Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Determining Flow Directions in River Channel Networks Using Planform Morphology and Topology

TitleDetermining Flow Directions in River Channel Networks Using Planform Morphology and Topology
Publication TypeJournal Article
Year of Publication2019
JournalEarth Surface Dynamics
Abstract / Summary

The abundance of global, remotely-sensed surface water observations has paved the way toward characterizing and modeling how water moves across the Earth’s surface through complex channel networks. In particular, deltas and braided river channel networks may contain thousands of links that route water, sediment, and nutrients across landscapes. In order to model flows through channel networks and characterize network structure, the direction of flow for each link within the network must be known. In this work, we propose a rapid, automatic, and objective method to identify flow directions for all links of a channel network using only remotely-sensed imagery and knowledge of the network’s inlet and outlet locations. We designed a suite of direction-predicting algorithms (DPAs), each of which exploits a particular morphologic characteristic of the channel network to provide a prediction of a link’s flow direction. DPAs were chained together to create “recipes”, or algorithms that set all the flow directions of a channel network. Separate recipes were built for deltas and braided rivers and applied to seven deltas and two braided river channel networks. Across all nine-channel networks, the recipes’ predicted flow directions agreed with expert judgment for 97% of all tested links, and most disagreements were attributed to unusual channel network topologies that can easily be accounted for by pre-seeding critical links with known flow directions. 

URLhttps://www.earth-surf-dynam-discuss.net/esurf-2019-19/
DOI10.5194/esurf-2019-19
Journal: Earth Surface Dynamics
Year of Publication: 2019
Publication Date: 05/2019

The abundance of global, remotely-sensed surface water observations has paved the way toward characterizing and modeling how water moves across the Earth’s surface through complex channel networks. In particular, deltas and braided river channel networks may contain thousands of links that route water, sediment, and nutrients across landscapes. In order to model flows through channel networks and characterize network structure, the direction of flow for each link within the network must be known. In this work, we propose a rapid, automatic, and objective method to identify flow directions for all links of a channel network using only remotely-sensed imagery and knowledge of the network’s inlet and outlet locations. We designed a suite of direction-predicting algorithms (DPAs), each of which exploits a particular morphologic characteristic of the channel network to provide a prediction of a link’s flow direction. DPAs were chained together to create “recipes”, or algorithms that set all the flow directions of a channel network. Separate recipes were built for deltas and braided rivers and applied to seven deltas and two braided river channel networks. Across all nine-channel networks, the recipes’ predicted flow directions agreed with expert judgment for 97% of all tested links, and most disagreements were attributed to unusual channel network topologies that can easily be accounted for by pre-seeding critical links with known flow directions. 

DOI: 10.5194/esurf-2019-19
Citation:
Schwenk, J, A Piliouras, and JC Rowland.  2019.  "Determining Flow Directions in River Channel Networks Using Planform Morphology and Topology."  Earth Surface Dynamics.  https://doi.org/10.5194/esurf-2019-19.