DAILY RAINFALL DISAGGREGATION COEFFICIENTS FOR THE DOCE RIVER BASIN, BRAZIL: REGIONAL APPLICABILITY AND THE RETURN PERIOD INFLUENCE

• Autor(a) principal: Passos,Jéssica B. de M. C.
• Data de Publicação: 2021
• Outros Autores: Silva,Demetrius D. da, Lima,Rafael P. C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Engenharia Agrícola
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162021000200223
• topic: daily rainfall disaggregation method; heavy rainfall; hydrology; pluviometric data; pluviograph gauge station

ABSTRACT Alternative methods to the intensity-duration-frequency equations have been used for intense rainfall study in places with no pluviographic data. A pioneering study, by CETESB (1986), established rainfall disaggregation coefficients for Brazil; however, the use of these coefficients take into account neither the rainfall characteristics of the interest locality nor the return period influence in obtaining the precipitation intensities. This study aimed to determine rainfall disaggregation coefficients for Doce river basin; to verify the validity of the regional coefficients use for the entire basin; and to evaluate the return period influence on these coefficients. Data from 19 gauges located in the basin, with rainfall associated with durations of 10 to 1440 min and return periods of 2, 5, 10, 20, 50 and 100 years, were used to obtain the coefficients. Student's t-test was used to assess the regional applicability of these coefficients and the return period influence. The coefficients do not provide regional validity for the entire basin; therefore, regional coefficients were estimated for five hydrologically homogeneous regions, confirming the validity of these coefficients use and the influence of the return period. We conclude that the disaggregation coefficients must be specific for the homogeneous regions and for each return period.