## 3 Results and Discussion
### Spatial-Temporal Description of Rainfall  
Table 2 presents the locations where the observed RP was greater than 30 years, with emphasis to the stations in Maringa, Londrina, Colorado and Arapongas, which obtained RP values greater than 100 years. The greatest accumulated rainfall in the period between September 2015 and February 2016 occurred in Londrina (2092.1 mm) and the second highest in Maringa (2049.4 mm). Although the absolute value was higher in Londrina, as the calculation of the RP considers the distribution adjusted to each historical series, a higher value of accumulated rainfall does not necessarily lead to a higher RP.  
Figure 4: Precipitation in Maringá, PR: 1980–2017. (**A**) Daily rainfall; (**B**) monthly rainfall; (**C**) Cumulative rainfall (six months). The red circle indicates EN 15–16, and the green circles in (**C**) indicate the years 1983, 1997 and 2010. Data source: Maringá Main Climate Station (ECPM)/INMET.  
The comparison between the data in Table 2 and the stations geographical distribution (Figure 2) shows that the highest RP values (above 150 years) occur in the central part of Northern Parana between the cities of Maringa and Londrina, where the rainfall was higher (Figure 5).  
Besides this core area where the rainfalls were larger (RP \(>\) 150 years) and taking into account accumulations with RP \(>\) 30 years, a study area was identified whose eastern border begins about 60 km east of the municipality of Londrina, extending westward to the south of Mato Grosso do Sul state. Latitudinally, the area extends between the Paranapanema River at the north and the boundary of the municipality of Umuvarama at the south. Considering these limits, the rainfall values were extraordinary (RP \(>\) 30 years) in an area of about 63,000 km\({}^{2}\) (450 km by 140 km). The northern edge of this area coincides approximately with the boundary between the states of Parana and Sao Paulo, entering the state of Mato Grosso do Sul to the west. The southern border, on the other hand, is approximately north of the city of Umuvarama, in the Parana state. This spatial delimitation of this event [22] exemplifies the functional connectivity [23; 24; 25] characterized by the temporal identification of the process responsible for the transfer of water and sediments with notorious repercussions on the landscape [26].  
\begin{table}
\begin{tabular}{l c c c} \hline \hline \multicolumn{1}{c}{**Municipality/**} & \multicolumn{1}{c}{**Code**} & \multicolumn{1}{c}{**Accumulated Rainfall**} & \multicolumn{1}{c}{**RP (Years)**} \\ \multicolumn{1}{c}{**Federative Unit**} & \multicolumn{1}{c}{**Code**} & \multicolumn{1}{c}{**(September 2015-February 2016) (mm)**} & \multicolumn{1}{c}{**RP (Years)**} \\ \hline Maringa/PR & 83767 & 2049.4 & 178.38 \\ Londrina/PR & 83766 and 2351003 & 2092.1 & 148.31 \\ Colorado/PR & 2251033 & 1767.7 & 106.6 \\ Arapongas/PR & 2351048 & 1957 & 103.9 \\ Porto Rico/PR & 2253002 & 1445 & 70.8 \\ Paranavai/PR & 2252027 & 1573.7 & 43.69 \\ Navirai/MS & 2354000 & 1725.5 & 43.68 \\ Umuvarama/PR & 2353008 & 1712.3 & 41.56 \\ Diamante do Norte/PR & 2252015 & 1527.5 & 39.33 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Rainfall cumulated between September 2015 and February 2016 and RP (return period) in rainfall stations in Northern Parana (showing only the stations with RP higher than 30 years).  
Figure 5: Rainfall cumulate (September 2015 to February 2016) RP (return period) in Northern Parana, Brazil.