Characteristics of Past Flood Behavior Reconstructed from Botanical Evidence in a Mountain Gorge River System
Characteristics of Past Flood Behavior Reconstructed from Botanical Evidence in a Mountain Gorge River System
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DOI：
10.13101/ijece.3.27
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
Takashi Kimura;Sunao Watanabe;S. Kim;T. Marutani
中科院分区：
文献类型：
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作者：
Takashi Kimura;Sunao Watanabe;S. Kim;T. Marutani
为了重建山区峡谷水道中高强度洪水的历史，对两个垂直隔离的阶地的植物学证据进行了调查，这些阶地被认为只受到大的、罕见的洪水的影响。最高水位是根据过去20年主要风暴事件期间的最高流量和堤坝流量估算出来的。灌木的伤害明显表明，1993年暴雨事件中下游梯田发生了溢流，但根据洪峰流量和漫滩流量的估算，没有洪水事件发生在两个梯田表面。我们还发现了1993年暴雨事件中，下游梯田对面斜坡上的一次滑坡导致了滑坡坝的现场证据。在1993年的事件中，滑坡大坝的形成可能导致当地溢流到下游梯田上。因此，不仅要研究山区峡谷水系的水文特征、流量大小和频率，而且要了解横向输沙的时空格局，才能了解山区峡谷水系的洪水行为。
To reconstruct the history of high-magnitude floods in a mountain gorge channel, botanical evidence from two vertically isolated strath terraces assumed to be affected only by large, infrequent floods was investigated. The maximum water level was estimated from peak and bankfull discharges during major storm events of the past 20 years. Injury of shrubs significantly indicated that overflow on the downstream terrace occurred in 1993 storm event, but no flood event overflowed both terrace surfaces according to the estimation of peak and bankfull discharges. We also found field evidences that a landslide on the slope opposite the downstream terrace generated a landslide dam in 1993 storm event. Formation of the landslide dam probably caused local overflow onto the downstream terrace during the 1993 event. Therefore, it is essential to investigate not only the hydrologic characteristics, magnitude, and frequency of discharge, but also the spatial and temporal patterns of lateral sediment input to the channel to understand flood behavior in mountain gorge river systems.