Effect of flow-related substrate alteration on Physical Habitat: A case study of the endemic river Loach Sinogastromyzon puliensis (Cypriniformes, Homalopteridae) downstream of chi-chi diversion weir, chou-shui creek, Taiwan
Journal
River Research and Applications
Journal Volume
18
Journal Issue
2
Pages
155-169
Date Issued
2002
Author(s)
Wang C.-F.
Abstract
Abstract This paper addresses the variation of substrate status with flow in the framework of habitat simulation. The Physical Habitat Simulation System (PHABSIM) was developed as a tool for water management and has become one of the most popular methods worldwide. Despite its many advantages, the variation of channel properties with flow is not addressed in PHABSIM. We modified PHABSIM by incorporating a sub‐program that can perform substrate analyses under five different schemes for evaluating the substrate suitability. These schemes include the conventional methods to specify the substrate attribute (scheme 1) and to use the mean grain size of the original bed material for determining the substrate suitability (scheme 2), or employ the threshold conditions for sediment entrainment to evaluate the nominal grain size of the stable substrate (schemes 3–5). As a case study, Sinogastromyzon puliensis in Chou‐Shui Creek (Taiwan) is selected as the target species for the habitat simulation. For schemes 1 and 2, the substrate attribute specified for each cell of a cross‐section does not change with flow. The nominal grain size of the stable armour material (scheme 5) is generally greater than the nominal grain sizes of the above‐critical bed material (scheme 3) and the static armour layer (scheme 4). The simulation results indicate that the suitability values specified in scheme 1 and the resulting habitat area are on the optimistic side, whereas scheme 2 tends to undervalue the suitability of the hydraulically worked substrate. The overall variation trends of the weighted usable area (or percentage usable area) curves for different substrate schemes are similar, especially in the in‐phase regions of the water velocity and depth. The results of this study appear to imply that the flow‐related habitat analyses are not usually sensitive to substrate. Copyright © 2002 John Wiley & Sons, Ltd.
SDGs
Type
journal article