Method for constructing network based on river characteristic morphology isoline

Abstract

The invention provides an isoline net construction method based on river characteristic forms, which comprises the following steps: determining characteristic lines such as left and right bank water surface lines, thalweg and the like of a river through measured data, fitting and encrypting a characteristic curve, and performing modeling through the encrypted characteristic curve and measured points to realize optimization and determination of the isoline of the river; performing linear interpolation on the underwater contour line by using the planned measuring line measuring points; and carrying out joint optimization modeling by utilizing characteristic lines of encrypted interpolation points such as left and right bank water surface lines, thalweg and the like and land actual measurement points to generate a land isoline. After optimization modeling, the underwater contour line truly expresses the river form, the land contour line has no crossing characteristic line, and the contour line is smoother and accords with the actual terrain. The automatically generated contour line is close to the real surface shape, the smoothness is good, and the automation degree is high. The method has good economic benefits and social benefits and is suitable for popularization and application.

Description

Technical Field

[0001] The 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] The river morphology is relatively complex, and the river topography measurement is carried out by laying out planned survey lines at certain intervals. When the contour lines are automatically generated, if the network construction is unreasonable, the following problems may exist: ① The 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 real terrain; ② Using traditional triangulation modeling, the underwater contour lines generate redundant nodes, the contour lines are not smooth and cannot represent the real river morphology; ③ The contour lines frequently cross the water surface line and the deep sea line, the contour lines cannot represent the real terrain and the workload of manual intervention is large. In order to overcome the above difficulties, the underwater contour lines use linear interpolation contour lines of the planned survey lines; the land contour lines are determined by the joint optimization modeling of the characteristic lines of the encrypted interpolation points such as the left and right bank water surface lines and deep sea lines and the actual measured points on land. Summary of the invention

[0003] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and provide a method for constructing a network of contour lines based on characteristic morphology of rivers, which utilizes the linear interpolation of underwater contour lines, left and right bank water surface lines, deep-sea lines and other encrypted interpolation points of planned survey lines and points, and jointly optimizes the modeling with the actual measured points on land to generate contour lines on land.

[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 line 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] Where n is the total number of water surface 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, which is specifically:

[0013] S201. When measuring underwater topography of a river channel, a planned survey line is laid out in a direction perpendicular to the contour line. The line connecting the deepest points of each planned survey line is the deep line. Suppose the data set of the planned 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 line data set 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 feature 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 and ends at the key point;

[0039] The plane coordinates of the interpolation point are calculated 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 elevations of the starting and ending points of the interpolation points respectively; Z l is the interpolation point elevation; X p ,Y p , X p-1 ,Y p-1 X is the plane coordinates of the starting and ending points of the curve; l ,Y l are the plane coordinates of the interpolation point.

[0045] Furthermore, the water surface line, the deep-sea line interpolation points and 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 deep-sea lines, and the contour line points between the two sides are calculated by 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 larger elevations; min cf It is the point with smaller elevation between the f-1th and fth measuring points;

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

[0051]

[0052] Among them, the interval between F contour lines is; [] 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 two points, respectively. The corresponding contour line points between the two points are interpolated according to the multiples of the contour interval. The underwater contour line is determined by connecting the contour line points with the same multiples in sequence;

[0054] S302, using the measuring points closest to the water surface line on the left and right banks, the water surface lines on the left and right banks, and the measuring points on the shore to establish an irregular triangulated network, 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 Plan survey lines and deep-water lines for the rivers of the present invention;

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

[0058] Figure 4 Interpolation of underwater contour lines of the present invention;

[0059] Figure 5 The 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 solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0063] Embodiment 1

[0064] 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;

[0065] The river morphological characteristic line includes a water surface line, which is composed of two lines, the left bank and the right bank, and is fitted by water surface characteristic 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 a water surface line data set:

[0066]

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

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

[0084]

[0085] The water surface line and the river channel depth line are fitted using 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 feature 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 deep water line of the left bank and the right bank 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 and ends at the key point;

[0098] The plane coordinates of the interpolation point are calculated 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 elevations of the starting and ending points of the interpolation points respectively; Z l is the interpolation point elevation; X p ,Y p , X p-1 ,Y p-1 X is the plane coordinates 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, deep-sea line interpolation points and 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 deep-sea lines, and the contour line points between the two sides are calculated by 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 larger elevations; min cf It is the point with smaller elevation between the f-1th and fth measuring points;

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

[0111]

[0112] Among them, the interval between F contour lines is; [] 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 two points, respectively. The corresponding contour line points between the two points are interpolated according to the multiples of the contour interval. The underwater contour line is determined by connecting the contour line points with the same multiples in sequence;

[0114] like Figure 4 As shown in the figure, the schematic diagram of the interpolation of underwater contour lines of 160m and 165m isolines is carried out based on underwater measuring points and deep-sea lines.

[0115] S302, using the measuring points closest to the water surface line on the left and right banks, the water surface lines on the left and right banks, and the measuring points on the shore to establish an irregular triangulated network, 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-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be based on the attached claims.

Claims

1. A method for constructing a network based on contour lines of river characteristic morphology, characterized in that: Including extracting river morphological characteristic lines, fitting characteristic lines, and encrypting and interpolating 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 line 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 )}; Where n is the total number of water surface 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.

2. A method for constructing a network based on contour lines of river characteristic morphology according to claim 1, characterized in that: The river morphological characteristic line also includes the river channel deep line, which is: S201. When measuring underwater topography of a river channel, a planned survey line is laid out in a direction perpendicular to the contour line. The line connecting the deepest points of each planned survey line is the deep line. Suppose the data set of the planned 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 line data set 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.

3. A method for constructing a network based on contour lines of river characteristic morphology according to claim 2, characterized in that: The water surface line and the river channel depth line are fitted using a cubic spline curve, specifically: The mathematical expression of plane fitting is: Among them, Y k is the ordinate corresponding to the kth segment feature 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.

4. A method for constructing a network based on contour lines of river characteristic morphology according to claim 3, characterized in that: 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: 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 and ends at the key point; The plane coordinates of the interpolation point are calculated 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 elevations of the starting and ending points of the interpolation points respectively; Z l is the interpolation point elevation; X p ,Y p , X p-1 ,Y p-1 X is the plane coordinates of the starting and ending points of the curve; l ,Y l are the plane coordinates of the interpolation point.

5. A method for constructing a network based on contour lines of river characteristic morphology according to claim 4, characterized in that: Using the water surface line, deep-sea line interpolation points and 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 by 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 larger elevations; min cf It is the point with smaller elevation between the f-1th and fth measuring points; Calculate the multiples of the contour lines between two points respectively and round them up: Among them, the interval between F contour lines is; [] 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 two points, respectively. The corresponding contour line points between the two points are interpolated according to the multiples of the contour interval. The underwater contour line is determined by connecting the contour line points with the same multiples in sequence; S302, using the measuring points closest to the water surface line on the left and right banks, the water surface lines on the left and right banks, and the measuring points on the shore to establish an irregular triangulated network, and determine the contour lines based on the irregular triangulated network through triangulation.

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