Dr. Valeria Krzhizhanovskaya,
Section Computational Science, Faculty of Science,
University of Amsterdam
The tsunami that struck Japan in March 2011 has shown once again that water can be devastating. History shows that water has always been a potential danger. To anticipate floods, research is necessary. Valeria Krzhizhanovskaya researches early-warning systems for floods in the UrbanFlood EU FP7 project (www.UrbanFlood.eu).
In the UrbanFlood project, researchers are developing flood early-warning systems. These systems monitor flood protection systems in real time. They can also predict the collapse of dikes. Krzhizhanovskaya: “So far, we have developed the first prototype of the early-warning system which we demonstrated at the International Workshop on Monitoring and Flood Safety in November 2010. The prototype monitors sensor networks installed in the dikes, detects abnormalities, calculates dike failure probability, and simulates possible scenarios of dike breaching and flood propagation. At the moment we are modeling city evacuations connected to the flood dynamics simulation.”
There are two kinds of dangers related to urban floods: weak dikes and the flood itself. Krzhizhanovskaya: “Usually dikes are visually inspected once every few years. However, this inspection does not detect the onset of dike deterioration, nor can it help in fast-developing critical situations like sea storms. A possible solution is sensor networks. These networks enable continuous monitoring of dike conditions and detect problems early enough to take measures. A test case dike in Groningen, connected to the UrbanFlood early-warning system has so far proved safe. Several more dikes will be equipped with sensors and connected to the UrbanFlood early- warning system: Ringdijk and Stammerdijk in Amsterdam, dikes in Rotterdam, in Boston (UK) and in St. Petersburg (Russia).”
The second danger is the flood itself, once a dike breaks. “Simulation of flood propagation helps city authorities to assess risks and to decide on evacuation. Modeling the process of city evacuation, related to the flood propagation can avoid chaos. Also it can protect critical facilities from flooding, like hospitals or nuclear and chemical plants. The authorities can, for example, decide to flood some fields and marshes upstream to reduce water levels.”
To predict the influence of seasonal and global changes on the stability of flood defense systems, modeling and simulation are necessary. Krzhizhanovskaya uses SURFsara’s HPC Cloud for these activities: “The key features that make Cloud technology very attractive to the UrbanFlood project are flexibility and on-demand resource availability. For urgent computing in critical situations, the high performance aspect is also very important. That's why SURFsara's HPC Cloud is the best solution for us.”
The research of Krzhizhanovskaya has shown some valuable results already: “Increased water levels would require serious work on dike reinforcement. The width of the dikes has to be increased with a certain aspect ratio. The problem is that this is often impossible in cities, because of roads and buildings. This poses a challenging engineering problem that requires advanced 3D modeling.”
Krzhizhanovskaya is happy to be working with SURFsara: “The computing resources as well as the technical support are remarkably fast and efficient. The consultants helped us with the configuration settings and multiple platforms from the very start. We've been working with SURFsara for almost a year, and applied to NWO for a BiG Grid grant to continue our cooperation.” An important development, according to Krzhizhanovskaya: “In cooperation with SURFsara, the UrbanFlood project can convince Europe and the world to build new-generation smart dikes and efficient early-warning systems to protect citizens.”
Simulation of flooded area of Science Park Amsterdam.