H$i Dja ly y^ TAi nguyen Moi trirfrng Thifa Thien Hue Hgi Dja ly Vict Nam
Cong nghe viin tham trong h6 tra tim ki^m CLFU nan va LPng pho thien tai
Pham Thanh An' Abstract
Remote sensing technology in support search&rcscue and natural disaster response In the context of global climale change today, learn the rules in order to study each step toward monitoring, disaster management is considered as an important task of each region or country.
Remote sensing has become a research method is very effective in disaster management by Ihe inherent advantages that the resources and traditional research methods can nol be Space lechnology and disaster management development has kept pace wilh each other in finding the accurate and efficient method lo prepare for prevention and response and relief
The objective of this paper mentioned the status of the search and rescue, with the role of remote sensing lechnology in support of search and rescue and disaster response and presents results using RADAR satellite imagery to monitor flooding in Thua Thien Hue region
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M 6 DAUTrong bdi canh bien ddi khi hau loan cau nhu hien nay, nghien ciiu tim hieu-qui luat nham tiing budc tien ldi Iheo doi, quan ly thien tai dugc xem la nhicm vy quan trgng ciia tirng viing lanh thd hay moi qudc gia.
NIU nhu trudc day, chii yeu sir dung phuang phap truyin thdng la do dac, thdng ke ngoai lhuc dia lhi ngay nay, vdi sy phat triln cua khoa hgc ky thuat, dac bi?l la cac cdng nghe ve thu nhan, xu ly hinh anh (vien tham) va phan tich khdng gian dia ly (GIS) da hd trg rat nhieu cho hudng nghien ciru nay. Cac khai niem vl viln tham da dan trd nen quen thugc do irng dung Ihyc lien da chiing minh nhiing uu viet cCia no so vdi cac phuang phap truyen thdng. Cac he thdng cam bien (sensor) lien tuc dugc cai lien, tir chd chi lhu nhan dugc nhung hinh anh don sic sii dyng cdng nghe analog tdi cdng nghe chup anh sd vdi nhirng dir lieu da phd (Muhispectral), sieu phd (Hyperspeclral), tdi sur dung ky thuat laser (Lidar), sdng ngin (Radar), hdng ngoai nhi?t...cung cip mgt lugng thdng lin ldn din ngudi sir dyng dl giai doan, nhan bill ddi tugng. Bai bao de cap hien trang cdng tac tim kiem cdu nan (TKCN) ciing vdi vai trd cdng nghe vien tham trong hd trg tim kilm cuu nan va u'ng phd thien tai.
2. HIEN TRANG CONG TAC T I M KIEM ClTU NAN VA iTNG PHO THIEN TAI
Trudc nam 1996, nudc ta chua hinh thanh to chiic qudc gia vl TKCN. Dam duong nhiem vu nay la cac Id churc chuyen nganh cd lien quan tryc tilp den TKCN nhu nganh Hang khdng dan dung, nganh Hang hai; cac bg, nganh thudng cd cac ban boat dgng dudi su chi dao ciia Ban phdng chdng lyt bao Trung uang. Quylt dinh 780/TTG ngay 23/10/1996 ciia Thii tudng chinh phu ban hanh, Oy ban Quic gia (UBQG) TKCN tren khdng va tren blln dugc ihanh lap. Day dugc xem la budc chuyin biln quan trpng vl nhan thiic cdng tac TKCN, tii do nudc la chinh thiic cd ca quan qudc gia vl TKCN,
Cac md hinh Id chiic trudc day la xuat phat tir tinh hinh thyc te cdng tac TKCN cua cac bd, nganh phai iing phd vdi su co thien tai va su cd tir cac boat ddng cua, bd nganh minh. UBQG TKCN ' Trung tdm Dich vu Ky thugt Cuu hg Cuv ngn/ Cue Bdn do BTTM
DAO TAO DIA L\'; PHl/ONG PHAP vA CONG NGH$ NGHIEN cOLl DIA LY
Hgi Dja ly va T^i nguyen Moi truo'ng Thii'a Thifn Hui Hgi Dja ly VietNam tren khong va tren biln thanh lap nam 1996, song tren thyc tl la ghep ggp cac Id chirc hien cd ciJa 2 nganh iren vdi cac to chtic cd chirc nang tuong tu viia Bd Thuy san va Tdng cong ty Diu khi ma chua cd nhirng Ihay ddi dang ke trong he thdng Id chiic phdi hgp TKCN.
Mo hinh to chirc phdi hgp TKCN hinh thanh the hien rd vl vai trd chi dao, chi huy phdi hgp dya theo ciu iruc md hinh hanh chinh chi'nh quy:
Chinh phu lUBQG TKCN Ban TKCN bd, nganh, dja phuong
Mo hinh tren da the hien rd quan diem co ban ciia Nha nudc ta ve xay dyng nganh TKCN, danh diu budc ehuyen biln co ban nhan thirc ve vai trd cdng lac TKCN, md hinh Id chirc phoi hgp TKCN xay dung theo cac lieu chi: dap ung yeu cau ve dac thii vl cdng tac TKCN; cd kha nSng huy dpng cao ngudn lyc loan xa hgi vao cdng lac TKCN.
De giam nhe thien lai, tham hpa va irng phd khan cap trong boat ddng TKCN, phuong cham la:
Chu ddng phong tranh, irng phd kip ihdi, khac phyc khan truong, cd hieu qua, lay phdng tranh la chinh. Huy ddng mgi ngudn lyc xa hgi de tham gia cdng tac TKCN, iing phd khin cap, thyc hien lot phuong cham "•/ tgi cho" (luc lugng, phuong lien, hau can va chi huy tai chd) trong cdng tac irng phii thien tai va TKCN, Mgt trong nhiing van de then chdt ciia cdng tac TKCN va irng phd thien tai do la can cd nh&ng thong lin gin thdi gian lhuc (near real time) d ca 3 giai doan trudc, trong va sau thicn tai. De giai quyet van de nay, tu lieu vien tham gan nhu la giai phap duy nhat, mang tinh dot pha.
3. VAI TRO CUA CONG NGIl£ VIEN THAM TRONG HO TRQi TKCN VA CTNG PliO THIEN TAI
Vdi dac diem la mdi ve linh cd chu ky chup lap va dp phan giai khdng gian khae nhau, do cac ve linh mang tren nd cac bg cam bien dugc Ihict ke tren nhirng nen tang cdng nghd khac nhau nhu quang hgc hay radar; loan sac, sieu phd, da phd, hdng ngoai hay nhiet. Nhtrng dang dii' lieu nay deu co the ung dung trong quan ly, irng phd, giam nhe thien tai va TKCN, tuy nhien hi?u qua cdn phy thugc vao cac d^c tinh phan xa phd cua cac ddi tugng mat dit, tinh chit va Ioai hinh Ihien tai. Danh gia vc dac diem ciia cac ve tinh se cung cap cai nhin long quan ve tinh phii hgp giii'a dang dii lieu ciia v? linh ddi vdi cac loai hinh thien lai khac nhau. Vi du nhu cam bien nhiet cd kha nang phat hien nguy ca ch£'y, cam bien hdng ngoai hay radar phii hgp hon cho theo ddi liln trinh lu lut va cac cam bien song ngin cd 'hi ghi Iai do am dat...
CiC cdng nghe khdng gian va quan ly thien tai phat trien ludn song hanh vdi nhau trong vice tim ra cac phuong phap hieu qua va chinh xac de chuan bj cho cdng tac phdng ngira va irng phd, ciru trg. O nudc ta, thien tai la mdt hien lugng kha phd bien, lau dai. Hien chung la chua co bi?n phap khac che hoan loan dugc chiing ma chi cd ihl dy bao, canh bao nham giam thieu thiet hai gay ra bdi thien tai va dan quen vdi khai niem coi thien tai nhu la mdt hi$n tugng di ciing sy phat triln nhir
"sdng chung vdi /«", "song chung vdi bao"...Cdng nghe vien tham cd the la ngudn cung cap thong lin chu dao trong nghien ciru ciing liic nhieu ddi tugng dia ly lien quan tdi sy hinh thanh va lien tricii thien tai theo khdng gian va thdi gian. Trong quan ly thien tai, quan trgng nhit la giam sat tinh hinh, theo doi liln trinh, md phdng thi gidi thyc dl dua ra cac md hinh d\i bao tot hon, dl xuit phuong an urng phd phii hgp va chuan bi san sang ca sd dir lieu khdng gian. Vdi viec tich hgp dir lieu vien tham vdi GIS (he thong tin dja ly) se giiip xac djnh dudng thoat hiem, lanh nan tai nhiing nai an loan va xay dyng cac kjch ban sat vdi thyc tl, hi trg ra quyll dinh diing din ciia cac dan vj chiic nang.
NhQng thanh cdng trong viec iing dung cdng nghe vien tham cd dugc nhu hien nay la su long hgp ciia hai yeu td, do la: ngudn tai lieu da dang, phong phu cimg vdi sy lien he chat che va qua trjnh phan tich, xu ly nhirng tai li?u dd da cd nhirng budc phat triln vugt bac. Tuy nhien, cd mpt thyc te la khdng cd bat ky mdt ngudn tai lieu viln tham dan le nao ma lai cd the cung cap diy du thdng tin cho 11 ^4 Hdi nghi Khoa hoc Dia ly Todn qudc ldn thu 6; Thdnh phd Hui 9/2012
Hgi Bja 1^ vji Tai nguyEn Moi Iriro^ng Thira Thi£n Hue Hgi Dja ly Vift Nam
viec nghien cii'u hay ung dung cu thi. Dl cho nhirng irng dung dugc thanh cdng, phai phan tich va phat hien nhirng thdng tin dac biet tdn t^i tren tu lieu vien tham. Mdi edng viec deu nham muc tieu giai quyet cac cau hdi ve ddi tugng, dd la: a ddu? bao nhieu? va nhu the ndo?.
Tir nhung dac diem vdn cd, cu the la tinh lien tuc ve mat khdng gian, ti'nh dong nhit, da thdi gian va pham vi bao triim rdng, cac dir lieu vien tham cd thi dugc sir dyng rit hieu qua, cho nhitng nhiem vy sau:
- Nhanh chdng danh gia miic dp nghiem trgng va anh hudng ciia Ihien tai nhu lu lyt, ddng dit, su CO tran diu va cac tham hga khac.
- Thilt l^p, thilt kl eac tuyln dudng thoat hilm, cuu tro hi?u qua.
- Xac djnh vi tri, khoanh viing anh hudng; nhihig vimg cd nguy co, sa bd danh gia thiet hai do thien tai.
- Giam sat viec lai thietsau thien tai,
- Ciip nhat ban dd theo timg giai doan: trudc, trong va sau thien lai.
Trong tuong Iai, cdng nghe vien tham se tien ldi cac ky thuat da cam bien dugc lap tren mgt bg cam giup cho cac nha phan tich thuan lgi cho nhilu img dyng khac nhau. Tiiy theo muc dich, yeu ciu ciia nhiem vu va lo^i hinh thien tai se quylt djnh din dang va chat lugng diu vao ciia anh viln Iham nhu anh ENVISAT (Chau Au), LANDSAT (My) cho nghien ciiu kliu vuc rgng ldn, hay anh SPOT (Phap).
QUICKBIRD (My), THEOS (Thai Lan) cho nghien cihj mgi khu vyc nhd ddi hdi dp chi tiet cao...
4. Sir dung tu lieu anh Radar thanh lap ban dd nhanh - rapid map (thyc nghiem trong trudng hgp xay ra thien tai lu lyt d Thira Thien Hue)
De xay dyng cac ldp thdng tin hien trang ngap lut, sii dyng anh vien tham SAR Radar, bdi vi anh chung cd kha nang ghi lai hinh anh trong dieu kien ihdi tiet xau, cd kha nang xuyen qua may mii vii mua, cung vdi do phii triim kha ldn nen nd la cdng cu rat hdu hieu de quan trac viing ngap lut.
Trong qua trinh thyc nghiem, chiing ldi da sir dung cac anh vien tham chyp khu vyc nghien ciru lai nhieu thdi diem khac nhau va dugc cung cap tir nhieu ngudn khac nhau. Nguon dii lieu dugc chi ra trong bang I.
Bdng 1. Die lieu vien thdm phuc vy chiit tach thdng tin ngdp lyil
1 2 3 4 5 6 7 8 9 10
Cdnh anh M0086356 ALPSRP096650320 ALPSRP0966503tO ALPSRP096650300 ASA APP 1PNUPA ASA IMP 1PNUPA PR-00CD1355BAC-PO00 PR-00CD1334A27-PO00 PR-008A9SCCDA-PO00-1 PR-00D8AABDE2C-PO00-1
V | tinh/bg cam RADARSAT-1 ALOS/PALSAR ALOS/PALSAR ALOS/PALSAR ENVI:AT/ASAR ENVISAT/ASAR E N V I S A T / A S A R ENVISAT/ASAR ENVISAT/ASAR ENVISAT/ASAR
Njray chup 06/11/1999 17/11/2007 17/11/2007 17/11/2007 14/9/2008 23/5/2004 25/9/2008 14/10/2008 02/11/2007 04/11/2007
Nguon cung cap Co quan Khfinq gian Canada Ca quan nghien CLTU hang khdng vil tru
Nhat Ban Ccr quan nghian ci^u h^ng khflng vu try
Nhal Ban Co quan nghien cihi hang khflng vu try
Nhiit Ban Co quan Khflng gianCh^uAu Co quan Khflng gian ChSu Au Tram thu anh Viet Nam Tram thu anh Viet Nam Tr^m thu anh Viet Nam Tram thu anh Viet Nam Thdng thudng, cac anh Radar khi mdi nhan vl chua Ihl hiln thj dugc ngay tren cac phan mim xir ly anh ma cin phai qua budc liln xir ly. Budc xu ly diu lien nay vo cimg quan trgng, nd giup cho ngudi xir ly anh cd the biet dugc cac thdng tin can thiet ve anh nhu loai anh, miic xur ly, tga dp so bg
DAO TAO D|A LY, PHUONG PHAP VA CONG NGIfe NGHIEN ClRJ DIA LY ITIJ
Hoi Dia ly va Tai nguyen Moi truong Thira Thien Hue HgiDjalyVijtNam ciia 4 gdc anh, kich thudc pixel, va mdt thdng sd ma ta phai ghi lai do la hing sd higu chinh (k). HSnj- sd nay giiip cho viec tinh loan nang lugng tan xa ngugc. Ddi vdi anh Radar thi kich thudc pixel ihco chieu dgc va chilu ngang la khdng nhu nhau, cd nghTa la anh Radar cd pixel hinh chii nh^L dl ti^n cho viec xii ly ngudi ta thudng lam vudng l^i pixel va ddng thdi chuyin doi gia tn pixel sang diing dau phiy ddng ma no luong duang vdi gia trj ciia anh cudng dp.
Xac dinh vimg ngap lut la vice chill lach ra cac dac tinh tan xa ngugc ciia nudc ma nd Ihudng xuit hien vdi tdng miu sam tren anh SAR. Trong nhirng trudng hgp dac bict, vi dy nhu khi cd gio hoac cd nhilu thuc vat trong nudc thi tan xa ngugc trd nen rat m^nh Iam cho tdng anh sang hon. Viec tiln xii ly va chill tach thdng tin, xu ly anh Radar dugc thyc hign bing cac phin mim chuyen dung (Ihudng do cac hang che lao ve tinh cung cap, nhu Best cho tien xu I;? anh Envisat ho|c Nest cho atih Alos), bing Erdas Imagine (phan mem xir ly anh ciia hang leica dugc thuong mai hoa, dung dl xir ly cac loai anh vien tham).
Kich hoathe thong cung c^pSnhkhicolhigntaixay
DC li£u anh trudc ngap lut
T X
Ti€p nhan anh
vi6n Iham SAR ^ Nan chinh hinh hoc
Doi saMI sa s^nh
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Chiet tach vCing ng|p lul
3i€n d6ng itudc va
Ihdi di^m ngtlp kit Ban do hien trang ngap lut
Hinh 1 Quy trinh cdng ngh^ thdnh lgp nhanh bdn do hien trgng nggp lyt Tinh loan nang lupng tan xa ngugc chinh la viec chuyen ddi gia tri ciia mdi pixel d budc tren sang he sd nang lugng tan xa ngugc. Mdi pixel se dugc tinh toan theo cdng thire:
jDNf . .
Trong dd: lio: he sd nang lugng tan xa ngugc; DN: Gia trj ciia pixel /: gdc tdi tai dilm giira ciia vgt quet; K: Hing sd hieu chinh tuyet ddi
Gia trj ciia uo cd the de d dang tuyln linh hoac cd the chuyen sang dgng decibel (dB) bing cong thtic: (ToidB) = lOx loglO(CTo Jinear).
Anh vg tinh da thdi gian la mdt tap hgp nhung canh anh chyp cimg mdt khu vyc nghien ciru nhung d nh&ng thdi dilm khac nhau. Nhung anh nay Khdng phai Iiic nao cung cd dp phii 100%. Vi vgy, de Iam viec vdi tap hgp anh nay chiing ta Ihudng phai lam cho cac anh chdng kbit len nhau. Anh Radar khi thu nhan cd mdt dac diem la thudng bi lat ngugc theo chilu tren dudi hoac theo chieu trai phai do chinhdactinhthunhan tin hieu ctia bd cam. Dinh vi anh dday chinh la lat lai anh cho dung vdi nguyen trang ciia nd ddng thdi dua anh vl diing he thdng tga dp ciia khu vyc nghien curu. Thdng thudng, khi thu nhan tin hi|u. Radar ciing ddng thdi Iuu tru: ca he quy chilu, tga d^ khung anh ... vi v?y vdi nhung anh Radar do phan giai trung binh khdng cin thiet sii dung DEM cd the djnh vi tga dg mgt each lu dgng thdng qua cac tham sd trong file header cua anh.
Hpi nghi Khoa hqc Dta ly Todn qudc ldn thic 6; Thdnh phd Hui 9/2012
HQl Dia ly yj T^j nguyen Moi truong Thira Thien Hue Hoi Dja ly Viel Nam De giam nhieu, cac phep lgc dugc sir dung. Ddi vdi anh Radar thi phep lgc adaptive filter vdi ciia sd lgc tir 7x7 den 11x11 thich hgp ban ca. Anh cd thi bilu diln dudi dang don sic hoac da phd.
Trong Irudng hgp td hgp miu chiing la cd the lya chgn Id hgp I-2-1 (1: anh trudc kbi xay ra lut, 2: anh sau khi lyt) de lam ndi bat su thay ddi. Neu bilu diln anh don sic, chiing ta cd the doi nd sang dang dB va phan ldp nd theo ngudng dl chiet tach ra cac doi lugng nude.
Hinh 2 Chtel tach thong tin hien trang ngap lut theo ngudng
Hinh 3. Tich hpp thdng tin ngdp lut lin CSDL GIS
Ket qua chiing tdi xay dyng ban do ng^p lul dugc thanh lap tii anh ve tinh phan anh hien trang ngap lut tai mdi thdi dilm chyp anh ciia vg tinh. Tap hgp cac ldp thdng lin ban do ngap lyt theo chudi thdi gian cd ihl phan anh xu hudng diln biln ngap lut theo thdi gian va theo myc nudc dang. Mirc ngap lut d day dugc dinh nghTa la ranh gidl dat - nudc iren anh ve linh tai thdi diem thu nh^n anh trong thdi gian ngap lyt. Ddi vdi anh radar, do dac diem phan xa ciia anh radar vdi ddi tugng mat nudc tuong ddi phang l^ng, gan nhu bi phan xa hoan loan vdi mdt gdc bang gdc tdi ciia sdng radar, nen bd cam radar gan nhu khdng thu nh^n dugc tin hieu tan xa tir mat nudc phang, do vay mat nudc phing trong anh radar cd dp sang sam hon so vdi cac ddi tugng khac. Ddi vdi viing nudc cd ggn sdng thi viec phan tach sS cd nhieu nhieu hon.
DAO TAO DiA LY; PHU'ONG PI I AP VA CONG NG! IE NGI IIEN CUD DIA L Y
Hpi Dja ly vk Tki nguyen Moi tru-ong Thua Thien Hue _ ^ H5i Dja ly Vigt Nam ok phan lach ranh gidi nudc - dal lir cac anh ve linh ndi tren, phuang phap lach lgc theo ngudnii dugc sir dyng. Ngudng phan lach la gia trj so ciia cac phan tii' anh nam d ranh gidi dal va nudc co gia tri s6 nhit dinh nim trong khoang cao hon gia tri sd cua khu vuc ngap nudc va thap hon gia Iri s6 ciia khu vuc khdng ngap. Sau khi da tach theo ngudng, khu vuc hicn trang ngap lyt (lach ra lir ranh gidi nudc - dit) dugc chuyin tir khudn dang raster sang dang vector cap nhat tren GIS va hieu chinh ihco tu lieu khao sat thyc te hoac cac tai ligu dang lin cay khac.
KET LUAN
Viln tham da va dang trd nen mdt phuong phap nghicn cim rat cd higu qua trong quan ly thicn lai bdi nhung uu the vdn cd ciia nd ma nhii'ng ngudn lu lieu va phuong phap nghien ciiu truyen thdng khiing ihe CO dugc.
De phal huy hieu qua cac dir lieu vien tham can phai cd chicn luge nham phd cap kicn thirc din ngudi sir dyng diu cuoi, cy tlie d day la cac dan vi dam nhan cdng lac tai dja phuong, khdng chi dimg lai 6 cac CO quan trung uong nhu hien nay. Dicu thuan lgi la chiing ta da di vao v^n hanh tir nam 2009 Tram thu anh vien tham va dang Irong Id trinh phong ve linh quan trac trai dal VNREDSatl. Cimg vdi do la cac du an, chuong trinh xay dung Trung lam Qudc gia nghien cuu ve cong nghe vu try dy kicn dat lai Hoa Lac (Ha Npi).
Cac ca quan cd chuc nang quan ly Nha nudc ve phdng chdng, li'ng phd Ihien tai va TKCN can lich cue tham gia vao cac dien dan, hgp tac vdi cac td chuc quoc le ve quan ly, giam nhe Ihien tai dc cd the nhan dugc sy hd trg ve ky thuat va nhal la ngudn dir licu anh ve linh gan thdi gian lhuc lai cat ihdi diem xay ra thien lai, tham hoa, Iam co sd cung cap thdng lin kjp thdi hd trg cdng tac TKCN.
danh gia thicl hai va giam sat tai thicl. Trung lam Dich vy ky thuat Cuu hp Ciru nan tryc thupc Cong ty TNHH MTV Trac dja Ban dd/Cyc Ban dd BTTM nam trong he ihdng TKCN cua Bg Qudc phong, ben c?nh la 1 trong 3 ca quan irng dung hang A ciia He thong Giam sat Tai nguyen moi trudng Viijl Nam vdi viec liep nhan dir lieu lir Tram thu anh ve linh. Day cdn la mdt Irong sd il nhirng dau moi cr Viet Nam cd the tiep nhan true tiep hinh anh lir cac ve tinh thdng qua cac dien dan chung ve quan i\
thien tai ctia qudc te nhu International Disaster Charter hay Sentinel Asia mdi khi cd thien tai xay ra.
TAI LIEU THAM KHAO
1. Thii ludng Chinh phii, Quyet dinh sd 172/2007/QD-TTG, Chiin lupc Qudc gia phiing chdng va gidm nhe thien tai den ndm 2020, ngay 16/11/2007.
2. UNDP project DMU VlE/97/002, Chiin luac vd ki hogch hdnh dpng gidm nhe thien tai a Vii-i Nam, m Nol 200\.
3. John.A. Richards (2009/ Remote sensing with imaging radar, Springer.
4. Janssen, 1. I. f. (2004), Principles of remote sensing, ilc education textbook .series, Third edition, enschede, Netherlands.
5. Li Jiren, Ycsou Herve, Huang shifeng, Li Jing, Li Xiufen, Xin Jingfeng, Wang Xingling and Andreoii Remi, Envisat asar medium and high resolution images for near real lime flood monitoring in China during the 2005 flood sea.son. 2006, Dragon symposium "mid-term results".
Santorini, Greece.
6. Qihao Weng Remote sensing and GIS integration: theories, methods, and applications, Mcgraw- hill professional, 2009.
7. Schultz, Gert A (2000), Remote sensing m hydrology and water management.
lldi nghi Khoa hoc Dia ly Todn qudc ldn thu 6; Thdnh phd Hue. 9/20C