Temporal distribution of rainfall in the Far West region of Santa Catarina, Brazil

Abstract

In the definition of design rainfall, one must determine the temporal distribution of rainfall. In Brazil there are few studies on the temporal distribution of heavy rainfall. This work aimed to characterize the temporal distribution of intense rainfall for the Far West region of Santa Catarina. Data from four rainfall stations were used. The rainfall was individualized and classified into four types according to the quartile with the highest intensity. With the total of 3212 rainfall events it was observed that the most frequent rains are of type I (37.6%) followed by types II (32.3%). The time variation curves of the four rainfall stations show differences of less than 5% in relation to the regional average. No significant seasonal differences were observed, however significant differences were found with respect to rainfall duration. The values of the temporal distribution with a probability of 50% were necessary for the rains of the four quartiles, as well as for the duration ranges, allowing the designer to adopt the most appropriate values according to the characteristics of the project.