Third International Conference on Statistical Climatology ESTlHATlON , REGIONALIZATION , AND SPATIAL AVERAGING OF E%TREtlE RAINFALL AT SHALL TIME-STEPS . * ** ~J O W with Institut National Agronomique Tunisien -Tunis -Tunisia Now with ORSTOM -Montpellier

A very practical problem i n the design of hydraulic structures i s that of extreme value flood analysis. Commonly based on long discharges series, the problem must be approached differently when such data i s lacking. In such a case, a possible solution consists i n using information derived from a more currently available variable, i. e. rainfall, together with other information, These reasons have led t o rising interest i n the Climatology of Extreme Rainfall, a t f i r s t mainly on a daily basis. However, concerns with smaller rural watersheds as well as needs i n urban hydrology soon raised interest i n shorter time-steps too, with the drawback of much less dense networks of recording raingages. This leads t o the problem of regionalizing sparse information, as well as that of the representativeness of point values for spat ia11 y extensi ve watersheds. method-1980-1

PHYSICAL INTERPRETATION AND SENSITIVITY ANALYSIS OF THE TOPMODEL

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