Benefits of grid computing for flood modeling in service-oriented spatial data infrastructures

In 2007, the European Commission has passed the "Flood Directive" (2007/60/EG) dealing with the identification of inun- dated areas and the creation of flood risk maps. The basis for flood modeling is provided by computationally and storage-intensive flow simulations. Digital terrain data is the starting point for generating two-dimensional flow models. When discretizing the computational mesh for hydraulic simulation, digital terrain models with a resolution of one meter or less have to be subjected to several elaborate pre- processing steps. A number of simulation and modeling tools for this purpose have already been developed as "classical" SDI applica- tions. However, building flood and risk models for a study area covering many square kilometers is not possible using common desktop GIS. The German GDI-Grid project (SDI-Grid, www.gdi-grid.de) extends regular OGC-based SDI services with grid computing capabi- lities. It focuses on WPS tools and an architecture for geoprocessing in the grid. At the example of flood modeling, this article shows which benefits can be generated in spatial data infrastructures by using grid technology.