A three-dimensional numerical model of the response of the Australian North West Shelf to tropical cyclones

A three-dimensional barotropic and baroclinic model is developed to simulate currents and temperature changes induced by tropical cyclones traversing the continental shelf and slope region of the Australian North West Shelf. The model is based on a layered, explicit, finite difference formulation using the nonlinear primitive equations with an embedded entrainment scheme; a mixed-surface-layer interface is defined, which is allowed to shift from one interface to another, depending on the strength of a storm. The model has been tested by simulating the currents and temperature changes induced by tropical cyclones Orson and Ian. The modelled currents and temperatures agreed well with the available measured records except near the seabed. It has been found that the pre-storm currents have very little influence on the peak of the storm-induced currents and the currents in the wake of a tropical cyclone. The model contained no coefficients which must be calibrated for a particular application and clearly illustrated the importance of the baroclinic effects on the storm-induced response over the North West Shelf of Australia

Evaluation of management scenarios for controlling eutrophication in a shallow tropical urban lake

Urban lakes are typically smaller, shallower, and more exposed to human activities than natural lakes. Although the effects of harmful algal blooms (HABs) associated with eutrophication in urban lakes has become a growing concern for water resources management and environmental protection, studies focussing on this topic in relation to urban lakes are rare and knowledge of the ecological dynamics and effective management strategies for controlling eutrophication in urban lakes is lacking. This study applied an integrated three-dimensional hydrodynamics-ecological model for a small shallow tropical urban lake in Singapore and evaluated various management scenarios to control eutrophication in the lake. It is found that in-lake treatment techniques including artificial destratification, sediment manipulation and algaecide addition are either ineffective or possess environmental concerns; while watershed management strategies including hydraulic flushing and inflow nutrients reduction are more effective and have posed less environmental concerns. In this study, inflow phosphorus reduction was found to be the best strategy after evaluating the advantages and drawbacks of the management strategies studied. Runoff from the watershed exerts significant influence on urban lakes and thus an integrated water resources management at the watershed level is critical for the control of eutrophicatio

Managing risk in the urban fabric

The State of Australian Cities (SOAC) national conferences have been held biennially since 2003 to support interdisciplinary policy-related urban research. This paper was presented at SOAC 4 held in Perth from 24 to 27 November 2009. SOAC 4 was hosted by the University of Western Australia, Curtin University, Edith Cowan University and Murdoch University and held at The University of Western of Australia’s Crawley campus.SOAC 4 was a collaborative venture between colleagues from the planning, geography and related disciplines across the four public universities. The meta-theme of this conference - city growth, sustainability, vitality and vulnerability – sought to capture the dynamic and complex nature and contexts in which Australian cities find themselves in the early 21st century. The last decade or so has seen Australian cities and many of their residents benefit from significant economic prosperity. With this economic prosperity, largely on the back of a resources boom, Australian cities and resources and mineral-rich regions, particularly in Queensland and in WA, have been subjected to profound demographic, social, economic, environmental and political changes. In the wake of the so-called ‘global financial crisis’ we have witnessed the rise of what might be called ‘neo-Keynesianism’ as various liberal democratic nations have pumped billions of dollars into their national economies via ‘bail outs’ or a stimulus package’ in an effort to stave off economic recession. The economic prosperity and more recent uncertainty that has been experienced in the last decade provides a fascinating and dare we say it a timely backdrop to critically reflect on the condition of urban Australia. All published papers have been subject to a peer reviewing process

A Wall out of Place: a Hydrological and Sociocultural Analysis of Physical Changes to the Lakeshore of Como, Italy

The construction of a flood protection structure that obscured views of the lake in Como, northern Italy, led to unprecedented public protest in 2009-2010 and to the eventual dismantlement of the structure. This provided a focus to investigate the delicate interplay of technical and cultural matters in environmental policy - in this case, catchment management and flood prevention. This article shows how a focus on hydrological control in isolation from the rest of the catchment and from the sociocultural context contributed to the project's failure. A key message of the article is that data and analyses from the environmental and social sciences are both pivotal to environmental planning, as they inform different yet interdependent components of a single project. There is value in integrating technical and sociocultural knowledge, both at the academic level, as illustrated by the mixed methods used in this article, and at the policy level, through management frameworks that emphasize cross-sectoral learning and public participation. The analysis also reveals that the notion of "place" has a central role to play in this process of integration, both as a conceptual bridge between technical and sociocultural components of environmental studies and as an emphasis in environmental planning activities to foster the interest and engagement of communities