Three-dimensional simulations of natural phenomena such as tsunamis and floods require tremendous computing capacity – and even then, clear-cut answers are slow to emerge. But now researchers at SINTEF ICT in Oslo have developed methods that cut that waiting time substantially. The key lies in using computer graphics cards.
Watch the simulation of actual and synthetic floods, including the 1959 collapse of Malpasset Dam in France that claimed more than 400 lives. The town of Fréjus was inundated, as depicted late in the video. (Simulation: doctoral research fellows André R. Brodtkorb and Martin L. Sætra)
Learning from computer games
Advances in computer game technology depicting graphics-heavy virtual worlds has led to the development of sophisticated graphics cards.
“Previously, only the computer’s main processor was used to run calculations. This required many computers to carry out the type of calculations we work with,” says Jens Olav Nygaard of SINTEF ICT. “Now we use the computers’ graphics cards as well. These can process more calculations simultaneously – so we extract far higher capacity from each computer.”
Mr Nygaard headed a project that received funding under the Research Council of Norway’s Research Programme on Core Competence and Growth in ICT (VERDIKT).
Faster than a Mississippi flood
During a research stay at the National Center for Computational Hydroscience and Engineering at the University of Mississippi, two doctoral research fellows in the project developed a code that speeds up the simulation of shallow-water waves several hundredfold.
Water driven by hurrican Katrina in 2005 flooded 80 percent of New Orleans. With a new code, the simulation can run faster than the flooding along the Mississippi River actually occurs.
“The simulation is the first of its kind that can be run faster than the flooding along the Mississippi River actually occurs,” explains Mr Nygaard. “If a dam breaks and we enter this into the simulation program, we can calculate how the water will flow, including water levels, faster than it occurs in reality. Based on the simulation we can determine which areas may need to be evacuated.”
“To speed things up we have developed a code to get the most from the computer’s graphics card. The calculations require us to enter data that describes the terrain in advance.”
The new method is cheaper and more environment-friendly than conventional computer simulations, according to Jens Olav Nygaard of SINTEF ICT. (Photo: Martin L. Sætra)
Many application areas
The simulations can also be used for flood-prone areas where other conditions such as landslides may cause flooding. All that is required is the input of a different data set. It is also conceivable that terrain data can be collected from other sources such as Google Earth.
The method could also streamline the visualisation of petroleum reservoirs based on data collected from the seabed. This is another application area that requires processing of massive amounts of data.
“We still need powerful computers,” says Mr Nygaard, “but with our technology the simulation process goes much faster than before.”
Lower-cost, easier on the environment
The new computing methods are not only fast, they are also cheaper.
“When the graphics card is used to run many parallel calculations simultaneously, there is less heat build-up in the hardware. So less energy is required compared to calculations run serially on the main processor. This makes the method both cheaper and more environment-friendly,” concludes Mr Nygaard.