Nghiên cứu cơ sở khoa học và đề xuất các giải pháp khoa học công nghệ đảm bảo sự ổn định và độ bền của đê biển hiện có trong trường hợp sóng, triều cường tràn qua đê xác định tần suất mực nước đê biển hiện có để đánh giá tần

Vi vay, can co mpt nghien ciru xdc dinh lai tin suat myc nude de bien hien cd de ddnh gid tan suit vupt tan suat thiet ke va xac djnh cac to hpp sdng, trieu vd nude dang ed the xdy ra tr

BO KHOA H(PC VA CONG NGHE

CHirONG TRINH KHCN CAP NHA NlTOfC KC 08/06-10

B6 TAI: "Nghiin cAu cas&khoa hgc vA dexudt cdc giii phdp khoa hgc cdng ngh$ bio dam sif on dfnh vd d^ bin cda di biin hi$n c6 trong truing hgp sdng, triiu cwemg trdn qua di"

MS s6: KC08.1S/06-10

BAO CAO XAC ejNH T A N S U A T M I / C NU'dC DE B|£N HIEN CO e £ DANH GlA

T A N S U A T VU-OT T A N S U A T THiei Ke vA xAc ojNH CAC T 6 HOP

SONG, TRieu vA NU'drc D A N G CO THi X A Y R A

TRONG VUNG BI^N tUT&C TA

Ca quan chu tri: Truang Dai hpc Thuy Igrj

Chu nhi#m <Sk tei: GS.TS Ngo Tri Vieng

BO KHOA HOC VA CONG NGHE

CHirONG TRINH KHCN cAP NHA NU'dC KC 08/06-10

D6 TAI: "Nghien cieu ca s& khoa hgc va de xuat cdc gidi phdp klioa hpc cong nghe bdo ddm sir on dinh vd dp ben cua de bien hien cd trong trie&ng hap sdng, trieu cirdng trdn qua de"

Mas6:KC08.1S/06-10

BAO CAO XAC DINH TAN SUAT NiyC NU'dC BE BI^N HIEN CO Dfi DANH GIA

TAN S U A T V U O T TAN SUAT THI^T Ke VA XAC D|NH CAC T 6 HgP

SONG, TRltU VA NUaC DANG CO THt XAY RA

TRONG VilNG BISN NU'dC TA

CHU NHIEM BE TAI

GS.TS.Ngd Tri Vieng

BAN CHU NHIEM

CHl/ONG TRINH KC.08/06-I0

^ ^ - f ^ e g ^ A N CHU TRI /^, Xl'mSiigxehi hpc TJmy ta

BO KHOA HOC VA CONG NGHE

Ha ndi, 2010

M G D A U 4 CHUONG 1 6

DE BifiN VIET NAM, NHAN T 6 ANH HLTONG & KHA NANG ITNG P H 6 VOl BlfiN

D6lKHfHAU 6 I.I.HSTH6NGD6BI£NVI$TNAM 6

1.1.1 Thyc trjingde bien Viet Nam 6

1.1.2 'i'eu ciu thiit ki de biin den nim 2010 (Chua xit den tic ddng cua BDKH) 7

1.1.3 Khi nang dng phd cua de biin vdi bi^n dii khi h^u 8

1 Tic dpng cda biin dii khi hiu toin ciu din myc nude bien dang d Vi^t Nam 8

2 Khi nang img phd cua De biin 9

a Nang cip de bien 9

b Quy hoach chlin lupcdebiin irng phd vdi myc nude biin dang 16n 9

1.2 HE THONG M 6 C , CAO D O PHVC VV TINH TOAN Ml/C NUGc BIEN 10

1.2.1 Moc cao do Bic bO - Thanh H6a 10

1.2.2 Mic cao dp Nam bd v4 Tmng bp 11

1.3 CAC TAC NHAN ANH HUONG DEN DIEN BifiN DlTdNG SG BifiN 19

1.3.1 Quan h? tuong tic dong chiy song vdi dien bien dpng luc viing cda sdng ven biSn

Viet Nam 19 1.3.2 Mot si yeu ti ty nhien liSn quan vdi diin bien dOng lye vung cira sdng ven biin ViSt

Nam 20 CHirONGII 30 CAC PHUONG PHAP TlNH TOAN Ml/C NlTdC BIEN THIET K£ 30

I Khai niem chung 30

n Tinh toan myc nude biin thiet ki 30

2.1 Trudng hppcd tai liSudo dac 30

2.2 Tinh toan rieng rS cac thanh phan rii ti hpp theo mpt qui luit xac dinh di c6 muc

nude thiit ki 34 III XAY DUNG DUONG TAN SUATMirCNlfOCTONG HOP 34

3.1Casddiili^u 34

3.2 Co sd toan hpc 42

3.3 Tinh toan cac d^c trung thiy triiu thiSn van 46

3.4 Tinh toan cac die trung nude dang bao 48

3.5 Xay dung dudng tan suit nude ding b5o 62

3.6 Xay dung dudng tan suit muc nude ting hpp ^ 66

CHUONG 3 ' 71

DUdNG TAN SUAT M U C N U O C TONG Hgp DQC THEO B O BIEN NAM DINH vA

CAC TtNH LAN CAN T U THAI BINH T(3l NINH BINH 71

L Gidi thiSu chung 71

II Dudng tan suit myc nude ting hpp tir Thii Binh tdi Ninh Binh 71

KfiTLUAN 78 TAI LIEU THAM KHAO 79

Md©Au

Trong thin gian gan day, cung vai sy bien doi khi h$u toan cau, cac thi?t hai do

thien tai co nguon goc khi tugng thuy v3n c6 chieu hu6ng gia tang tren toan the gidi Cac corn bao co chieu hudng trd nen m ^ hon, trd thanh nhung sieu bSo co sure tan pha nang ne Cac hi^n tupng mua Idn, gi6 gi$t, loc xoay ciing x^y ra thudng xuyen hon Cac nghien cOru mdi day nhat tren the gidi cho thay rSng s\r gia tSng byi trong khi quyen do cac hoat d$ng ciia con ngudi da lam bien doi cdc qua trinh nhi$t dpng lyc

hpc trong may, tSng khd nSng gdy mua ldn, t6, l6c, voi rbng vd mua dd Tai nhi^u noi

tren the gidi, hi$n tu(?ng dpng dat va song than cung xdy ra thudng xuyen vd gay nhieu h^u qua vo cung nghiem trpng

Hien nay, vdi sir phdt tri^n kinh t^, xa h6i, nhu ciu ddm bdo an ninh qu6c phong ciia cd nude, cling vdi chien lupc vuon ra bien de khai thae mpt each hieu qua hon vung bien nude ta, ngay cang co nhieu ho^t dpng xa hpi, kinh te va qu6c phong tren pham vi toan vimg bien Dieu do lam tang rat nhieu khd ndng thi^t hai do cdc thien tai thdi tiet gay ra t^i vimg bien vd vung ven bien Viet Nam Van de ndy co the dupe xem xet tren hai mat Thtjr nhat la cae hoat d6ng kinh te xa h6i tai vimg bien va ven bien da gdy ra nhiing thay ddi v^ mdi trudng ty nhien theo hudng bat Igi vd 1dm gia tang thien tai va thi?t h£ii ciia thien tai Viec xdy di^g cdc cong trinh ven bd bien da ngan cdn dong van chuyen bun cdt tu nhien dpc bd, gay ra bdi lap tai cac luong tau va xoi Id bd tai nhiiu ncri Cac hd chua nude dupe xdy dvmg tai thupng nguon cdc con song ciing ngan ddng van chuyen bun cat ra biSn, 1dm tinh hinh xoi Id bd bien ngay cdng trd nen nghiem trpng 6 rat nhieu khu vuc, rimg ng$p man va rimg phdng hp ven bien da bi tan phd dd Idy dAt cho cdc ao dam nudi hdi san Cac rung ngap man vd rimg phong hp

bj mit khong nhiing gay ra nhung bien doi ve mdi trudng sinh thai theo hudng cd hai,

ma cdn giiip cho sdng ldn ddnh thing vao d6 bien, gay va d6 bien vd ngap lut Nhiing diiu tra sau can bao so 7 (bao Damrey) ngay 27/9/2005 cho thay nhOng khu vuc rimg ngap man va rirng phdng hp ven bien cdn dupe bao vp tdt thi de bien khong bi vd Thur hai la cdc ho^t dOng kinh te xa hpi tren biin vd vung ven bien da t^o nen su tap trung rit cao vl cac cdng trinh xay dyng va tai sdn cd gia trj cao ciing nhu dan cu d vung ven biin Diiu ndy ciing lam gia tang miic dp thi^t hai m^t khi thiSn tai thdi tiet xay ra Thi du, con bdo so 7 (Damrey) nam 2005 cung vdi gid manh da gay song ldn vd nude dang t^i vimg bd biin ciia nhiiu tinh thupc viing ven biin Bac Bp nhu Hdi Phong, Thai Binh, Nam Dinh, Ninh Binh, Thanh Hoa Song ldn, nude ddng kit hpp vdi trieu cudng

da 1dm va de tai nhiiu vj tri, gay thiet hai vl kinh te xa hOi hdng ngan ty ddng Gin

dSm nhieu tau danh bdt xa bd va 1dm nhiiu ngu dan thi^t meing M^c dii chua dupe khdng dinh vdi cac bdng chiing day dii, nhung mpt so kit qud phdn tich gin ddy da cho thay rang bien doi khi han dang 1dm gia tdng thien tai Trong nhimg ndm gin day, nhihig can bao co cudng dp sieu m^mh tren bien dudng nhu ngdy cdng trd nen pho bidn vd gia tang siic tan pha doi vdi kinh tl, xd hpi vd mdi trudng tren pham vi toan thi gidi Chi trong khodng 15 ndm gin ddy, tai khu vyc Nam A da xuat hipn 2 can bao ldn, giet hai hdng trdm ngdn ngudi Ndm 1993, mpt can bao do bp vao Bangladesh da gay nude dang 1dm 138.000 ngudi chit vd mat tich va gay nhihig thi?t hai vd cung to ldn vS tai san Gan ddy nhat, vao dau ndm 2008, con bao Nargis do bp vao Mien Di?n kem nude dang tdi 6m da lam khodng 140.000 ngudi chit vd mit tich Ddc bi$t, tran sdng than ngay 26 thang 12 nam 2004 tai An Dp Duong da lam chit gin 300.000 ngudi vd hdng trieu ngudi mat nha ciia

Bao manh thudng k^m theo nude ddng bao Trong trudng hpp nude dang bao xdy ra ddng thdi vdi triiu cudng, mye nude cao giup s6ng ddnh true tiep vao de bien, tran qua de gay xdi Id vd cd thi v5 de, gay ng|ip lyt tren dipn r^ng va thiet hai rit ldn cho vimg ven bien Vi vay, can co mpt nghien ciru xdc dinh lai tin suat myc nude de bien hien cd de ddnh gid tan suit vupt tan suat thiet ke va xac djnh cac to hpp sdng, trieu vd nude dang ed the xdy ra trong vimg bien nude ta

Bt BIEN V H : T NAM, N H A N T 6 ANH HUdNG & KHA NANG (TNG P H 6

V d l B I 4 N B 6 I KHi HAU

1.1 Hf T H 6 N G Bf; B l i N V l f T NAM

Hien nay, Vi$t Nam cd khoing tren 2800 km de bifo thu^c 28 tinh vi Thinh phd, bio ve khoing 0,70 trieu ha dat canh tic, BChu dd thi, Khu cdng nghiep, Cing vdi khoing 5 tripu dan Trong dd 85% song bing ndng nghiep Vi vay, chinh sich xay dyng, tu bo, cung co he thong de bien li mpt chien lupc rat quan trpng trong vipe phit trien kinh te xi h0i ben virng, djc bipt li kinh tS bien d nude ta

Xay dyng de bien vira li bien phip phdng, chong vua li thich dng vdi bao lut, nude biSn ding vi xam nhip min Nude ta, nim 1410 bit diu dip de biin Tai Ninh Binh, nam 1471, de Hdng Ddc cb^y td Bic Yen Md den Phung Cdng, nim sau trong dat lien each bd biin hipn nay 25km Be bien thu hai dupe dip nim 1830 d Than Phu -Dien Hp cich con de thu nhat khoing 8km vdi thdi gian lan bien dii den 369 nam Con de thu ba tien ra bien them chimg 7,5km dip vio nhihig nam 1830 - 1927 (97

nam) Con de thu tu dip vio nam 1959 (32 nam sau) tiin them ra bien 8 km nila

De bi6n Thanh Hoi, Hi Tinh va Bmh Dinh (De Ddng) dupe hinh thanh tu nhiing nam 1929 - 1930 Hiu h6t de bijn, de cua sdng cac tinh MiSn Trung va Nam

Bp dupe dip khoing trudc va phan ldn li sau nam 1975

De biSn li h6 thdng dap, cdng, ke, de (bing dit, di, beton cdt thep ) ngin man bio ve cda sdng, bd bien, khu dan cu vi nhihig boat ddng kinh td ven biSn vi dim bio

an nmh qude phdng Khic vdi de sdng, de biin lim vipc thudng xuyen hang ngiy cdn

de sdng chi lim viec theo mua lii

Bd bidn nude ta dai 3354 km, song mdi ed 1400 km de t ^ c tiSp vdi biin vi khoing 1400 km de cda sdng, chiim 42,3% Trong dd hai ttah Nmh Thuan vi Btah Thuan cd thi coi nhu chua cd de bien (Ninh Thu^n cd 6,23 km, Bmh Thuan cd 10,71

km de biin song phin ldn la de cda sdng Cii Phan Rang, Phan Thiit vi ke Mui Ne)

1.1.1 Thyc trang dS bien Vi?t Nam

a Hiu hit dip bing dat (de lin bien, ngin min), do din ty xay dyng, chu ddng, song thiiu qui ho?ch, nin dit yiu Theo chu ky lin biin da t?o ra nhi$u M thdng bio

vp trong v i ngoai

song do thiiu qui hogch, bi dpng, nin dat yiu, tuyin de thudng kh6ng phii hpp vdi tuydn chinh tri nen nhieu lin bi pha, ddp lai vd nhieu lin di ddi, luon ludn la noi lo

c Chua dap ling yeu ciu thiit kl

1) Dinh cdn thip: So vdi yeu cau cao trinh dinh hau hit cdc tuyin de cdn thieu khoang 0,5 ~ 1,0 m

2) Chat lupng de bien con thip do v|it li?u ddp (phan ldn la dat boi, dit cat) thiet bi ddp, ky thuat dap khdng ddp ling yeu ciu thiit kl

tudng Chinh phii Phe duy?t Chuang trinh dau tu cung cd, bao \& va ndng cap de bien

hien cd tai cdc tinh cd de tu Quang Ninh din Qudng Nam:

1) Tieu chuin thiit kl: Trudc mdt den ndm 2010 ddm bao h? thdng de bien cd the chdng dupe bdo cip 9 td hpp vdi triiu cudng tin suit 5%

- Ddi vdi cac tuyin de bao ve true tiep cdc khu vuc dan cu t$p trung phdi dupe thiet

kl bao dam an todn chdng gi6 bao cap 12 vdi myc nude triSu tdn suat 5%

- Ddi vdi cac tuyin de ngoai, de bdo v? san xuit, nudi trdng thuy, hdi san thiet ke chdng gid bao cip 9 vdi miic triiu tin suit 5% chip nhan mpt phin song leo tran qua dinh de khi gio bao vupt mure thiit kl nhung khdng gay vd de

2) Giai phdp ky thuat:

- Cling cd, nang cip cdc tuyin de bien, de ciia sdng tao thanh cac tuyin de khep kin kit hpp vdi lam dudng giao thdng vdnh dai ven biin nham bdo v§ ddn sinh, tao ca sd phdt triln kinh t l - xa hpi va ddm bdo an ninh, qu6e phdng;

- Chilu rdng mdt de tdi thiiu tir 5,0 m din 6,0 m, de phdi dupe kien cd, gia cd du cao trinh chdng vdi miic gid bao thiit kl (cip 9, cip 10, khu vyc dan cu cip 12 vdi miic triiu tin suit 5%), giam thiiu dupe nguy cp v5 d6 khi bao vupt miic thiit kl;

phai coi diy li bipn phip bit bupc, kien quyit doi vdi tit ci cac khu vyc, tuyen de cd the cdn t-ong dupe ciy chin sdng; ding thdi cii t?o h^ sinh thii viing ven biin;

- Doi vdi cic khu vyc biin tiin, xim thyc, ein nghien ciju giii phip cdng trinh cit

song, t?o bai boi nhu xay dyng ki md ban, phun cat nudi bii timg budc trong cay

chin sdng de dim bio on djnh liu dii;

- Cic tuyen de xung yiu tryc di$n vdi bien phii dip them tuyin 2 dy phdng phia trong nham dim bio an toin cho nhin dan, him chi thipt hji khi tuyin I (tayin t ^ c dien vdi bien) bj vd khi gid bao vupt qui khi ning chong dd ho§c sdng trin qua;

- Bo tti cic tayin dudng ngang (dudng xuong ci) dl vira lim dudng so tin dan, cira

hp de khi xay ra sy c6 de diiu; cic tayen dudng niy sS cd tic dyng phin vung ven biin thinh cic d khep km, dpc lip, nhim giim thieu di^n tjcb bi ngap lut, nhiem min, h ^ che thipt hai khi xiy ra sy co de biin;

- Nghien cuu, ung dyng khoa hpc vi cdng nghp phyc vy cung co, bao vp cic tayin

de, ke biin vi vvmg cua sdng, xu ly xdi Id, bio vp de, bai phu hpp vdi diiu ki?n ty nhien, thuy, hii vin

s i p den, Chinh phu sS cd Quyit dinh phe duypt "Chuong trinh cung cd, ning cip va xay dyng mdi de biin cic tinh tu Quing Ngai din Kien Giang"

1.1.3 Kha ning irng phd ciia de bien vdi biin doi khi hau

1 Tic dpng cua bien doi khi h^u toin cau den myc nirdc bien ding d Vi^t Nam

Theo nghien cdu ciia chiing tdi thi myc nude biin ding d vimg ven bien Bic Bp

vi Nam B0 (biin Ddng) trung binh tang 2-3 mm/nim theo chudi so myc nude biin quan trie dupe trong hon 30 nim (1976 - 2006) Vimg ven biin Trung Bd ting trung btoh 1~2 mm/nam Nhu viy chung ta ed thi khing djnh din nim 2010 myc nude bien dang khdng qua 10 em so vdi nim 1976

Theo IPCC, din 2100 myc nude biin ding len Im, dipn tich dat bj ngjp: -14520 km^ (khoang 4,4% di|n tich dit cua Vipt Nam)

- Trdn 60% hay 39 trong so 64 tinh vi 6 trong 8 vung kinh tl cua Viet Nam se bi inh hudng

- Khoing 20% hay 2057 trong sd 10511 xa tren ci nude se hi ngap mdt phin hoic toinb$

km tai vung Dong Bing Sdng Cdu Long

- Ndi m$t cich tong quit, trong thi kj" 21 myc nude bien ting tomg binh 1cm / 1 nim

2 Kha nang irng phd ciia Be bien

a NSng cap d€ biin

1) Thyc iiipn thinh cdng Quyet djnh cua Thu tadng Chinh phii vl vipc nang cip de biin din nim 2010

2) Tiip tyc nghien ciiu Tieu chuin de biin vi giii phip ky thuit de biin Bdi vi thyc

tl din nim 2010, tic dpng lim ding cao myc nude bien cdn chua ding kl, song din nam 2020, 2050, 2070, 2100 dii rd ring la mpt vin de Idn Trong khi do, Tieu chuin thiet ke tinh den nim 2010 ehua xet din mdt cich rd rang vl h^u qui nude biin ding len Trong Tieu chuin chi qui djnh 2 yiu to myc nude dinh triiu ung vdi p - 5% vi gid bao ung vdi cip 9, cip 10, cip 12, khdng cd yiu to nao die trung cho gii trj myc

nude biin dang len, mic du trong yiu td myc nude trieu 5% cd thi cd hin quan song

khdng dang kl

3) Gid bao ciing li yiu td chiu tic ddng cua biin doi klii hiu do lim tang cudng dp

vi tin suit xuit hi^n song chi ed tic dung nang cao sdng bien tic thdi Vi the, trong Tieu chuin thiit kl de biin khdng nen gia tang cip gid bao qui ldn (cd thi cip 12 li dil) NIU qui Idn thi ldn din diu? trong khi xu thi bao ngiy cing tang mi thdi gian

gay hai thi rit ngin ed thi cho sdng biin trin qua nhung khdng cho phep di vd Hien

nay khoa hpc cdng nghp hien dji thi gidi v i ngay d nude ta diu cd thi giii quyet 4) Qui hoach vi xiy dyng mdi he thdng de biin tir Quing NgSi - Kien Giang bio dim cic tuyin xudi thu$n, nin mdng vihig, v$t lipu phu hpp, ky thuit xiy dyng hipn dai an toin Diy li hp th6ng de biin cd d$ an toin thap nhit nude ta song s8 bio v? nhiing vung bi nggp nhiiu nhat nude ta

5) Xay dyng hp th6ng de biin thinh mpt hp thong giao thdng quic gia ven bien dim bio an ninh quoc phdng c6 rimg ngip min phdng h$, bio v$ mii Cic vimg ed dieu ki$n cho pMp cin xiy dyng tayen de 2, dy phdng, thuin lpi cho vi^c so tin din khi cd

sycddtaydnde I

b Quy hoach chiln luprc dS biin ihig pho vdi myc oirdc biin dang ISn

1) Dinh gii dp tm ciy cda cac kich bin biin d6i khi hiu

nhiet dp tang d miic 2°C va giii miic 450 ppm CO2 vao nam 2050

3) Qui hoach Chien lupc cap thoat nuac nuoi trdng thuy, hai san trong do khong loai tru bien cac cua song ven bien thanh to hpp tren ciu dudi cong ngdn trieu, man, giii ngpt, thoat lii, giao thong thuan lpi

4) Chien lupc de biin can xet theo quan diem phat trien lau ben kinh te viing, ket hop hiiu ca giira kinh te bien va kinh te dat lien va chien lupc dam bao an ninh quoc phong Can cd qui hoach de bien vdi tam nhin xa 20 nam, 50 nam, 70 nam va tinh chat pham vi xem xet rpng ldn hem va khong on djnh so vdi de song vi no anh hudng ciia cac cira sdng ciia dia hinh - dja mao lan can, dong thdi chiu tac dgng ciia nen dja chat tren toan tuyen Ddc biet la chju tac dpng ciia bien doi khi hau sau sac

Da den liic can nhan thuc de bien co mpt vi tri chien lupc, Id sir ton vong cua quoc gia

1.2 HE THONG MOC, CAO DO PHVC Vy XiNH TOAN Ml/C NlT^C B I £ N 1.2.1 Moc cao do Bac bp - Thanh H6a

Theo thong ke co the ke den loai moc cao do:

(1) Cao dp luc dia do Phap xay dung gpi tdt la sd "0 luc dia" lay tning vdi muc nude trung binh nhieu nam chuoi quan trdc muc nude tai Hon Dau

Anh 1: M6C Qude gia tai Hon Dau (2) Cao dp hdng hai do Phap xay dung gpi tdt la sd "0 hai dd", liy tning vdi muc nude

Theo bing thuy trieu 2001 cua ttmg tam Khi tapng Thuy van biin thi ven biin Bic bp vi Thanh Hda so "0 hii do" thip hem so "0 lyc dja" khoing 1,9 m (3) Cao dp sdng Hong (moc dupe gin tai tadng cua Bp Thuy lpi cd) cd cao dO +10,80m Cao dp niy thap hon "0 lye dja" li +0,162 m

(4) Cao dp Qu6c gia, liy theo so "0 lye dja" Moc hien tai dit tai Hdn Diu (inh 1) Moc "0 lyc dja" thdi Phip hipn cdn d dip Diy, dip Bai Thupng Thanh Hda

Nam 1994 da hoin thinh hipu chinh cao dp cac tr^m thuy vin theo cao dp Qude

Gia thing nhit trong toan quic (trd m^t s6 trgm Hii vin van cdn liy theo so 0 hii do) Ngoai 4 loai cao dp ndi trdn, trudc 1994 do chiln tanh cic mdc bi dinh mit hay bi phi nen timg dja phuong sir dyng mdt s6 mic rieng mang y nghTa gii djnh hoic dya vao mdc thuy lpi, mpc hii do hay moc lyc dia tim thiy d dia phuong Dd li cic mic gii dinh do cic Ty Thuy lpi, Ty Giao thdng, Ty Hang hii, Dudng sit v.v lip 1.2.2 M I C cao dp Nam bp v i Trung b$

Trong myc niy can giii dip ba van de:

1 Trong vung cd miy lo?i mdc cao d$ vi quan h? giiSa chung Sy nhan dang va so dd

he thdng cic loai moc dd

2 Myc "0" Thuy van (Hang giang - HG) vi mdc "0" ddng mdng (Lyc dia - LD)

3 Myc "0" mit dit vi myc "0" cua bin dd

1 Cic moc cao dp trong ving - Quan h | giii-a chiing

Sy nhan d^ng vi so dd b$ thong cic loai mdc dd Thdng qua cac tii lieu thu thap dupe ttong phdng va ngoii thyc dia, chung tdi nit ra mdt sd nhan xet sau:

a CA hai h | thong binh cbu4n d^c d Nam bp li:

1) Hp thdng binh chuin d?ic Rignier, do Sd Dia du Ddng Duong tliilt lip vao giiia nhihig nim 1903 - 1914 liy theo myc nude biin trung btoh tai Vimg Tiu dupe quan trie trong khoing thdi gian do Cic myc tieu bing cac chdt sit trdn, cd mpt tim bing chi trdn dd ghi ddng chO: "Rivellement General De la Cochmchme" cao d0 vi sd li^u ghi hdn cpih myc tieu

2) He thdng bmh chuin d?c Hansi vi Lefebre do Sd Cdng chinh thiit lap vio nim

1938 - 1944 dCmg chung cho ci miin Trung, Tiy Nguyen vi Nam Bd liy theo myc

lipu ben canh mue tieu, tuy nhien cd vdi myc tieu khdng ghi so Upu

Vao ndm 1967, Cye Do d£ic quan dodn cdng binh My cd d§t them mpt h? thong moc cao dp t$p trung chu yiu d xa Ip BiSn Hda, Lien tmh Ip 15, quoc Ip 15 khu quan sir cua My nhu kho Long Bmh, khu Long Thanh, khu Nha B^, edng Sai Gon

b Ngo^i 4 h$ thong moc tren cdn c6 3 h$ thong cAc moc khdc:

- H? thong moc Hdng Giang, dupe dimg cho cdc tram thiiy vdn cao dp din din

theo m0t trong 4 he thing moc ndi tren, nen thieu thong nhit Myc tieu dupe ghi nhan bdng niim dat d$t tren chop hinh thdp, hay m0t cdi danh tron hay dupe gdn ngang vao tudng nhd, ho$c tim bia gin tram

- H^ thing moc dja phuang: Cdc dja phuong xay dyng cdc cdng trinh Thiiy lpi, giao thdng ddn tir mdt hudng khdng thong nhit Cde mye tieu dupe diic theo timg khdi try beton

- H? thong mdc Nam Triiu Ti6n, hi^n rit it, con le te d mOt so vung quanh Thanh phd Hd Chi Minh

Trong 7 he thdng neu tren, he thing mdc cao dp ciia Nha Dia du Qude Gia (Ba Lat) NGD hoan chinh hon ca Thdi gian xdy dung h? thdng NGD khoang 8 ndm Ndm

1964 - 1966 thiit lap va do d^c dia hinh; Nam 1964 - 1968 tinh toan vd tir cudi nam

1968 kilm tra lai cdc ket qud tnidc dd Dua vao nhimg tai li?u thu thap dupe d cac tinh, chiing tdi ISn sa dd hp thdng moc NGD toan Ddng bdng Sdng Ciiu Long va Ddng Nai vd kilm tra thuc dia nh$n thiy cd nhftng vimg "trdng mdc" Dd la:

Toan bp vimg U Minh Thupng vd Ha

Toan bp viing phia nam tryc 10 B^c Lieu - Cd Mau

Todn bp huySn Duyen Hdi

Dpc theo cdc sdng Idn phia ddng dudng so 4 va ven bien

Rieng khu Ddng Thdp Mudi trudc ddy da cd he thdng NGD, cae nam vl sau cac mdc deu bj mit mat thit l^c

2 Moc "0" Thuy van (HG) v^ moc "0" dSng ru§ng NGD

Nhu trSn da ndi, moc HG trudc ddy chua dupe thdng nhit hoan toan vdi moc NGD Chiing tdi dd kilm tra va din I^i moc cho 15 tram chinh tren Ddng Bdng Sdng Ciiu Long va Dong Nai Trong s6 dd cd 4 tram do cho ket qud cao dp khac vdi tri sd cii tir 0,24m d6n +l,00m va bo chinh cao dp tuy?t dii theo NGD cho hai tmm do trudc ddy chua cd (bdng 1.1)

khic bift do Doin SHI (Sai hpc Thuy Lpi kiem tra lai)

H(o) mdi -4,91 -4,17 0,00 +0,93 +1,00 -2,54

Ghi chd

dau cpc 1

Qua so sinh mic HG vi mic NGD, ein bing myc nude fen cimg tayin sdng, giira sdng vi npi dong, thay ring cic myc NGD ngoii trj sd cao dp dupe ghi trong vin bin, chung tdi nghi ngd li cdn cd so hipu chinh chenh Ipch rieng cho tdng vimg quy ude, hay li sy nhim lin sai sdt (3) Vi dy Trim Thily vin R^ch Gii, theo moc Hansi

133 - Xn - C tinh theo NGD (trong sin cdng quin R^ich Gii) lai phii -1,00m mdi cin bang myc nude so vdi tii ii^u cu

d Gd Diu Ha ciing v|y - nlu liy theo moc cao dp hien tai thi myc nude cao nhit trong miia lu tai Gd Diu Ha chi S^t tdi + 1,60m, trong khi dd t^i Mdc Hda, hay tai

cac vi tri d Cu Chi, Hoc Mdn myc nude ldn nhit diiu tra dupe diu ldn hon +l,60m thim chi dat tren +2,00m Chiing tdi cho kilm t a Iji mdc NGD tai Cil Chi, Phu Cudng vdi mdc HG cho chenh Ipch khoing +I,00m Cd phii ching moc cao dp NGD d vimg niy cdng them 1,00m vio gii tri da cho

3 M6C " O " mit dat v i moc "O" ciia bin d^ dia hlnb

Hai myc "O" niy khdng gidng nhau Theo vin bin de lai tlii cao dp "O" cua cic losi bin dl cua Sd Dia du Ddng Duong (SGI) li tmh theo mdc cua Regnier Mudn dua vl cao d? Lefebre phii cpng them m$t s6 hi^u chhih +0,463 Thyc tl diiu dd chi diing cho vi tri Vung Tiu, ncri ma cd dO sai Ipch giiia hai mic Resgnier, qua dieu cha thyc dia vl tudi, tiSu ty chiy d cic tinh Cdu Long, Tiin Giang, An Giang, Kidn Giang, Ddng Thip, B$c Lieu, Ci Mau va Thinh phi Ho Chi Muih diu nhin thay dieu dd

4 Q u i trinh chuyin doi vl mic quic gia

Tai hai tram Viing Tiu (Nam 30) vi Qui Nhon (Trung B$)

1) Ty Thuy Dao lap ngiy 10/6/1964 lai theo sy tinh bl chinh nim 1959 cua Nha Dia Du

- Lim concordance R?ch Dda vi Phan Thiet vi quy djnh s6 "O" tam sau tai Phan Thiit

- So "O" Nivellement Gdnerad (NG) dupe ning cao len

5,928 - 5,8809 = 0,0471

Giii thich vipe sua chila BCD tai R^ich Dira (Vung Tiu):

- True dia CBD so hipu FZl i (230 - XVI -1) ed 2 cao dp do Nha Dia Du cung cip

+ Cao dp +5,928 di cd tir ttudc 1955, chua bo cUnh

Thyc tl Miy triiu k^ Bin Di sau ngiy giii phdng, miy ngung boat dpng Ngiy

4 - X - 1976 may boat ddng Igi vdi miy cu tryc ddng cua Tiy Dire Dat miy mdi ngiy

24 - 12 - 1977 theo miy frye ngang cua My

Thuy chi cu d^t sit nen cao hon diem miit hipn tai khoing 0,20m

Thyc ra cao d$ Resgnier da ghi sin ngay tren moc li +6,391 Nlu dua vl he thing Mui Nai sS la +5,881 (theo Ty Thuy D?o)

+ 5,928 (Ty Hing Giang) vdi d0 cMnh 0,047 nhu viy: + 5,881 - 4,00 = 1,881

va cao d0 diu cpc se li: 1,881 - 0,789 = 1,092 hay H(o) = -4,908 ~ -4,91

1) Nam 1983 Thing I.VII, quan ttic d tram cu (bd ta) cao dp gia dinh R„:

5000 VIII - XII quan t i c 6 tram mdi (bd hChi), cao dp gia djnh R„: 3433 Tram cu va moi cich nhau khoang 500m Nam 1983, do ddng thdi t^li 2 vj tri tren 20 ngay 24/24h/ngay cung he thing cao dp gii djnh, chenh Ipch AH cho phep

Anh 2: Tram Hai van Quy Nhon - Binh Djnh

Nam 1984: Cao dp gia djnh, xay lai moc chinh phia ha luu tuyin do idioang 9,50m, R<, =+3,585

Mdc cing Qui Nhon -0 (Theo td ky thuat cap)

Rai RP (Cou Ddi): +3,014 Ngay 1 l-K-1985, xi nghipp KSTK Thuy lpi - Thuy dien dan cao dp qude gia tir cau ddi den chen thuy chi tram li: -1404 Thuc te mdc 0,00 cua thiiy chi dupe gii djnh li 0,200 Vay cao dp thuc la -1,604

3) Theo "Chuang trinh Dieu tra nghien ciiu bien KHCN -06, De tai: 06-06: Nghien ciiu xic lap chuan "O" dp siu quoc gia phan lanh the "VN nam 2001": Tir dp sau "O" Hdn Diu theo cao dp Qude gia la -1,752, khdi tinh hang 1 VTnh Linh - Ha Tien VL-HT 119 cd dp cao H = +0,812 Tu do din "0" tram L = 7,3km + qua eo biin 658m (7300 + 658 = 7958m) do xudng "0" ttam (day gilng) la -1,546m, liy tdn -I,55m hay H(o) Qui Nhon = - 1,55m

Theo bang thuy trieu 2001 thi dp sau "0" Hdn Dau theo cao dp Quoc gia li 1,90 - 1,75 = 0,15m hay H(o) Qui Nhon = - 1,70m

-Kit qui hieu chinh -1,604m trung gian giua 2 ket qui ndi tren

dO Q u o c gia ( Z Q G ) v i chSnh I$ch giu^ cao d$ Q G vdi b$ cao dp cii (Z^)

4.150 2.430 2.281 2.770 3.016 1.829 3.565 1.920 2.660 10.800

6.333 2.877 4.024 2.376 0.888 3.294

3.718

1.220 4.027 1.387 2.620 3.403 1.122

TuyetDii

Gia Djnh Song Hong Song King S.H6ng S.Hing S.Hing

TL Thanh Hoa TL.Thanh Hoa S.H6ng

Cao dp QG

ZQG(m)

2.004 2.288 2.053 2.625 2.699 1.418 3.350 1.636 2.621 10.638

3.881 3.950 2.097 0.879 3.109

3.730

1.673 3.624 1.169 2.332 3.174 0.869

21.688

1.281

13.018

Chenh l?ch Zqc-Zccm) -2.146 -0,142 -0,228 -0,145 -0,317 -0,411 -0,215 -0,284 -0,039 -0,162 -0,262 -0,27 -1,90 0,004 -0,074 -0,279 -0,009 -0,185

0,012

0,453 0,403 0,218 -0,288 -0,229 -0,253

0.132

0.022

-0,217

900

5.713 14.042 44.209 5.766 8.017 8.000 2.863 1.755

H? cao dp

TL Thanh H6a

TL Thanh Hda TL.Thanh Hda S.Hing B.B cu Giao thong Giao thong

S.Hing Dudng Sit D.Sit Thiy Lpi D.sat Cii djnh D.Sit Regier Regnier Gia dinh Gia dinh Lefebre Gii dinh Nha Dja Du G.Djnh Q.Gia Gii djnh Gii djnh Gii djnh MQi Nai Miii Nai

1.710 3.092 2.367 2.540 1.081 1.573 1.530 0.761 2.261 2.053 1.790 2.232 1.438 2.948 2.218 1.336 1.681 0.773 1.124 2.088 1.499 1.106

2.206 1.541 2.780

3.930

H§ cao dp Mui Nai MQi Nai MQi Nai MQi Nai Tuy^t doi MQi Nai

MQi Nai

MQi Nai MQi Nai Gii djnh MQi Nai MQi Nai MQi Nai Mui Nai Gii djnh Gia djnh Gia dinh MQi Nai MQi Nai Mui Nai Mui Nai MQi Nai Gii djnh Gii dinh MQi Nai MQi Nai MQi Nai MQi Nai

ZQo(m) 1.306 2.995 1.673

1.559 1.370 1.292 2.448 1.545 1.303

1210 1.182 1.589 1.692 1.391 1.860 1.124 0.879 1.714 1.200 1.505 0.312 0.939 1.515 0.622 0.832

1.921 1.626 2.535

3.657

2536

ZQo-Zccm) -0,178 -0,108 -0,4003 -0,16 -0,151 -1,722 -1.075 -0,092 0,464 -0,270 -0,320 0,421 -0,672 -0,361 -0,399 -0,372 -0,314 -2.069 -0,504 -0,136 -0,176 -0,461 -0,185 -0,573 -0,877 -0,274 -0,04 -0,285 -0,085 -0,245

-0,273

-0,264

H? cao dp MQi Nai Mui Nai Gii djnh Gii djnh

Z(iG(m) 5.466 4.863 2.458 3.120

Zgo-Zccm) -0,159 -0,046 -1,168 -1,098

1.3 CAC TAC NHAN ANH HlTdNG D^N D I £ N B1±N DlTdNG B d B I £ N

1.3.1 Quan h$ tuorng tic ddng chiy sdng vdl diin biin dpng lyc vimg cira song ven bien Vif t Nam

Theo thong ke eiia dl tii KT-03-14 thiy ring hipn fang xdi Id bd biin chi mdi bit diu tir 1930 frd l^ii diy Trudc nim 1930, duy nhat chi cd 2 diim xiy ra xdi Id bd tai Hau Lpc - Thanh Hoi Ndi chung toan dii bd bien Vipt Nam luc do tuong ddi on djnh vi qua trinh bii ty chiim uu thi Sau nim 1930 phit triln bdi xdi ra phia Bic vi

phia Nam TCr nim 1970 ttd \^i day, hi$n tupng xdi Id bd da diin ra hiu khip cic bd

cua cic ttoh ven bien

Lipu sau bao nhieu nam niia thi trd Iji t-ang thii In dinh ban diu hay la xu th6 xdi Id vin tiip tyc k^o dii mai khi tic d^ng cua biin dii khi hau toin ciu cdn diin ra mgnhme?

Tuy theo tic gii, myc dich, gdc dp nghien ciiu mi cd thi qui cac nhan td chtoh inh hudng din xdi, bdi bd biin, cda sdng thinh cic nhdm vdi nhimg ten gpi khic nhau song suy ra cho cimg cQng cd thi coi li nhit t i Chiing tdi qui thanh 4 nhdm nhin td chinh sau diy theo so dd hinh 1.1 [2]

o Ddng sdng: Bao gdm lii, bvm cat, ngudn nude

b bdng bien: Bao gim sdng, nude dang do gid, bao, nude biin dang, ddng ven, thuj' triiu, ddng triiu

li Bd biin: Bao gom dja htoh, dja mao, dit di, dirt gay, tan kiln tao

d Con ngirdi: Bao gom khai hoang - lin biin - cing, khai khoing, trdng vi phi rimg diu nguin, rimg ngip min, khai fliic san hd, xay dyng h i chiia, dip, phit thii

/ /

Lu, biin cat, nguon nude

DONG BIEN

Sdng, nude ddng do gid, bdo

Nude bien dang, d6ng ven

Thuy tri^u, d6ng tri^u

^ \ \

CON NGUOl Khai hoang, lin bien, phd rimg, cdng, khai khodng, san ho, ho, phat thdi

Bd B1£N Dja hinh, dSt da tan ki^n tao

/

^

x 6 i Ld, B 6 I LAP

Bd BlfiN, CCTA SONG

Hinh 1.1: So dd cac tac nhan den xdi Id boi lip bd bidn, cira sdng

Nhu vay, tiiy theo timg vimg khac nhau md miic dd dnh hudng cua cdc tdc nhdn

gay nen dien bien bd bien la khac nhau Qua do cd the danh gia mpt each so bd miic

dp dnh hudng cua ddng chdy sdng din de cita sdng ven biin timg vimg

L3.2 Mot so yiu to ta nhi@n lien quan vol dien bien dpng lire viing cira song ven

biin Vi^t Nam ^ Ddi vdi nhan td ddng chay sdng, ro rang dnh hudng din de biin chii yiu la

ddng chdy mua lu Ddng chdy nay ket hpp vdi cdc yeu td ddng lire biin nhu trieu

cudng, nude dang do bao lam muc nude dang cao, dnh hudng den an todn de Do do,

dl cd thi ddnh gia anh hudng ciia yiu to ddng chdy lu din de viing cira sdng cin xem

xet nd trong mdi quan he tuorng tdc vdi cac yeu td d^ng lire khdc viing ciia sdng ven

biin

So dd phdn viing miia lu, miia can ven biin Vi^t Nam dupe thi hi?n trong bang

1.3 Trong bdng tai c0t thii 3, tii so la miia lu, mau so la miia can, sd La MS trong

ngo^c dom Id thdng mua lu, miaa can theo chi ti6u "vupt trung binh", ngodi diu ngoac

Id theo chi tieu "cip nude"

Bang 1.3: Sff dl6 phan viing miia 10, miia can ven biin Vi^t Nam [U]

Dam Ha - Cam Phi

Hdng Gai - Yen Hung

Hai Phdng - Thanh Hoi

Quynh Luu - Can Lpc

Tb?ch H i - Bo Trjeh

Ddng Hdi - Hii Ling

Phong Dien - Cam Ranh

V ( V I ) - K X-IV(V) V(VI)-X X-IV(V) V(VI)-IX X-IV(V) V(VI)-X XI-IV(V) VIII-XI

xn-vii

DC-XI

xii-vn ix-xn

I-VIII

X - X I I

I - I X LX-Xl

xn-vin vm-x xi-vn

VI(VII)-XI

xn-v(vi) vin-xn

I-VII

Thdi ky mua IQ tieu man

Hii Phdng - Nmh Btoh

Thanh Hoi - Nghp An

Ha Tinh

Vmax (m/s) 40-45 45-50 35-40 45-50

7

8

9

10

Quing Ngai - Phii Yen

Khinh Hoi - Btoh Thuin

Vimg Tiu - Sdc Tring

Ci Mau - Kien Giang - B^c Lieu

40-45 20-25 25-30 20-25

Bang 1.5: Stf Hh phdn viing lupng mva ven bien Vi^t Nam [11]

Mdng Cii - Hong Gai

Yin Hung - Tam Dipp

Nga Son - Can LOc

Thach H i - Tu Nghia

Mp Diic - Cam Ranh

Ninh Hii - Bic Bmh

Him Thuin - Him Tan

VGng Tiu - Gd Cdng

Tra Vinh - Sdc Trang

Bac Lieu - Rach Gii - Hi Tien

Xo(mm)

2000 - 3000

1600 - 2000

1600 - 2000 2000-3000 1500-2000 500-1000 1000-1500 1000-1500 1500-2000 2000-2500

Ximax (mm/ngiy)

600 - 700 500-600 700-800 700-800

700 - 800 400-500

400 - 500 100-200 100-200 100-200

Bang 1.6: Sa do phan vung mOa mira, mila kho ven bien Vi^t Nam [11]

Ven biin Hii Phdng - Thanh Hoi

Quynh Luu - Cam Nhupng

IX-XI

xii-vm K-xn i-vm

IX-XI

xii-vm vin-x xi-vn

10 Rach G i i - H i Tien

V - X I XII-IV IV-XI XII-III

So do phin vimg lupng mua theo 2 chi tieu: lupng mua nim trung binh nhiiu nim Xo (mm) v i lupng mua ngiy ldn nhat Xi„j™, (10 vung - bing 1.5)

So do phin vimg mda mua, miia khd (10 vimg-bing 1.6)

So do phin vung mdc dp inh hudng lu (8 vimg - bing 1.7)

Bang 1.7: So d l phin vikng miic d$ inh hudng lu ven bien Vi$t Nam |11|

Hdi Phong - Thanh Hod

Quynh Liru - Can L0c

Thach Hd - Bo Trach

Ddng Hdi - Cam Ranh

Ninh Thu?in - Binh Thuan

Viing Tdu - Cd Mau

RachGid-HaTiSn

Miic dp anh hudng lii M^inh

YIU Trung binh Trung binh manh Manh Tnmg binh manh

Yiu

Manh

So do phan vimg che dp thuy trieu (10 vimg - bang 1.8)

BSng 1.8: Stf do phin vung chi d$ thuy triiu ven biin Vift Nam [11]

Thira Thidn - Hul

D i Ning - Quing Nam

Quing NgSi - Nha Trang

Cam Ranh - Miii Ne

Chi d$ trieu Nhit triiu diu thuan nhat Nhit triiu khdng deu Ban nhit triiu khdng diu Bin nh^t triiu diu Bin nhit trieu khdng diu Nhit triiu khdng diu Tap triiu - nh^t trieu khdng

Dp Idn triiu (cm) 4,0 ~ 2,5 m 2,5-1,2 m 1,2 ~ 0,6 m 0,6 ~ 0,4 m 0,6-1,2 m 1,2-1,8 m 1,8-2,0 m

8

9

10

Phan Thiit-Ham Tin

Vitag Tiu - Mui Ci Mau

Mui Ci Mau - Ha Tien

Chi dp triiu diu la chu yiu T^ip triiu bin nhit triiu khdng diu li chu yeu Bin nhit t i i u khdng deu T^p triiu bin nh^t tripu khdng diu li chii yiu

Dp ldn triiu (cm)

2,0 ~ 2,5 m

2,5-3,5 m 0,8-1,2 m

So dd phan vimg nude dang do bao d$c trung (6 vimg - bang 1.9)

Bdng 1.9: Sa dh phdn viing nirdc dang do bdo ddc trung

Thanh Hoa - Nghe An

Nghe An - Quing Ngai

Quing Ngai - Ninh

Thuin

Nmh Thuan - Ci Mau

Chi tieu Vung biin khdng sau thoai bso =30m (dO sau cinh bd li 50 km)

Dp siu biin ldn hon (I)

Dp siu biin ldn hon (I) vi (II) hso a50m

Dp sau bien Idn hon (I), (II),

(m)

hso =100 m

DO siu biin ldn hon (I), (II), (m), (rV) hso =270 m; h =85 m Thoii, khdng die

hso =5 - 85 m; h =22 m

Dp cao nude dang

do bao p = 3% 304-320

bien Nam Bd, rimg ngap m ^ cdn gill dupe nhieu quin xa, nhiiu loii Cdn ven biin Trung BO hi tin phi manh, si loai bj giim, diOn tich bj thu hpp rat ldn

So dd phan vung cic die diim dja mjo theo nguon goc phit stoh (10 vimg bing 1.10)

-Bang 1.10: Stf d l phin viing die diim dja m^o theo nguon goc phat sinh

Do Son - Nga Son

Nga Son - Mdi DOc

(Deo ngang)

Miii DOc - Son Tra

Son Tri - Sa Huynh

Die diim dja m^o

Bd phin cit xim thyc kiln tao vimg vjnh, nhiiu dio niii sdt, yiu t l biin thong trj

-Bd tmh tu ding bing delta, phit trien nhanh, yiu td song chiim uu thi

Bd tich ty ding bing nhd ven biin, xen bd mii mdn di gflc djng nui sdt, bd khi bing phing, do yiu tl song biin tic ddng

Bd tich tu cit biin da dupe lim phang (chan dim phi ben trong) yeu tO bien thing trj

Bd tich ty ddng bing nhd ven bien, xen bd mai mdn di gdc, dupe t£io kha bang phing, do bien, sdng tic dpng Doan bd khdc khuyu nhit (dang rang cua), nhiiu vung vinh nhd va bin dio di gdc, thinh tao do tich tu mdt phia (chu yeu tir phia DOng Bac), yeu tO biin thdng tri

Bd mii mdn tich tu, khi phing vdi cac miii da goc, yeu

to biin uu the

Bd tich ty delta ciia sdng, hinh thinh do yeu tl sdng biin

Bd tich tu ria delta do biin li chii yiu

Bd tich ty biin xen bd mii mdn di gdc, vQng vjnh va nhiiu dio nhd, yiu t l biin li chii yiu

Dd Son - Tam Dipp

Nga Son - Deo Ngang

Deo Ngang - M.Ba Ling An

Cudng dp xdi Id va bd

>200m 15%

> 5 m/nam 30% 80% 74% 52% 29% 73% 88%

Kieu dudng bd biin

Bd biin thip vi bai bien

Bd bien thip bi xdi Id

Bd dyn cit - bai cit

Bd dyn cit - bai cit bi xdi Id

Bd lagoon, vung cua sdng bi chin bdi cic

barrier cit

Bd lagoon, vyng ciia sdng hi chin bdi cic

barrier cit hi xdi id

Bd vung vjnh

Bd di thap cd bai biin

Bd di thip khdng cd bai bien

Cliffcd bai biin

Cliff khdng cd bai bien

Tong dp dii (km) 1.216,5 404,0 655,0 228,5 122,5 28,3 93,5 51,0 99,5 132,0 577,0 3607,8 Tren co sd phan vung cic tie nhin tic dOng ddn dien bien dudng bd bien ndi chung vi de vimg ciia sdng ven biin ndi chung n6u tr6n cd thi phin vimg bd biin Viet Nam thanh 8 vung nhu bing 1.13 dudi day

(3.607,8 km bd biin chia thinh 8 vimg bd vi 391 d o ^ kilu bd)

Bd phan cdt xdm th\rc kiln tgo

nhieu dao mii sdt Dia hinh ddi nui thip Dd ciirg chii yiu

- Nh§t trieu diu thuin nhit

- Nude dang do bdo H5% = 250 -300 cm

Hgi6mCia = 4 0 - 5 0 c m

dnh hudng lu m^nh

- Bim cat sdng it:

p = 50~100g/m^

- Rimg ng$p mdn phat triln

- Lin biin chii yiu

- Khdng cd d6 sdng

- Hudng DB - TN

Bd tich ty ddng bdng del-ta Kiln

tnic hinh thdi phi hu>' Dd bd rdi

- Nhat triiu deu thuan nliat

- Nude ddng do bao H5%=300cm

Niii phiic nep loi Dd bd rdi xen

ki bd (M Cling

- Nh$t triiu khdng diu

- Nude ddng do bao H5% = 250-300cm

Hgi6m£ia= 15-50cm

- Anh hudng lii trung bhih

- Bim cat sdng:

p = 200~300g/m^

Cdc doan kilu bd bien

25 doan bd vdi 5 kilu bd:

Kieu 1: 8 d o ^ : 127,5 km- Lin biin Kilu 2: 1 doan 2,0 km - Biin ldn Kilu 7: 7 doan: 44,0 km - on dinh Kilu 9: 3 doan: 34,5 km - on dinh Kieu 10: 6 doan: 103,0 km-on dinh

40 d o ^ bd vdi 3 kieu bd:

Kilu 1: 22 doan: 235,5 km - Ldn bien Kieu 2: 17 doan: 94,0 km - Biin lin Kieu 9: 1 doan: 15,0 km- dn dinh

1

43 doan bd vdi 6 kilu bd:

Kieu 1: 18 doan: 123,5 km-Lan bien Kilu 2: 15 doan: 73,5 km - Biin lin Kieu 6:1 doan:

10 km-on dinh Kilu 7: 2 doan: 4,5 km - on dinh Kilu 8: 2 doan: 6,0 km - dn dinh Kilu 10: 5 doan:

- Biin lin va lin biin

- Hudng Bde - Nam

- Bd khiic khuyu, nhieu viing vinh, ban dao dd gdc

- Nhat trieu khdng deu la chii yeu

-Hdgi6n«ia= 15-50 cm

- Lu ldn, lupng nude mua can rat

it do cd dap dang d thupng ngudn

- Biin cat sdng p=100-250g/m^

- Xdi Id trung binh

- Hipn tupng xdi Id manh xdy ra chii yiu d cdc vimg cira sdng

120 doan bd vdi 10 kilu bd:

Kilu 1: 21 doan:

138 km-Lan biin Kilu 2: 3 doan: 7,5 km - Biin lin Kilu 3: 27 doan:

341 k m - D i ddng Kilu 4: 11 doan: 32,5 km - Bien lan Kilu 5a: 3 doan: 32,0 km - Ldn biin Kieu 6:4 d o ^ : 83,5 km - on dinh Kieu 7: 2 doan: 4,5 km - dn dinh Kilu 8: 2 doan: 2,5 km - In dinh Kieu 9: 3 doan: 58,5 km - on dinh Kilu 10: 33 doan: 290,5 km - In djnh

- Bin nh^t triiu khdng diu li chu yiu

- Xdi Id bd bien tuong dii manh

- Hudng DB - TN vi NB

- Bd tich ty delta Di bd rdi

- Ban nhit triiu khdng deu

-HdH„5% = 100-150cm

-Hdgi6mi„= 1 5 - 5 0 cm

- Anh hudng lu yeu

- Xdi Id tuong dii manh

- Bim cit sdng

p = 200-300g/m'

- Hudng TB-BN

- Bd tich ty ria delta xen mii mdn

di gic, viing vinh, nhieu dio nhd ven bd Di bd rdi xen di goc

- Ban nhit triiu khdng deu

39 doiin bd vdi 2 kilu bd:

Kilu 1: 21 doan: 395,0 km-Lin biin Kieu2: 18do?n:

227 km - Biin lin

15 do?n bd vdi 2 kieu bd:

Kilu I: 10do?n: ; 161,0 k m - l i n biin Kilu 10: 5 doan: 63,0 k m - I n djnh

Qua bing phin tich 1.13 cd die thiy hiu hit cic doan dudng bd biin thudc kieu

In djnh bay lin biin Chi cd mOt sd dojn li biin lan Tuy nhien, theo phin tfcb die diim cua vimg bd biin cd cic doan niy thi inh hudng ciia lu thudng li yiu mi chu yiu do cic yiu t l dOng lyc biin tic dOng

CAC PHlTOfNG PHAP TINH TOAN M V C NlTdC BIEN THIET KE

I Khdi ni|m chung

Muc nude biin dupe hilu la gia trj ting hpp ciia thuy triiu do tuorng tdc giQa cac lire vu tru ma trong dd tucmg tdc gitta m$t trdng - m$t trdi vd trdi dit ddng vdi tro Idn nhdt, dja hinh ddy biin t^ii khu v\rc tinh todn vd nude ddng do bao, gid, ddng chdy

va cdc dao dpng ngiu nhien khdc

Nhu vay cd thi thiy myc nude biin la s\r kit hpp ngau nhien cua cac thanh phan sau:

Thiiy triiu tai diim tinh todn

Nude dang do bao, gid vd cdc nhieu dpng ngau nhien khac tao ra

M0t dieu can phdi luu y Id diem tinh todn phdi ndm hoan todn ngoai bien, khdng chiu dnh hudng cua sdng thi mdi phdn dnh ddng gid tri m\rc nude

n Tinh todn myc nirdc biin thiit ke

2.1 Tnrdng hpp co tdi li^u do dac

Muc nude do dac d mdi tram Id tong hpp ciia thiiy trieu, nude dang va cdc dao dpng ngau nhien khac Neu tdi li^u do dac muc nude tai cdc tram dpc theo bd biin vdi thdi gian du dai (it nhit Id 20 nam vd dupe dua dua ve mdc chuin qude gia Hon Dau) thi cd thi tinh todn muc nude thiet ke khi sir dyng mpt sd hdm phdn bd xdc suat phii hpp tuy theo muc dich Cac hdm phan bd thudng dimg cung phu thudc vao loai muc nude cin tmh todn Vi du tinh todn muc nude biin ldn nhit thudng sir dung hdm Gumbel, trong khi tinh muc nude trung binh hay muc nude nhd nhat thudng sii dung phan bd Piee xon HI

Vdi muc dich tinh todn thiit kl dS biin, cac loai mirc nude sir dung bao gom:

- Mijrc nu^c ldn nhit su* d^ng de tinh todn xac dinh cao trinh dinh de: neu chuoi tdi lieu du ddi cd thi sir dyng phuang phdp chpn m§i nam mpt tri dl t|lp hpp thanh chuSi tdi li^u muc nude ldn nhit va xay d\mg dudng tin suit xdc djnh muc nude thiit kl

- Myc nirdc trung binh phyc vu thiit kl toi uu cac ldp bdo v$ mdi de vi trong trudng hpp nay cd thi chpn Idp bao vp mdi tren m\rc nude trung binh thiit kl khdc vdi ldp dudi, noi tiep xuc thudng xuyfin vdi sdng vd ddng chay

Xem xet cdng thiic tren (2-1) chiing ta thiy cd m^t so van de sau:

- Vipc chpn tan suat cdn cii vao tieu chuin ciia ngdnh, tuy nhien can cii chpn Id chua thuyit phuc, chdng h ^ myc nude liy vdi p = 5%, nude dang p = 20%, sdng leo khdng rd tmh theo tin suat ndo

- Vipc tinh toan cao trinh dinh de ve thyc chat theo quan diim khdng cho phep trdn (tinh theo sdng leo), nhung thuc te nude van tran de ngay ca frong nhihig dieu kien chua phai la nhiing to hpp bat Ipi nhat

- Cdng thiic tinh toan chua phdn anh dung hdn chit eiia hi^n tupng, chdng ban khai niem thiiy trieu cd mang y nghia tin suat vd neu xem rang muc nude tai train la thuc do thi nude ddng da phdi nam frong do rdi va nhu v$y frong cdng thiic (2-1) nude dang da dupe tinh 2 lan

Vdi nhiing vin dh da dupe thao luan d tren day, frong diiu kipn chiing ta con thiiu tdi lieu thuc do muc nude t6ng hpp cua cdc fr^im hdi van da cd mdt sd ncd xii ly

nhu sau:

- Tan dyng tdi da sd lieu cua m$t so it tram hdi van cd lipu dai nhu Hdn Dau (Hai Phong), Hdn Ngu (Nghp An), Phii Qu^, Dd Ndng, Viing Tau, Cdn Dao vd xac dinh mue nude thiet ke

- Su dung chudi si li^u tiiuy vdn (da thing nhit mdc chuin quic gia) dl tinh toan muc nude thiet ke

sd diem phii luu y trong qui trinh tinh toin Dd li:

- So lieu cac tram iiii vin khdng nhiiu vi mii tjim diu sir dyng cao dp hii dl rieng, khdng cung chuin qude gia nen khdng thi so sinh dupe vdi nhau Cho din nay

vin chua thing nhat dupe cao dp cic tr^m hii vin nen rit khd khin trong tinh toin thiet ke cic cOng tmh ven biin Do v^y tong mOt s i trudng hpp nlu phii di theo

hudng nay thi phii chu y xii ly t i n h gay ra sai sdt trong tinh toin

- Su dyng tii lipu thyc do ciia cic tr^m thuy vin d cda sdng ven biin Cic tram niy thudng nim siu trong sdng vi chju inh hudng Idn ciia lu sOng vio miia mua lu, nhung l^i cd thi^n lpi la cd h? cao dp di dupe dua vl chuin quoc gia

Do cic t ^ quan trie thih toin tin suit thuOc khu vyc cda sdng vimg trieu, chiu inh hudng ddng chiy sdng nen trong tinh toin chung tdi sir dyng thudng dung dudng cong tin suit ly thuyit phin b l d?ng Pearson ID Dudi day li mpt sd vi dy tinh toin myc nude thiit kl cua cic t^m Ba Lat (1960-2006), Djnh Cu (1960-2006), Cua

c i m (1961-1996) Cic kit qui tmh toin trinh biy ttong bing 2-1 den 2-3

Bang 2-1: Tin suit H™, Uam Ba Lat; N* = 180; Cv = 0,15; Cs = 0,15

se dupe trinh bdy d phin sau

2.2 Tfnh todn rieng rS cdc thdnh phin roi to hpp theo m$t qui luat xdc djnh dl c6 myc nirdc thiet ke

Nhu da frinh bdy d tren, myc nude tong hpp Id sy kit hpp ngiu nhien eiia thiiy trieu vdi nude dang do gid, bdo vd cdc nhieu dpng khdc tTng dyng ly thuyit xdc suit chiing ta cd the xdc djnh dupe myc nude tong hpp fren ca sd cdc dudng tin suit frieu thuin tiiy vd tin suit nude ddng

Phdn dudi day trinh bdy cdc kit qud nghien ciiu xay dyng dudng tin suat nude ddng ting hpp dpc theo bd biin Vi$t Nam d o ^ Qudng Ninh - Qudng Nam va trich kit qud cho khu vyc nghien ciiu thupc tmh NAM D^NH

ra XAY D V ^ G ©irdNG TAN SUAT MV^C Nirdc T6NG H(;)fp

Dudng tin suit dam bdo d$ cao triiu - nude ddng bao dupe xdy dyng fren ca sd phan tich chudi sd lipu do dac myc nude ddi ngay tai vj tri edng trinh, sii dyng phucmg phdp md hinh so frj dl bo sung cdc dii lipu do sy h^n che vl dp dai ciia so li$u quan frdc, ciing nhu dp dung cdc md hinh xac suit thong ke Tii kit qud phdn tich cdc sd lipu

do dgc muc nude timg gid frong thdi gian cd bao hogt dpng tai mpt sd fram hdi vdn ven bd da chi ra rang nude dang do bao cd thi xdy ra d bat ky pha frieu ndo, tir do cd the coi hai qua trinh muc nude do trieu thien van va do bao la d^c lap Tinh dpc lap eiia 2 qua trinh nay cho phep nghi6n eihi cdc ddc tnmg thiiy frilu thien van va myc

nude dang bao mdt each rieng bipt, sau do tong hpp \a\ theo tinh chdt cua 2 qua trinh

ngiu nhien dpc lap Cy thi nhu sau:

3.1 Ca sd dii' li^u

3.1.1 Ban dl dia hinh

Cac tu lipu vl dia hinh bao gim cdc so lipu, ban dd, cdc bao cdo vl diiu kidn ty nhien nhu dia mao bd bai, hinh thdi bd va dia hinh day biin Ddi vdi khu vye tir tinh Qudng Ninh din tinh Qudng Nam da sii dyng cac tai li|u sau:

- 60 mdnh ban dl dja hmh viing dit ven biin, t^ Ip 1/25.000, hp tpa dp Qude gia VN2000, do Nhd Xuit hdn Bdn do, B0 Tai nguyen vd Mdi trudng san xuit tir ndm

2001 din nam 2006

- 25 manh bdn do dia lunh viing dit ven biin, t^ I^ 1/50.000, he tpa dp Qude gia VN2000, do Nha Xuit bdn Ban dl, Bp Tdi nguydn vd Mdi trudng san xuit tir ndm