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. -- (Hh HYDRAULIC ENOINEERINO "94 ~S"45' GAl:AlS_VWUNIAINS .....,IOHAl.p,Ul1C ------- ,..,. - I , ' " I ..L..J _____ 1.____. .. .....our:1EM +---,.. I .~. 1,.-' 1,".1 Fi 'ure l.-.Majur gcognlphic rCillUrcs U.~lhC. R,i1VCIl fnrk Ba.o.;in. g Swain Cuunly. Nmlh (3111In\ol. f d mining peuk discharge in any slrc31.11 U:-;e of the :dope-area m.clhodh 0 'teet~~I'I"" "'u"h us channel gradient, hydnlUlll.: . I ' r hYSical carat.: ns .......-... . h' ter require." conSll eraUon 0 ~ . . .. d of h draulic characteristics, SUI,: as. w~ . roughness. and reach uRlfOrlmty. an ~ of this aper is to evaluate the m(hrCl"t surface profile and state-or.lIow. The purpo. 'ky 11~untuin strcal11-.with rcspert Iu . , . R' en Fork.-.. sleep. rOt; . '. measuremenll~~~ ~ .I~ dUlv liseuss methods and problems of analysIs. these charadensttcs an 0 (. . Study Area I r R" The Raven Fork drainap.c , 'h t t the ().;ona u tee lvcr. . k' Raven Fork IS a t~1 u ary ~' , ountains Nationall'o.uk lInd the Chern ('\: basin (fig. I) is located 10 theGre~t Sn~;lkY ~ 'n the basin range from 610 to I,K1tl Indian Re:\ervation. Nort~ Carohna. I:. e;~.tlon~~nsisl~ of coniferous and deciduous m. At the higher clevatlOn~, the vegeta.loned h coniferous species. Rhododendron spcc:ies. and the I.ower .eleva~~ons ~re dO~~~~er efevations and ~ll: '11~, slre.nns at I~w~r is prevalent on hilltops and l'nde s opes a g d (J M GarriSon 1ennes."ce Vallcy ~Icvations. T~e National par~l}~~~~.e'a~~t~:t ~iUI~ I~gl:!inl! ~r l:ic:tr~nL! tillS oct:.tl~rc.'ll Authority. wnUen I:~mmun.:. .' 1:~1: horderin the Cherokee Indmn ReservaUnn. in the basin ex.cept 10 areas,. m~~?th the Straight I;!Pork drainage hasin (fig. I). partil:ularly along the boun( ary ----- . ItN::! FI.OOl)._.NORTII ('^R()I.IN^ 1>17 Field Condlllons and Computallon ot Discharae Th\~ rCiKh sdccted fur the :\Iopc-arca I11caStltCfllel1l UI1 R<lven Fork is in Ihc ('herukn' Indian Reservation about 4.5 km east of SlI1okcmont (fi~. II. Favor<lhlc .Illrihuu:~ of the :>clcl:"ICd rem.:h il1dudc.~d (I) .1 lilrgC' I.:han~c in wulcr-surfilce c!evllli(111 (fall), (llullironu dmnllclgcumclry throughoullhe read, and (.l) a I<lrgr numhcr tlr g(Knl high-wah'r 11l.lrks to dcrille Ihe waler'~mrfilcc profile. The dmillage ,Ireu 01" R.1VC'1l Fork UIlhis sile is IM~ km2. Iligh-wulcr l11arks were surveyed along 130111 uf the rcul.:h. Tht.' reach is stnli~hl throughouI il:> lell~lh cxn'pt for a slighl hend to Ihe ler..' nCilr the duwnslrcam limit (If Ihe rc.lC.:h. F1nodflnws were confinl:d 10 Ihe main dml1nel and a nOlrrnw overflow plain 1111 the h.'l"I rnmk. The mnin dlanncl ranged from 20 In](I m in width. ill1t1lhe dmnnel ht,d was composed primariiy of l'O;.lrSC malerial, flinging in si7.c from 11.15 10 1.5 111. '111t' left flood plain was narrow, mnging from 5 to 20 m in widlh, and l.:onsist('tI of <l heavy growlh of vines, :>mall brush, ..nd Irees. The righl h.lI1k WllS stcep lIm' ditll1(11 uVl'rflnw. It h.ul hl'en l.twercd with a IighlgfOwlh of sfll<lll hushes .mtltrl'\'s, musl tlf whidl wen: stripped to rUl'k durin!! the flond. On the basis of high-w<lh'r murh, ma:dl1lul11 waler dcpths during the nootl nmged from 4.S 10 S.U m in the mailll.:hmll1d fll1d from (I.X tu 15 In in Ihc left tlo(xl plain. lligh-w;ucr mmks "long Ihe steep ri!!hl bank were mostly wash lines (lines ;11111l~ Ihc.~ hank marking where Ihe l1o(xlnow erotled the soil). The wash line_s UPI)Cllrt'd In provide a "fair" (within 3U mm) 10 "!!ood" (within 15 111m) represenlalion oflhr truc high-Willer level. On the leU bank away from the fast vc!t)(:ity in Ihe main dlillllld, s(."(.'(1 and fille-debris lines were diSl:overcd in trees und along the overnow Imnk. Tht,SC lincs were gencnllly raled "good" to "exl.:c1lcnt" (within 5 nnn). Six. cross set:tions were selected and surveyed. Cross ~Cl:tions were chosen on Ihe basis oflhe high-water mark profile, and t:lIre was taken to avoid locating Ihem in urciI," where free fall over rod~ and houlder!ii could have occurred during the nood. On Iht, hasis of geometry. ..Unoss sections were !iiulxtividcd III Ihe lOp of Ihe len b.lI1k. Mnnning's roughness I:oeffit:icnls (II valut.'s) were selected in the field ;:md n1nged from 0.055 10 O.05K in Ihe main l.:hannel and from n.OKS 10 H.InU in the left ovcrnnw. The hil!h-water mark profiles of the left and right banks were analY1...cd to dt'lcnnine willer-surf<h:C elevations al cross-!iicl.:linn lerminuses, InHiOlI cumplll,uiollS imlil."ated thallhe slale-of-now was suocritic.1I at all cross sttlions eXl:ept for the one liulhest downslream, where a Inlllsilion to ~upcn:ritk<ll now npparemly hOld ol.'l'urred. This l:TOSS scl.:tinu was eliminated from the l.:tlI11()UI.llions. The l.:ross sct.:tion jll~1 upstream of Ihe Insl cross st..'Ction alsn W<lS eliminalcd frum Ihe fin<lll.:omputillinn lll'1.:ause of inl:ondusive high.walcr marks on the right banko-a large hedrot.:k nutt.:Tt'p jutting inlo Ihe slream jusl downsln."lllll rrom Ihis scrtioll appillt'luly 11IlKhll.{'tl signilkunl "pil('-up" of waler. The final cnmpulution of disl.:hargc used only 111l' fuur 1Illslrcam-mosl I:TOSS sections. The rClld. lenglh iIlNl full were K5.6 m and 1.07 III, respC'l'livcly. The I:ross-sC'ctional area of the reach c,,"pill1dcd sli~hlly lhnm~h till' I"ir\t Ihree cross set,:1ioI1S, und then cOl1lral.:\ed belween Ihe third and fmlllh nos." 'it'clion", The I:omplllcd disch<lrge WilS 460 m !:>, and avcrage main channel f1nw vclot.:ili\.... ntnged from 3.99 to 4.24 m/s. The m.:ompuled now obtained by usilll% tlll~ fnur ups1rcl.1m-most cross seclions wus subcritlnllhroughoullhc rcm..:h. I.ess th.11I I pl'rn.1I1 (If lhe now was carried in lhe len overbank. :lRcfcrences to "left" or "right" are made fl'l;uivc In the duwnslream dif(.'{'lion.