Stream Power and Geomorphic Changes on the Blanco River Post 2015 Memorial Day Flood of Record in Wimberley, Texas, USA
Date
2022-12
Authors
Schlandt, Allyson
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Abstract
Stream power is an indicator of a river’s ability to trigger geomorphic changes within their channel and surrounding landscape. In May of 2015, the Blanco River watershed experienced a flood of record, the 2015 Memorial Day flood, which initiated multiple geomorphic disturbances. In this study, I aim to determine (1) whether unit stream power had a direct influence on the amount and severity of initial geomorphic disturbance that occurred within a 12,000-meter reach of the Blanco River near Wimberley, Texas, and (2) what types of in-stream and channel changes/adjustments have occurred in the reaches since the Memorial Day flood that could be attributed to annual peak flows. I also examined geomorphic changes proximal to three tributary confluences. My research uses a combination of observation-based aerial imagery analysis, nonparametric statistics, and flood frequency analysis. Results of this study show that unit stream power has weak correlations with the types of geomorphic disturbances, and while the 2015 Memorial Day flood produced substantial changes, no major changes to the study area’s width have occurred since 2015. This study contributes to the literature on bedrock rivers, how they respond to catastrophic floods, and whether geomorphic changes can be attributed to high magnitude, low frequency floods or low(er) magnitude, high frequency floods.
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Keywords
fluvial geomorphology, floods, flooding, stream power
Citation
Schlandt, A. (2022). Stream power and geomorphic changes on the Blanco River post 2015 Memorial Day flood of record in Wimberley, Texas, USA (Unpublished thesis). Texas State University, San Marcos, Texas.