tJNG DUNG PHUONG PHAP 3S TRONG GIAM SAT, CANH BAO

tJNG DUNG PHUONG PHAP 3S TRONG GIAM SAT, CANH BAO NGAP LUT VUNG

D 6 N G B A N G Q U A N G

TRI

Nguyin Tic Ddn, Dd Huy Gudng, Trdn Anh Tudn, Nguyin Dice Thdnh, Trinh Hodi Thu, Nguyin Thi Giang Huang

I.

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Trong nhiing ndm gdn ddy, su bid'n ddi khi hau toan cdu ddng thdi vdi su tan pha mdi trudng efla con ngudi ma nhidu tham hpa tu nhidn rdt khdc liet, dac bidt la lu lut da xdy ra ngay mdt nhidu. Thidt hai gay ra do loai hinh tai bid'n nay khdng chi tfnh bang sd ngudi chd't va sd tai san, mdng vudn bi chdn vui dudi lan nudc lu ma phai kd dd'n nfla la sd ngudi bi chd't ddi, chd't do dich bdnh, do mdt mfla gay ra sau dd (nam 1945 lu trdn sdng Hdng lam vd 52 doan dd gay ndn nan ddi lich sfl la chd't hon 2 tridu ngudi).

Midn Tmng Vidt Nam vdi dia hinh ha thdp dot ngdt tfl vflng nfli xud'ng ddng bang, do vay sdng sud'i chay qua vung ddi nfli chuyen ngay xud'ng ddng bang, khdng cd vung tmng luu. Cac sdng d day ddu ngdn, hep va dd'c, luu vuc thanh phdn nhd, lai hi che that bdi cac cdn cat ven bidn, ndn thdi gian tap tmng nudc nhanh, cung vdi didn thd' thdi tidt phfle tap va khdc nghidt nhu: bao, dp thap nhiet ddi, kd't hpp vdi gid mfla ddng bac, gdy ra mua ldn, hinh.J|ianh cac tran lu ldn, dinh lu nhpttv cudng sua't muc nudc cao, tdc dp ddng chay sudn dd'c va trong sdng rat ldn, gay sat Id cac sudn va bd sdng, tai mdt lupng bfln cat hat thd ldn, bdi ldp ddng rudng va cac efla sdng. Bdi vdy, noi ddy dupe coi la mot trong nhiing vflng cd didu kidn thudn lpi cho qua trinh lu lut xay ra, trong dd cd Quang Tri la noi bi anh hudng rdt nang nd.

Trude thuc td ndu trdn, da cd nhidu cdng trinh nghidn cuu ve lu lut, nhdm nghidn cflu cac nguydn nhdn hinh thanh chflng, ddng thdi dd xud't cac giai phap phdng tranh va flng cuu de giam thidt hai dd'n mflc td'i thidu. Trong cac cdng trinh nghidn cun dd, dd tai cd'p Vidn khoa hpc va cdng nghd Viet Nam: "ling dung td hgp ba phuang phdp: Viin thdm, he thdng tin dia ly vd he thdng dinh vi todn cdu de nghien ciiu, ddnh gid hien trgng ngdp lut vung Quang Tri" dupe thuc hidn trong hai nam 2002 - 2003 la mdt trong nhihig cdng trinh sfl dung td hpp cac cdng nghd hien dai RS (Remote Sensing), GIS (Geographic Information System) va GPS (Global Positioning System) nghidn cflu ve lii lut, ma qua dd hidn trang mdt sd tran lu tidu bieu da dupe lap lai va dang ke la dd tai da dd xuat mot gai phap mdi nham giam sat, canh bao lu lut qua cac mat cdt tu ddng d cac mflc ngap lut khac nhau.

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PHUONG PHAP NGHI£N

ctru

2.1. Ca sd tdi lieu

De dat dupe muc tidu nghidn cflu cua dd tai, vide flng dung cac cdng nghd hidn dai trong nghien cfln ngap lut dua trdn co sd tai lieu: anh radar sar chup ngay 6 thang U nam 1999; anh Landsat TM chup ngay 25 thang 12 nam 1998; anh SPOT XS chup ngay

18 thang 5 nam 1995; Ban dd dia hinh ty Id 1:50.000 cho toan tinh Quang Tri va ty Id 1:10.000 vung ddng bang Quang Tri; cac cdt mde canh bao lu tren dia ban tinh Quang Tri; Cac ban dd vd didu kidn tu nhidn, kinh te xa hdi tinh Quang Tri.

2.2. Cdc phuang phdp nghien ciiu 2.2.L Phuang phdp viin thdm (RS)

a. Xfl ly anh radar de xac dinh hidn trang ngap lut vung Quang Tri

ANH SAR 16 BIT

THU'C DIA

ANH SAR 8 BIT NAN HINH HOC

LOC BANG THUAT TOAN KUAN

GIAI DOAN MAT THUDNG PHAN N G U O N G T U D O N G ;

Max = Mean + 2 do lech chuSin Min = Mean - 2 do lech chuain BAN DO K6'T Q U A

Hinh 1: Cdc bicac thdnh lap bdn dd dien phdn bd lu tic dnh RADAR

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uan a) va sau khi loc Kuan b)

Thdng thudng, lu thudng di kem mua keo dai va bdu trdi bi phfl may day dac. Dieu nay can trd vide quan sat bd mat Trai Ddt tfl vd tinh cd gdn cac sensor vidn tham quang hpc. Cac vd tinh trang bi rada dng md tdng hpp SAR (Synthetic Aperture Rada) cd uu the trong quan sat lu chinh la nhd kha nang chup trong mpi thdi tid't va kha nang tach bidt td't dd'i tupng nudc va ranh gidi nudc td't hon cac anh vd tinh quang hpc.

Vide sfl dung anh vd tinh radar phdn nao cho thdy mdt sd dac diem efla lu khu vuc nghidn ciru trong nam 1999, dac bidt didn bid'n phan bd theo thdi gian.

Hinh 3: Dien phdn bd' ng^p liit duac svi ly tin dnh mdat viing Hue-Qudng tri (chtip ngdy 6/11/1999)

b. Xfl ly anh vd tmh quang hpc xac dinh hidn trang su dung dat tmdc khi ngap lut Nham xac dinh cac dd'i tupng sfl dung ddt trong vflng nghidn cun dd danh gia mflc dp thidt hai do ngap lut gay ra cho dia phuong, chflng tdi da tid'n hanh xfl ly anh sd vd tinh dd thanh lap ban dd hidn trang sfl dung ddt.

2.2.2. Phuang phdp he thdng dinh vi todn cdu (GPS)

He thd'ng dinh vi toan cdu GPS bao gdm 24 vd tinh bay quanh trai dat theo quy

dao nhd't dinh hai vdng trong mdt ngay va 5 tram mat ddt dd theo ddi va didu khidn cac vd tinh nay. Cac vd tinh nay ludn cung cdp nhftng thdng tm dd xac dinh toa dd (2 va 3 chidu) tai bd't cfl noi nao trdn Trai Dd't vdi thdi gian 24/24 gid. Tfl may thu GPS, ngudi sfl dung cd thd xac dinh vi tri dia ly efla minh. Vi tri va thdng tin ddn dudng la vd cflng quan trpng trong rdt nhidu boat ddng nhu danh ca, trdc dia hang khdng, hang hai va xac dinh vi tri su cd thidn tai.

Trong dieu kidn binh thudng, ngudi ta cd thd dinh vi mdt didm bang cac vi tri didm md'c nhu nhu dudng sa, kdnh muong, cdu cdng, nha efla... Khi xay ra ngdp lut thi nhidu vi trf trdn cd thd bi ngdp trong bidn nudc, do vay vide dinh vi chinh xdc mdt dia didm nao dd dd flng cuu kip thdi la mdt didu khd khan.

He thd'ng dinh vi toan cdu giflp cho chflng ta xac dinh vi tri chfnh xac ngay ca khi trdn ddng bang bi chim trong bidn nudc. Mat khac, he thdng dinh vi toan cdu giflp cho cac nha nghidn cfln didu tra, khao sat hudng ddng lu, xac dinh chfnh xdc vi tri ngdp cung dd ndng, sdu, vi trf thoat lu, ... de cd ke hoach flng phd tflc thi va phdng chd'ng lu trong tuong lai.

2.2.3. Phuang phdp he thdng tin dia ly (GIS)

* Ca sd phuang phdp:

Trdn the gidi cung nhu d Viet Nam, hidn cd rdt nhidu md hinh dd du bao didn phdn bd va dd sdu ngdp lut. Mdt sd nha nghidn cflu dflng md hinh thuy van dd du bao didn tfeh ngap lut. Theo md hinh nay thi ddng bang ngap lut dupe coi nhu la mdt bd mat nghidng thoai va cac luu vuc thanh phdn dupe khdng chd' rd't rd rang. Nhu vdy, nd thudng dupe ap dung cho cac ddng bang tam giac chdu rdng ldn, bang phang va tinh phdn bde dia hinh thd'p. Dd'i vdi ddng bang Quang Tri, khd cd the dp dung nd bdi day la ddng bang hi chia cat manh, chidu ngang cua ddng bang hep, gifla ddng bang xudt hidn nhidu ddi gd, he thd'ng kdnh muong vudng gdc vdi ddng chay va mdt he thd'ng cdn cat ndm sat bidn.

Chung ta bidt rdng, ddng chay be mat la qua trinh rd't phfle tap, phu thudc rd't ldn vao dia hinh. Phdn ddng bang Quang Tri cd dac didm hinh thai luu vuc ngdn, hep va dp ddc bid'n ddi nhanh, cac bdn chfla nudc nhd lai cd cac cdn cat che chan ven bidn, ndn nhihig sai sd nhd trong md hinh mflc dp ngdp lut cd thd ddn dd'n sai sd ldn trong md hinh tfnh toan.

Dd khdc phuc nhupc didm trdn, chflng tdi dua vao cac cdt md'c vdi cac toa dp xdc dinh cd gia tri dd cao chdn dd' tuong flng vdi gid tri sd dia hinh va cd gia tri ngdp lut cua trdn lut thang XI ndm 1999, cflng vdi anh radar dupe ghep nd'i vdi md hinh tfnh todn, dd hidu chinh sai so cho ra kd't qua cac mflc ngdp khac nhau.

Nhu vdy, bd mat cac mflc ngdp lut nay khdng phai la mdt mat phang ma la mdt bd mat phu thudc rdt ldn vao cac bdn chia nudc nhd trong ddng bdng.

* Phuang phdp tinh:

- Gid tri dp cao tgi mot diem:

Gia sfl md hinh sd dp cao (DEM) dupe bidu didn dudi dang ma trdn dp cao sd Gnm nhu sau:

Gnm = [ Gij] vdi i =1, 2,... n, j =1,2,...m Trong dd: Gij: Gia tri dp cao so tai toa dp i,j

n: Tdng sd hang m: Tdng sd cot

Tap hgp log dp tgi cdc md'c chudn Gor_std:

Cor_std = [ (i„j,), (ij, ,J2), (ip, jp)...(h,jk)]

Trong dd: p = 1,2,...k la thfl tu cac md'c do thuc td' k = Tdng so cac md'c do

Tap hgp cdc mice dp ngdp (theo chieu cao cdt nudc):

flood_std = {flood - hi , flood - hj, ... flood - h,;}

Trong dd: Flood_std: Chidu cao cdt nUTfc flood-h,: Chidu cao cot nudc tai mflc 1 flood-h,;: Chidu cao cdt nudc tai mflc k

- Dp sdu ngdp tgi tog dp cdc diem do chudn (theo md hinh):

Flood_deep(q) = Flood_level(q) - Gij, Gij < Flood_level(q) Trong dd: q = 1,2, ... M (M sd lupng md hinh theo ly thuyd't)

Dp lech giUa mice ngdp tinh theo md hinh vd mice ngdp thue te:

Do dia hinh bi chia cdt tao ndn cac bdn thu nudc khac nhau ddn ddn mflc ngdp thuc td cd su sai khac so vdi md hinh. Mflc sai lech ve dp sdu dd la:

Dif_Flood_Deep(q)= nAbs {Flood_deep(q)- Flood_std (q)}

Trong dd: Abs {Flood_deep(q)- Flood_std (q)}: Tri tuydt dd'i dd sdu ngdp tai tpa dp cac diem do diuan tinh theo md hinh va cac muc dp ngap theo chidu cao cdt nudc.

Gia tri dp lech nay se dupe hidu chinh vao md hinh tinh dd cho cac kd't qua dung vdi thtte td'hon.

* Ket qud xii ly:

Thdng tin ve didn phan bd ngap lut ung vdi mflc ngap tfl 0,2 dd'n 5,0 m vdi khoang each mflc ngap each nhau 0,2 m. Dd la cac mflc: 0,2: 0,4; 0,6; 0,8; 1,0; 1,2; 1,4; 1,6; 1,8;

2,0; 2,2; 2,4; 2,6; 2,8; 3,0; 3,2; 3,4; 3,6; 3,8; 4,0; 4,2; 4,4; 4,6; 4,8; 5,0.

Tuong flng vdi nd cd 22 ldp thdng tin vd dd sau cot nudc hay dp sdu ngdp flng cho 22 mflc ndu trdn.

III. Mot sd ket qua umg dung

3.1. Lap lgi Men trgng cdc trgn lu. ldn

Hidn tai Quang Tri cd 81 cdt md'c carih bao lu. Theo phuong phap nay ndu chflng ta cd sd lieu do cac trdn lu ldn d mot sd cd md'c cdng vdi tu lieu anh vd tinh cho phep khdi phuc lai hidn trang cac trdn lu ldn.

Hinh 4: Dudng qud trinh trdn lU tic 1 8111 ndm 1999

500 H(ctn)

4/XI 5/XI 6/XI e/xi Thai gian

3.2. Xdy dung nhanh chdng cdc bdn do du bdo

Tfl cac thdng tin vd lupng mua, gid tri muc nudc tai mdt so cdt md'c trong 81 cdt md'c canh bdo lu hidn cd, cho phep du bdo mflc dp thidt hai dd'n hien trang sfl dung ddt tai cac vi trf trdn ban dd. Dd danh gia mflc dp thidt hai cac mflc ngdp khac nhau dd'i vdi vdn dd sfl dung dd't cua khu vuc. Ban dd hidn trang sfl dung ddt dupe chdng ghep ldn cdc mflc ngdp cho ta bid't hidn trang ngdp d cdc mflc khac nhau, tfl dd cd thd thd'ng kd dupe cac dpn vi sfl dung dd't cung nhu didn tfeh ngdp lut tuong flng vdi mflc ngdp do.

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(b)

Hinh 5: Quan he giita sdhd ngdp vd dp sdu ngdp lut huyen Gam Ld, Gio Linh (a) vd Hdi Lang, Trieu Phong, thi xd Ddng Hd (b)

3.3. Gidm sdt, cdnh bdo ngdp lut bdng He thdng tin dia ly (GIS).

3.3.1. GIS vd vd'n de ednh bdo ngdp lut.

Hidn nay, GIS dupe sfl dung trong rd't nhidu nghien cflu flng dung d nhidu linh vuc khac nhau. Ddy la mdt cdng cu rd't huu hidu trong vide phdn tich khdng gian, md hinh

hda, cac kd't qua ddu ra thd hidn da dang dudi dang cac ban dd, bieu dd, cac mat cdt, bang bidu... cho chflng ta cai nhin true quan vd kd't qua nghidn cfln. Dac bidt, nd cdn la cdng cu cd thd dd dang thay ddi, cap nhat cac thdng tin mdt each nhanh chdng, chinh xac va dua ra mdt phuong an ung cflu kip thdi trong tmdng hpp kh£n cd'p.

Dd'i vdi nghidn cfln lu lut, cho dd'n thdi didm nay, GIS dupe sfl dung dudi hai each:

Lidn kd't vdi cac md hinh thuy van, thuy luc.

Qua cac cdng cu san cd, cd thd tinh toan va hien thi cac thdng tin vd ngdp lut dudi dang cdc dd thi, ban dd, bieu dd.

Cdch sfl dung thfl hai, dac bidt phfl hpp vdi nghidn cflu va danh gia hidn trang ngdp lut, vi nd cd thd cho kd't qua mdt each true quan vd pham vi va mflc dp ngdp lut trong vung nghien cuu. Tuy nhidn, mflc dp canh bao chinh xac dd'n mflc nao hoan toan phu thudc vao co sd dfl lieu vd vflng nghidn cflu, vi dd'i vdi GIS vdn dd cd tinh chdt quydt dinh, anh hudng dd'n kd't qua ddu ra dd la co sd dfl lieu. Vdi mpi cdng trinh nghidn cflu ndi chung va nghidn cfln lu lut ndi ridng, thi GIS ludn ddi hdi phai cd mdt co sd dfl lieu chudn. Do vay, vide xay dung mdt co sd dfl lieu hoan chinh cd y nghia ldn trong vide ra quyd't dinh efla chflng ta.

3.3.2. Xay dung ea sd die lieu GIS lien quan den Men trgng ngdp.

Cflng vdi cac kd't qua the hidn hidn trang va mflc dp ngap lut, dd tai cdn cung cap mdt CO sd dfl lieu tuong ddi hoan chinh, bao gdm nhieu ldp thdng tin khdc nhau vd cac didu kidn tu nhidn, kinh td' xa hdi cd anh hudng dd'n qfla trinh lu lut, cung nhu vide sfl dung chflng trong danh gia mflc dd thidt hai d cac mflc ngdp khac nhau. Tuy nhidn, cac dft lieu nay tdn tai dudi nhiing dang khac nhau va chua dupe chudn hoa. Qua phan tfeh va danh gia mflc dp tin cdy cua cdc dfl lieu dd, cdc tac gia da chuydn chflng vd dang sd, vdi mdt CO sd toan hpc thd'ng nhd't. Ddy cd thd ndi la mdt tu lieu quan trpng, khdng nhiing phuc vu cho qua trinh nghidn cflu lu lut, ma cdn cd thd sfl dung cho rd't nhidu nghidn cflu chuydn nghanh khac vd Quang Tri.

3.3.3. Gidm sdt dp sdu ngdp lut bdng ede mat eat tudpng.

Ban dd didn ngdp lut cho chflng ta bid't vd didn tfeh vflng bi ngdp vdi cac mflc ngdp tuong flng, tuy nhidn nd lai khdng the hidn dupe dp sdu ngdp lut tai nhung didm khac nhau trong vflng ngdp d mflc ngdp dd. Van dd nay dac bidt dupe quan tdm vi nd cung cd'p cho chflng ta thdng tin dd thid't kd' cac cdng trinh ddn dung d nhung cao trinh hpp ly de tranh bi ngdp khi cd lu lut xay ra.

Tfl trude tdi nay, cac thdng tin vd ngdp lut thudng dupe thd hien dudi dang cac ban dd mflc dp ngdp lut d cac khoang gia tri khac nhau ma khdng thd hidn dp sdu ngdp lut mdt each lidn tuc tai mpi diem cua vung bi ngdp. Kd't qua nghidn cun efla chung tdi, ngoai vide thd hidn nhung ban dd d dang dd, cdn cung cd'p cac gia tri dp sdu ngdp lut tai mpi diem dupe the hidn qua cac mat cat so sanh tu dpng, thd hidn quan he vd dd sdu ngdp lut vdi mflc ngdp tuong flng d mpi thdi diem khac nhau. Day la mot ung dung rdt hidu qua trong vide giam sat dp sau ngap lut tai mpi didm khac nhau trong vung h\ ngdp vdi mpi mflc ngap khac nhau.

IV. KET LUAN

Kd't hpp cdc cdng nghd hidn dai nhu vidn tham, he thdng tin dia ly, he thd'ng dinh vi toan cdu dd nghidn cflu lu lut dang la mdt phuong phap cd nhieu uu diem, khdng nhflng trong vide xdy sung cac ban dd vd lu lut, ma qua dd cd thd dua ra cdc bidn phdp phdng chd'ng huu hidu va cac giai phap flng cfln trong trudng hpp khdn cd'p.

Cflng vdi cac kd't qua the hidn hidn trang va mflc dp ngap lut, dd tai cdn cung cdp mot ea sd die lieu tuong dd'i hoan chinh, bao gdm nhidu ldp thdng tin khac nhau vd cac didu kidn tu nhidn, kinh te xa hdi, cd anh hudng dd'n qfla trinh lu lut, cung nhu vide sfl dung chflng trong danh gia mflc dp thidt hai d cdc mflc ngdp khac nhau. Cd the ndi ddy la mdt tu lieu quan trpng, khdng nhiing phuc vu cho qua trinh nghidn cflu lu lut ma cdn cd the sfl dung cho rd't nhidu nghidn cflu chuydn nganh khac vd Quang Tri.

Mdt trong nhung kd't qua flng dung dang chu y cua dd tai la vide dd xudt mdt giai phap nham gidm sat va canh bao ngdp lut, thdng qua cac mat cdt tu ddng vdi su hd trp cua cdng nghd GIS. Ddy la mdt sang tao mdi cua tap thd tac gia, va trong bai bao nay tap thd tac gia mong mud'n cac kd't qua nghidn cflu khdng chi ditag lai trong pham vi tinh Quang Tri ma cd thd dupe dupe dp dung rdng rai d nhidu noi, dd tflng budc ddng gdp phdn hftu hidu vao cdng cude phdng chd'ng thidn tai lu lut va bao vd mdi tmdng.

0.0 0.000

Do cao cot nudc

Dien ngSp lut

Be mat dia hinh

0.060 '•' " 0.07S ' 0.100 0.125 Dlstencs (M«ters)

Hinh 8: Mat eat bieu diin quan he dp cao cdt nude vdi miic ngdp 3m

Do cao c6t nudc

Dien ngap lut

Be mat dia hinh

Hinh 9: Mat eat bieu diin quan he dp cao cdt nUde vdi miie ngdp 4m

TAI LIEU THAM KHAO

1. Dd Huy Gicdng, Wang Rui Sheng (1999): Danh gia hidu qua cua phuong phap GIS - GPS - RS trong nghidn cflu ngap lut nam 1988 tai tinh Hd Bde. Tap chi Mdi trudng luu vuc sdng Trudng Giang. So 1 nam 1999 (Tieng Trung Qud'c).

2. Dd Huy Gicdng, Nguyin Tic Ddn vd nnk (2003): Md hinh dd'i tupng khdng xac dinh va flng diing trong nghidn cflu xac dinh ranh gidi cac dd'i tupng bien va dai ven bien. Cdng trinh Dia chat va Dia vat ly bidn. Sd dac bidt nhan dip ky niem 10 nam thanh lap Phan vien Hai duong hpc ta'i Ha Ndi. NXB KHKT. Ha Ndi.fr. 196-201

3. Nguyin Tic Ddn, Nguyin The Tiep, Dd Huy Gudng vd NNK (2001): Ap dung cdng nghd vidn tham va GIS, nghidn cflu mdt sd qua trinh dia chat ddng luc chfnh vung Quang Tri. Dd tai cap Vidn. Ha Ndi 2001. Luu trft tai Phdn vidn Hai duong hpc tai Ha Npi.

4. Nguyin Tic Ddn, Dd Huy Gicdng, Nguyin Dice Thdnh, Trinh Hodi Thu (2000):

Ap diang tdng hpp vidn tham he thdng tin dia ly he thd'ng dinh vi toan cau trong nghidn cfle danh gia hidn trang ngdp lut. Cac cdng trinh nghidn cflu Dia chat va Dia vat ly bidn. Tap VI. NXB Khoa hpc va Ky thuat. Ha Ndi. Tr. 158 - 168.

5. Gao Ddng Du (2000): Lu lut d mien Trung va cac van de cdn nghidn cflu. Tap chf Khf tupngThuy van 4 (472) - 2000. Ha Ndi. Tr. 3 - 6.

6. Bid DiccLong, Nguyin Ghi Yen (2000): Tran lu lich sfl dau thang 1 nam 1999 d mien Trung va cdng tac du bao phuc vu. Tap chf Khf tuong Thuy van 2 (470) - 2000. Ha Npi. Tr. 12-18.

7. Nguyen The'Tiep, Nguyin Tic Ddn vd NNK (2001): Dieu tra, danh gia cac loai hinh tai bid'n dia chat va dac didm phdng xa ddi ven bidn Viet Nam, de xudt cac giai phap lam giam nhe thidn tai. Du an didu tra co ban cdp Nha nudc. Ha Ndi.

8. Bid Dodn Trpng, Lgi Anh Khdi vd NNK (1999): Ung dung anh radar trong xay dung ban dd hidn trang ngap lut d ddng bang sdng Cflu Long. Hdi thao: IJhg dung vidn tham trong nghidn cflu, quan ly mdi trudng Viet Nam. Ha Ndi, 10/1999. Tr. 162 -169.

9. Sd Khoa hpc, Cdng nghe & Mdi tricdng tinh Quang Tri (1999): Hidn trang Moi trudng Quang Tri 1994 - 1995. Bao cao luu trft tai Sd KHCN&MT Quang Tri.

IQi.Trdn Vdn Y, Lgi Vinh Gdm vd NNK (2000): Du bao didn va mflc dp ngap lut do lu theo md hinh thuy van va he thd'ng thdng tin dia ly (GIS) luu vuc sdng Thach Han, tinh Quang Tri. Bao cao Khoa hpc. Luu trft sd KHCN & MT tinh Quang Tri.

11 .Diishmanta Diitta, Srikantha Herath and Katiimi Musiake (2000).- Distributed Hydrologic Model for flood inundation simulation. Journal of Hydrosience and Hydraulic Engineering. Vol.18, No.l May, 2000, 11-20.

12. Diishmanta Dutta, Srikantha Herath and Katumi Musiake (2000): Flood inundation simulation in a river basin using a physical based distributed hydrologic model. Hydrological Processes. 14,497-519.

SUMMARY

Application of 3s method in Supervising and forecasting flood in Quang Tri delta By Nguyen Tu Dan, Do Huy Guong, Tran Anh Tuan,

Nguyen Due Thanh, Trinh Hoai Thu, Nguyen Thi Giang Huong

Based on the three methods of Remote sensing (RS), Geographic information system (GIS) and Global positioning system (GPS), the authors have established the database and models for monitoring and forecasting flood status. On the basic of field- surveyed data, flooding model and theoretical calculation, the experiment results show the different flood levels, flood profiles and multi-time comparison. The integrated methods in this paper can be efficiently applied to study and forecast flood in coastal zone areas

Ngudi sfla bai: TS Dd Chid'n Thdng Phan vidn Hai duong hpc tai Ha Ndi