masterThesis
Análise da precipitação no semi-árido potiguar
Fecha
2011-06-30Registro en:
GARCIA, Joema Ferreira da Costa. Análise da precipitação no semi-árido potiguar. 2011. 63 f. Dissertação (Mestrado em Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica) - Universidade Federal do Rio Grande do Norte, Natal, 2011.
Autor
Garcia, Joema Ferreira da Costa
Resumen
The semiarid rainfall regime is northeastern Brazil is highly variable. Climate
processes associated with rainfall are complex and their effects may represent
extreme situations of drought or floods, which can have adverse effects on society
and the environment. The regional economy has a significant agricultural component,
which is strongly influenced by weather conditions. Maximum precipitation analysis is
traditionally performed using the intensity-duration-frequency (IDF) probabilistic
approach. Results from such analysis are typically used in engineering projects
involving hydraulic structures such as drainage network systems and road structures.
On the other hand, precipitation data analysis may require the adoption of some kind
of event identification criteria. The minimum inter-event duration (IMEE) is one of the
most used criteria. This study aims to analyze the effect of the IMEE on the obtained
rain event properties. For this purpose, a nine-year precipitation time series (2002-
2011) was used. This data was obtained from an automatic raingauge station,
installed in an environmentally protected area, Ecological Seridó Station. The results
showed that adopted IMEE values has an important effect on the number of events,
duration, event height, mean rainfall rate and mean inter-event duration.
Furthermore, a higher occurrence of extreme events was observed for small IMEE
values. Most events showed average rainfall intensity higher than 2 mm.h-1
regardless of IMEE. The storm coefficient of advance was, in most cases, within the
first quartile of the event, regardless of the IMEE value. Time series analysis using
partial time series made it possible to adjust the IDF equations to local
characteristics