VIEN DIA LY • VIEN KH&CN VIET NAM HOI DIA LY V I E T J ^ A M DIEN BIEN T R U O T LO DAT 6 TINH QUANG NAM Nguyen Thj Thu Hien'''' Mai Trgng Thdng'''' SUMMARY Landslide is a natural hazard often occurring in[.]
VIEN DIA LY • VIEN KH&CN VIET NAM HOI DIA LY V I E T J ^ A M DIEN BIEN T R U O T LO DAT TINH QUANG NAM Nguyen Thj Thu Hien' Mai Trgng Thdng' SUMMARY Landslide is a natural hazard often occurring in hilly and mountainous areas of Ouang Nam province Based on statistical analyses of data on landslide in the past time and results collected front the field work in October 2009, this paper analyses progress of landslide in Quang Nam province from 1980 lo 2009 and current status of landslide in some roads at the end of October 2009 The paper also analyses some causes regarding geolog)', geomorphology meteorology and human activities which lead to landslide in the study area 1.M6D.A.U Trugt Id sudn dugc liic:ii la cac chuyen ddng tuong ddi nhanh ciia khdi dai da Ihco mgt mat sudn xuong phia dudi trgng lire Dd la su dd Id, trugt, sut, hay chay xuong ciia khdi \at chat la dat da, manh vim hoac hdn hgp Qua trinh phd bien d mien mii va gay tac hai Idn la bien tugng trugt dat, cac khdi dat lan da thudng sung nude, trugt xudng chan sudn theo mdt mat trugt (phang hoac cong), ddng thai hinh tren sudn cung trugt \a \ach trugt kich tlurdc khac Trugt Id sudn thirdng la ngudn cung cap \'at lidi cho tai bidi Ifi biin da [!] Quang Nam la mdt tinh thugc trung trung bd, cd dien tich tu nhien hon 10.408knr Cac dang dja hinh kha da dang bao gdm viing nui, trung du, ddng bing ven bien va theo hudng thap dan tii' lay sang ddng Vimg niii d phia tay chilm 72% dien tich lanh thd vdi nhieu dinh mii cao, dja binh ddc va chia clt manh Lugng mua trung binh nam tren loan tinh la 2000-2500inni, dd cac viing mii cao va trung binh d tay bflc \a la) nam c6 the dat 4000nim/nain Lugng mua Idn va tap trung chu ylu thdi gian khoang thang (tir thang 9-12), chilm khoang 80% tong lugng mua ca nam Quang Nam la noi bi anh hirdng llurong xuyen ciia tai biln trug-l Id dll, Theo sd Tai ngu\en va Mdi tru'dng tinh cac vu trirgl dll thudng hay xiiy d cac huydi mien nin ciia tinh, chii yeu tren sudn mii hoac tren mai taliiy dudng di qua viing mii Trugt Id dat gay thiet hai nang nl ca vl ngudi va tai san tai dja phuong II DIEN BIEN TRUOT LO DAT TINH QUANG NAM Sd hdi thong ke ciia phong Quan li mang dudng giao thdng so cho thly nhfrng nam 80 cua the ki trudc, mdi nam cd khoang 20.000in^ vat lieu bj trugt xuong cac dudng ciia tinh Quang Nam Tu nam 1990 khdi lugng da tang len, trung binh khoang 30.000m'Vnam va dat tdi tren 50.000m^ nam 1994 va gin 130.000m' nam 1995 (Bang 1) ^ Tnrdug Dgi Hgc Su pham Ha Ndi ' 'ien Dia Iv sie Hdi nghi Khoa hgc Dia ly Todn qud'c lan th&S - Hd Ndi, 2010 VIEN DIA LY - VIEN KH&CN VIET NAM HOI DIA LY VIET NAM Tir nam 2004 den nay, nhfrng bien ddng ciia thdi tiet, hiiii cac can bao bg vao Quang Nam kt;in theo mua Idn da tang len, cudng nuii Iran mua cfmg lang len dang kc Dieu da lam cho hidi lugng trugt Id dat xay tren didi rdng vdi khdi hrgng dat trugt cang Idn Nam 2004, cac 19-28/12, bao sd ket hgp vdi khdng lanh a phia bic da gay mua Idn tren dja ban tinh vdi lugng mua phd bien tir 300-400mm, ca bid cd nai mua tren OOOinm nhu Hiep Dire 966inin, Tra My 827inni, Tien Phudc 662nini Mua Idn lam lu xuat hidi dong thdi d tat ca cac luu vuc sdng, dac bid tren be thong sdng Thu Bdn da xuat hidi dgt lu lien tiep vdi nuic ki Idn nhit da vugt bao ddng III Khu vuc ddng bang bj ngiip hit dai ngay, khu vuc mien mii bj Ifi quel va sat Id manh Bimg I Khdi hri/ng diu trugt tren cdc diidiig cua tinh Qudng Nam giai dogn 19S0-1995 STT 10 11 12 13 14 15 16 Nam 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 Khoi krgng (ni"') 19 503 291 700 # 20 700 21 000 16 000 40 960 15 975 26 151 12 870 55 100 1069 28 545 26 059 53 632 127 784 (Nguon: [4]) Trong dgt mua Idn nay, tdng khdi lugng sat Id Ircn cac tuyen dudng d tinh Quang Nam khoang 680.000 m^ (Bang 2) Bdng Khdi lugng sat Id dudng giao thdng anh hudng ciia bdo so vd dot ngap hit tir 19 ttin 28/11/2004 Khoi lugng sat Id (m^) 387.500 36.500 240.000 111.000 41.000 12.000 1.000 1.500 500 21.000 5.000 256.460 684.960 Tuyen dirdng Quoc 15 Dudng QL- 148 Duong QL- 14D Dudng QL-14E Dudng tinh Dudng DT- 604 Duong DT-610 Dudng DT-614 Dudng DT-615 Dudng DT-616 Dudng DH- 110 Du'dng dja phuong Tong (Ngudn: Uv ban nhdn ddn tmh Qudng Nam- nam 2005) Hdi nghi Khoa hgc Dia ly Todn qud'c lan th&S-Hd Ndi, 2010 819 HOI D | A L'r VIET NAM VIEN DIA LY • VIEN KH&CN VIET NAM Cac tu>en du'dng Hd Chi Minh, qudc Id 14B 14D, 14E va tinh Id len miln niii hlu bit bi ach tic vdi khyi lugng sat Id tren 400.000m-\ Cac tuyen dudng huyen, dudng lien xa lien thon d cac huydi miln mii bj xdi Id nghiem trgng gay init lien lac tir cac xa din trung lain huyen Tren tuyen qudc Id A, nhieu doan bj sat Id va ngap sau khidi aiao thdng bj gian doan tii' chilu nga>' 27 din trua 28/11/2004 Trona nam 2005 bao so (ngay 28/10) va ap thip nhiet ddi (13/9 va 06/10) da anh hirdng true tilp den cac dja phuong cua tinh Quang Nam Bao, ap thip nbid ddi kit hgp vdi khdng lanh da gay mua Idn tren toan tinh, xual hidi dinh It! tren song Vu Gia xIp xi mirc bao ddng III Ngoai ra, trang nam 2005 cd dgt mua to tren dien rdng Mua Idn gay lu lut va sat Id dat Tdng khdi lugng dat bj sat Id la 448.684m- [6] Nam 2006 co bao so dd bd trirc tiep vao phd Da Nang va cac huyen phia bic cua tinh Quang Nam Baa manh kem theo mua Idn da sinh mdt Iran hi Ion vugt miic bao dgng III tren sdng Vu Gia gay thid hai Idn ve ca sd tang Khoi hrgng dll bj sat lo bao so khoang 470.000nr' [6] Trong nam 2007, thdi tiet, hiiu d Quang Nam cd nhfrng dien bien rit phirc tap Mua lu xay lien tiep vdi lugng mua va cudng mua rat Idn Chi tinh thdi gian ban thang tii' 1/10 den 7/12/2007, anh hudng ciia khdng lanh phia bic va cac bao so 5, sd tren dja ban tinh da lien tiep xay dgt mua Idn vdi long lugng mua tren loan tinh phd bien tii' 1800-2000mm, dac b i d d Tra My lugng mua len ldi 2910nim Tren cac sdng da xuat hien dgt lu Idn vdi mirc nude deu xap xi hoac tren bao ddng 111 Mua lu keo dai khien cho hidi tugng Id dat, Iii quel xay d nhieu noi tai viwig mii, tinh trang sat Id bd sdng, xdi Id, boi lap rugng vudn dien kha nghiem trgng, Theo bao cao ciia sd Giao thdng van tai Quang Nam, dgt lu nay, cac tuyen dudng giao thong bj sat Id nghiem trgng Dudng Hd Chi Minh bj sat Id nhieu vj tri vdi khdi lugng tren 60.000m' Qudc Id 14B, 14D bj cudn trdi nhieu doan, sat Idtaluy duong, nhieu vj tri giao thdng bj ach tic Cac tuyen tinh Id quan trgng nhu DT604, DT616 bj sat Id taluy duong Cac tuyin dudng DH, DX bj sat Id tren 240.000m' [6] Trong nam 2009, chju tac ddng true tilp ciia can bao so 9, tren dja ban tinh Quang Nam co mua rat to vdi lugng mua tir 500-600inin chi thdi gian 1-2 Cudng mua Idn gay ngap kit tren didi rgng va sat Id nhieu tuyen dudng giao thong Bdng Tmh hinh sat Id tren nwt so tuyen dudng a Qudng Nam anh hudng ciia can bdo so (28-29/09/2009) STT 1 II Tuyen dudng Quoc 16 QL 148 QL 14D QL14E Cac tuyen tinh 16 DT604 DT608, 609,610, 6108 DT614 DT615 DT 616 Tonsi Khdi luang (m'') 36.000 110.000 20.000 45.000 20,000 5.000 6.000 152.530 394.530 (Ngudn:f6]) 620 Hdi nghi Khoa hgc Dia ly Toan qud'c lan th&S - Ha Ndi 2010 VlgN DIA LY • VIEN KH&CN VIET NAM HOI DIA LY VIET NAM Sat Id mii tai thdn I xa Tra Nam (luiycn Nam Tra My) da lam nsiudi chit, hoc sinh bj llurong nang, va dat toan bg bu)'eii Nam Tra My vao tinh trana cd imuy ca cao ve sat Id Nhu vay, nhfrng nam gan day tinh trang sal Id dat tren dja ban tinh Quang Nam xay cang manh Khdi krgng dat da bj sat Id va viii lap Idn hon nhilu so vdi nhfrng nam 80, 90 ciia the ki trudc va co xu hudng cang tang len III HIEN TRANG TRUOT LO DAT O QUANG NAM QUA DOT KHAO SAT CUOI NAM 2009 Chimg tdi lien hanh khao sat bicn trang trugt Id tren mdt sd tuyen dudng thdi gian tir 20/10 den 02/11/2009 (sau bao so 9) Kel qua cho thly bicn tugng trugt Id, sat Id xay kha phd bien tren cac tuyen dirdng giao thdng chay qua midi mii - Tuyen tinh Id DT 616 Tinh Id DT 616 tir Tam Thanh (ihinb phd Tam Ki) di Tac P6 (Nam Tra My) dai 103kni Tai bien trugt Id dat da xay cbii yeu tren doan dudng tir Bac Tra My di Nam Tra Vly noi cd dja binh ddi mii Tren doan dirdng da thdng kc dugc tren 30 diem trugt Id, cbii yeu la trugt taluy diroiig Trugt dat thudng xay Iren da magma xam nhap, hoac da tram tich bj bicn chat, d nhfrng khu vuc cd sudn ddc va dai, vd phong hda day, ldp pbii thirc vat thua thdt Dang clui y nhat la diem trirgt gan thiiy didi sdng Tranh 2, cd dien tich khoang 50iii * 30iii Day la diem xay trugt dat lap lai thdi gian ngan Sau Iran trirgt dat trudc dd ngudi ta da phai lam ke da chdng trugt vdi chieu dai khoang 50ni, cao 3m, rdng 2ni Tai thdi diem khao sat, dat da trugt xuong pha vd ke da ddng thdi day mdt phan kc xa khoang 2-3iii so vdi vj tri ban dau Quan sal cho tluiy diem trirgt xay tren dja hinh cd sudn ddc 30-40 , ldp plui llurc vat bj pha luiy, chii yeu la cay bui Trugt dat khdng chi xay d tren tuyen dudng, nam khu vuc ddi mii toan bd huyen Nam Tra My cd nguy co' cao ve trugt Id Dgt intra Idn bao sd gay sat Id mii tai Tra Nam kim ngudi chet Thj Iran Tac Pd (huyen Ij Nam Tra My) nam tren khu vuc rat nhay cam vdi trugt dat Cac cdng trinh ciia huydi (trudng hgc nha cdng vu ) dugc xay dung tren cac sudn ddi hoac vj tri san iii doi mii, \a> hau het deu phai cd cac cdng trinh chdng trugt, - Tuyin Imh Ig DT604 Tinh Id DT 604 doan tir Prao din Tiiy Loan xuat bien 67 diem trugt Id, dd Idn nhll la dilm ki quel d ban Ka Tum va diem trugt Id tai ddc Kien Lfi qud xay vao kic 6h30' sang 30/09/2009 tai ban Ka Tum, xa A Tinh, huyen Ddng Giang Tran hi quel da cudn trdi hoan loan ngdi nha song may man la khdng cd thid hai ye ngudi Tai hien trudng, san phim tir ddng ki qud bao gdm da tang, dam, biin set hdn ddn nim tren mdt dai dai khoang 250in, rdng 50ni Quan sat tren dinh ciia vd ki qud cho thly ldp pbii thuc vat bj pha hiiy, chi cd cay bui hoac dat trdng Dilm Doc Kiln nim d ranh gidi gifra Quang Nam va phd Dii Nang Day la khu vuc tlurdng xuyen xay trugt Id dit Tai thai diem khao sat, trugt dat xay vdi quy md Idn, dien tich khoang 300m*50ni, khdi lugng dit da bang chuc nghin m' gay ach tic giao thdng nhilu Xung quanh khu vuc cdn cd 3-4 diem trugt Id khac vdi qu)' md nhd bon - Tuyen quoc Ig 14E Hdi nghi Khoa hgc Dia ly Todn qud'c lan th&S - Ha Ndi, 2010 821 VIEN DIA LY \ I E N KH&CN VIET NAM HOI DIA LY VIET NAM Khao sal Uiyln quoc Id 14L doan tit lla Lam di Tan An thdng ki; dugc dicni trugt xa> a cac sudn mii nam each dudng khoang 200-3OOm Cac diem trugt na) ddi CO qu> md nho xa\ tren da magma xam nhap granit granodioril d khu \'irc cd Idp phu thuc \ai llura chu >eu ki ca_\ bui hoac keo trdng - Tuven qudc Id I4B Quoc 16 14B doan tir Tiiy Loan di Thanh My dai 42kni Ket qua khao sat cho tha\ tren tu\en cd khoang 30 diem trugt Id Dudng di cbii yeu tren dja hinh ddi mii co ddc khoang 30-40", tren nIn da phien biotit, bdt ket cat ket thudc cac he tang Kham Dire \a Nong San Trugt dat xa\ chu \eu Ircn cac \acb talu)' duang vdi qu_\' mo nho Didu trugt Idn nhat quan sat dugc co didi tich khoang 100in*30in, tren dia binh doc 40", tao khoang 10.000m' dat da ga\ ach tac giao thdng - Trirgi Id Iren dudng Hd Chi Minh Dudng Hd Chi Minh doan tir i hanh My di Prao dai ban 30km Trong dgt nitra can biio so doan dudng na>' bj sat lo' ngbicMu trgng, ket qua kluio sat ghi nhan dugc 55 diem irugl la Cd nhfrng doan trirgt Id xa} lien tiep vdi ca taluy duang \a taluy am Didn dang cbii y la khu vuc na)' cd ldp plui thuc N'at luong ddi day nlurng bicn lugng trirgt lo' kha bicn dja binh ddc, nen da dugc cau lao bang cac da bgt cat kd da phien bj nirl ne manh Quan sal mdt sd diem trugt cho thay cd bicn tugng nude cha) qua mill dudng mua Idn, be thdng thoat nude qua tai Vi \ ay nude mua tir sudn don xudng tao ap lire day dat da xudng dudi chan sudn Nude cha)- qua dirinig plui huy nuil dudng dong thdi gay xdi Id taluy am Vi vay rat nhieu diem trirgt Id xay dong thai \di ca taki) am \a taluy duong W NGUYEN NHAN GAY RA TRUOT LO DAT Co rat nhieu nguyen nhan gay sat trugt Id dll d tinh Quang Nam nhicn CO the ggp nhdm nguyen nhan chinh la dja chit, dja mao, tugng va boat dgng nhan sinh - Nguyen nhdn dia chdt Dcic diem cua da va vd phong boa la nguycMi nhan dja chll chinh lien quan den lidn nang phat sinh trugt Id dat Cac loai da d day bao gom cbii yeu la da magma xam nhap; magma mafic \a sieu mafic; cac trim tich luc ngu)en giau thach anb, chira cuoi kd cat ket ; cac da bicn chit; da phien silic, da philn sericit,,, Cac loai da tlurimg tao nen ldp vd phong hda day dc dan den trugt Id dll cd mua Idn - Nguven nhdn dia mgo Phan phia tay Quang Nam cd dja hinh cao, doc Idn va chia clt manh tao luing krgng dja hinh Idn thuiin Igi cho trugt dll cd ngudn goc trgng krc, day cac dang dja hinh cd doc tir 15-30" chilm mgt dien tich rdng, dac bid khu vuc cd dudng 116 Chi Minh di qua doc tren 30" tuong doi biln Kit qua khao sat cho llilv cac didn trugt la xa\ chu )'lu Iren dja binh cd doc 30-50" - Nguyen nhdn lirgng Mua Idn hoac mua kco dai la ngu)cn nhan chinh ga) trugt la dll da Tmh Quang Nam co lugng mua trung binh nam Idn 2000-2500inni' Miil khac, a da) thuang xa) nhfrng dot mua Idn kco dai \di cudng manh anb huong kit hap'cua bao, ap thap n^hict dai va khong lanh Nam 2007 thdi gian bo'n ihang (lu 1/10 den 0, 12) tren dia ban tmh xa) dgt mua Idn \di ldng lugng mua phd biln Ui 522 Hdi ng-hi Khoa hgc Dia ly Todn qud'c lan th&S - Ha Ndi 2010 VIEN DIA L-i" • VIEN KH&CN VIET NAM HOI DIA LY VIET NAM 1800-2000mni, ricng lai Tra My len ldi 2919mm i i o n g lir 15 den 18/10/2008 lugng mua Iren loan linh dugc tir 500-700miii, diic bid tai Tra My krgng mua la 980inm Gan day can bao sd 9, lir 28 den 29/09/2009, gay mua Idn tren loan linh vdi hrgnu mua tir 500-600iiini Lirgng mua Idn, cudng cao va keo dai nhieu niiiv kd hgp vdi cac )'cu td kluic la ngu)en nhan ga) lai bicn Irirgt Id - Cdc hogt ddng nhdn sinh Hoat ddng dial pha, ddi rirng lam mat Idp plui tlurc vat Va ngu)'en nhan quan ga) Irirgt Id dat da Hau bet cac diem trugt ghi nhiin dugc xay dicu kien Idp plui llurc vat rat thua thdt, chu )cu la cay bui Hoat ddng cat xen chan sudn ddc xay dirng cac cdng trinh giao thdng (dirimg Ho Chi Minh), nha cdng vu (huydi Ij Nam Tra My) la tac nhan gay trugt Id dat d (^uang Nam trugt Id dat xay la sir kcl hgp ciia ca nguyen nhan irC-n Tuy nhien, nguyen nhan chinh dan den hien lugng trugt dat d day la mua Idn va keo dai vdi cudng numb KET LUAN Quang Nam la tinh cd nguy CO xay trugt Id dat cao Trong 30 luim (1980 2009) hidi lugng Irugl Id dll d Quang Nam cd xu hudng gia tang vdi khdi hrgng dat da trugt Id cang Idn, diic bid la irong nhfrng nam gan day Nguyen nhan true tiep cua trugt Id dat la tac ddng ciia nhfrng dgt intra Idn vdi cudng manh lam gia tang cic qua trinh Irugl Id trgng lire d viing mii Su gia tang hidi lugng trugt Id dat d Quang Nam Irong nhfrng luim gan day lien quan cbiit che den nhfrng bien ddng ve hau- thdi tilt, dac bid la cac bao, ap thip nbid ddi, front lanh, dan den lam gia tang ca ve Uin suat va cudng ciia cac dgt mua Idn vdi didi rdng tren loan vimg, TAI LIEU T H A M KHAO [IJ Le Dire An, 2008 Mgt sd van de ve nghien ciru Irugl la vd du bdo chimg Tuyin tap cac bao cao khoa hgc Hdi nghj khoa hgc Dja li loan qudc lan thii [2] Nguyen Cin, Nguydi Dinh lloe, 2007 Tai biin mdi trudng NXB DHQG Hi Ngi [3] Nguyin Vi Dan, Nguydi Midi, Ngd Van Liem, 2006 Trugt la ddt vd budc ddu dir bdo vung trugt Id ddt a Bdc Trung Bg bdng phuong phdp dia mgo iii) en tap cac bao cao khoa hgc Hdi nghj khoa hgc Dja li loan qudc lan thu' [4] Dang Vii Khlc, 2007 Su dung GIS de ddnh gid nhay cam cua Irugl ddi: trudng hgp dogn di qua tmh Qudng Nam cua dudng Hd Chi Minh Vidi dja chat Vidi Khoa hgc va Cdng nghe Viet Nam [5] Mai Thanh Tan, 2009 Bdo cdo thuc dia chuyen di Dir an hgp tac Viet Nam - Dan Mach "Danh gia nhfrng tac ddng ciia bien ddi kbi bau den dieu kidi tu nhidi, mdi trudng va phat triln kinh tl - xa hdi d Trung Trung Bd Viet Nam"" (PI- 08 Vie) [6], Uy ban nhan dan tinh Quang Nam Bdo cdo tdng kit cdng tdc phdng chdng lut bdo ndm 2004, 2005, 2006, 2007, 2008 vd bdo sd ndm 2009 Hdi nghi Khoa hgc Dia ly Todn qud'c la'n th&S- Ha Ndi, 2010 823 ... DIA LY • VIEN KH&CN VIET NAM HOI DIA LY VIET NAM Sat Id mii tai thdn I xa Tra Nam (luiycn Nam Tra My) da lam nsiudi chit, hoc sinh bj llurong nang, va dat toan bg bu)''eii Nam Tra My vao tinh trana... tuyen dudng, nam khu vuc ddi mii toan bd huyen Nam Tra My cd nguy co'' cao ve trugt Id Dgt intra Idn bao sd gay sat Id mii tai Tra Nam kim ngudi chet Thj Iran Tac Pd (huyen Ij Nam Tra My) nam tren...VIEN DIA LY - VIEN KH&CN VIET NAM HOI DIA LY VIET NAM Tir nam 2004 den nay, nhfrng bien ddng ciia thdi tiet, hiiii cac can bao bg vao Quang Nam kt;in theo mua Idn da tang len, cudng