Method for generating spatial and temporal synthetic hourly rainfall in the Valley of Mexico

Hydrological risk analyses require a dense pluviometer network and a long period of records with an adequate time resolution; usually pluviometer networks have short periods of simultaneous records, so it is required to extend the number of records by means of synthetically generated rainfall events. This paper describes the development and implementation of a method based on a daily rainfall disaggregation for generating synthetic rainfall events distributed spatially and temporally. It uses the information recorded in 49 rain-gauge stations in the network of the basin of the Valley of Mexico during the rainy season from 1988 to 2006. Within various methods found in the literature, we consider that this one provides a greater simplicity for a practical implementation. The tests carried out showed that rainfall events generated with this method properly reproduce the statistical parameters of the historical records, including those that are not implicitly incorporated in the model, as is the case of the synthetic hourly rainfall, whose statistical values are virtually identical to the historical ones despite that the proposed method only uses the probability distribution of maximum daily rainfall.