Tiiu hem Cdc Khoa hgc vi Trdi ddt ISBN 978 604 913 016 8 TONG QUAN VE DANH GIA D Q NGUY HIEM SONG THAN VUNG VEN BIEN VIET NAM AN OVERVIEW OF TSUNAMI HAZARD ASSESSMENT IN COASTAL ZONE OF VIETNAM Tran T[.]
Tiiu hem: Cdc Khoa hgc vi Trdi ddt ISBN: 978-604-913-016-8 TONG QUAN VE DANH GIA D Q NGUY HIEM SONG THAN VUNG VEN BIEN VIET NAM AN OVERVIEW OF TSUNAMI HAZARD ASSESSMENT IN COASTAL ZONE OF VIETNAM Tran Thi My Thanh, Vien Vat ly Dja ciu 18 - Hoang QuIc Viet, Ciu Giiy, H i Ndi Email: tmythanh(a)yahoo.eom Tdm tat: Tir sau thdm hog sdng thdn gdy bai dgng ddt Sumatra Mw 9.3 ngdy 26-122004 vdn di nguy hiim sdng thdn a viing ba biin Viit Nam tra thdnh mdi quan tdm lan a nuac ta Mdt sd di tdi nghiin cim theo huang ndy da dugc tiin hdnh dem lgi nhung kit qud ddnh gid budc ddu vi nguy ca sdng thdn a viing ba biin Viet Nam Trong bdi ndy chung tdi xem xet cdc kit qud nghiin cim vi xdc dinh, ddnh gid cdc viing ngudn ddng ddt sdng thdn tiim dn viing Biin Ddng, xdy dung cdc kich bdn ddng ddt diing tinh lan truyin sdng thdn di ddnh gid nguy ca sdng thdn a cdc viing ba bien vd hdi ddo Viet Natn Bdi bdo ciing giai thiiu bdn nguy hiim sdng thdn viing ven biin Viet Natn Kit qud trinh bdy bdi cho thdy birc tranh tdng quan vi nghiin cim sdng thdn vd cung se gdp them cdc sd lieu mai phuc vu cdng tdc nghiin cim ddnh gid nguy ca sdng thdn a nuac ta Abstract: After the tsunami caused by the Sumatra earthquake magnitude 9.3 on 26 December 2004, the tsunami hazards along the coast of Vietnam has become a major concern for our country A number of research studies in tsunami risk along this coast has been undertaken and has produced some preliminary results to help evaluating this risk In this paper, we will investigate the results of the studies to determine and evaluate the earthquake sources that can cause tsunami in the Eastern Sea We will build some scenarios using the tsunami propagation model to evaluate the tsunami hazards along the Vietnam coast and the offshore islands This paper also introduces the tsunami hazards map along the Vietnam coast The result presents an overview of the tsunami research studies and help to gain a better understanding of tsunami risk in Vietnam I M O DAU Nhirng nim trudc diy Viet Nam cd it nghien cim ve ST, chii yeu li cic edng bd de cap den ehe ddng dit d Bien Ddng v i co ehe hinh thinh sdng thin eua tie gii Pham Van Thue Tir sau thim hga ST Sumatra 26 - 12 - 2004 (Mw = 9.3) vin de nguy hiem ST d cic viing bd bien nude ta trd thinh mdi quan tam ldn cua nhi nude v i nhin din Trong giai doan d i tien hanh mot sd nghien cim cd tinh chit quy md va ehi tiet ve nguy hiem ST nhu eac de tii nghien cim cip Vien KH & CN Viet Nam: 'Nghien cuu dinh gia nguy hiem ddng dat vi sdng thin d viing bd biin Viet Nam vi dl xuit cic giii phip cinh bio, phdng trinh', ( Nguyen Dinh Xuyen, 2005 - 2006); "Quy Uinh edng nghe dinh gii nguy bilm sdng thin vi cinh bio nguy eo sdng thin tren viing ven biin Viet Nam (phii hgp yeu eiu eua he thing 220 Hgi nghi Khoa hgc kv niem 35 ndm Vien Khoa ligc vd Cong nglie Viet Nam - Hd Ngi 10 2010 cinh bio khu vyc)", (Trin Thj My Thinh, 2007 - 2008); Dy in KHCN cip Bd Tii nguyen vi Mdi trudng "Xiy dung bin dl cinh bio nguy co sdng thin eho eic vimg bd bien Viet Nam" (Vu Thanh Ca, 2007-2008); Dy in hgp tie khoa hgc giiia Vien Vat ly dja ciu ya Vien Khoa hgc dja chit vi Hat nhin Niu Di Lin "Dinh gii nguy hiem vi nii ro sdng thin vi sy img phd ciia Viet Nam" (2007-2008); D I tii cip nhi nude "Nghien cim dinh gii nguy hiem eua ddng dit vi sdng thin tren viing ven bien vi hii dio Viet Nam vi de xuat cac giii phip phdng trinh vi giim nhe hiu qui", (Biii Cdng Que, 2007 - 2009) Cic ket qua nghien cim mang tinh tdng quan ve nguy hiem dgng dit vi ST vi eic bien phip phdng trinh tren viing ven bien Viet Nam II NGUON GOC SONG THAN VA CAC KET QUA KHAO SAT SONG THAN O VUNG BO BIEN VIET NAM Lich sir the gidi ghi lai nhieu trin ST thim khdc gay thiet hai khdn ludng ve ngudi vi ciia Ddng Nam A li khu vyc phit sinh nhieu sdng thin ngudn gdc khie nhau, giy nhirng thim boa sdng than ldn nhit, dien hinh nhu tran sdng thin ngudn kinh hoing ngudn gdc ddng dit xiy ngiy 26-12-2004 d Sumatra Theo eic danh muc ddng dit sdng thin ciia NOOA (My), Indonesia, Philippin, cho thiy ST giy thiet hai nghiem trgng lich su li it ed ning xiy d viing ven bien nude ta Tuy nhien eic nghien cim eua eic nhi khoa hgc Viet Nam [14] cho thiy ljeh sir ed the di tirng xiy ST vdi cudng manh Viee tim hieu nguyen nhin vi ning giy ST d bd bien Viet Nam duge tien hinh bing eich thu thip, dieu tra nhin din nhirng sd lieu thyc ve hien tugng sdng thin, sdng bio da xiy d cic viing bd bien qui khir Nguyen Dinh Xuyen [14] di dua ning ST ljeh sir tai bd bien Viet Nam dd li bien Tri Cd (1978), bien Dien Chiu (cudi the ky 19 diu the ky 20) vi ST d Nha Trang (1923) Vii Thanh Ca [15] sau di tien hinh khio sat lai tai cie viing bien tren da dua ket luin tai bd bien Dien Chiu ed the li sdng thin cd nguyen nhin trugt Id dit Nam 2007, cae tic gii Cao Dinh Trieu, Ngd Thj Lu [] eiing edng bd mdt sd ket qui ban diu ve phuong phip nghien cim cd ST Tuy eic ket qui edn chua rd ring vi chic chin nhung ciing da mang den eho ngudi dgc mdt suy nghT ve ning ST di xiy tren bd bien nude ta Nhu viy cic ket qui nghien cuu eho thiy ST cd ning da xay tren bd bien Viet Nam, vdi nguyen nhin: ddng dit, trugt Id dit vi niii lira sinh ST tren bien Viet Nam III CAC VUNG NGUON CO KHA NANG PHAT SINH DONG DAT SONG THAN VUNG BIEN DONG Khu vyc Ddng Nam A ndi chung vi Bien Ddng Viet Nam ndi rieng ed eiu tnic kien tao vi ljeh sir phit triln dja ddng lye rit dde dio vi phiie tap [8] Vinh dai ddng DNA tren thyc te ed eiu tnic rit phire tap, bao gdm eic ming vi tieu mang cd ngudn gdc khie Chiing hoac thudc vl luc dja chiu A, hoac la cic minh vd phieu di tir phia An-Uc hoac Thii Binh Duong Sy tin tai va phit trien eua eic ddi tieh eye vinh dai ddng DNA la cie ngudn cd ning giy ddng dit va sdng thin manh Dya vio dieu kien phit sinh sdng thin, tir cie tii lieu da cd ve kiln tao dja ddng lye khu vyc Ddng Nam A, ket qui nghien cuu boat ddng mii lira, nang trugt Id d viing them lue dja Viet Nam theo eic tii lieu dja chin thim dd diu khi, eic nghien cuu trude da xie djnh mdt sd viing ngudn cd ning giy sdng thin khu vyc Bien Ddng: Ddi hiit chim Manila; Ddi hiit chim bien Sulu gdm doan vdi chieu dai 368km vi 642 km; Ddi hut chim Celebes; Ddi hut chim Makasart; Cie ddi hut chim bien Banda Bic vi Nam; Ddi dirt gay thim lue dja Bic Bien Ddng; Ddi dirt giy Tay Biin Ddng hay dirt gay kinh tuyen 109°'; Ddi dirt gay bic Borneo; Ddi dirt gay bien Jawa Cie die trung cua cic viing ngudn dugc danh gia nhu sau (bing 1): 221 ISBN: 978-604-913-016-8 Tiiu ban: Cdc Khoa hgc ve Trdi ddt - Vi tri, phuong vj eua eic viing xic djnh theo ban dd bin dd - Hudng cim, gdc dd xie dinh theo mat eit phan bd chin tieu theo siu - Ddng dit eye dai Mmax xie dinh theo cic phuong phip thdng ke Gumbel, ngoai suy dja chit vi quy md dirt giy - Tin suit ddng dit dinh gii theo quan he magnitude-tin suit, van tdc dich ehuyen eiia dut gay vi djch chuyen chin tieu Bing 1: Tham sl die trung eic viing ngudn ed ning giy ST viing Biin Ddng TT Ten vimg ngudn Ming siu Malina - Doan - Doan Bie Bien Ddng - Bdn triing Chiu Giang - Nam Hii Nam-nam Tiy Bien Ddng - Doan 1: nam Hii Nam-Tuy Hoi - Doan 2: tir Tuy Hoi ve phia nam Palawan - Doan - Doan Bien Sulu - Doan - Doan Bien Celebes - Doan l(bie Sel Sea) - Doan (nam Sel Sea) Bien Banda bac Bien Banda nam Makasart - Doan - Doan Bien Jawa (nam Bomeo) - Doan - Doan 2 10 Die trung kien tao Ddi hut chim Dut giy trugt bing thuin Dirt giy trugt bingthuin Diit gay nghjch Ddi hut chim Ddi hut chim Ddi hut chim Ddi hut chim Ddi hiit chim Dut gay nghieh dii, km 1153 292 1087 Mmax V 0,88 (Mo=5.) 0,95 0,80 0,80 0,80 0,90 0,12 0,06 0.06 0,0103 8,2 7,3 7,2 7,0 548 811 B 6,1 6,6 0,86 158 533 6,9 7,7 0,86 368 642 0,42 7,5 7,8 0,86 0,42 0,75 346 648 632 7,4 7,8 7,8 0,86 304 7,2 0,86 167 326 7,0 7,4 592 200 7,8 7,1 0,86 0,33 0,86 0,57 IV NGUY CO XAY RA SONG THAN - KET QUA TINH LAN TRUYEN SONG THAN VUNG BOf BEN VIET NAM Nguy eo sdng thin viing tren viing bien vi hii dio Viet Nam, duge danh gii dya tren cao vi thdi gian lan truyen eua sdng thin tir ngudn tdi eic vi tri ven bien va hii dio theo cac kich bin ddng dit sdng thin Tren thi gidi ed rit nhilu chuong trinh tinh lan truyin sdng thin 222 Hgi nghi Khoa hgc ky' niem 35 ndm Vien Khoa hgc vd Cong nghe Viet Nam - Hd Ngi 10 2010 nhu MOST, MIKE21, DELFT3D, INGV Cae nghien cim cua Viet Nam ehu ylu sir dung chuong trinh MOST ( Method Of Splitting Tsunami model, V.Titov vi Gonzalez xiy dyng) [28] de tinh lan truyin ST viing bien Viet Nam MOST li mdt chuong trinh cd the md phdng lai mdt eich trgn ven mdt trin sdng thin duge tao bdi ddng dit: phit sinh, lan truyen Chuong trinh dugc viet bing ngdn ngir Fortran vi chay tren he dieu hinh Linux hoac Unix Tuy nhien chuong trinh chi cho ket qui tdt d nhiing noi ed siu diy bien ldn hon 10m Md hinh MOST hien dang duge sir dung rdng rii tren the gidi vi duge USGS diing tinh eho quy md toin eiu Sd lieu siu diy bien Cd nhieu ngudn sd lieu sau Bien Ddng Ngudn sd lieu hien dang duge sir durig rdng rai nhit d Viet Nam hien li sd lieu dja hinh ET0P02 eua Hoa Ky Diy li ngudn sd lieu dja binh diy bien ciia Trung tim dii lieu bien Anh Qude (BODC British Oceanographic Data Centre) vdi phin giii 1' x 1' Ngudn sl lieu niy cd chinh xic chip nhan duge tai khu vyc giira Bien Ddng, noi ed siu ldn Tuy viy, d gin bd, sai sd siu bien xae djnh theo bd sd lieu niy li rit ldn vi eic ket qui tinh toin tao va lan truyen sdng thin tren bien sir dung siu bien xie dinh theo ngudn sd lieu niy khdng the sir dung Cae kjch bin ddng dit sdng thin duge xiy dyng cho tirng viing ngudn rieng biet theo quan diem kjch bin gay sdng than cd the li mdt tran ddng dat manh hoac td hgp cua nhieu (hai hoac hon) trin ddng dit xay d eic vi tri lin can xic djnh khie Cae thdng sd ddng dit diing de tinh lan truyen sdng thin bao gdm toa chin tim, chieu dii ddi dirt gay (L), chieu rdng ddi dirt gay (W), sau chin tieu ddng dat (h), gdc cim {5), gdc trugt (2.), gdc phuong vi (6*) Magnitude eye dai dugc xie djnh theo eic edng thirc thyc nghiem lien quan tdi kich thudc dirt gay [Wells va Coppersmith (1994)] Theo ket qui dinh gii nguy hiem sdng thin eua nhieu kjch bin ddng dat sdng thin (10 kjch bin (Nguyen Dinh Xuyen, 2006), 25 kjch bin (Vii Thanh Ca,), 35 kjch bin ( TMT), 10 kich bin (BCQ)) cho thiy Viing ngudn nguy hiem nhat li ddi hiit chim Manila Thdi gian lan truyen ST tir ddi niy tdi bd bien Viet Nam khoing gid Khu vyc cd nang chju inh hudng manh nhit cua sdng than la khu vyc Trung Trung Bd, tir Di Ning tdi Quing Ngii V BAN DO Yi() NGUY HIEM SONG THAN VUNG VEN BIEN VIET NAM Bin dd nguy hiem sdng thin dugc xiy dyng tir ket qua tinh lan truyen sdng than eua cic tran ddng dat kich bin, nd bieu dien cao eye dai mi sdng thin cd the dat tdi iing vdi cic chu ky thdi gian khae Bin dd NHST duge xay dyng gidng nhu bin dd NHDD theo ly thuyet Cornel (1968) Phuong phip tinh theo NHDC dugc phat trien rdng rii nhirng nam 2000 [18, 21, 45, 57, 58, 59] thudng cd budc tinh: 1) Xic djnh tham sd ciia vimg ddng dit va khoing sai sd 2) Xac djnh phuong trinh (d day la eao ST tai bd bien phu thudc vio ngudn) 3) Tinh xac suit 223 ISBN: 978-604-913-016-8 Tiiu ban: Cdc Khoa hgc ve Trdi ddt Cic nghien cim trudc d i cho ket luan vl ning lan truyin sdng thin viing Biin Ddng cua eic ddng dit sdng thin xiy tren ddi hiit chim Manila la cd inh hudng ldn nhit tdi viing ven bien Viet Nam Tir kit luan quan trgng cac kjch bin ddng dit xiy tren ddi Manila (bing 2) li duge chgn lim eo sd sd lieu tinh bin dd NHST vimg ven bien Viet Nam chu ky 950 nam (hinh 1) irv ™ fL» ICA iif : • • » ' ! ^1 CT^.^^ 'Qv^^:^^ \f v.^ •'^ V~>XV>''9TU&i?'* ^"S/ < i ^ ^ » - J k ' - V J ^ ri-» X < J5 ^ J ' 'ô ^"^"'Vj^""" St c "*vJs!' ã* \ ^~\ '" A ^ " ' " v^c;'" " ^ ^ - ' ^ S f c r * MM :( li " Sv /^*"" ' «^ v/(7 »^-*'«'^- Cac kit qui cho thiy khu vyc mien Trung la vimg ed ning chju inh hirdng sdng thin ldn nhit Viing Tam ky, Quing Ngii eao sdng len tdi hon 6m d chu ky 950 nim Mien bic vi mien Nam li viing it bj inh hudng eua sdng thin •'. -n^ > \ \JI j " • ' c k 1- i- ^.11i i^'"\5iL ) J>^"*" :, ir''-'\^jCshi " \JW^V—KOIT'*'"" , r^— i 1 1-" 1 I - •BB''" •••I'" ^ • s ^ ^ ^ ^ ' ^ ^ ' ^ » ^ \ if' lV^*v—1^**^ ^-^^^ ^i'-'"-" J mg^ * „ ,„_.„_„„,„, jft C- .T vMtv -M w Ha:* Hinh 1: Bin dd nguy hiem sdng thin viing ven bien Viet Nam ehu ky 950 nim Bing Cae kjch bin ddng dit giy ST viing bien Ddng diing xiy dyng bin dd nguy hiem ST Viet Nam KB Md hinh MNLl MNL2 MNL3 MNL4 MNL5 MNL3+4 MNLl+2+3+4+5 MNL6 Do siu 20.88 40 19.12 40 17.13 40 15.08 40 13.33 40 Tga 120.00 119.79 119.18 119.18 120.01 119.10 17.5 20 Chieu dii 201.3 243.9 234 223.5 242.3 Chieu rgng 154.5 154.5 116.9 80.0 94.6 Dudng phuong 334.46 33.29 359.81 360.02 311.69 Gdc ddc 15 15 20 30 25 Gdc truot 90 90 90 90 90 Mw 158 45 357 40 90 8.0 8.5 8.6 8.5 8.3 8.4 VI KET LUAN Cie ket qui nghien cim ST giai doan niy deu cd mdt sd ket luin ehung sau diy: - Viing ngudn ddng dit giy ST nguy hiem nhit eho viing ven bien Viet Nam li ddng dat xiy tai ddi hiit chim Manila.' - Viing bien mien Trung tir Ddng Hi tdi Phan Rang li khu vyc chju inh hudng ST ldn nhat tren viing linh thd Viet Nam Khu vuc bien mien Bic v i mien Nam it ed ning bj inh hudng eua ST - Cin tiep tue nghien cim bd sung de cd the ning cao mirc ehinh xic vin de xic djnh vi dinh gii cic tham sd viing nguon cd ning giy ST anh hudng tdi bd bien Viet Nam Ciing nhu ning xiy sdng thin cac nguyen nhin khie nhu trugt Id dit, phun trio niii lira ngim 224 Hgi nghi Khoa hgc ky' niem 35 ndm Vien Khoa hgc vd Cong nghe Viet Nam - Hd Ngi 10'2010 TAI LIEU THAM KHAO Abe K (1975) Reliable estimation of the seismic mement of large earthquakes; J Phys Earth, 23, 381-390 Aida, I (1969) Numerical experiments for the tsunami propagation-The 1964 Niigata tsunami and the 1968 Tokachi-oki tsunami Bull Earthquake Res.Inst., Tokyo Univ 47, 673-700 Aida, I (1988) Tsunami hazard probability in Japan Bull Seism Soc Am 78, 3, 1268- 1278 Bautista P Leonila Ma., Kazuo Dike Estimation of the Magnitudes and Epicenters of Philippine Historical Earthqukes Teetonophysics 317 (2000) 137-169 Donald L Wells and Kevin J Coppersmith (1994), "New Empirical Relationships among Magnitude, Rupture Length, Rupture Width, Rupture Area, and surface Displacement", Bull Seism Soc Am., 84(4), pp 974-1002 Geist, E L., Tom Parsons, 2006 Probabilistic analysis of Tsunami hazards Nutural hazard, 37, 277 - 134 Le Nhu Lai, Phiing Van Phich, Biii Cdng Que, Nguyen The Tiep, Trin Vin Trj, Pham Ning Vii, Phan Trung Dien, Ngd Vin Dinh Bin dd eau tnic kien tao viing bien Viet Nam vi kl can, ty le 1: 2000 000 D I tii KHCN-06 vi KC-09-24 Vien Dja chit va Dja vit ly Bien, Ha Ndi 2006 Bill Cdng Que, Phiing Vin Phich Ve nhiing yeu td cau tnic-kien tao chinh tren vimg bien Viet Nam vi ke can Tap chi Khoa hgc vi Cdng nghe bien 4(T.l), Ha Ndi 2001 Titov V.V and F I Gonzalez 1997 Implementation and testing of the method of splitting tsunami (MOST) model NOAA technical memorandum ERR PMER-112, Pacific Marine Environmental Laboratoty, 10 Nguyen Dinh Xuyen, 2006 Nghien cim dinh gia nguy hiem ddng dit vi sdng thin d vimg bd bien Viet Nam va de xuit cic giii phap cinh bao, phdng tranh Bao cao de tai cap VKHVN, luu thu vien Vien Vat ly Dja ciu 225 ... Giang - Nam Hii Nam- nam Tiy Bien Ddng - Doan 1: nam Hii Nam- Tuy Hoi - Doan 2: tir Tuy Hoi ve phia nam Palawan - Doan - Doan Bien Sulu - Doan - Doan Bien Celebes - Doan l(bie Sel Sea) - Doan (nam. .. tdi viing ven bien Viet Nam Tir kit luan quan trgng cac kjch bin ddng dit xiy tren ddi Manila (bing 2) li duge chgn lim eo sd sd lieu tinh bin dd NHST vimg ven bien Viet Nam chu ky 950 nam (hinh... gii nguy hiem vi nii ro sdng thin vi sy img phd ciia Viet Nam" (2007-2008); D I tii cip nhi nude "Nghien cim dinh gii nguy hiem eua ddng dit vi sdng thin tren viing ven bien vi hii dio Viet Nam