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J \ ~ , ': ': ( ( I, " ,. I ( .: i , \ I , , i f \ f I i I ! ! i ( ( I ~ , i i i I I i I I i damage for a structure without basement is 55 to 75 percent of the same structure with a basement. This can be illustrated by overlaying Figures A-5 and A-6, and Figures A-7 and A-8. The difference iS'quite uniform over the full range of flood hazard factors. Figure A-11 shows that for flood hazard factors equal to 8.0 the expected damage for the 1SNB and 2SWB is essentially the same. This Similarity continue.s for flood hazard factors greater than 8.0 feet. Sensitivity to Ratio of Contents Value to Structure Value An analysis of total expected annual damage using four ratios of contents value to structure value (.20, .35, .50, .65) showed a consistent trend with variations in FHF, event at first floor and type structure. Only skew M data were analyzed. Generally, structure damage was 37 to 50 percent of the total damage before taking into account the reiative value of contents to structure. For example, for a 1SNB structure the percent structure damage varied from about 46% to 37% for FHF's of 2.0 and 20.0, respectively. Also, for a given FHF the percentage is relatively insensitive to the event at the first floor. For example, for a 1SWB the percentage varies from 37% to 41% for the 2 year to 100 year event at the first floor and a FHF ; 4.0. When the relative value is taken into account the percentage of the damage which is attributable to the structure ranges from 83 to 75% with a ratio of 0.20 (VC/VS) to 61 to 47% with a ratio of 0.65 (VC/VS). Within each range the percentage decreases as the FHF increases. Figure A-20 shows the variation in expected annual damage for a 1SNB with the 10 year event at the first floor. The percentage differences shown in the table are typical for all type structures and all events at the first floor. This analysis shows that the percentage difference between ratios of value of contents to value of structure - 0.20 to 0.35, 0.35 to 0.50, 0.50 to 0.65 - generally varies from 10 to 19% over the full range of flood hazard factors and events at the first floor. Thus, expected annual damage is only moderately sensitive to reasonable variations in the ratio of contents value to structure value and more importantly this variation can be estimated. For example, if a ratio of 0.40 were assumed initially but later revised to .50 the expected annual damage could be expected to increase approximately 15 percent. Sensitivity to Depth-Damage Data Source Figures A-21 and A-22 show the influence of the three different depth-damage data sets discussed previously upon expected annual damage. For a single story structure without basement the difference is relatively uniform and the curves regular. Figure A-21 shows that as the event at the first floor increases and goes into the 15 to.25 year range the difference is moderate (about 1.0 percent of structure value). For the 5 year and 2 year events the difference increases to 3 and 7 percent respectively. For a single story structure with basement the (unctions are nonuniform and irregular for flood hazard factors less than about 8.0 feet, but become more stable as the flood hazard factor increases beyond this point. The differences between different data sets is considerably greater than for structures without basements over most flood hazard factors, but decrease as the flood hazard factor increases. The irregularity of the curves for structures with basements is caused by the differences in depth-damage functions below and above the first floor (Figure A-3). Below the first floor, for example, the Huntington data shows the greatest damage and the 1970 data considerably less. Above the first floor the Huntington data shows damage considerably less than the .1970 data. This reversal of damage functions causes the irregularities shown in Figure A-22. The 1974 FIA data varies considerably from the other and generally yields the least expected annual damage. A-10