Channel Morphology, Streamflow Patterns, and Sediment Transport of Two Intermittent Rivers along the Balcones Escarpment

<p>Despite a recent increase in intermittent river research focusing on the mechanisms driving flow intermittence and the role they play in the biological community, first order controls, such as the geology, land cover, and climate of the watershed, are not well understood. The rise of interm...

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Bibliographic Details
Main Author: Dorn, Taylor C.
Language:EN
Published: University of Louisiana at Lafayette 2019
Subjects:
Online Access:http://pqdtopen.proquest.com/#viewpdf?dispub=10811929
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Summary:<p>Despite a recent increase in intermittent river research focusing on the mechanisms driving flow intermittence and the role they play in the biological community, first order controls, such as the geology, land cover, and climate of the watershed, are not well understood. The rise of intermittent river research coincides with them becoming increasingly more prevalent on Earth due to climate change and water abstraction. While these problems are observed more clearly in arid regions, little research is focused in areas with greater rainfall amounts, such as in central Texas, where there are currently no known studies focusing on intermittent rivers. Here, we collected data over the course of nine months (April 2017 ? January 2018) within Schulle Canyon and Spring Lake Preserve, to determine how their morphology changed over time, their capacity to transport sediment, and the drivers of their intermittency. To answer these questions, three methods were used: 1. Ten cross-sectional surveying points were taken in each river to show how each river?s morphology changes over time, 2. Passive Integrated Transponders were inserted into 60 grains varying in size to track, via GPS, how far those grains traveled after a rainfall event, and 3. 30 Stream, Temperature, Intermittency, and Conductivity sensors were longitudinally deployed down each river to determine where and when water is present. From these collected field data, we found that Schulle Canyon?s morphology did not change over nine months, while Spring Lake saw a change in five of its cross sections, most notably cross sections 6, 9, and 10. Water levels were estimated to depths of 30 cm mostly between August 26 - 28, 2017, which coincided with Hurricane Harvey. In each intermittent river, little to no sediment transport was recorded, with all grain sizes staying within 12 m of their starting point. This study provides much-needed data on sediment transport in intermittent rivers.