Modelagem da precipitação pluvial diária intra-anual da bacia hidrográfica Paraná III associada aos eventos Enos.

Abstract

The hydrological systems engineering comprising principles, theoretical formulations and procedures used in modern modeling and simulation needed to build more realistic models for each natural phenomenon involved in planning, especially the phenomenon of precipitation, are decisive in contemporary designs, especially when the need is increasing in a rapidly developing society. The Western Region of Parana State, covering the Parana Basin III, the area defined for this study, has an agricultural system still largely dependent on climatic conditions and especially the rainfall. Thus, the aspects that involve the construction of probabilistic models, able to determine parameters of occurrence and quantification of the daily precipitation has emerged as a necessary and fundamental to the achievement of regional projects in all areas. Therefore, the objective of this project was to undertake a detailed analysis of the aspects that involve the construction of these models considering the occurrence of ENSO phenomena (El Nino - Southern Oscillation), using to this purpose, data from 34 weather stations with higher grades 21 years of daily records, which were obtained from the ANA (Agenda Nacional de Aguas). The novelty of this work can be attributed to intra-annual modeling of daily rainfall, stratified by event-scale ENSO (El Nino - Southern Oscillation). Modeling the occurrence of daily precipitation was treated by the hypothesis of persistence, i.e., Markov processes, while modeling the precipitated amount was determined by fitting the theoretical model of the distribution function of probability range for two parameters. For the validation of the setting it was used the Kolmogorov-Smirnov test at a significance level of 5% of probability. The results indicated the existence of a direct relationship between precipitation occurred in the catchment area of Parana III basin and the rates of anomalies associated with ENSO events, which for years characterized by El Nino events the increase in average precipitation, when stratified by ten-years period, shows an increasing trend in precipitation in all seasons. Regarding the studied the methods of estimation of the parameters a and p, it can be concluded that the maximum likelihood method provided the best fit between the evaluated methods, since it presented statistical significance in only one series and the method of moments was characterized as the most sensitive method for the detection of extreme precipitation events. According to the proposal and from the obtained results it was established that this methodology can be applied to the simulation of synthetic series of daily rainfall in each of the 34 rainfall stations of the Parana III basin, to ENSO events (El Nino - Southern Oscillation), with the purpose of enhancing the level of certainty in the implementation of agricultural systems and use for planning and management of water resources.