Keywords

Landcape Evolution, Steady State, Transient State

Abstract

The evolution and organization of landscapes result from the competition between tectonic uplift, fluvial incision, and hillslope diffusion. Understanding how these processes interact under varying external conditions (i.e., extreme climatic events) is critical for predicting landscape dynamics and long-term geomorphic adjustment. Using a physically based landscape evolution model, we first investigate how variations in the fluvial incision coefficient (K) and soil diffusion coefficient (D) mimic different climatic conditions and control the transient and steady-state organization of landscapes. Results indicate that landscapes with the same non-dimensional index (defined as the ratio of the timescales of advective (fluvial) to diffusive (hillslope) processes) and thus the same characteristic length scale may exhibit distinct geomorphic and topologic characteristics. Topographic analysis of natural landscapes further shows that varying climatic conditions imprint distinct signatures on the branching structure of channel networks. We then explore the effects of temporary precipitation intensification, achieved by increasing K and D and subsequently reverting them to their original values. Results show that while the mean elevation recovers, the drainage structure and channel organization retain persistent signatures of the transient forcing, highlighting asymmetric adjustment timescales and process coupling between diffusion and incision. Further, identifying hotspots of geomorphic sensitivity using Incremental Area–Sediment Yield analysis and Optimal Transport theory reveals that low-order tributaries are zones of higher sediment export during transient-states. Finally, we investigate the origin of a transient elevation overshoot, or “hump,” which arises when fluvial incision surpasses the critical threshold relative to soil diffusion, marking the onset of channel branching. Together, these findings demonstrate that transient dynamics, rather than steady-state conditions, govern the persistent organization and topological memory of channelized landscapes.

Completion Date

2025

Semester

Fall

Committee Chair

Singh, Arvind

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Civil, Environmental, and Construction Engineering

Format

PDF

Identifier

DP0029812

Document Type

Thesis

Campus Location

Orlando (Main) Campus

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