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<br />March 23" ),9'10 DraH f'"'pe,,-t - FOR REVIB~ ONLY
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<br />d{:::'ffic.nstrab?!d by successful national pro~F>ams i.n tither c:ountrif::.1sh !/Corrective
<br />mr.\aSUre'E~ bas:.cd on apP}-ctpriate res;t~arch and enforced by locCll requlationE:., can
<br />lead to dri::tmi:1tic reductic(n~:j. in J.and~:.1 idf:~ losses.. Thii:~ has been demc(n:.t)-l::lter.l in
<br />t:he LDs. Angeles flrea, whl;.~re reductions in lCtssE's of more than 90 percent have
<br />tH2€'1l ar.hif-:ved 'fnr nE'W constructionl! (National F{f.:>Seai-ch Council, i9B5L,
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<br />There are many types of lane/slides, all of ",~hir.:h an:? characteri~~ed by df.:l\<'JDl#ard
<br />and outward mClvement of soi 1 ~( rock and vegetation under gr avi tat1.onal
<br />influence.. Landslides are trigg~?'reti by bf:ith nC:ltln-al and man-induced r:ha.nge5 in
<br />thp environment" Geology, climate, hydrology and cOfls.truc::tjn)l act;jvjt..:ic'~s
<br />contr'ibut.e t.o slope instability aT'lei fi..~:i.lurf2 HJold and .JDc:him, 1989) ~
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<br />Onp type,! elf land::,lide~ thl~ flIudflcq"J, is most closely relt~tE:d to floodplain
<br />m:magc.:?ment and is proposed for c:redi t under the Communi ty Rating System (CES)
<br />of the Nation2il Flood Insuronc:e Prcl~rram (NFIP)" ThE~ 1:':'ederaJ InsurF.rnc.t!
<br />,:)dmini.stratiofl (FIA) includes c:ovt:~rBge of mudslide damag83:' in 'its E.t.anr.l~..n-d
<br />f:Jood in!'5HranCe policy';. bIJ'C nettE's the differencE' betwflen E,l, modf'ioh1!: l1a l-jVf:~r of
<br />liqui.d and flow]nq ml.\dH~ and C:l landslide, HmO\lement Cof a mas.::,s of rock or
<br />L~t~\r t:h,,)1 For :\.nsurancf? purpclsPs, one r.:ourt case ruled thad; CD\"(~~r i'-:l~~e ~;,!a~ }:i m:) -ccd
<br />t:c l'i.q\.!_ld~ as opposed to plastic~ floltJ, and that, d€1maqe due to iflund~"'\t:io:n \->Ja2-
<br />nt':.'cf:'!'S-sar-y for' a successful claim (FIA, .1985)"
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<br />The- definltion of mudfltlws is cE?'I'lh'al to mapping and managing them~ at. leas'c a~j.
<br />fi:lr 1:)5 the National Flood Insur'ianc:e Pr-ol.rram i5 concenlE?dh A !::cd 1 Ecjt7mtj~~t!=:.
<br />ds-fini,tion Df mudflDw is an eart.hflc(~'1 that consists of materiEd thai; is wet
<br />E'rwl.I~~h to f.lOltJ rapidly and thai.; contain!..:; i~,t least 50 perTE'nt EFrnrJ'", silt.., 2nd
<br />cl~1'1--5izE~d particles (Varnes, lS178). Utah County~ UT define;; mudflDtr'J
<br />(!-l'ypt?rconcentratf~d sediment fltq",l) as a class of debr-)!:.s flow h!hen;:~ =oJ:Jlis
<br />e-::CD\..lf\t fClj- l~O~~ to 70% Df the fle,od by weight, wi thout reference to the
<br />compoffiition (Rob]son~1 1989)" Another study says that liffiUdfjclt~s 2n'e at thE:
<br />Im'-J21'" end of the hyperconCf2ntraterJ flf.)t~.l range, and thE' scrJifIh?nt Bnd debl~is:.
<br />cCll1centration by volume j,s abt'ut 20~;..-l10% (LioLl,- 1989)" FIA jrpziln ~~nr::E~ coverag-\:~
<br />include:_ !l... l[l~~se!..; (recurring as a j"esult of inundation from fflurls:.l ides c:,::::;used
<br />by accumulations ef ~"',/ater on or unde?r the ground """ II and Il"." muds.l..1.de damage
<br />and loss and related pn)blems Bl'"e :.~im"i.lar' to those ii"wolved in other kinds of
<br />flr.lDds" (FlAy 1"185)"
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<br />It: hi:.1S br2en c;"!l--gued that. when FEt1PI inc:luded ilmLlds_lidel! in its insurance cO'./8rage
<br />in 1969, it did ncd:. adequately dc-:-fj,ne the term. !lIn F..\ffect;, it has ~~ddQd a
<br />~,uhc13ss- of landslides to the floDd inSUl"C::1nce pi""[;gram ~;J:d,:hDut, c1el3rl')" def'i"ning
<br />that subclass""" FEMf'1 ."" haE been unable to implf.?ffit:mt an eff'E"~ct.:ivf.:' mllds'lidO'
<br />insur 3nCf:.~ pl'eg1'am largE~ly bp-l:ause of technical difficul til::~s. in mappj nq muos.l idE:'
<br />hB70rd zone-.lS" These te-chnical difficulties inc~lurJe deJ.ineatjng hB:;.:a\--dous
<br />pDrti.ons Df the la.nr.!5cape~ similar to flood hazard mapping, and (j:i.sl..::iogLdshing
<br />mudsl:iclc'5 fl-om other t'!,pl'?S of J.andsJ.idos!1 (Ol!shansky and R09E'rS~ j987)" FJr~
<br />al-gL\(~s, t.hat the NFIP haE paid 11.=:5S than 500 lHudflD~4J claim2.~ denied p3ym8nt of
<br />1.281. other c}i3ims~ i::mcl that its interpretation of ffiudf1 O\;,l!S __i~, l!"~,, \c~d:i]y
<br />tHlder!;;=,t.Dod by property i"f'i5ur-ance p.rt:~fe:?,sionals~ NFIP 11I2:lnagemt?i1t, t:he Con9res~;;,
<br />our poJ ic.yholclErs~ ,~nd the cDurts ". ~ 11 (FIA, 198~;)"
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<br />t1an3.gelHr~nt of rnudflo~" hazards
<br />re"moYf:lJ (If f2>:isting !,,::,.t:ruc:ture!:i-
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<br />may include regulation of rl~::O~'J d!?1/21 opmcnt,
<br />subjl2r.:t to rnudflow damaS1E\~ and controJ J ,jng the
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