# A Systematic Revision of the NFIP Claims Hazard Data in Florida for Flood Risk Assessment
## 3 Results and Discussion
### NFIP Claims Hazard Revision
#### 3.1.1 Catastrophe Event Number Matching  
Our first task was to attribute meteorological events to claim data that were grouped by a _catastrophe number_ or _date of loss_. Using a summary table provided by NFIP, the authors were able to determine the causative event for most of the groups of claim data. The results of this work were used to determine which historical events should be focused on in our modeling studies. These results, however, did not provide details of the cause of loss on the individual claims level. Our initial focus was on determining the types of events that we may need to consider in order to update the FPFLM hazard models.  
Among the paid claims, 34,257 (22.3%; money-wise USD 498,827,000 (13.4%)) did not include catastrophe event numbers. The HURDAT2 tropical cyclone information was used to match tropical events to the NFIP claim data. If loss claims were located within 700 km of a storm center during the event date, it was considered that the claims belonged to that storm event. Of the 153,751 claims studied, 108,244 were detected by the HURDAT2 storm name check within claim event dates to keep and/or modify the original catastrophe event number. In addition to the provided claim count and paid amount, the revised statistics are shown in Table 1 for selected catastrophe events. The event number zero was assigned for the unidentified events. While the distinguishable number of claims were now attributed to several of the last century's hurricanes (Major Hurricane (MH) Frederic (1979), MH Georges (1998), MH Mitch (1998), etc.), not many claims were modified for recent hurricanes, perhaps because of a better collection system for claim data in the NFIP. An example of catastrophe event number updates is shown in Figure 5.  
Many claims around Miami and Keys were attributed to the event of MH Mitch (1998). The majority of claims were assigned to more reliable and accurate meteorological events in the NFIP flood loss data.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Provided**} & \multicolumn{2}{c}{**Revised**} \\ \cline{2-6}
**Catastrophe Event** & & \multicolumn{2}{c}{**Paid Amount**} & \multicolumn{2}{c}{**Paid Amount**} & \multicolumn{2}{c}{**Event**} \\ \cline{2-6}
**Number** & **Claim Count** & **(Thousands of USD)** & **Claim Count** & **(Thousands of USD)** & \\ \hline
0 & 34,257 & 498,828 & 27,080 & 374,330 & \\
22 & 32 & 814 & 897 & 8686 & [PERSON] (1979) \\
131 & 3248 & 40,163 & 4258 & 51,425 & [PERSON] (1998) \\
133 & 1466 & 20,518 & 854 & 14,323 & [PERSON] (1998) \\
134 & 8 & 51 & 206 & 2471 & [PERSON] (1998) \\
182 & 2492 & 49,429 & 2515 & 49,656 & [PERSON] (2004) \\
564 & 3247 & 139,821 & 3278 & 140,967 & [PERSON] (1992) \\
615 & 241 & 3386 & 779 & 11,787 & [PERSON] (1998) \\
641 & 3278 & 106,816 & 4789 & 139,913 & [PERSON] (2004) \\
643 & 10,353 & 945,500 & 10,619 & 959,392 & [PERSON] (2004) \\
646 & 3800 & 90,497 & 3918 & 93,128 & [PERSON] (2004) \\
649 & 3375 & 109,045 & 3698 & 116,507 & [PERSON] (2005) \\
659 & 9411 & 355,267 & 9616 & 363,625 & [PERSON] (2005) \\ \hline \hline \end{tabular} H: hurricane, MH: major hurricane.  
\end{table}
Table 1: NFIP catastrophe event number revision (selected events among total 158 events).