How do macrophyte distribution patterns affect hydraulic
resistances? In eutrophic river systems, macrophytes attain high
biomass with reduced drainage and increased flooding risk. To
avoid these problems, water managers remove vegetation. Total
removal, however, increases wash out of macro-invertebrate
communities reducing the ecological value of rivers. Partial
vegetation removal reduces this washout and prevents an increase
in hydraulic resistance. In this, study the hydraulic
performance of three partial vegetation removal patterns was
tested. From the results it was seen that hydraulic resistance,
expressed as Manning's n, was varying between 0.025 m−1/3 s and
0.050 m−1/3 s. Compared with the empty situation, the different
distribution patterns increased resistance between 14 and 23%.
Hydraulic resistance of these patterns was also significantly
influenced by the species present in the vegetation patches.
Three groups of macrophyte plants (emerged, floating leaved and
submerged) with significantly differ