INVESTIGADORES
GARCIA RODRIGUEZ carlos marcelo
congresos y reuniones científicas
Título:
Numerical and physical modeling of pool-riffle sequences for low- gradient urban streams
Autor/es:
RODRÍGUEZ, J. F.; BELBY, B.; BOMBARDELLI, F.; GARCÍA, C.M.; RHOADS, B. L.; GARCÍA M.H.
Lugar:
Tempe. Arizona. USA.
Reunión:
Simposio; International Symposium on Environmental Hydraulics,; 2001
Institución organizadora:
International Association of Hydraulic Engineering and Research (IAHR)
Resumen:
Channelization limits the geomorphological and biological diversity of many urban streams.Whenever the existing infrastructure prevents re-alignment of the channel planform, in-channelstructures of the pool-riffle type offer an alternative means to provide some degree of variabilityin the flow pattern. Traditionally, artificial pool-riffles have been designed based oncharacteristics of pools and riffles located in mountain areas. When used in low-energy systems,this type of structure tends to produce important backwater effects, with the associated problems of stagnant flow zones and higher water levels. A novel design of pool-riffle structures intended to naturalize low-gradient streams in heavily urbanized areas has been proposed 1. The design is based on the characteristics of pool-riffle sequences found in natural low-gradient streams.Accordingly, pool areas are narrower than riffle areas, transitions are gradual and the spacingbetween consecutive pools or riffles is 5 to 7 times the stream width. Preliminary analysis hasshown the capability of the structures to fulfill four requirements: to increase flow variabilityduring low and moderate flows; to produce minimal increase in the water levels during highflows; to self-maintain in terms of bed erosion and sediment deposition, and to provide in-streamhabitat for fish 1. This paper presents numerical simulations and physical experiments carried outto further explore the hydraulic performance of the design. Two existing numerical models, one3D (FLOW-3D®) and the other depth-averaged (STREMR), have been applied to the pool-riffle structures and the results have been compared to measurements performed on a 1:7 Froude scale physical model.
