CIUNR – Ciencias Exactas y Tecnológicas - Comunicaciones a Congresos

URI permanente para esta colección

https://rephip.unr.edu.ar/handle/2133/8857

Examinar

Mostrando 1 - 10 de 10

Acceso Abierto
A Framework For The Ecogeomorphological Modelling Of The Macquarie Marshes, Australia
(2014-12) Rodriguez, Jose F.; Seoane Salazar, Manuel; Sandi, Steven G.; Saco, Patricia M.; Riccardi, Gerardo A.; Saintilan, Neil; Wen, Li
Acceso Abierto
Calibration, validation and predictive capability of a wetland evolution model for subtropical estuaries.
(2016-04) Rodriguez, Jose F.; Sandi, Steven G.; Saco, Patricia M.; Riccardi, Gerardo A.
Acceso Abierto
Coevolution of hydraulic, soil and vegetation processes in estuarine wetlands.
(European Geophysical Union, 2014-04) Trivisonno, Franco N.; Rodriguez, Jose F.; Riccardi, Gerardo A.; Saco, Patricia M.; Stenta, Hernan R.
Estuarine wetlands of south eastern Australia, typically display a vegetation zonation with a sequence mudflats - mangrove forest - saltmarsh plains from the seaward margin and up the topographic gradient. Estuarine wetlands are among the most productive ecosystems in the world, providing unique habitats for fish and many terrestrial species. They also have a carbon sequestration capacity that surpasess terrestrial forest. Estuarine wetlands respond to sea-level rise by vertical accretion and horizontal landward migration, in order to maintain their position in the tidal frame. In situations in which buffer areas for landward migration are not available, saltmarsh can be lost due to mangrove encroachment. As a result of mangrove invasion associated in part with raising estuary water levels and urbanisation, coastal saltmarsh in parts of south-eastern Australia has been declared an endangered ecological community. Predicting estuarine wetlands response to sea-level rise requires modelling the coevolving dynamics of water flow, soil and vegetation. This paper presents preliminary results of our recently developed numerical model for wetland dynamics in wetlands of the Hunter estuary of NSW. The model simulates continuous tidal inflow into the wetland, and accounts for the effect of varying vegetation types on flow resistance. Coevolution effects appear as vegetation types are updated based on their preference to prevailing hydrodynamic conditions. The model also considers that accretion values vary with vegetation type. Simulations are driven using local information collected over several years, which includes estuary water levels, accretion rates, soil carbon content, flow resistance and vegetation preference to hydraulic conditions. Model results predict further saltmarsh loss under current conditions of moderate increase of estuary water levels.
Acceso Abierto
Coevolution of hydrodynamics, vegetation and channel evolution in wetlands of a semi-arid floodplain
(EGU General Assembly 2015, 2015-04) Seoane, Manuel; Rodriguez, Jose F.; Sandi, Steven G.; Saco, Patricia M.; Riccardi, Gerardo A.; Saintilan, Neil; Wen, Li
The Macquarie Marshes are located in the semi-arid region in north western NSW, Australia, and constitute part of the northern Murray–Darling Basin. The Marshes are comprised of a system of permanent and semi-permanent marshes, swamps and lagoons interconnected by braided channels. The wetland complex serves as nesting place and habitat for many species of water birds, fish, frogs and crustaceans, and portions of the Marshes was listed as internationally important under the Ramsar Convention. Some of the wetlands have undergone degradation over the last four decades, which has been attributed to changes in flow management upstream of the marshes. Among the many characteristics that make this wetland system unique is the occurrence of channel breakdown and channel avulsion, which are associated with decline of river flow in the downstream direction typical of dryland streams. Decrease in river flow can lead to sediment deposition, decrease in channel capacity, vegetative invasion of the channel, overbank flows, and ultimately result in channel breakdown and changes in marsh formation. A similar process on established marshes may also lead to channel avulsion and marsh abandonment, with the subsequent invasion of terrestrial vegetation. All the previous geomorphological evolution processes have an effect on the established ecosystem, which will produce feedbacks on the hydrodynamics of the system and affect the geomorphology in return. In order to simulate the complex dynamics of the marshes we have developed an ecogeomorphological modelling framework that combines hydrodynamic, vegetation and channel evolution modules and in this presentation we provide an update on the status of the model. The hydrodynamic simulation provides spatially distributed values of inundation extent, duration, depth and recurrence to drive a vegetation model based on species preference to hydraulic conditions. It also provides velocities and shear stresses to assess geomorphological changes. Regular updates of stream network, floodplain surface elevations and vegetation coverage provide feedbacks to the hydrodynamic model.
Acceso Abierto
Estuarine wetland evolution including sea-level rise and infrastructure effects.
(EGU General Assembly 2015 © Author(s) 2015. CC Attribution 3.0 License., 2015-04) Rodriguez, Jose F.; Trivisonno, Franco N.; Sandi, Steven G.; Riccardi, Gerardo A.; Stenta, Hernan R.; Saco, Patricia M.
Estuarine wetlands are an extremely valuable resource in terms of biotic diversity, flood attenuation, storm surge protection, groundwater recharge, filtering of surface flows and carbon sequestration. On a large scale the survival of these systems depends on the slope of the land and a balance between the rates of accretion and sea-level rise, but local man-made flow disturbances can have comparable effects. Climate change predictions for most of Australia include an accelerated sea level rise, which may challenge the survival of estuarine wetlands. Furthermore, coastal infrastructure poses an additional constraint on the adaptive capacity of these ecosystems. Numerical models are increasingly being used to assess wetland dynamics and to help manage some of these situations. We present results of a wetland evolution model that is based on computed values of hydroperiod and tidal range that drive vegetation preference. Our first application simulates the long term evolution of an Australian wetland heavily constricted by infrastructure that is undergoing the effects of predicted accelerated sea level rise. The wetland presents a vegetation zonation sequence mudflats - mangrove - saltmarsh from the seaward margin and up the topographic gradient but is also affected by compartmentalization due to internal road embankments and culverts that effectively attenuates tidal input to the upstream compartments. For this reason, the evolution model includes a 2D hydrodynamic module which is able to handle man-made flow controls and spatially varying roughness. It continually simulates tidal inputs into the wetland and computes annual values of hydroperiod and tidal range to update vegetation distribution based on preference to hydrodynamic conditions of the different vegetation types. It also computes soil accretion rates and updates roughness coefficient values according to evolving vegetation types. In order to explore in more detail the magnitude of flow attenuation due to roughness and its effects on the computation of tidal range and hydroperiod, we performed numerical experiments simulating floodplain flow on the side of a tidal creek using different roughness values. Even though the values of roughness that produce appreciable changes in hydroperiod and tidal range are relatively high, they are within the range expected for some of the wetland vegetation. Both applications of the model show that flow attenuation can play a major role in wetland hydrodynamics and that its effects must be considered when predicting wetland evolution under climate change scenarios, particularly in situations where existing infrastructure affects the flow.
Acceso Abierto
Hydrodynamics, vegetation transition and geomorphology coevolution in a semi-arid floodplain wetland.
(EGU General Assembly 2016 © Author(s) 2016. CC Attribution 3.0 License., 2016-04) Sandi, Steven G.; Rodriguez, Jose F.; Saco, Patricia M.; Riccardi, Gerardo A.; Wen, Li; Saintilan, Neil
Acceso Abierto
Incorporating Infrastructure and Vegetation Effects on Sea Level Rise Predictions in Low-Gradient Coastal Landscapes
(2015-12) Rodriguez, Jose F.; Sandi, Steven G.; Trivisonno, Franco N.; Saco, Patricia M.; Riccardi, Gerardo A.
At the regional and global scales, coastal management and planning for future sea level rise scenarios is typically supported by modelling tools that predict the expected inundation extent. These tools rely on a number of simplifying assumptions that, in some cases, may result in important overestimation or underestimation of the inundation extent. One of such cases is coastal wetlands, where vegetation strongly affects both the magnitude and the timing of inundation. Many coastal wetlands display other forms of flow restrictions due to, for example, infrastructure or drainage works, which also alters the inundation patterns. In this contribution we explore the effects of flow restrictions on inundation patterns under sea level rise conditions in coastal wetlands. We use a dynamic wetland evolution model that not only incorporates the effects of flow restrictions due to culverts, bridges and weirs as well as vegetation, but also considers that vegetation changes as a consequence of increasing inundation. We apply our model to a coastal wetland in Australia and compare predictions of our model to predictions using conventional approaches. We found that some restrictions accentuate detrimental effects of sea level rise while others moderate them. We also found that some management strategies based on flow redistribution that provide short term solution may result more damaging in the long term if sea level rise is considered.
Acceso Abierto
Modelling estuarine wetlands under climate change and infrastructure pressure
(Piantadosi, J., Anderssen, R.S. and Boland, J., 2013-12) Trivisonno, Franco N.; Rodriguez, Jose F.; Riccardi, Gerardo A.; Saco, Patricia M.; Stenta, Hernan R.; Modelling and Simulation Society of Australia and New Zealand Inc.
Abstract: Estuarine wetlands are an extremely valuable resource in terms of biotic diversity, flood attenuation, storm surge protection, groundwater recharge, filtering of surface flows and carbon sequestration. The survival of these systems depends on a balance between the slope of the land, and the rates of accretion and sea-level rise. Climate change predictions for most of Australia include both an accelerated sea level rise and an increase on the frequency of extraordinary river floods, which will endanger estuarine wetlands. Furthermore, coastal infrastructure poses an additional constraint on the adaptive capacity of these ecosystems. In recent years a number of numerical models have been developed in order to assess wetland dynamics and to help manage some of these situations. In this paper we present a wetland evolution model that is based on computed values of hydroperiod and tidal range that drive vegetation preference. Results from a 2D spatially distributed model of wetland dynamics in area E of Kooragang Island (Hunter estuary, NSW) are presented as an example of a system heavily constricted by infrastructure undergoing the effects of sea level rise. Area E presents a vegetation zonation sequence mudflats - mangrove - saltmarsh from the seaward margin and up to the topographic gradient and is compartmentalized by the presence of internal culverts. The model includes a detailed hydrodynamic module (CTSS8), which is able to handle man-made flow controls and spatially varying roughness. The model continually simulates tidal inputs into the wetland and computes annual values of hydroperiod and tidal range to update vegetation distribution based on preference to hydrodynamic conditions of the different vegetation types. It also computes soil accretion and carbon sequestration rates and updates roughness coefficient values according to evolving vegetation types. In order to further explore the magnitude of flow attenuation due to roughness and its effects on the computation of tidal range and hydroperiod, numerical experiments were carried out simulating floodplain flow on the side of a tidal creek using different roughness values. Even though the values of roughness that produce appreciable changes in hydroperiod and tidal range are relatively high, they are within the range expected for some of the wetland vegetation. Both applications of the model show that flow attenuation plays a major role in wetland hydrodynamics and that its effects must be considered when predicting wetland evolution under climate change scenarios, particularly in situations where existing infrastructure affects the flow.
Acceso Abierto
Modelling soil, carbon and vegetation dynamics in estuarine wetlands experiencing sea-level rise
(2013) Trivisonno, Franco N.; Rodriguez, Jose F.; Riccardi, Gerardo A.; Saco, Patricia M.; International Association for Hydro-Environment Engineering and Research (IAHR) 2013
Estuarine wetlands are among the most productive ecosystems in the world, providing unique habitats for fish and many terrestrial species. They also have a carbon sequestration capacity that surpasses terrestrial forest. In NSW, and most of south eastern Australia, they typically display a vegetation zonation with a sequence mudflats - mangrove forest - saltmarsh plains from the seaward margin and up the topographic gradient. Estuarine wetlands respond to sea-level rise by vertical accretion and horizontal landward migration, in order to maintain their position in the tidal frame. In situations in which accretion cannot compensate for sea-level rise and buffer areas for landward migration are not available, estuarine vegetation can be lost due to unsuitable hydraulic conditions. Predicting estuarine wetlands response to sea-level rise requires simultaneous modelling of water flow, soil and vegetation dynamics. This paper presents some preliminary results of our recently developed numerical model for wetland dynamics in wetlands of the Hunter estuary of NSW. The model continuously simulates tidal inputs into the wetland and vegetation types are determined based on their preference to prevailing hydrodynamic conditions. Accretion values based on vegetation types are computed and the topography is updated accordingly. The model is driven by local information collected over several years, which include estuary water levels, accretion rates, soil carbon content, flow resistance and vegetation preference to hydraulic conditions. Model results predict further wetland loss under an accelerated sea-level rise scenario and also under current conditions of moderate increase of estuary water levels.
Acceso Abierto
Predicting Sea-level Rise and Infrastructure Effects on Coastal Wetlands
(Editorial to conference proceedings of 13th Hydraulics in Water Engineering Conference. HIWE2017, 2017-11-13) Rodriguez, Jose F.; Saco, Patricia M.; Sandi, Steven G.; Saintilan, Neil; Riccardi, Gerardo A.
: Climate change predictions for Australia include an accelerated sea-level rise, wich challenges the survival of estuarine wetlands. Furthermore, coastal infrastructure poses and additional constraint on the adaptive capacity of these ecosystems. This paper presents results of wetland evolution based on hydro period and inundation depth experienced by vegetation, and computed using a hydrodynamic model. The application simulates the long-term evolution of wetland on the Hunter Estuary heavily constricted by infrastructure that is undergoing the effects of predicted accelerated sea-level rise. The wetland presents a vegetation zonation sequence mudflats –mangrove –saltmarsh from the seaward margin, but it also affected by compartmentalization due tu internal road embankments and culverts that effectively attenuates tidal inputs. Results of the modelo show that flow attenuation can play a major role in wetland hydrodynamics and that its effects can increase wetland vulnerability under climate change scenarios, particularly in situations where existing infrastructure affects the flow.

Examinar

Examinando CIUNR – Ciencias Exactas y Tecnológicas - Comunicaciones a Congresos por Autor "Riccardi, Gerardo A."

Resultados por página

Opciones de ordenación