Environmental Flows: Habitat Modeling
Aquatic habitat modelling is commonly used in riverine wetlands for environmen.tal flow assessments as a means of defining the empirical relationship between environmental variables, and usable habitat for selected target species, life stages or aquatic communities. Aquatic habitat modelling is used to determine environmental flow strategies by estimating the effects of historic, current or future flow scenarios on habitat availability. The origins of aquatic habitat modelling for determining environmental flows can be traced to the development of the Instream Flow Incremental Methodology (IFIM) and the set of computer programs required to implement an IFIM study, i.e. the Physical Habitat Simulation (PHABSIM) system. More recently, other models have used alternative approaches, such as CASiMiR (Computer Aided Simulation Model for Instream Flow and Riparia) that utilises a mix of expert opinion and fuzzy logic based rules to describe the habitat use of target species or the application of multidimensional, i.e., two-dimensional and to a lesser extent three-dimensional hydraulic-habitat models. These enable an enhanced representation of the hydraulic environment and allow the calculation and modelling of turbulent flow properties. However, a knowledge of how biota respond to and are influenced by these properties remains an ongoing challenge to incorporate them into environmental flow setting.
KeywordsIFIM PHABSIM CASiMiR Habitat suitability curves Hydraulic habitat models Fuzzy logic
- Bovee KD. A guide to stream habitat analysis using the IFIM – report FWS/OBS-82/26. Fort Collins: US Fish and Wildlife Service; 1982.Google Scholar
- Jowett Consulting. RYHABSIM. 2011. http://www.jowettconsulting.co.nz/home/rhyhabsim. Accessed 23 June 2014.
- Nestler J, Milhous RT, Layzer JB. Instream habitat modelling techniques. In: Gore JA, Petts GE, editors. Alternatives in regulated river management. Boca Raton: CRC Press; 1989. p. 295–316.Google Scholar
- Thomas R. Payne and Associates. RHABSIM version 3.0. http://trpafishbiologists.com/rindex.html. 2013. Accessed 23 June 2014.
- Waters BF. A methodology for evaluating the effects of different stream flows on salmonid habitat. In: Orsborn JF, Allman CH, editors. Instream flow needs. Bethesda: American Fisheries Society; 1976. p. 254–66.Google Scholar
- Wilkes MA, Maddock I, Visser F, Acreman MC. Incorporating hydrodynamics into ecohydraulics: the role of turbulence in the swimming performance and habitat selection of steam-dwelling fish. In: Maddock I, Harby A, Kemp P, Wood P, editors. Ecohydraulics: an integrated approach. New York: Wiley; 2013. p. 9–30.Google Scholar