Calculation Method of Fractal Dimension of Irregular Boundary Channel and Riverbed Surface

Abstract

The invention provides a method for calculating fractal dimension of surfaces of river ways and river beds with irregular boundaries, and belongs to the field of river bed movement. The concept of the fractal dimension is applied to description of surface morphologies of the river beds, on the basis of establishing DEM of the surfaces of the river beds and according to a surface area-yardstick method principle, the irregular boundaries of the river beds are treated, aspects such as calculation of area of space quadrilateral and judgment of a scale independent rang are improved, and the fractal dimension of the surfaces of the river beds is calculated. The method has good applicability on fractal calculation of surfaces of natural river ways and river beds, can calculate the fractal dimension of the surfaces of the river beds under the irregular boundaries on the basis of DEM of the surfaces of the river beds, quantitatively describes irregularity and multi-scale property of the river beds, explains river zigzag degree and complexity of the surface morphologies, and then analyzes river regime, fluvial facies change and even river pattern movement in river bed movement.

Description

technical field [0001] The invention relates to the field of river bed evolution, in particular to a method for calculating the fractal dimension of the river bed surface with irregular boundaries. Background technique [0002] Rivers carry water flow and sediment transport with a certain boundary shape and are affected by natural forces and human activities. The river bed is exactly the boundary that controls the movement of water and sediment in the river. This boundary has two main features: mobility and three-dimensionality, among which mobility is its biggest feature: the river bed is not only the constraint of the river water and sediment movement, but also the result of the river water and sediment movement. As a boundary, it affects the flow structure and resistance of the river flow, which in turn affects the sediment transport, and the process of sediment transport will reshape the river bed. Another characteristic of the river bed is its three-dimensional shape....

AI Technical Summary

Problems solved by technology

[0013] Obviously, there is a certain degree of estimation in the calculation of the surface fractal dimension by the above three methods, and they all have different requirements for the regularity of the boundary. If the surface area-scale method is used for calculation, there will still be large errors

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