In this work is presented an analysis of the evolution of the Middle and Lower Paranà River (Argentina). The longitudinal (1-D) evolution of the river is simulated by using two different tools: one numerical model as the Hec-Ras code (by US. Army Corps of Engineers) and an own-developed quasi-analytical model. The quasi-analytical model assumes the validity of the Local Uniform Flow hypothesis which is fitted for long term (e.g., 10^3 years) simulations. The river satellite images are applied to assess the discharge-width relations that simulate the vegetation growth effectiveness on the hydraulic-conductivity of river cross-sections. The Hec-Ras code is able to simulate the water surface and bed slope changes at shorter time scale (e.g. 10^2 years) and to represent river cross-sections with a detailed topographic survey. The models are calibrated against various water stage and sediment data. The models comparison bears out a quite good agreement, the deviation being mainly due to the different representations of cross-sections and corresponding conductivities. The effects of flow-discharge variability on 1-D morphodynamics are investigated by applying two hydrological scenarios provided from two different combinations of Global and Regional Climate models with the same scenario, A1B,for CO2 emission. A significant increasing of the effective discharge and of the flow-discharge variability are observed passing from theXXcentury time-series to the forecasts that increasing twice the bed-level change with respect to the XX century simulation. The largest sensitivity of bed level to hydrological scenarios is observed at Lower Paranà, which corresponds to the flow-regime maximal effectiveness in changing the cross-section conductivity.
Nones M., Di Silvio G., Guerrero M., Pastorello L. (2012). 1-D long term simulation of the Paraná River morphodynamics in the light of climate variability. London : CRC Press, Taylor and Francis Group.
1-D long term simulation of the Paraná River morphodynamics in the light of climate variability
NONES, MICHAEL;GUERRERO, MASSIMO;
2012
Abstract
In this work is presented an analysis of the evolution of the Middle and Lower Paranà River (Argentina). The longitudinal (1-D) evolution of the river is simulated by using two different tools: one numerical model as the Hec-Ras code (by US. Army Corps of Engineers) and an own-developed quasi-analytical model. The quasi-analytical model assumes the validity of the Local Uniform Flow hypothesis which is fitted for long term (e.g., 10^3 years) simulations. The river satellite images are applied to assess the discharge-width relations that simulate the vegetation growth effectiveness on the hydraulic-conductivity of river cross-sections. The Hec-Ras code is able to simulate the water surface and bed slope changes at shorter time scale (e.g. 10^2 years) and to represent river cross-sections with a detailed topographic survey. The models are calibrated against various water stage and sediment data. The models comparison bears out a quite good agreement, the deviation being mainly due to the different representations of cross-sections and corresponding conductivities. The effects of flow-discharge variability on 1-D morphodynamics are investigated by applying two hydrological scenarios provided from two different combinations of Global and Regional Climate models with the same scenario, A1B,for CO2 emission. A significant increasing of the effective discharge and of the flow-discharge variability are observed passing from theXXcentury time-series to the forecasts that increasing twice the bed-level change with respect to the XX century simulation. The largest sensitivity of bed level to hydrological scenarios is observed at Lower Paranà, which corresponds to the flow-regime maximal effectiveness in changing the cross-section conductivity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
