Title: Computational Modelling of Hydrological Impacts - Open source software developed by the Australian Federal Government.
  		

Speaker:
Ole Nielsen, Geoscience Australia
Ole.Nielsen@ga.gov.au	
	
	
Modelling the effects on the built environment of natural hazards such
as riverine flooding, storm surges and tsunami is critical for
understanding their economic and social impact on our urban
communities.  Geoscience Australia and the Australian National
University have developed a hydrodynamic inundation modelling tool
called ANUGA to help simulate the impact of these hazards.


The core of ANUGA is a Python implementation of a finite-volume method
for solving the conservative form of the Shallow Water Wave equation.
This method allows the study area to be represented by an unstructured
mesh with variable resolution to suit the particular problem.  The
conserved quantities are water level (stage) and horizontal momentum.
An important capability of ANUGA is that it can robustly model the
process of wetting and drying as water enters and leaves an area. This
means that it is suitable for simulating water flow onto a beach or
dry land and around structures such as buildings.

To set up a particular scenario the user generates a mesh with regions
and boundary segments identified by symbolic tags used to bind values
to arbitrary functions supplied during the simulation.  In addition,
all quantities may be assigned or updated by supplying either constant
values, arbitrary functions or general expressions combining existing
quantities.  Arbitrary forcing terms such such as wind stress or
atmospheric pressure gradients may also be supplied.  While this
interface provides great flexibility due to Python's object model,
dynamic typing and constructs such as generators, the computationally
intensive components are written for efficiency in the C language
working directly with the Numerical Python structures.

ANUGA has recently been released as Open Source. This strategy will enable
free access to the software and allow the risk research community to
use, validate and contribute to the software in the future.

The talk outlines the model implementation, provides validation
results, identifies remaining challenges and describes ANUGA's role within
the Australian Tsunami Warning System.