Systematic connectivity in single thread meandering alluvial rivers: statistical generalization of hydraulic geometry

River Morphodynamics;Bankfull Hydraulic Geometry;Connectivity

Czapiga, Matthew ; Parker ; Gary

关键词: River Morphodynamics;    Bankfull Hydraulic Geometry;    Connectivity;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/44498/Matthew_Czapiga.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

System connectivity is achieved when some intrinsic organization allows inter-medium travel.Depth connectivity is investigated in alluvial meandering streams as a solution to rivernavigability. These types of rivers are naturally ordered systems, which exhibits self-similarityamongst many scales. Four river sections and four experimental runs were used to investigatepatterns in depth connectivity with varied path dimensions. Dimensions of measured depth andconnective path were made dimensionless through bankfull hydraulic geometry. As these meanstatistics scale with river discharge, connective paths should follow the same trends. Systematicconnectivity was computed through a numerical calculation that determines the success rate forevery combination of dimensionless depth, path width, and path length. Distributions of depthare presented as hypsometric curves; the standard deviation of these distributions quantifiesdepth variability. The experimental runs shows larger magnitude depths and more variability indepths larger than bankfull channel depth. Experimental runs also display lower internalconnectivity than the rivers. Connectivity results show similarity as a function of dimensionlesspath dimensions, a dimensionless threshold depth, and the reach-averaged hypsometric standarddeviation. A first order model is presented which adequately predicts general patterns, butaccuracy decreases through increases to either the width factor or hypsometric standarddeviation.