# A Systematic Revision of the NFIP Claims Hazard Data in Florida for Flood Risk Assessment
## 3 Results and Discussion
### Further Analyses for Flood Risk Assessments
#### 3.2.2 Loss Convergence in 30 Zones  
The Flood Standards [1] require that modelers create a minimum of 30 geographic zones and verify that any Monte Carlo simulations required by the flood model to estimate losses converge to within a standard error of 5% in each zone of Florida (unless otherwise justified). The authors developed a preliminary set of zones based on the nearest coastal target location using a carefully selected set of 30 target coastal city locations. All zones were developed to have coastal exposure, so that storm surge risk affected every zone. The zones were made somewhat smaller in more vulnerable regions and larger in less vulnerable regions, to ensure a sufficient loss in all zones, while maintaining a reasonable size and structure, so that risk convergence was suitably ensured over all of Florida. These zones are subject to revision once stochastic losses are available and we have better understanding of the distribution of the vulnerability. As stochastic losses had not become available, the NFIP claims data was used for guidance. Figure 8 shows the preliminary set of 30 zones, along with the target coastal locations that define the zones. In addition, the NFIP losses are  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Loss (Millions of** & **\% of NFIP** & **Remarks** \\  & **USD)** & **\%** & **Includes surge due to nontropical cyclones** \\ \hline \multicolumn{1}{c}{Nontropical} & 574 & 15 & Includes surge due to nontropical cyclones \\ \multicolumn{1}{c}{Nontropical} & 394 & 11 & Excludes all surge \\ \multicolumn{1}{c}{Nontropical} & & & \\ \multicolumn{1}{c}{rain-related} & 372 & 10 & Excludes surge and other/unknown \\ \multicolumn{1}{c}{Nontropical} & **228** & **6** & Greater than 1 km to coast \\ \multicolumn{1}{c}{rain–inland} & \multicolumn{1}{c}{} & & \\ Total NFIP all causes & 3714 & 100 & \\ \hline \hline \end{tabular}
\end{table}
Table 6: Breakdown of the revised NFIP paid loss amount due to nontropical events.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Claim Count**} & **Loss (Thousands of** & \multicolumn{2}{c}{**Event Duration**} & \multicolumn{1}{c}{**Remarks**} \\ \cline{3-5}  & **USD)** & **Begin** & **End** & \\ \hline
702 & 29,671 & 9 December 2009 & 20 December 2009 & 17 December 2009 heavy rain \\
1154 & 14,302 & 24 December 1997 & 10 April 1998 & El Nino record event \\
558 & 13,618 & 28 October 2011 & 2 November 2011 & Possible related to tropical \\
529 & 11,999 & 12 March 1993 & 24 March 1993 & disturbance \\
467 & 11,244 & 12 May 2009 & 29 May 2009 & Possible remnant of tropical \\ \hline \hline \end{tabular}
\end{table}
Table 7: The top five NFIP nontropical loss events in order of paid loss amount.  
shown for each zone in millions of USD (paid losses). The Pensacola zone had the largest loss, at USD 592 million, mainly due to Hurricane Ivan (2004). Next were Miami (USD 423 million) and Navarre (USD 415 million). The least vulnerable zone was St. Augustine Beach, at USD 11 million. Note that these losses were heavily influenced by singular events and thus should not be interpreted as an overall measure of risk. If a zone were to have no or negligible losses, then convergence may not be possible.