S202, the data set of the mth planned survey line is: in, is the coordinate of the left endpoint of the planned survey line; is the coordinate of the right endpoint of the planned survey line; S203, the data set of each sounding point of the mth planned survey line is: C m ={(X C1 ,Y C1 ,Z C1 ),(X C2 ,Y C2 ,Z C2 ),…,(X Ci ,Y Ci ,Z Ci )}; Where i is the total number of water depth measurement points; X Ci ,Y Ci ,Z Ci is the three-dimensional coordinate of the i-th sounding point; S204, the deep point of the mth planned survey line is: D m =min(Z C1 ,WITH C2 ,…,WITH Cj ,…,WITH Ci ); Among them, D m is the deepest point on the mth survey line; j is the number of the deepest point, and the corresponding three-dimensional coordinates are X Cj ,Y Cj ,Z Cj ; S205, then the deep-sea line dataset is: E={(X 1j ,Y 1j ,Z 1j ),(X 2j ,Y 2j ,Z 2j ),…,(X mj ,Y mj ,Z mj )}; Among them, E is the deep line data set; X 1j ,Y 1j ,Z 1j is the three-dimensional coordinate of the deepest point on the first survey line; X mj ,Y mj ,Z mj is the three-dimensional coordinate of the deepest point on the mth survey line; The water surface line and the river channel depth line are fitted with a cubic spline curve, specifically: The mathematical expression of plane fitting is: Among them, Y k is the ordinate corresponding to the kth segment characteristic line; X k is the horizontal coordinate corresponding to the kth segment characteristic line; a0, a1, a2, a3 are the coefficients to be determined in the expression; Solve for the coefficients using the least squares method: Where, u is the number of fitting points; Using the fitting characteristic line function, encrypt the points on the interpolated characteristic line and calculate the three-dimensional coordinates of the points, specifically: Function interpolation is performed with the rate of change of the first-order derivative of the curve not exceeding 0.2 as the increment interval; Among them, X l ,Y l is the horizontal coordinate of the lth point; l is calculated from the starting point of the piecewise function to the end point; Calculate the plane coordinates of the interpolation point as: Among them, X l ,Y l is the plane coordinate of the interpolation point; Elevation is done via linear interpolation: Among them, Z p , Z p-1 are the starting and ending elevations of the interpolation points respectively; Z l is the elevation of the interpolation point; X p ,Y p 、X p-1 ,Y p-1 X is the plane coordinate of the starting and ending points of the curve; l ,Y l is the plane coordinate of the interpolation point; Using the water surface line, the abyssal line interpolation points and the measured points, a network is constructed to generate contour lines, specifically: S301, underwater contour lines are generated by interpolation of underwater measured points and deep-sea lines, and the contour line points between the two sides are calculated using the elevations of the measured points on the planned survey line; The calculation method for the interpolation contour points of the f-1th and fth sounding points on the mth planned survey line is: Among them, max cf The f-1th and fth measuring points have the largest elevation; min cf The point with smaller elevation between the f-1th and fth measuring points; Calculate the multiples of the contour line between two points and round them up: Where F is the contour line spacing; [] is the rounding function; G and H represent the contour line multiples between high and low points respectively; Contour line interpolation: F×G and F×H are the maximum and minimum values of the corresponding contour line between the two points, respectively. The corresponding contour line points between the two points are interpolated according to the multiples of the contour interval. The contour line points with the same multiples are connected in sequence to determine the underwater contour line; S302: Establish an irregular triangulated network using the measuring points closest to the water surface lines on the left and right banks, the water surface lines on the left and right banks, and the measuring points on the shore, and determine the contour lines based on the irregular triangulated network through triangulation.

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