Dataset associated with "Spatial and temporal patterns of sediment storage and erosion following a wildfire and extreme flood"
Date
2019
Authors
Nelson, Peter A.
Brogan, Daniel J.
Journal Title
Journal ISSN
Volume Title
Abstract
Post-wildfire landscapes are highly susceptible to rapid geomorphic changes at both the hillslope and watershed scales due to the increases in infiltration-excess overland flow, hillslope and channel erosion, and downstream deposition. While there have been numerous studies of these processes at the hillslope scale, relatively few studies have documented larger-scale post-fire geomorphic changes over time. In this study we used five airborne laser scanning (ALS) datasets collected over four years to quantify valley bottom changes in two ~15 km2 watersheds, Skin Gulch and Hill Gulch, after the June 2012 High Park fire in northern Colorado and followed by a large mesoscale flood 15 months later. The objectives were to: 1) quantify spatial and temporal patterns of erosion and deposition throughout the channel network following the wildfire and subsequent flooding; and 2) investigate the extent to which these changes can be related to precipitation amounts and intensities, burn severity, and valley and basin morphology. Geomorphic changes were quantified using a DEMs of difference (DoD) approach for the channel network segmented into 50-m lengths. The DoDs show net sediment accumulation after the wildfire in the valley bottoms in both watersheds, with the greatest accumulation after summer thunderstorms in the first two years after burning in areas with wider and flatter valley bottoms. In contrast, the mesoscale flood caused large amounts of net erosion, with the greatest erosion in those areas with the greatest post-fire deposition. Volume changes for the different time periods were low but significantly correlated to, in order of highest correlation, contributing area, channel width, percent burned at high and/or moderate severity, channel slope, confinement ratio, maximum 30-minute rainfall, and total rainfall. These results suggest that morphometric characteristics, when combined with burn severity and a specified storm, can indicate the relative likelihood and locations for post-fire erosion and deposition. This information can help assess downstream risks and prioritize areas for post-fire hillslope rehabilitation treatments.
Description
Data provided include digital elevation models (DEMs), DEM of Differences (DoD), rainfall depth and maximum 30-minute intensity (MI30), and morphometric data for analyses on two burned watersheds, Skin Gulch (SG) and Hill Gulch (HG), just west of Fort Collins, Colorado, U.S.A. The DEMs and DoDs cover the channel networks, while the precipitation data cover the entire watersheds. For more detailed information about the methodology in creating these data and how the data were used please refer to Brogan (2018).
Walter Scott, Jr. College of Engineering
Department of Civil and Environmental Engineering
Walter Scott, Jr. College of Engineering
Department of Civil and Environmental Engineering
Rights Access
Subject
wildfire
floods
erosion
deposition
sediment availability
high-resolution topography
Citation
Associated Publications
Brogan, Daniel Joseph, Spatial and temporal channel changes across the watershed scale following wildfire and floods. (Unpublished doctoral dissertation), Colorado State University, 2018. https://hdl.handle.net/10217/193215
Brogan, D. J., Nelson, P. A., and MacDonald, L. H.: Spatial and temporal patterns of sediment storage and erosion following a wildfire and extreme flood, Earth Surf. Dynam., 7, 563-590, https://doi.org/10.5194/esurf-7-563-2019, 2019.
Brogan, D. J., Nelson, P. A., and MacDonald, L. H.: Spatial and temporal patterns of sediment storage and erosion following a wildfire and extreme flood, Earth Surf. Dynam., 7, 563-590, https://doi.org/10.5194/esurf-7-563-2019, 2019.