On the Relationships Among Climate, Topography, and Discharge-Driven Fluvial Incision Using an Asynchronously Coupled Climate-Landscape Evolution Model

No Thumbnail Available
Can’t use the file because of accessibility barriers? Contact us with the title of the item, permanent link, and specifics of your accommodation need.

Date

2021-09-22

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

One of the primary drivers of landscape evolution is climate-driven river incision. The amount, frequency, and distribution of water discharge and runoff within a channel governs river incision, and these characteristics will change based on climate regime and topography. It is essential to distinguish between discharge distributions in different climatic and topographic settings to understand how river incision shapes landscapes. In this study, we analyze discharge distributions generated using an asynchronously coupled landscape evolution and climate model and examine their effect on river incision across a range of latitudes from 0S to 40S, with and without a topographic barrier. We first characterize each discharge distribution by calculating values for mean discharge and discharge variability and then extrapolate these discharge distributions to larger flood values, which then drive incision in a 1D river model. We find landscape sensitivity to climate-topography feedbacks is climate-regime dependent, with the most extreme changes to discharge characteristics and channel morphology in drier climates (20S and 30S). Finally, our results indicate that mean discharge and runoff are the principal factors in changing river concavity and relief for a given latitude or mountain height. Discharge variability becomes important for driving fluvial incision, only when mean discharge between two settings is similar, but discharge variabilities are different. We demonstrate the utility of using a coupled climate-landscape model to characterize discharge distributions across climate regimes and in response to topographic growth and determine the most important climatic variables for driving landscape evolution.

Description

Keywords

Geomorphology, Climate, Bedrock Rivers, Streamflow

Citation

Lynch, B., Yanites, B., Shen, H., & Poulsen, C. 2021. On the Relationships Among Climate, Topography, and Discharge-Driven Fluvial Incision Using an Asynchronously Coupled Climate-Landscape Evolution Model. JGR: Earth Surface

Journal

DOI

Link(s) to data and video for this item

Relation

Rights

Type

Dataset