Laserfiche WebLink
<br /> <br />>24 <br /> <br />ROGER A. PIELKE. JR. <br /> <br />J.S. floodplains containing 9.6 million households with $390 billion in property <br />FIFMTF, 1992, p. 3-2). (Table 1 summarizes these data on floodprone regions; <br />,ee also Thompson and White, 1985). The wide disagreement among these data <br />mggests a growing recognition of regions subject to flooding, but caution is advised <br />in drawing definitive conclusions until more reliable data is available. <br /> <br />Population at Risk <br />A consequence of me lack of data on the areal extent of floodplains in the United <br />States is that a difficulty exists in assessing trends in and current levels of popula- <br />tion at risk to floods. Trends in population at risk to flood events are an important <br />factor in any determination as to whether societal vulnerability to floods in de- <br />creasing, increasing, or remaining relatively constant. One can easily hypothesize <br />that increasing population and urbanization in the United States has led to a com- <br />mensurate increase in population at risk. Yet, one can also hypothesize that the <br />various societal responses to floods may have more than compensated for popula- <br />tion growth and in fact fewer people are today at risk to flood events. Currently, <br />daln is lacking to reliably assess trends in population at risk to noods events, and <br />therefore it not possible to systematically assess whether societal vulnerability to <br />floods has increased or decreased over recent decades. <br /> <br />. <br />~ <br />v; <br />~ <br />B <br />'c <br />:J <br />" <br />" <br />,= <br />~ <br />" <br />] <br />~ <br />9 <br />~ <br />.~ <br />~ <br />~ € <br />'" !!. <br />~ ~ <br />9 <br />il <br />" <br />'" <br /> <br />Properly at Risk <br />Accurate determination of property at risk to flooding faces many of the same <br />obstacles facing accurate determination of people at risk to nooding. Table I sum- <br />marizes the findings of the various studies (cf, Goddard, 1973, Table 5). The Table <br />shows that there is relatively little systematic data collected on property at risk to <br />flooding. Again, the lack of data limits what can be said about trends in vulner- <br />ability to flooding. It is likely that the Federal Insurance Administration, which <br />operates the National Flood Insurance Program, has in its records data on property <br />at risk to floods for the communities which it has worked with since the early 1970s. <br />However, this data has seen only limited use, e.g., in determination of repetitive <br />losses and substantial damages over 50%, and has yet to be systematically assessed <br />from the standpoint of trends in societal vulnerability to floods. <br />Differences in the estimates of people and property at risk to floods are at- <br />tributable to actual demographic changes, but also to d.ifferences in floodplain <br />definitions, and simply that the data has not been collected and systematically <br />analyzed. The data that does ex.ist allows fOf only gross generalizations and thus <br />limits what can be authoritatively concluded about trends in societal vulnerabil- <br />ity to floods (d. Changnon et aI., 1983). An understanding of trends in societal <br />vulnerability is one factor (along with trends in climate, policies, etc.) that would <br />comprise an evaluation of the effectiveness of U.S. flood mitigation policies. <br /> <br />. <br />" <br />'0 <br />g <br />" <br />~ <br />~ <br />~ <br />o <br />!;' <br />~ <br />o <br />'" <br /> <br />~C5 <br />~:3 <br /> <br />NINE FALLACIES OF FLOODS <br /> <br />s ~ <br />.,; ';; <br />:! '" <br />.,; <br /> " <br /> ~ ~ -. <br /> 0 E <br /> ;; '" <br /> ~ ~ vi <br /> .. to ;; <br /> <br />0:: <br />00 <br />~ <br /> <br />< <br />~ <br /> <br />00 <br />~ <br />~ <br /> <br />, <br />'" <br />. <br />" <br />~ <br />'" <br /> <br />~ <br />~ <br />~ <br />u <br />'" <br />" <br /> <br />B <br />00 0 <br />~~" .; <br />~ oc !;; <br />l"l N .n <br /> <br />o <br />00 <br />~.' <br />0; <br />N <br /> <br />~ <br />'" <br />g <br />N <br /> <br />o <br />~ <br />~ <br />.;, <br /> <br />'" <br />M <br />, ~ <br /> <br />8 <br />:6~ <br />- ~ <br /> <br />~ <br />'" <br />N <br />vi, <br /> <br />M <br />~ <br />-i, <br /> <br /> ~ " <br /> '. <br /> 0 0., .~ g <br /> E ~ '. -. <br /> " " 8 ~ ~ <br />" ;; '. '0 > <br />:E " 0. ';; ~ !!. ~ ~ <br />. -. ~ " ';; 0 ~ e <br />~ . u !!. <br />" 8 g -e 0 <br />;;: g > 0 e <br />~ :J " <br /> ~ 0: ~ <br /> <br />;;- <br />~ <br />~ <br /> <br />'" <br />'" <br />'" <br />:J <br /> <br />i" <br />~ <br /> <br />"' <br />U <br />'" <br />< <br /> <br />'" <br />~ <br />~ <br /> <br />"' <br />o <br />u <br /> <br />"" <br />'" <br />~ <br /> <br />425 <br /> <br />" <br />~ <br />:B <br />o <br />~ <br />M <br />~ <br /> <br />..:""" E ~ <br />\0 U 0: u u"",:" <br />~ ci u: ~ ~t! <br />'~gae-<; <br />30'0€p.Eu <br />~~2.s~~ <br />e ~ ~ Ii ~~ <br />''5; ~ 5.g g:g <br />.~::~~~;;- <br />VlC?.9.g ;>,~ <br />,"c-;' ~ Vl 2!- <br />~ = ~ ~~;:- <br />_ U -0.= t f- <br />",.OJ c ii'E':.~ <br />13 >. ~ E OJ e:: <br />u ~- c u _ u. <br />zE~Q.~.5 <br />5EOJ..513-o <br />.~ Bl". ... u. 1;1 <br />c: 1i~.E -o.~ <br />~Er;n~~ <br />c u - > " <br />o - -- .- .-. <br />u.5 ij' "i d ~ <br />" " ~ E ," <br />~ -i3 :::I ~ &. a <br />3 ~ ~ :t: .Q ] <br />1! "'.~;;; 0 E <br />~ ~ ~:; -:: s- <br />'0:::1 '0 _ c u <br />Vl5lu--E~ <br />'- u 0 U p..... <br />~ ': vj.:; ~ 13 <br />o ~ :::J -d > ..<:: <br />E~~~O~ <br />~. r- '0 c..g <br />.:;;:;;-~~...~ <br />-r- '''0 €:::I <br />~ 0\ 'E c=>. <br />.g:::..g : 1! "r; <br />... t?"8 u ....= <br />?: ~ 0 ~ elJ'~ <br />r:-.~::i ~.~ ~ <br />~Jj~~~~ <br />::::''0 ~ ~ c.~ <br />~~~Q~.-g <br />;:: U ~ d ii:I: <br />.~ ;>,.5 ~ E ;,; <br />elJ E ;::: c a ?i' <br /><e: -< ~:c: fr c: <br />'Ovi~~O~ <br />E::i;:;j"--1:!2l <br />E1!~'7~;' <br />~~<c;~~ <br />fru.5 -08. E <br />~ci'E1!~Vl <br />~ .c:-:~ @-~" .'-'8 <br />::> 9... G :Q U:. <br />-.; gfl E ..2' <br />8:.2 ~ '", .-;:: .....:.. <br />5 ~ '" .5 .g :i; <br />~~*o:o~ <br />