Cellular automata algorithms for drainage network extraction and rainfall data assimilation
Erika Coppola, Barbara Tomassetti, Laura Mariotti, Marco Verdecchia, Guido Visconti · Hydrological Sciences Journal · 2007
Since 2002, within the framework of the Cetemps Centre of Excellence at the University of L'Aquila, a distributed grid-based hydrological model (CHYM) has been developed to provide a general purpose model for operational flood warning activity. This paper presents two new cellular automata (CA) algorithms used respectively for drainage network extraction and rainfall data assimilation. The first is a cellular automaton-based algorithm for the extraction of a drainage network from an arbitrary digital elevation model. It has been implemented and tested on a large number of different domains. This algorithm is able to define the flow direction at every point on the digital elevation model where singular points are present (pits or flat areas). The second is a CA-based numerical technique for assimilating different data sources of rainfall to rebuild the rainfall field on a grid. This technique has been shown to produce a reasonable rainfield shape without any geometrical artefacts that often produce unrealistic rain gradients in the rainfield.