Natural Streams and the Legacy of Water-Powered Mills
Natural Streams and the Legacy of Water-Powered Mills
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DOI：
10.1126/science.1151716
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发表时间：
2008-01
期刊：
影响因子：
56.9
通讯作者：
R. Walter;D. Merritts
中科院分区：
文献类型：
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作者：
R. Walter;D. Merritts
砾石层河流被认为具有典型的曲流形式，其边界是自生的细粒洪泛平原。这一理想指导着数十亿美元的河流恢复产业。我们已经绘制了许多沉积物的地图和日期，这些沉积物沿着大西洋中部的河流，形成了这个被广泛接受的模型的基础。这些数据以及历史地图和记录显示，在欧洲人定居之前，这些河流是广泛植被湿地内的小分支通道，几乎没有沉积物，但储存了大量的有机碳。随后，1至5米的静水沉积，在成千上万的17至19世纪的磨坊坝后面，用细泥沙掩埋了定居前的湿地。这些研究结果表明，大多数洪泛平原沿着大西洋中部的溪流，实际上是填补阶地，和历史上切割渠道不是自然的原型蜿蜒的河流。
Gravel-bedded streams are thought to have a characteristic meandering form bordered by a self-formed, fine-grained floodplain. This ideal guides a multibillion-dollar stream restoration industry. We have mapped and dated many of the deposits along mid-Atlantic streams that formed the basis for this widely accepted model. These data, as well as historical maps and records, show instead that before European settlement, the streams were small anabranching channels within extensive vegetated wetlands that accumulated little sediment but stored substantial organic carbon. Subsequently, 1 to 5 meters of slackwater sedimentation, behind tens of thousands of 17th- to 19th-century milldams, buried the presettlement wetlands with fine sediment. These findings show that most floodplains along mid-Atlantic streams are actually fill terraces, and historically incised channels are not natural archetypes for meandering streams.