Transport Mechanisms across Geomorphic Transitions: Capturing Spatial and Temporal Evolution of River-Floodplain Connectivity within the Trinity River System

University Of Texas At Austin, Austin TX

Investigators

Abstract

Connections between rivers and floodplains control the transport of water, nutrients, pollutants, and other materials through river systems, thus affecting the functioning of rivers, storage of carbon on floodplains, sediment movement, and ecosystem functioning. This project harnesses recent advancements in high-resolution topographic analyses and modeling capabilities, applied to the Trinity River in Texas, to enable new understanding of the interactions between rivers and floodplains. An innovative approach to analyzing the dynamic boundary between river and floodplain is used to improve understanding of how water and other materials move through this complex interface. Project activities also contribute to development and dissemination of river modeling capabilities and the advancement of research-based learning experiences for high school and college students. This project combines an extensive collection of field observations, lidar data sets, numerical modeling, and advanced tools for feature extraction and analysis, to quantify river-floodplain connectivity of the Trinity River, Texas. The research is articulated around a two-part overarching hypothesis that (i) accurate characterization of exchanges in water, solutes, and solids between a river and its floodplain requires treating channel banks as moving internal boundaries, and (ii) these moving boundaries regulate the flow of water and sediment between the two domains in ways that differ in time and space. This research changes the way in which the boundary between the river and its floodplain is commonly viewed and analyzed; from a static boundary demarcating where the river ends and the floodplain begins, to a geomorphic transition whose spatial and temporal evolution controls the interactions between a river and its floodplain. Multiple planned activities integrate research and education to advance the inclusion of diverse groups in the geosciences and engineering and to bridge the gap between data analysts and modelers. This award is co-funded by the Geomorphology & Land-use Dynamics and Hydrologic Sciences programs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.