Hyporheic and total transient storage in small, sand‐bed streams
Hyporheic and total transient storage in small, sand‐bed streams
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小型沙床溪流中的潜流和总瞬时储存
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
G. Fox
中科院分区：
文献类型：
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作者：
J. Stofleth;F. Shields, Jr.;G. Fox
河流生态系统中的关键过程与水力滞留有关，水力滞留是指河流水流偏离理想的“活塞流”，反映了通过地表和潜流储存区的流体运动。大多数关于潜流交换的现有信息都是基于水槽研究或在床层比沙子粗的相对陡峭的河流中进行的实地测量。流示踪剂研究可用于量化整体水力滞留，但表面和潜流滞留的分解仍然很困难。在自由流和阻塞流条件下，采用水流示踪法计算了两条小型砂床水流短河段中水流与蓄水区（总蓄水量）中水的交换率。将示踪曲线拟合至一维转运和流入储存模型奥蒂斯-P。压力计网络用于测量河流和地下水之间的比流量。在所研究的砂床河流中，描述总滞留量的参数位于文献汇编数据的前50%，其中大多数代表床层比砂粗的河流。然而，潜流储存是一个微不足道的组成部分，总的水力保留，仅占0.01 - 0.49%的总交换，这一部分并没有增加后，安装流动障碍。总滞留量不随床料尺寸而系统变化，但在流动受阻后增加50-100%。去除粗糙元素，如大型木材和碎片坝，对依赖于小型砂床流中瞬时储存的过程有害。版权所有© 2007约翰威利父子有限公司.
Key processes in stream ecosystems are linked to hydraulic retention, which is the departure of stream flow from ideal ‘plug flow’, and reflects fluid movement through surface and hyporheic storage zones. Most existing information about hyporheic exchange is based on flume studies or field measurements in relatively steep streams with beds coarser than sand. Stream tracer studies may be used to quantify overall hydraulic retention, but disaggregation of surface and hyporheic retention remains difficult. A stream tracer approach was used to compute the rates at which stream water is exchanged with water in storage zones (total storage) in short reaches of two small, sand‐bed streams under free and obstructed flow conditions. Tracer curves were fit to the one‐dimensional transport with inflow storage model OTIS‐P. Networks of piezometers were used to measure specific discharge between the stream and the groundwater. In the sand‐bed streams studied, parameters describing total retention were in the upper 50% of data compiled from the literature, most of which represented streams with beds coarser than sand. However, hyporheic storage was an insignificant component of total hydraulic retention, representing only 0·01–0·49% of total exchange, and this fraction did not increase after installation of flow obstructions. Total retention did not vary systematically with bed material size, but increased 50–100% following flow obstruction. Removal of roughness elements, such as large wood and debris dams, is detrimental to processes dependent upon transient storage in small, sand‐bed streams. Copyright © 2007 John Wiley & Sons, Ltd.