ORCID

0009-0001-1493-2154

Keywords

River Netwroks, Dynamic Cluster, Phase Transition, River Delta, Avulsion, Lateral Migration, Non-linearity

Abstract

River network (RN) structure has a significant impact on flux transport, aggregation and ecosystem connectivity. In this dissertation, the structural control of RN on flux transport was investigated by the application of integrated framework of dynamic clusters and network graph theory. This new framework has been proposed to determine sub-catchment connectivity using minimum and maximum flow criteria. Our analysis on synthetic and natural RNs across United States demonstrates that basin scale connectivity at low flow conditions is efficiently governed by the abundance of side branching junctions whereas this characteristic slows down the flux convergence rate at maximum flow condition.

Furthermore, our study identifies the existence of a phase transition in which aggregation of flux condition shifts from a scattered state to a congested regime during downstream flux movement. Our analysis on natural RNs from different climatic regions reveals an interesting relationship between the critical distance—defined as the distance that fluxes travel from the sources when the phase transition occurs—and climate. The findings of this study indicate that the timing of this transition is influenced by the climate, with humid basins undergoing earlier phase transition due to the higher density of side tributaries. These results suggest that the RN topology intrinsically governs the climate dependence of transport dynamics.

Finally, we investigated the impact of transport dynamics in river delta evolution. River avulsion—abrupt channel jumping—and lateral channel migration are closely linked to flux transport and shape landscape over different time scale. The results based on the data analysis collected from depositional system-based experiments exhibit the distinct signature of avulsion and lateral migration on deltaic topography.

Completion Date

2025

Semester

Spring

Committee Chair

Singh, Arvind

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Department of Civil, Environmental and Construction Engineering

Identifier

DP0029379

Document Type

Dissertation/Thesis

Campus Location

Orlando (Main) Campus

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