Erosion and channel changes due to extreme flooding in the Fourmile Creek catchment, Colorado
Erosion and channel changes due to extreme flooding in the Fourmile Creek catchment, Colorado
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科罗拉多州四英里溪流域的极端洪水导致侵蚀和河道变化
DOI：
10.1016/j.geomorph.2017.03.030
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发表时间：
2017
期刊：
影响因子：
3.9
通讯作者：
W. Ouimet
中科院分区：
文献类型：
--
作者：
Will Wicherski;D. Dethier;W. Ouimet
罕见的大规模地貌事件在地质学上的短时间尺度上产生可量化的变化，对理解景观演化至关重要。机载激光雷达调查和现场测量被用来调查沿Fourmile Creek，科罗拉多，2010年野火后，2013年严重洪水破坏的19.5公里范围内的洪泛区侵蚀和沉积沿着。2013年9月9日至15日，Fourmile集水区降雨量超过350 mm，在Orodell水位计处产生的流量超过平滩流量超过120 h，整个研究河段的当地单位水流功率大于300 W m− 2。泥石流发生在最强烈的燃烧区的陡峭山坡和支流通道上。激光雷达差异测量和实地研究突出了研究河段沿着的局部沉积区，但显示Fourmile洪泛区19.5 km河段的总体净侵蚀约为0.25 m，主要是由于河道拓宽。支流交界处的泥石流沉积物进入河漫滩和当地单位流功率的减少控制了一些地区的沉积。总体而言，质量平衡计算表明，Fourmile Creek洪泛区和山坡的总泥沙流失量约为91，000 - 161，000 m3，这与71，000 - 111，000 m3的河道泥沙通量估计值大致一致。Fourmile流域的测量结果表明，洪泛区侵蚀是2013年洪水中沉积物的主要来源，并表明以长时间洪水和高总能量消耗为特征的罕见事件可以占山溪中总沉积物运输的很大一部分。
Infrequent, large magnitude geomorphic events generate quantifiable change on geologically short timescales and are crucial to understanding landscape evolution. Airborne lidar surveys and field measurements were used to investigate floodplain erosion and deposition along a 19.5 km reach of Fourmile Creek, Colorado that was devastated by severe flooding in 2013 that followed a 2010 wildfire. > 350 mm of rain fell on the Fourmile catchment from September 9–15, 2013, generating discharge that exceeded bankfull for > 120 h at the Orodell gage, with local unit stream power > 300 W m− 2throughout the study reach. Debris flows occurred on steep hillslopes and tributary channels in the most intensely burned areas. Lidar difference measurements and field studies highlight zones of local deposition along the study reach, but demonstrate overall net erosion of ~ 0.25 m for the 19.5 km reach of Fourmile floodplain, mainly by channel widening. Tributary junctions where debris-flow sediment entered the floodplain and local decreases in unit stream power controlled some zones of deposition. Overall, mass balance calculations show that a total sediment loss of ~ 91,000–161,000 m3from the Fourmile Creek floodplain and hillslopes, which is broadly consistent with channel sediment flux estimates of 71,000–111,000 m3. Measurements from the Fourmile catchment demonstrate that floodplain erosion was a major source of sediment in the 2013 flood and demonstrate that infrequent events marked by long-duration flooding and high total energy expenditure can account for a large fraction of total sediment transport in mountain streams.
影响因子：
12.1
作者：
O. Korup
通讯作者：
O. Korup