TIP dil DIA CHAT loMA .jj^fl u^nnii „ -n.-K
^ r A r ? A ? « 5 ! ^ i ? x ^ ^ ^ ' ™ ^ U DEN S^r PHAT SINH CAC TAI BIEN DIA CHAT NGOAI SINH TAI KHU VlTC
BINHTRI THIEN
DO QUANG THIEN
Trudng Dgi hpc Khoa hoc DgihgcHui. 77NguyinHue. TP Hui
- ^^ nhgn su xudt hif n vd ca cl^ hinh Ihdnh El-Ninn I^hrt^^ ~ i_
^^'t'^^n'vnhiin.dgcbiitldl^.^.l^^ifj'^l^^
dpngcZ7mol!7'''^V'^^'^'^.'^^'^'^
- Di xudt chi sdmua tuang ddi (Z) di vgn dvng phdn cdp vd ddnh gid dnh '««^g<='"'tung chi dp mua ddi vdi cdc tai biin dia chdt ngogi sinh
•^ BAN CHAT, c a CHg HiNH THANH Gan niia tfie ky qua, khi hdu, tfidi tiit ^ °^"* ^'^^ *="* EL-NINO, UV-NINA tten Trai dit biin dii ngay mpt mgnh me Bdn chit, co chi hmh tfianh vd diln va bat tfiuong, do do dd gay ra nhihig hdu bifn hifn tirpng El-Nino vd La-Nina Id qua^ nghiem ttpng vi kinh ti xd hpi d cac tdc nhdn quan tt^ng gdy biin dii khi nhieu nude tten tfii gidi ciing nhu d Vift ^^ vd Idm phdt sinh cdc tiii biin ty nhifn.
Nam. Tir nhung cap nhgt vi cdc kit qud ^ * ^^y- Mdt ttdi Id nguin cung cip n ^ f n ciiu, quan ttic nhiiu ndm ve dien "f^g ' " ^ g *=''° Trdi dit, khi quyin. Id bien vd hdu qua biin dpng di tfiudng cua ^^"^ ^T ' ' ^ ^ * ^ ^ ^^ ''•en dii khi hdu khi hdu Trai dit, da s i cdc nha khoa hpc ^ ^ ^^ ^"^ ^ ^ *"y *"9C vdo vj tti diu cho ring El-Nino, La-Nina la hai hien K ° " ^ ^ ^ ' ^"^ ^'^^' ^ ' ^ * ^ g "^ ^o t«9ng ddc ttung, ding tfidi Id hai tdc nhdn S . ! ^Z ? ? ' "T^^ *fu ^^ "^ ^^^ "^
^ ' , "gay cdng mgnh me vd phiic tgp hon.
Nhdm budc diu nghien ciiu vi sy xuit ^""^g ^' ^o chi vgn dpng, hrong tdc dgi hifn vd ddnh gid dnh hudng ctia hai hifn ''"?P^ " ^ ''"y^" * • * " vyc nhift ddi tirpng ndi tt€n dii vdi cdc tai biin dja chit 1 1 ^ ^ " * Duong cd vai ttd quyit djnh ngogi sinh tii Qudng Bmh din ThitaThien v * cdc d|c diim, chi dp hodn luu khi - Hui, tgp tfii tdc gid dd nghifn ciiu cac ^ ™ u?* '"^^'^ ddng-tay d Thdi Bmh n$i dung dupe ttinh bdy dudi ddv " ' ^ g ' ^ nhu quanh ndm Id noi khi dp cao va CO gid Ddng Bdc hodc gid Ddng (gid Tm phong) 6 Bdc bdn ciu, gid Ddng
73
Nam hodc gid Ddng d Nam ban ciu hogt dpng. Hai luong tin phong d Bdc vd Nam ban cau ndi fr6n ciing hdi ty tgo tfidnh ddi gid Ddng xich dgo tfidi vi phia Tdy Thai Bmh Duong. Su phat triin hodn luu khi quyfn tfieo hudng tii Ddng sang Tdy Thdi Bmh Duong. Dd la tac nhan lam nhift dp khdng khi tdng d khu vuc Tay Thdi Binh Duong va gidm a Ddng Thdi Bmh Duong. That vdy, nhd tdc ddng cua gid Ddng, ddng hdi luu Humbold kdo nude am don ve phia tay, cdn nude lgnh tir cac tang sau dun Ifn (nude tt^i)"vd ttting nhihig ndm khdng cd El-Nino d ngodi khoi Nam My (Ddng Thai Binh Duong) nijdc bifn tirong ddi mdt hon so vdi viing bien nhift ddi Tdy Thdi Binh Duong Thi nhung, vin cd nhihig tfidi khodng biin ding tirong tdc dgi duong - khi quyin xdy ra d khu vyc Ddng Thdi Binh Duong tfieo chieu hudng ngupc Igi vdi biiu hifn khi
ip gidm vd gid Ddng suy yiu, tfi§m chf xudt hifn gid Tin phong tfidi tii tay sang ddng. Do gid Tin phong E)dng-Tfiy suy yeu hodc ddi hudng ma nude ttii suy giam, nude biin ngodi khai Nam My ngay mpt ndng len. Hifn hrpng gid Tin phong Ddng-Tay yiu di hay ddi hudng (Tay-Ddng) vd nude biin d Ddng Th^
Binh Duong ndng Ifn tiong nhiing tfidi dogn nhat djnh la nhimg biiu hifn ciia su xuat hifn El-Nino. Ndi khdc di. El-Nino la hifn tirpng nhift dp nude biin bi mdt khu vyc xich dgo tiimg tdm vd Ddng Thai Binh Duong tdng cao di tfiudng (I 1-3 gOQ so vdi ttung binh kfo dai lifn tyc'tyc'tii 6 den 18 tfidng va xdy ra vdi chu ky 2 -7 ndm. Theo tfidng kf ciia Nguyin Diic r^gtt 11, 2] ttong niia cuii tfii ky XX ttfn vdnh dai nhift ddi vd mpt s i khu vyc on ddi dd xuat hifn 14 dpt El-Nino, ttong dd cd 8 dpt mgnh va rit mgnh (Bdng 1).
Bdng 1. Thd. gian xudt hl^n. dao -«„g „ , , ^ . , « „ , ^ , , , „ ^^^
(Nguyfn Ddc Ngii, 2000) *
NBUOC lai kii- ^ " ^"-Nma mgnh r o XI- 1 • V * '"V"B ni-iNino,
i f - ^ ^ ' ^ ' ^ ^ y ' ^ khi nhift dp nude biin be mdt khu vyc xich dgo ttung tdm vd Bong im Binh Duong hg t h i p ^ i i L thuimg (gidm hi 1.2 - 2''C) dudi nWfVdJ
tu 8 - 22 tfidng (Bdng 1).
thdnh El-Nino, La-Nina dd di d p d ttfn.
"«llll5
a III
lb];
'ffl:-
iititi' taai
%
rd rdng hai hifn hrpng ddi nghich nay Id nau qud ctia su hrong tac khi quyin - dai duong khu vuc xich dgo Thai Binh Duong vd ddng tfidi chiing lai la nguyfn nhan gay ra biin dii khi hdu Trdi dit cimg nhu c ^ tai biin tfiien nhifn d nhiiu noi tten the gidi vd d nude ta.
KHIHAII^'' BIEN COA CAC OAC TRlfNG
Dien bien nghjch hudng vd dj hudng tfieo khdng gian, tfidi gian cua cdc dac tiimg khi hau chu yiu la co so di nhin biet El-Nino, La-Nina. Thyc tien nghiSn ciiu cho tfiiy, ttxing nhimg nam khdng xdy ra El-Nino, La-Nina tfidi tiit van bit tfiudng, tfiifn tai vin phdt smb. Tuy vgy, ttong nhihig dpt El-Nino, La-Nina khi L hju, tfidi tiet thudng biin ddng cue doan H hon, tfiiSn tai xdy ra nhiiu hon va khic
~ lift hon. Ngodi ra, ttxing cdc nude khdc nhau tfiupc mpt khu vyc hay d cdc viing khdc nhau cua m^t nude, tfidm chi mpt thih tdc ding cua El-Nino, La-Nina cimg tfiudng khdng ding diu, ki cd ttai ngupc nhau. Vi vdy, di nhdn biit, ddnh gid, dy bdo cdc hifn hrpng tfidi tiit di tfiudng nay cdc nhd khoa hpc [1, 2, 3, 4] dd tgp ttung nghifn ciiu diln biin mft s i ddc ttimg khi h|u chu yiu nhu Id co sd (tif ii chi) nhdn biet El-Nino, La-Nina dudi ddy:
- El-Nino, La-Nina tdc dpng hodn luu khi quyen, nhat Id gid mua Nam A, E)dng Nam A, bdo vd dp tfiip nhift ddi:
Theo kit qud nghien ciiu cua cdc nhd khi ttrpng [1, 2], ttong nhihig ndm cd El-Nino gid mua miia he tfiudng bit diu mupn, cudng dp yiu hon, nhung Igi kit tfiiic sdm hon so vdi nhiing ndm xdy ra La-Nina. Vdo cdc ndm La-Nina s i lupng bdo, dp tfiip nhift ddi dnh hudng din tfidi tiit nude ta (8,3 con/ndm) nhieu hon rd rft so vdi ndm El-Nino (5,3 con/ndm).
Mdt ddc diem dj tfiudng khdc niia ciia hodn luu khi quyin Id tin s i front lgnh ttong nhihig ndm xuit hifn El-Nuw,
La-Nina tfiudng thip, chiim khoang 70%
cac dpt gid mua Ddng Bdc cua nhihig nam binh thirdng.
Bifn dpng ciia lupng mua do tdc ddng El-Nino, La-Nina:
Ve biin dpng lupng mua, hiu hit cac dpt El-Nino gay ra tfiam hut lupng mua d phan Idn cdc vung trong ca nude [2] tii 25 tdi 50% vd do dd, hgn hdn, mit miia, chdy rung tfiudng xdy ra a nude ta ciing nhu d nhieu nude teen flii gidi nhu da di cap d tim. Tuy vgy, vin cd nhimg bp phdn idnh tfid vdn hgn hdn tfiudc khu vuc ttimg tdm vd Ddng Thdi Bmh Duong (Pf ru, Chi Le, Achentina v.v..) Igi xdy ra mua Iu Idn gay tdn tfiat vf ngudi vd cua ttong cdc dpt El-Nino manh 1982-1983,1997-1998.
,Ngodi ra, tfieo kit qua tfiong ke diln bifn mua trong cdc ndm La-Nina d Austtalia cd tdi 71 % difn ti'ch Idnh tfid phia Ddng nude ndy cd lupng mua vupt teung binh ndm so vdi 63 % difn ttch cd lupng mua dudi miic ttimg binh ndm ctia cdc ndm El-Nuio.
IV. CHl S6 MlfA TUXTNG B 6 | U CO
%9.J'l!^ *=/''• °^" GIA ANH HifdNG CUA CHe DO MU-A D 6 | Vtfl TAI BI^N DIA
CHAT NGOAI SINH
- Chi so mua hrong dii (7^) nhu Id tieu chi ddnh gid, dy bdo El-Nmo, La-Nuia:
Tu nhiing din lifu tiinh bdy d tten, dl ddng nhdn tfiiy El-Nino, La-Nina Id hai tdc nhan ^ y biin ddi khi hdu, tfidi tiit trfn Trdi dit, ddc bift d vdnh dai nhift ddi Thai Bmh Duong. Tuy chung dupe phdn bift bdng ddc diim biin dii cdc ddc himg khi hau chu yiu nhu khi dp, niuft dd, lupng inua vao nhung tfidi dogn nhit djnh tgi nhifu khu vyc khdc nhau tfiuOc xich dgo •Thdi Bmh Duong, nhung chinh cac yeu tt) khi hdu ddc ttimg ndy Id CO sd khoa hpc de cdc nhd khi hrpng phdn bift EI-Nuio vdi U-Nina, phdt hifn vd xdc
75
djnh su xuat hien, tfidi gian va cudng dp hogt dpng cua chting ttfn nhihig Idnh flid n ^ f n ciiu nhat djnh. Tuy vdy, ngodi yiu to khi dp, nhift dp ciia nude biin va khdng khi, cdc nha nghien ciiu [3, 4] vin cdn chua xem yiu td mua nhu la mpt tieu chi quan ttpng ttong danh gid, dy bao hai hien tirpng cua El-Nmo, La-Nina.
De bi sung tieu chi ddnh gid, du bao tac ddng cua El-Nmo, La-Nina dii vdi bien ddi khi hdu, tfidi tiit vd su phdt sinh tai bien dja chit ngogi sinh, tac gid di nghj van dyng chi s i mua tirong dii 7^.
Do Id ty s i gi&a lupng mua hang ndm vdi lupng mua ttimg bmh nhiiu ndm d cac t i ^ do mua phdn bi ben cdc bp phdn khdc nhau ctia khu vyc nghiSn ciiu va dupe bieu hifn tfieo cdng tfiiic dudi ddy
Xi lupng mua hdng ndm (mm); A' lupng mua ttung bmh hdng ndm (mm).
- i n , ^ ."*" ^•'"°' s^ ' ' ? " mua (1961- 2011) tgi 7 ttgm do mua ddc ttung d tinh
Bdng 2. Chi . 6 7 : trung binh, ch6ao
Che do mua
Quang Biitfi [5], tdc gid tiin hdnh xdc djnh chi s i mua tirong dii ttimg binh hdng ndm vd dupe trinh bay d Bdng 2.
- Sii dyng chi s i mua hrong doi danh gid, dy bdo El-Nino, La-Nina va phan cap, ddnh gid che dp mua doi vdi tai biin dja chat ngogi sinh:
Theo tfiyc tiin danh gid dy bdo mua thai g^ian qua, cac nhd khi hrpng phdn ra ba che dp mua: chf dp mua it, chi d$ mua vua (ttung binh), chi d^ mua nhifu. Cdch phan chia chf dp mua ndy viia chua dua vao CO sd Idioa hpc ro rdng nao, viia khong xet den sy bien dpng phiic tgp ciia che dp mua ttong dieu kifn biin dii khi hgu ngdy mOt gia tdng hifn nay. Vi vdy chi so mua tuong ddi chinh Id tifu chi cQ dupe vdn dyng ttong danh gid, dy bdo El- Nino, La-Nina ciing nhu phan cip, ddnh gia dnh hudng chf dp mua dii vdi cdc qud tiinh dja chat ngoai sinh. Nhu dd di cdp d h-eii d nhimg khu vyc chju tdc dpng ciia bl-Nmo, La-Nina, lupng mua ttung binh hang ndm tfiudng rat tfiap khi cd El-Nino vd rat cao khi La-Nina xuit hifn.
mu-a vd hogt d^ng El-Nino, La-Nlna
NNino. La-Nina~
Thi gidi,
1982 1983 1984 1985 1986 1%I 1962 1963 1964 1%5 1966 1967 1968 1969 _I970^
1971 1972 1973 1974 1975 1976 1977^
1978 [979 1980"
i98r 1982"
1983 1984 1985 1986
- M L -ML JJA_
1.05 1.09 0,96 0.93 1,40 0.92 1.01 1.22 0.97 0.70
JM
1.07 I 0.99 1.04 0.86 1.02 0.82 0.85 1.39 0.94 1.12 1.16
J-OL
I J 6 1,01 1.14 1,05
mua \ira mua nhieu mua vifa mua nhieu
nma qui nhieu mua vua mua nhieu
mua viia mua qui it
mua it mua it nua quA n h i ^
mua vira mua nhieu
mua \'ira mua nhieu
mua ^Tja mua nhieu mua vira
El-NiDa
l.a-Nina
El-Nino
La-Nina
El-Nino La-Nina El-Nino La-Nina El-Nino La-Nina El-Nino La-Nina
La-Nina El-Nino El-Nino
El-Nino 2008 2009 2010 2011 1987 1988 1989 1990 1991 1992 1993 1994 1995 19%
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
1.05 1,03 1.20 1,18 1,05 0,80
146 1 3 1,19
1,12 0.90 1.86 1.26 1.25 0.79 0.90 1,14 0,89 0.89 0,86 0.68 0.89 1.00 0.91 1.17 1.05
1.18
mua vifa inna vilra imnnfaieu mua nhieu
nwa it
pgniquanlufai mua nhieu
nan it muaqjihieu
mua ft mua nhieu
mua ft
mua qui it mua it mua\ifa mua nhieu
mua vira mua vira mua viia mua nhieu mua nhieu
Lfr^ina
La-Nina
El-Nino
El-Nino La-Nina
El-Nino El-Nino
El-Nino La-Nina
Bdng 3. Phdn d p ch^ a» mtra theo chi s6 mu^ ndm Ufpng d6i 72 Khodng bien tfiien L
L <0,75 0,75 < / „ <0,9I 0,92 < /„<1,08 1,09 < /„<1,25
t. > US
Che dp mua Che dp mua qua it
Che dp mua it
Che dp mua viia (bimg binh) Che dp mua nhieu
Mdt Wide, ddi sdnh cdc gid tti chi sd mua ttrong dii d lanh tfii nghien ciiu ctia cac ndm chju dnh hudng hai hifn tiipng tten xdy ra tten th£gidi vd 6 Vift Nam <& dang phdt hifn /,,ciia nhflng ndm El-Nino tfiudng thip hon 0,75, cdn nhihig ndm cd La-Nina hogt dpng thi Idn hon ^ > 1,25.
Tu nhtfaig ludn cu vita din, chi s i mua ndm tirong dii /„ <0,75 se iing vdi ndm
Che dp mua qua nhiiu hay che dp mua nhieu dj tfiuong chiu tac ddng El-Nuio vd 7^ > 1,25 hrong ling vdi ndm cd La-Nina xuit hifn.
Giiia hai gidi hgn tten, dua vdo ! ^ cd tfii phan tfidnh 3 cip chi dp mua trung gian vdi tf n gpi khac nhau nhu ttinh bay tren Bdng 3.
V.K£TLUAN
Tir nhihig ludn gidi trinh bdy d ttfn CO tiie nit ra mpt sd kit ludn budc diu dudi ddy:
77
- Hai hifn tirpng tfidi tiit eye doan dii nghich El-Nino va La-Nina tdc dpng chua tfiat mgnh m6 d khu vyc nghifn ciiu.
Trong Ichodng tfidi gian 50 ndm, tien tfii gitji, kf ca Vift Nam da xuit hifn 12 dot El-Nino vd 8 dot La-Nina, tiong dd d Qudng Bmh chi mdi xdy ra 2 dot El-Nino vd 4 dpt La-Nma.
- Chi sd mua nam tuang dii ^ cd thi sii dyng nhu Id tifu chi khoa hpc di phan djnh El-Nino, La-Nina ciing nhu phdn cap, ddnh gid chi dp mua tixing sy hinh tfidnh, phdt tiiin cdc tai biin dia chit ngogi sinh.
Nguy CO phdt sinh tai biin tfiien nhien, tai bien dja chit ngogi sinh cd quan hf chdt che vdi chi dp mua: chi dp mua it vd qud it (tiling vdi ndm El-Nino) rit cd nguy CO gdy ra hgn hdn, chdy rimg, sa mgc hda, cdt bay; che dp mua nhiiu vd qud nhieu (cd La-Nma xuit hifn) tgo diiu kifn gay ra m lyt. IQ quet. tiirpt Id dit dd.
xdi Id - bii ty sdng ngdi, cdt ti^i phdt sinh vd phdt tiiin.
VAN L i f u
1. Glantz M., 1997. Examines tfie El- Nino phenomenon and discusses suggestion tiiat recent events may be related to global warning. Our planet UNEP. vol9, No 3.
2. Nguyin Dire Ngii, 2000. Nhimg difu cdn biet vf El-Nino vd La-Nina. Nxb Khoa hpc vd Ky thugt. Hd Npi.
3. Nguyin Dire Ngii, Nguyin Trung Hifu, 2004. Khi hau vd tai nguyfn khi hdu Vift Nam. Nxb NN. Hd Ndi
4. U Nguyen Tu*ng, 1998. Thir nghifm ddnh gid kha ndng anh hudng cua ENSO den lupng mua d nude ta. Tdp san KTTV. HdNdi
5. UBND tinh Quang Binh, 2007.
Thu tiidp vd qudn ly s i lieu khi hrpng - thiiy vdn tinh Qudng Binh tir 1956 - 2005.
SUMMARY
Impacts of Climate chanfle causing exogenous geohazards m Bmh Trj Thidn Region
T«„i fi .1. «• Od Quang Thifn
- Clarifying tfie abnormal changes of tfie main r-ii^of u • '.
mipacts ofEl-Nino, La-Nina as tfie criterilfi^^iTf-A 1^ characteristics due to the area. ^ "'''"^"'^"^ ^"-^ "^^"tifying tfiese phenomena in tfie shidy
- Proposing tfie relative rainfall index r F ^ t„ i,» . AC , ..
Nguai bien tdp: TS. Phimg Vdn Phdch.