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A framework for evaluating the spatial configuration and temporal dynamics of hydraulic patches
Author(s) -
Wallis C.,
Maddock I.,
Visser F.,
Acreman M.
Publication year - 2012
Publication title -
river research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.679
H-Index - 94
eISSN - 1535-1467
pISSN - 1535-1459
DOI - 10.1002/rra.1468
Subject(s) - ecotone , hydrology (agriculture) , spatial variability , environmental science , hydraulics , flow (mathematics) , bedform , hydraulic structure , geology , geotechnical engineering , ecology , mathematics , geomorphology , geometry , sediment , statistics , engineering , sediment transport , shrub , aerospace engineering , biology
A framework for evaluating the spatial configuration and temporal dynamics of hydraulic patches was tested in a UK lowland river. Detailed hydraulic assessment was carried out at four discharges between 0.303 m 3 s −1 and 1.410 m 3 s −1 in a 56 m reach. Five hydraulic patches, as combinations of depth and mean column velocity, and the transitional zones between them were delineated using fuzzy cluster analysis. The composition and configuration of the hydraulic patch mosaic was quantified using spatial metrics. Results showed that the proportion, size, shape and relative location of hydraulic patches all varied with discharge, however intermediate flows appeared to support the most diverse hydraulic patch composition and configuration. This suggests the spatial influence of mesoscale bedforms on hydraulic patches is mediated by temporal variations in discharge. Transitional areas between hydraulic patches occupied a significant proportion of the reach at all flows (33–38%) and may function as in‐stream ecotones. The framework addresses the need for a quantitative, spatially explicit approach to hydraulic assessment which could be used to assess the implications of flow regulation and hydromorphological alteration on hydraulic diversity. Copyright © 2010 John Wiley & Sons, Ltd.