1. Replacement of artificial riffles in canalized rivers is a widely-used tool in river rehabilitation but its effectiveness is only infrequently evaluated. In this paper artificial riffles, placed in a 2-km length of lowland stream in eastern England, were evaluated using geomorphological, function
The biological effectiveness of artificial riffles in river rehabilitation
โ Scribed by MOHAMMAD EBRAHIMNEZHAD; DAVID M. HARPER
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 188 KB
- Volume
- 7
- Category
- Article
- ISSN
- 1052-7613
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โฆ Synopsis
The biological effectiveness of a series of artificial riffles constructed from cobble-sized local material in the channelized Harper's Brook (Northamptonshire, England) was measured by comparing the macroinvertebrate communities of three new riffles with a control natural riffle upstream, and with three original channelized stretches (runs).
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The mean diversity of macroinvertebrates in the seven sites was significantly different: diversities of the natural riffle and two shallower artificial riffles were highest, whilst those of the other deeper, artificial riffle and the three channelized runs were lowest.
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There was significant negative correlation between diversity and depth; significant positive correlation between diversity and velocity.
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Artificial riffles, if correctly constructed, do improve the habitats and increase biodiversity of macroinvertebrates to levels similar to a natural riffle. A minimum velocity of 40 cm s 71 and maximum depth of 25 cm is necessary during low-flow discharges for artificial riffles to function biologically as natural riffles.
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