Shore-based monitoring of flow dynamics in a steep bedrock canyon river

Saber Ansari,Jeremy G Venditti,Eva Kwoll,Colin D Rennie,Kirsti Fairweather,A Paquier,N Rivière

doi:10.1051/e3sconf/20184006025

Saber Ansari, Jeremy G Venditti + Show 5 more

Open Access

https://doi.org/10.1051/e3sconf/20184006025

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Abstract

The pace of landscape evolution is set by bedrock erosion in canyons. This phenomenon occurs by various geological processes including plucking of bedrock blocks and abrasion by saltating bedload and suspended load in highly turbulent flows. For a better understanding of the river flow characteristics in bedrock rivers, a comprehensive study of flow dynamics was undertaken in Black Canyon in the Fraser River, British Columbia. We used shore-based video imagery of the river to study surface flow dynamics. The shore-based monitoring system consisted of a Campbell Scientific camera mounted at the top of the canyon walls. We monitored the water surface boils due to upwelling and determined river surface flow velocities from the shore-based imagery. Automatic detection of the upwelling surface boils leads to a better understanding of the secondary circulation patterns and flow structures in this large steep river bedrock canyon. The data collection and analytical procedures developed in this research are cost-effective tools for remotely determining flow dynamics, which can be applied to other rivers.

Highlights

Understanding river hydraulics in bedrock canyons is crucial in the better quantification of incision processes. This can lead to the development of more robust sediment transport models in steep bedrock canyon conditions
The advent of low cost, high-resolution digital cameras and the fast development of different computer vision methods have led to the broad usage of image-based monitoring systems in earth sciences
A shore-based monitoring method was proposed for a better understanding of the flow characteristics in a steep bedrock canyon

Summary

Introduction

Interconnected dynamic interior and exterior earth processes affect surface landscape in long-term. Bedrock canyon erosion is amongst the most significant processes affecting landscape dynamics. Bedrock incision in rivers can be the result of plucking and abrasion processes. Understanding river hydraulics in bedrock canyons is crucial in the better quantification of incision processes. This can lead to the development of more robust sediment transport models in steep bedrock canyon conditions. The advent of low cost, high-resolution digital cameras and the fast development of different computer vision methods have led to the broad usage of image-based monitoring systems in earth sciences. Development of different monitoring systems has led to the application of these cost-

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