Accumulation of fine sediment within substrate gravels along two regulated rivers, UK
Accumulation of fine sediment within substrate gravels along two regulated rivers, UK
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英国两条受监管河流的基底砾石内细小沉积物的积累
DOI：
10.1002/rrr.3450020208
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
G. Petts
中科院分区：
文献类型：
--
作者：
G. Petts
河床物质对湖相生物群有显著的影响。试验研究表明，水流调节，特别是洪水事件的减少，可能导致细颗粒渗透到支流沙源下游的开阔框架砾石中，并使这些泥沙集中在这些砾石中。本文研究了英国高地两条受管制河流的河道底质砾石中细粒(小于2毫米)的分布。
使用了批量取样和冷冻取样技术：后者产生的罚金是前者的五倍。这突出了大样本采集过程中的冲刷问题，特别是在致密、粗糙的砾石基质中。然而，两个数据集都揭示了相同的空间格局。在这两条受管制的河流，底质细度小于2毫米的比例按重量计算超过支流汇流下方的20%，而非管制地点的比例不到5%。在汇流处下游，基质沉积物的数量和大小都减少了。这种影响的空间规模很小，由此产生的底质沉积的生态后果可能是局部性的。
The channel-bed materials have a marked influence on the biota of lotic systems. Experimental studies suggest that flow regulation, specificially the reduction in magnitude of flood events, may lead to the infiltration of fine particles into, and the concentration of these sediments within, open framework gravels downstream from tributary sediment sources. This paper examines the distribution of fines (sub-2 mm), within channel substrate gravels along two regulated rivers in upland Britain.
Bulk- and freeze-sample techniques were used: the latter yielded volumes of fines five times those of the former. This emphasizes the problem of wash-out during bulk-sample collection, especially in compact, coarse gravel substrates. Nevertheless, the same spatial pattern was revealed by both data sets. Along both regulated rivers, the proportion of the substrate finer than 2 mm exceeds 20 per cent, by weight, below tributary confluences, contrasting with values for non-regulated sites of less than 5 per cent. Both the amount and size of matrix sediments decrease downstream from the confluences. The spatial scale of the impact is small and the resultant ecological consequences of substrate sedimentation are likely to be localized.