Effects of riparian vegetation on topographic change during a large flood event, Rio Puerco, New Mexico, USA

Journal of Geophysical Research F: Earth Surface
By: , and 

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Abstract

The spatial distribution of riparian vegetation can strongly influence the geomorphic evolution of dryland rivers during large floods. We present the results of an airborne lidar differencing study that quantifies the topographic change that occurred along a 12 km reach of the Lower Rio Puerco, New Mexico, during an extreme event in 2006. Extensive erosion of the channel banks took place immediately upstream of the study area, where tamarisk and sandbar willow had been removed. Within the densely vegetated study reach, we measure a net volumetric change of 578,050 ± ∼ 490,000 m3, with 88.3% of the total aggradation occurring along the floodplain and channel and 76.7% of the erosion focusing on the vertical valley walls. The sediment derived from the devegetated reach deposited within the first 3.6 km of the study area, with depth decaying exponentially with distance downstream. Elsewhere, floodplain sediments were primarily sourced from the erosion of valley walls. Superimposed on this pattern are the effects of vegetation and valley morphology on sediment transport. Sediment thickness is seen to be uniform among sandbar willows and highly variable within tamarisk groves. These reach-scale patterns of sedimentation observed in the lidar differencing likely reflect complex interactions of vegetation, flow, and sediment at the scale of patches to individual plants.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Effects of riparian vegetation on topographic change during a large flood event, Rio Puerco, New Mexico, USA
Series title Journal of Geophysical Research F: Earth Surface
DOI 10.1002/jgrf.20073
Volume 118
Issue 3
Year Published 2013
Language English
Publisher AGU Publications
Contributing office(s) National Research Program - Central Branch
Description 17 p.
First page 1193
Last page 1209
Country United States
State New Mexico
Other Geospatial Rio Puerco