Saturday, March 26, 2011

Modelling dam breaks, tsunamis and other geophysical events

CSIRO (Australia): CSIRO mathematicians are creating computational models of events like floods, dam breaks and tsunamis to aid understanding and planning for these phenomena. Catastrophic events like floods, dam breaks, tsunamis, storm surges, volcanic eruptions, and mud slides involve large-scale movement of fluids and solids. They can have serious economic, environmental and humanitarian effects.

These geophysical flow events are difficult to observe and measure. They are also very complex to model because they involve:
  • movement of solids and fluids in large volumes over large areas
  • many kinds of physical processes
  • events occurring over an expanse of time and space.
New geophysical flow modelling techniques developed by CSIRO can be used to assist at-risk regions and nations by accurately visualising potential disaster scenarios to allow evidence-based decision making for emergency services management.

CSIRO has been developing computational fluid dynamics (CFD) methods, specifically particle-based smoothed particle hydrodynamics (SPH) code and granular flow (GF) code, to accurately model events like dam breaks and tsunamis using real three-dimensional (3D) topography obtained from digital terrain models. Using real topographic information means the results can be directly compared with disaster scenarios. Particle-based methods for modelling geophysical flows have numerous advantages over traditional grid or mesh-based continuum methods....Projects currently being undertaking using these methods include:
  • refining a 3D simulation of the 1928 St Francis Dam break in California. Results from the computer simulation agree closely with historical data about damage from the real event.
  • modelling the hypothetical collapse of China's Geheyan Dam, one of the world's largest dams. This project is a collaboration with the Chinese Academy of Surveying and Mapping.
  • simulating a hypothetical flood of the Bellinger River in NSW, due to a storm surge
  • predicting areas affected by a hypothetical tsunami inundating the Californian coastline
  • dynamic prediction of flooding in several Australian cities due to dam breaks, tsunamis, floods and other disasters….
The St. Francis dam before it was destroyed in 1928

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