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<br />'!.e~ponse. The ben"f it. of a "arning syatem are ulttIM.rely
<br />decermlned by the response of dis",ler preparcd~co. agencies and the
<br />public.
<br />
<br />syate". can"" found In repons by the ~usqCleh"nn.; 'l.i~er .::lastn Com-
<br />, (29), (12) . ~ ~ , (l)
<br />"lss~on any ~y vo"''''ng. 4
<br />
<br />People respond to "arnlni" in dHfercne 'mys, SOIl\C:nay react
<br />l""..ediately and others may either disbelieve the .,arutng or bi!
<br />reh,ctant to leave until it is tOo late for resc"e. Factors that
<br />motivate people to respond to a flood "arning are'
<br />
<br />The Susquehanna River Basin Commisston (SRBC) h,," heen "c~lv~ In
<br />developing "elf-help flood "~rning systems which oper,<te at the sub
<br />badn leve 1. As of June 1978, ~here \oIere 16 S<lCh "yste"", In operation
<br />and they co~ered o~er 5,000 sqLl~re ..!l~~ in Penn~y1"~n1a. 4.dditional
<br />syateIllll are being in"taUed.
<br />
<br />. T1_ of day or day of week.
<br />. 1{umber of times" warnlng is re"eived.
<br />. Visual r~"-ognltion of J. flood threat (ralnhll, r1sing
<br />streams).
<br />. Reception of .) warning fro.. a known public official, such as
<br />thetll"yor, ora policeman, or from a relative or persoa well known,
<br />sLlch as a neighbor, member of a co~uniry organization, or A buslness
<br />associate.
<br />. Content of loIarning
<br />. 'the UOl<' elapsed slace .~ past flood ev~nt; if a flood has
<br />occurred"1thinthenleOloryofapersort, the respol"lse is LlS\1sllYOlore
<br />positive.
<br />. Recognition of other people e~acuat1ng the area.
<br />
<br />A prOtotype system i. currently (October 1981) being installed by
<br />the NWS In cooperation \oIith the Appalachian RegIonal Co~1s.ion in a
<br />l2-county regioo at the intersection ()fKentucky, West Virginia ,and
<br />VIrginia. The sy.te!D.include. cooperativc observcrs, radio rain gages,
<br />and<luto"",Ucaensor., Altogether, therewil1beaolllelOOraingagea,
<br />6Q atream gages, 12 microprocessor~ at the county level, and 3 mini-
<br />computers at state emergency operation centers. The mlnico~puter" aC
<br />state level further proceaa data and communicate with the XIIS and other
<br />.."",rgency "rg~nh"t1"n&. Expansion to an 80-county area is being
<br />planned.(8)
<br />
<br />5inc~ th~ dlsseminatlon and response to a fle.h flood ~drnlng ar..
<br />rclev~~t to the potential benefits of a warning system, rheae <Ire
<br />d16Cus~..d Llur In ev,.tu,,~io"a Qf existtn" .yne",,; and CaSe sCLldles of
<br />p~st fLoodo.
<br />
<br />The community of Gatlinb~rg, Tennesae", baa a flash flood warning
<br />syste", instaUed i~ 1980. ihe basin upstream fr~.. the dty I.. 41.6
<br />..quar~ ..Uea and the war~ing time for f1ood~ ranges fro!:'. about 1/2 hour
<br />to 2 hours. High ground in moat areaa hO'ole~et', is 100 yard" or less
<br />Away. Th~ cl~y, the Tenne~aee Valley Au~hority, and ~he N\I~ concluded
<br />that ~rad1t10nal manu,,"l rain gages or up.tream warning gsges \oIere not
<br />adequate. ihe .y.tem consl.t. of five t~in gages, two .tream gagea,
<br />and a central ~tAtl~n. All gages have oelf-cont~ined pO\oler and
<br />CO[Jmmnlcate by radio, e"cept for a at rea... gage in the cen~er of th<!
<br />clty whIch 'ero~ts by telephone. The central gtation i" at the fire
<br />d"part1llent. At this loc~tio", there I. a <elnlcompLlcer to utiliz..
<br />in~om!ng data Ln a software hydrologtc oodel of the ba~in. Th~ only
<br />'na"~"l op@ucor tnput 1< ~ fl"sh n",_,d 1'''t"ntLal lnd~" th~t t~
<br />
<br />::XAHPLES OF FLASll FLOOD WARt>n-G S\:STrHS
<br />10 ~ld in conalderln~ the e.tabllsh~ent of a flash flood ~drning
<br />.y.te", .",me e~"mp\eo Of "xl.ting systems .ue presenc"d. In "ddtti"n
<br />:0 the ,>ubllcHions pr~vi<ll,"l' ctted. sddttio<M\ g'.,ld.."."~ ~" ~..'r"bg
<br />
<br />~2
<br />
<br />.,
<br />o.
<br />
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