HYDROMETEOROLOGICAL ASPECTS OF THE 1994 FLOODING

IN THE UPPER PO RIVER BASIN:

FREQUENCY CHARACTERISTICS AND REAL-TIME PREDICTABILITY

Armando Brath

Institute of Hydraulic Structures

University of Bologna

Viale Risorgimento,2 40136 Bologna, Italy

The predictability of the flood event occurred in the Piedmont region (Northern Italy) during November 1994 is investigated. Statistical analyses are performed on both rainfall and hydrometric observations in order to assess the return period of the flood event. The possibility of forecasting the flood event is also investigated. At the present state of technology real-time flood forecasting is limited in the region, mainly because of the lack of reliable real-time forecasting of rainfall. However, quantitative rainfall forecasts obtained from the General Circulation Model of the European Center for Medium Range Weather Forecasting (ECMWF) are in good agreement with the observed precipitation fields. Although these rainfall forecasts are at present not suitable for real-time flood forecasting systems in small basins, because of the insufficient space-time resolution, their use for flood warning in medium and large basins seems to offer interesting perspectives.