Stochastic generation of spatial rainfall for urban drainage areas

Data from a dense network of rain gauges in the city of Antwerp (Belgium) has been used to study the stochastic structure of spatial rainfall at the small spatial scale of small hydrographic or urban catchments. The derived spatial rainfall model contains two structures: a deterministic structure for the physical description of individual rain cells and cell clusters, and a stochastic structure for the description of the intrinsic randomness in the sequence of different rain events. Such a model forms the basis of the stochastic generation of spatial rainfall for urban catchments. Spatial rainfall generations have many applications: long-term time series of spatial rainfall can be used as input to urban drainage models for the accurate generation of runoff, or to study model-uncertainties and -biases by the simplified use of point rainfall as a model input.