Planform geometry comparison of modern river channels in relation to their channel belts

Abstract

As a river avulses over time it creates an amalgamation of all previous flow paths of the river. The outer most points of the previous flow paths is the channel belt. Where these prior flow paths overlap one another on the channel belt is an unconformable point. To better understand these ancient rivers, modern river systems are being mapped to find mathematical relationship between current flow path and the channel belt of river systems. It is important to examine a wide range of systems in terms of age, size, and location. The rivers are being mapped using a Planform Geometry toolbox within ArcGIS and aerial photographs. There are three features being mapped on modern river system; the width of the river in relation to the width of the channel belt; the curvature of the meander scars on the channel belt; and the number of unconformable points within a given distance on the river. We have three hypotheses for these mapped features. First, the ratio of current width to that of the channel belt will be consistent from river system to system. Two, curvature density of the river will be consistent to the curvature density of the channel belt. Third, a ratio created from river width to downstream length should yield a consistent number of unconformable points for any river system.

AAPG Datapages/Search and Discovery Article #90221 © 2015 Mid-Continent Section, Tulsa, Oklahoma, October 4-6, 2015