IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Hydro-environment : Environmental flow assessment based on physical habitat simulation in a small river in the southeast...
Environmental flow assessment based on physical habitat simulation in a small river in the southeastern brazil
The physical habitat simulation system within the framework of the IFIM (Instream Flow Incremental Methodology) uses
hydraulic variables and habitat suitability indices of target aquatic species to predict how different in-stream flows affect
their habitats. This habitat modelling approach was adopted to simulate and to assess the effects of different stream
flows on three tropical fish species of different orders (Bryconamericus ornaticeps, Ancistrus multispinis and Geophagus
brasiliensis) in two stretches of an Atlantic Forest stream in Southeastern Brazil during the Summer 2013 and the Winter
2014. Topographic and hydraulic characteristics (depth, velocity and substrate type) were measured, and underwater
direct observation of the fish by snorkelling was performed to assess microhabitat use. Microhabitat suitability curves
were developed for the three fish species; based on those curves we performed the physical habitat simulation in a
representative stretch. Thus, we obtained the average Habitat Suitability Index (HSI) and Weighted Usable Area (WUA)
vs. flow curves, and the relevant flow rates upon such curves to conserve the fish habitat for the three fish species. The
results indicated a minimum flow rate of 0.25 m3 s-1 as a minimo-minimorum to conserve the fish habitat; an optimum
range of 0.65-0.85 m3 s-1 was considered relevant for setting e-flow regimes to conserve the fish habitat in this Atlantic
Forest stream. These results can support the first proposal of an e-flow regime in the frame of an adaptive management
process of the water resources, in order to conserve healthy rivers with the diverse social benefits they provide.
File Size : 290,829 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Hydro-environment
Date Published : 28/08/2015
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