Author(s): F. Schoberl
Linked Author(s): Friedrich Schöberl
Keywords: Eco-hydraulics; Instream habitat models; Habitat suitability; Spatial resolution; Gravel-bed rivers
Abstract: An extended study was performed to analyze the results of habitat modeling based on different spatial resolutions. For this comparison different reaches of the river Lech/Austria were investigated using the CASIMIR software. The aim of the investigations rested on a detailed comparison of 1D-and 2D-modelling results. Bed geometry for the 2D models was represented by a dense structured grid adapted to the terrestrial survey data. For 1D-simulations closely spaced cross-sections (10m-20m distance in the streamwise direction) were deduced from the 2D-grid. The 1Dwater levels were calibrated using 2D results. The habitat evaluation was based on the WUA-index. 1D-WUA-values depicted strong differences depending on the life stage of the investigated species as well as the kind of river course. Particular overestimations could be observed for adult fishes in braided reaches but restricted to lower flow rates. However, for juvenile fishes and higher flow rates, 1Dcomputations in general tended to underestimate the possible suitable area..
Year: 2009