Rates and processes of channel development and recovery following the 1980 eruption of Mount St. Helens, Washington
Rates and processes of channel development and recovery following the 1980 eruption of Mount St. Helens, Washington
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DOI：
10.1080/02626668909491318
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发表时间：
1989-04
期刊：
影响因子：
--
通讯作者：
D. F. Meyer;H. Martinson
中科院分区：
文献类型：
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作者：
D. F. Meyer;H. Martinson
1980年5月18日，圣海伦斯火山爆发后，河道的发展导致了地球上任何地方有记录以来最大的沉积物产量。在北福克图特尔河（North Fork Toutle River）2.7 km 3的泥石流存款上开发新的河道，每年造成的净侵蚀量高达1.3 x 105 t km−2。这些渠道的发展遵循四个阶段的序列，渠道的启动，渠道切割相对恒定的宽深比，渠道拓宽伴随着加积，和渠道拓宽伴随着回填和填充，在平均渠道高程变化不大。这些水道在宽度和高度上都不稳定。火山泥流影响了火山两侧的通道和山谷形态。陡峭的上游河段在喷发后的第一年内普遍切割和加宽，并在随后的三年内加积。第一年，下游缓坡河段加积和加宽，随后切割。
Abstract Stream channel development in response to the eruption of Mount St. Helens on 18 May 1980, resulted in some of the largest sediment yields documented anywhere on earth. Development of new channels on the 2.7 km3 debris-avalanche deposit in the North Fork Toutle River caused net erosion of as much as 1.3 x 105 t km−2 annually. Development of these channels followed a four-stage sequence of channel initiation, channel incision with relatively constant width-to-depth ratio, channel widening accompanied by aggradation, and channel widening accompanied by scour-and-fill with little change in average channel elevation. These channels remain unstable both in width and elevation. Lahars affected channel and valley morphology on all flanks of the volcano. Steep, upstream reaches generally incised and widened during the first year following the eruption and aggraded during the following three years. Gently sloping downstream reaches aggraded and widened during the first year and incised during the followin...