Author(s): B. N. Bockelmann; B. Lin; R. A. Falconer
Linked Author(s):
Keywords: River Restoration; Ecohydrology; River Modelling; Curvilinear Grid; Hydroinformatics; FST-Hemispheres
Abstract: The main aims of this combined field and numerical study were the development and validation of an integrated ecohydraulics tool, which links the hydraulics, the morphology and the ecology to assess the overall stability and ecological quality of river restoration schemes. The primary objective of river restoration schemes and environmentally-sensitive morphological designs is the regeneration and enhancement of ecological diversity. Typically, the creation of morphological features and meander bends gives a hydrodynamic environment which is enriched by longitudinal and lateral variations in bathymetry, water depth and bed armour material. A unique ecological and hydromorphological data set was collected along the stream, which was used for calibration and validation of the ecohydraulics model. The morphological development of characteristic cross-sections was surveyed and sediment sorting processes, especially across meander bends, were observed as an indication of the development of diverse habitat. Additionally, FST-hemisphere measurements were carried out and reported bed shear stresses were compared with model results. The two dimensional model DIVAST (Falconer, 1993; Falconer et al., 1998), which is based on the finite difference method, was used in conjunction with a curvilinear grid, which was found to best represent and adapt to the meandering channel form, to solve the hydrodynamics of a double meandering section. This ecohydraulics tool was then combined with habitat preference indicators to predict suitability for the instream biology, i.e. benthic macroinvertebrates in this study.
Year: 2003