Abstract
ABSTRACT This study aimed to investigate information gain by using rainfall intensity-duration-frequency (IDF) relationships, with data gathered within N+M years from seven rain gauge stations located in the Lagoa Mirim Watershed (South Atlantic basin). After N years of daily rainfall, the transition probabilities of a time homogeneous two-state Markov chain were defined to simulate rainfall occurrence, as well as gamma distribution to measure it; for that, daily rainfall series were composed of N+M years, with M being the generated series. The series were adjusted to Gumbel distribution, being used in annual maximum daily rainfall disaggregation for durations of 10, 20, 30, 40, 50, 60, 120, 360, 720 and 1440 min. Daily rainfall disaggregation was validated through IDF relationships taken from pluviograph records of N years and from N+M years, using the “t” test of relative mean squared error. We can infer that there was information gain using IDF relationships of rainfall occurrence when using N years of observed data and M years of generated data by stochastic modeling compared to those obtained from a composed series of N years.
Highlights
The Lagoa Mirim Watershed has a prominent role in terms of water resources management, since it is a cross-border basin between Brazil and Uruguay
Long series of rainfall data are available for the Lagoa Mirim watershed but with missing records, hindering estimation of the intensity-duration- frequency (IDF) relationships
Garcia et al (2011), aiming to obtain intense rainfall equations for the municipalities of Cáceres, Cuiabá and Rondonópolis, in Brazil, used pluviograph analysis, 24- h rainfall disaggregation, and the Bell’s method (1969). These authors used a discontinuous series and concluded that the disaggregation method was most sensitive to such series size if compared to the Bell’s one
Summary
The Lagoa Mirim Watershed has a prominent role in terms of water resources management, since it is a cross-border basin between Brazil and Uruguay. Water- flow information are scarce, which complicates the design of hydraulic structures as spillways, drainage canals, as well as those related to soil and water conservation, among others (TEIXEIRA et al, 2011). To get around this situation, hydrological models have been applied for rainfall-runoff transformation (FIORIO et al, 2012; LALOZAEE et al, 2013). Garcia et al (2011), aiming to obtain intense rainfall equations for the municipalities of Cáceres, Cuiabá and Rondonópolis, in Brazil, used pluviograph analysis, 24- h rainfall disaggregation, and the Bell’s method (1969). For different durations and return period, the disaggregation method has shown better performance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
