1. B TI NGUYN V MI TRNG KCH BN BIN I KH HU,NC BIN DNG CHO VIT NAM H NI, 2011

2. MC LC TrangMC LC .................................................................................................................... 2LI GII THIU.......................................................................................................... 3DANH MC CC CH VIT TT............................................................................... 4CC THUT NG CHNH .......................................................................................... 6DANH MC BNG .................................................................................................... 10DANH MC HNH ..................................................................................................... 11TM TT KCH BN BIN I KH HU, NC BIN DNG CHO VIT NAM VNHNG IM MI C BN .................................................................................... 151. BIU HIN CA BIN I KH HU, NC BIN DNG .................................. 171.1. Biu hin ca bin i kh hu, nc bin dng trn th gii ............................ 171.2. Biu hin ca bin i kh hu, nc bin dng Vit Nam ............................. 212. PHNG PHP XY DNG KCH BN BIN I KH HU, NC BINDNG CHO VIT NAM ............................................................................................. 262.1. Yu cu cp nht kch bn bin i kh hu, nc bin dng cho Vit Nam ..... 262.2. La chn kch bn pht thi kh nh knh ........................................................... 262.3. La chn phng php xy dng kch bn bin i kh hu, nc bin dng choVit Nam.................................................................................................................... 282.4. Mt s lu v cc kch bn bin i kh hu, nc bin dng v bn nguyc ngp ..................................................................................................................... 383. KCH BN BIN I KH HU, NC BIN DNG CHO VIT NAM................. 403.1. Kch bn bin i kh hu i vi nhit .......................................................... 403.2. Kch bn bin i kh hu i vi lng ma ..................................................... 563.3. Kch bn bin i kh hu i vi kh p v m ............................................. 703.4. Kch bn nc bin dng cho Vit Nam ............................................................. 714. NGUY C NGP THEO CC MC NC BIN DNG .................................... 74KT LUN V KHUYN NGH ................................................................................. 96TI LIU THAM KHO ............................................................................................. 98PH LC................................................................................................................. 103Kch bn bin i kh hu, nc bin dng cho Vit Nam2 3. B TI NGUYN V MI TRNG LI GII THIU Bin i kh hu ang din ra quy m ton cu, khu vc v Vit Nam do cc hot ng ca con ngi lm pht thi qu mc kh nh knh vo bu kh quyn. Bin i kh hu c nhng tc ng tiu cc i vi con ngi, kinh t - x hi v mi trng. Vn bin i kh hu , ang v s lm thay i ton din v su sc qu trnh pht trin v an ninh ton cu nh lng thc, nc, nng lng, an ton x hi, chnh tr, vn ha, kinh t, ngoi giao v thng mi.L mt trong nhng nc chu tc ng nng n nhtca bin i kh hu, Vit Nam coi ng ph vi bin i khhu l vn c ngha sng cn. ng ph hiu quvi bin i kh hu, nhng hiu bit v kh hu trong tng lai thng qua cc kchbn bin i kh hu l rt cn thit. Trong nm 2009, da trn c s tng hp cc nghin cu trong v ngoinc, B Ti nguyn v Mi trng xy dng v cng b kch bn bin i khhu, nc bin dng cho Vit Nam. Cc kch bn bin i kh hu, nc bin dng to c s cho cc B, ngnh, a phng nh gi tc ng ca bin i kh hu,xy dng v trin khai k hoch hnh ng ng ph. Thc hin ch o ca Chnh ph v vic cp nht v chi tit ha cc kch bnbin i kh hu v nc bin dng cho Vit Nam, B Ti nguyn v Mi trng giaoVin Khoa hc Kh tng Thy vn v Mi trng ch tr, phi hp vi cc c quannghin cu v cc n v qun l nh nc, tnh ton chi tit ha mc thay ica cc yu t kh hu, tp trung vo cc yu t chnh l nhit , ch ma, ncbin dng cho cc a phng v cc khu vc ven bin Vit Nam. Cc tnh tonc da trn kt qu phm vi ton cu ca Ban lin chnh ph v bin i khhu v cc iu kin kh hu c th ca Vit Nam v c trnh by trong bo co"Kch bn bin i kh hu, nc bin dng cho Vit Nam".B Ti nguyn v Mi trng trn trng gii thiu Kch bn bin i kh hu,nc bin dng cho Vit Nam lm c s nh hng cho cc b, ngnh, aphng nh gi tc ng tim tng ca bin i kh hu, xy dng v trin khai khoch ng ph hiu qu vi bin i kh hu, nc bin dng. Nguyn Minh Quang B trng B Ti nguyn v Mi trngKch bn bin i kh hu, nc bin dng cho Vit Nam 3 4. B TI NGUYN V MI TRNGDANH MC CC CH VIT TTAR4Bo co nh gi ln th t ca IPCC v bin i kh hu (Four Assessment Report)BKH Bin i kh huCRUS liu ti phn tch ton cu vi phn gii 0,5 x 0,5 kinh v (Climate Research Unit)DBHD D bo hn diDEMM hnh s cao, M (USGS Digital Elevation Model)TDB i tng d boERA40S liu ti phn tch ton cu vi phn gii 2,5 x 2,5 kinh v ca Trung tm D bo thi tit hn va, Chu u.FARBo co nh gi ln th nht ca IPCC v bin i kh hu (First Assessment Report)GCMM hnh hon lu chung (General Circulation Model)GISH thng thng tin a l (Geographic Information System)IMHENVin Khoa hc Kh tng Thy vn v Mi trng (Vietnam Institute of Meteorology, Hydrology and Environment)IPCC Ban Lin Chnh ph v bin i kh hu (Intergovernmental Panel on Climate Change)JAMSTECCc Cng ngh v Khoa hc Tri t i dng, Nht Bn (Japan Agency for Marine-Earth Science and Technology)JMACc Kh tng Nht Bn (Japan Meteorological Administration)KNKKh nh knhMAGICC/Phn mm t hp cc kch bn pht thi kh nh knh (Model for the Assessment of Greenhouse-gas Induced Climate Change/ RegionalSCENGEN Climate SCENario GENerator)MOSThng k u ra ca m hnh (Model Output Statistics)MRI/AGCM Vin Nghin cu Kh tng Nht Bn (Meteorology Research Institute)/M hnh hon lu chung kh quyn (Atmosphere General Circulation Model)NCAR Trung tm Nghin cu Kh quyn Quc gia, Hoa K (The National Center for Atmospheric Research)NOAA C quan i dng v Kh quyn Quc gia, Hoa K (National OceanicKch bn bin i kh hu, nc bin dng cho Vit Nam4 5. B TI NGUYN V MI TRNG and Atmospheric Administration)NTDB Nhn t d boPCMDIChng trnh chun on m hnh kh hu v so snh ln nhau (Program for Climate Model Diagnosis and Intercomparison)PP Phng php s dng s liu "phn tch li" kt hp vi s liu quan trc tng ng thit lp m hnh (Perfect Prognosis)PRECIS M hnh kh hu khu vc ca Trung tm Hadley, Vng quc Anh (Providing Climate Information for Impact Study)SD Chi tit ha thng k (Statistical Downscaling)SDSM M hnh chi tit ha thng k (Statistical Downscaling Model)SIMCLIMH thng m hnh tch hp nh gi tc ng v thch ng vi bin i kh hu (The Simulator of Climate Change Risks and Adaptation Initiatives)SLRRPChng trnh ci tin d bo mc nc bin dng (The Sea Level Rise Rectification Program)TARBo co nh gi ln th ba ca IPCC (Third Assessment Report)TNMT Ti nguyn v Mi trngWMOT chc Kh tng th gii (World Meteorological Organization)XTN Xoy thun nhit iKch bn bin i kh hu, nc bin dng cho Vit Nam5 6. B TI NGUYN V MI TRNGCC THUT NG CHNH Ban lin Chnh ph v bin i kh hu Intergovernmental Panel onClimate Change (IPCC): IPCC l t chc quc t hng u v nh gi BKH do Tchc Kh tng Th gii (WMO) v Chng trnh Mi trng Lin Hip Quc(UNEP) thnh lp nm 1988. L t chc khoa hc Lin Chnh ph ca tt c ccnc l thnh vin ca Lin Hip Quc v T chc Kh tng Th gii. Bng quyn - Cryosphere: Cc khi bng v tuyt (trn t lin v bin) catri t. Bin ngy ca nhit - Daily (Diurnal) Range of Temperatures: Phmvi bin i ca nhit trong vng 24 gi. Bin i kh hu - Climate Change: S thay i ca kh hu (nh ngha caCng c kh hu) c quy trc tip hay gin tip l do hot ng ca con ngilm thay i thnh phn ca kh quyn ton cu v ng gp thm vo s bin ngkh hu t nhin trong cc thi gian c th so snh c. Bin i kh hu xc nhs khc bit gia cc gi tr trung bnh di hn ca mt tham s hay thng k khhu. Trong , trung bnh c thc hin trong mt khong thi gian xc nh,thng l vi thp k. Chun (kh hu) - Normals (Climate): Trung bnh ca thi k, tnh cho mtthi k nh nhau l 30 nm Chun sai kh hu - Climatic Anomaly: (1) lch ca gi tr mt yu t khhu so vi gi tr trung bnh ca n; (2) S khc bit gia gi tr ca mt yu t khhu mt ni v gi tr trung bnh ca yu t ly theo vng v tuyn i qua ni . Chu trnh cacbon - Carbon Cycle: Cc qu trnh t nhin chi phi s trao iccbon (di dng CO2, ccbnt v cc hp cht hu c v.v...) trong kh quyn, idng v tri t. Cng c Khung ca Lin Hip Quc v Bin i kh hu - UNFramework Convention on Climate Change (UNFCCC): Thng gi tt l Cngc kh hu, c hn 150 nc k ti Hi ngh Thng nh tri t Rio deJaneiro nm 1992. Mc tiu cui cng ca Cng c l n nh nng kh nhknh trong kh quyn mc c th ngn nga c s can thip nguy him ca conngi vo h thng kh hu. Cng bc bc x - Radiative Forcing: S thay i trong cn cn bc xca tri t gia bc x ti ca mt tri v bc x i ca tri t di dng bc xhng ngoi v sng ngn. Nu khng c cng bc bc x, bc x mt tri ctri t hp th s gn bng bc x hng ngoi pht ra t tri t. Vic c thm khnh knh hp th thm mt phn bc x hng ngoi trong kh quyn, bc x trli tri t, to ra nh hng gy nng ln ton cu. Dao ng kh hu - Climatic Fluctuation: Bin ng kh hu gm bt kdng thay i c tnh h thng no, d thng xuyn hay khng thng xuyn, trcc xu th v bt lin tc (thay i t ngt trong mt giai on, t gi tr trung bnhny sang gi tr trung bnh khc). c trng bng t nht hai cc i (hay cc tiu) vmt cc tiu (hay cc i), gm c hai u chui s liu. ixit cacbon hay CO2 - Carbon Dioxit: Mt cht kh trong t nhin, cng lmt sn phm ph ca vic t cc nhin liu ha thch v sinh khi, cng nh ccKch bn bin i kh hu, nc bin dng cho Vit Nam6 7. B TI NGUYN V MI TRNGqu trnh thay i s dng t v cc qu trnh cng nghip khc. l cht kh nhknh ch yu do con ngi sinh ra, nh hng n nhit tri t. N l cht khtham chiu tnh tim nng nng ln ton cu ca cc kh nh knh khc. CO2chim gn 0,036% kh quyn. Gin n nhit ca cc i dng - Thermal Expansion of the Oceans: Vikhi lng khng i, th tch cc i dng v mc nc bin thay i theo mt ca nc bin. Mt c quan h ngc vi nhit , do , khi cc i dng mln, mt gim v cc i dng gin n. Thay i v mn khu vc nh cnglm thay i mt v th tch nc bin, tuy nhin tc ng ny tng i nh trnquy m ton cu. Hn - Drought: Mt hin tng t nhin xy ra khi lng ging thy dimc trung bnh nhiu nm, khin mc nc h thp v cy ci cht. Hn gy nhngtn tht cho cng ng (tn tht ma mng, thiu cung cp nc). H thng kh hu - Climate System: Ton b kh quyn, thy quyn, bngquyn, sinh quyn v thch quyn cng cc tng tc ca chng th hin cc iukin trung bnh v cc tr ca kh quyn trong mt thi k di ti mt khu vc ca bmt tri t. Hiu ng nh knh - Greenhouse Effect: Hiu qu gi nhit tng thp cakh quyn nh s hp th v pht x tr li bc x sng di t mt t bi my vcc kh nh hi nc, ccbon ixit, nit xit, m tan v chlorofluorocacrbon, lmgim lng nhit thot ra khng trung t h thng tri t, gi nhit mt cch tnhin, duy tr nhit tri t cao hn khong 30 oC so vi khi khng c cc cht kh. Hon lu chung ca kh quyn - General Circulation of the Atmosphere:H thng trung bnh ton cu ca gi v cc h thng thi tit km theo. S chuynng ca khng kh gy nn bi s t nng khc nhau trn b mt tri t v khquyn v do tri t quay, vi cc khc bit v a hnh gy nn cc bin i aphng. Hi tip kh hu - Climate Feedbacks: S tng tc gia cc kh nh knhv nhng c ch kh hu quan trng nh lp thc vt, hi nc, lp bng, my vi dng. Cc tng tc c th lm tng, gim hoc trung ha s m ln dotng nng cc kh nh knh. Kh hu - Climate: Tng hp ca thi tit c c trng bi cc tr s thngk di hn (trung bnh, xc sut cc cc tr v.v...) ca cc yu t kh tng bin ngtrong mt khu vc a l. Thi k tnh trung bnh thng l vi thp k. Theo nhngha ca WMO: Tng hp cc iu kin thi tit mt khu vc nht nh c trngbi cc thng k di hn cc bin s ca trng thi kh quyn khu vc . Kh nh knh - Greenhouse Gases (GHGs): Cc kh nh knh (KNK) lmgim lng bc x ca tri t thot ra v tr, do lm nng tng bn di khquyn v b mt tri t. Kh quyn - Atmotsphere: Lp kh bao quanh tri t v b gi y do lchp dn ca tri t. Kh quyn c chia thnh nhiu tng: tng i lu (t mt tn khong 8 17 km); tng bnh lu (ln n 50 km); tng gia (50 90 km) vtng nhit to thnh vng chuyn tip ra v tr. S pha trn gia cc tng l ccchm.Kch bn bin i kh hu, nc bin dng cho Vit Nam 7 8. B TI NGUYN V MI TRNGKch bn bin i kh hu - Climate Change Scenario: L gi nh c c skhoa hc v tnh tin cy v s tin trin trong tng lai ca cc mi quan h giakinh t - x hi, GDP, pht thi kh nh knh, bin i kh hu v mc nc bindng. Lu rng, kch bn bin i kh hu khc vi d bo thi tit v d bo khhu l n a ra quan im v mi rng buc gia pht trin v hnh ng.Mtan - Methane (CH4) : Mt trong su kh nh knh c kim sot bi Nghnh th Kyoto. N c thi gian sng trong kh quyn tng i ngn: 10 2 nm.Cc ngun kh mtan ch yu l bi rc thi, m than, rung la, cc h thng kh tnhin v sc vt nui. c tnh tim nng lm nng ln ton cu (GWP) ca mtanl 21 trong vng 100 nm ti.M hnh hon lu chung- General Circulation Model (GCM): Mt cng ccn bn nghin cu tc ng ca s tng nng kh nh knh i vi kh hu.GCM c bn l mt m hnh thy ng lc ca kh quyn trn mt li im hayphn gii ph, qua cc phng trnh khi lng, nng lng v ng lng chokh quyn v i dng c tch phn vi nhau theo thi gian, trn mt khu vcca a cu m phng s vn ng ca h thng i dng - kh quyn thc.Nhn t kh hu - Climatic Factors: Cc iu kin vt l nht nh (khc viyu t kh hu) iu chnh kh hu (v , cao, s phn b t, bin, a hnh, ccdng chy i dng v.v...).Nhin liu ha thch - Fossil Fuels: Than, du, xng v kh t nhin cngcc hydrocacbon khc c gi l nhin liu ha thch v chng c to ra t ccxc thc vt v ng vt giu cacbon ha thch. Cc xc c chn trong cclp trm tch v nn qua thi k a cht, dn dn chuyn thnh nhin liu.Nhit cc tr - Extreme Temperatures: Nhit cao nht v thp nhtt c trong thi gian nht nh.Nng ln ton cu - Global Warming: Ni mt cch cht ch, s nng ln vlnh i ton cu l cc xu th nng ln v lnh i t nhin m tri t tri qua trongsut lch s ca n. Tuy nhin, thut ng ny thng ch s tng dn nhit trit do cc cht kh nh knh tch t trong kh quyn.Nc bin dng - Sea Level Rise: L s dng ln ca mc nc ca idng trn ton cu, trong khng bao gm triu, nc dng do bo... Nc bindng ti mt v tr no c th cao hn hoc thp hn so vi trung bnh ton cu vc s khc nhau v nhit ca i dng v cc yu t khc.xit nit - Nitrous Oxide (N2O): Mt trong su kh nh knh c kim sotbi Ngh nh th Kyoto, pht sinh t vic t cc nhin liu ha thch v ch tophn bn. N c tim nng lm nng ln ton cu (GWP) l 310 trong vng 100 nmti.Pht thi - Emissions: (nh ngha ca Cng c kh hu). S thi cc khnh knh v/hoc cc tin t ca chng vo kh quyn trn mt khu vc v thi gianc th.Sinh quyn - Biosphere: B phn ca tri t v kh quyn ca n, trong cc sinh vt sng. B cha chu trnh cacbon ton cu, trong cha cc sinh vtsng (thc vt v ng vt v vt cht hu c t s sng (rc v mn)). Sinh quyntri t gm h sinh vt (thc vt v ng vt), rc v vt cht hu c trong t trnlc a v sinh quyn bin gm h sinh vt v mn i dng.Kch bn bin i kh hu, nc bin dng cho Vit Nam8 9. B TI NGUYN V MI TRNG Sol kh - Aerosols: L cc ht rt nh gy ra hin tng m. Chng phn lnl nc v cc ht cht nhim nh axit sulphua v mui bin. Sol kh trong tng ilu thng c ging thy qut i. Cc sol kh c mang ln tng bnh luthng lu hn nhiu. Sol kh tng bnh lu ch yu l cc ht sunphat tcc v ni la phun, c th lm gim ng k bc x mt tri. Thch quyn - Lithosphere: Lp bn trn (thuc i dng v lc a) caphn tri t rn, gm ton b v tri t v phn cng, dn ca v trn cngca tri t. dy ca n thay i t 1 n 2 km dy sng ni gia i dng,nhng dn dn tng t 60km gn sng ni ti 120 140 km bn di v idng c tui cao hn. Thi tit Weather: Thi tit l trng thi kh quyn ti mt a im nhtnh c xc nh bng t hp cc yu t: nhit , p sut, m, tc gi,ma, Thy quyn - Hydrosphere: Phn ca tri t bao gm nc, l idng, bin, bng, h, sng v.v... T chc Kh tng Th gii - World Meteorological Organization (WMO):Mt c quan chuyn mn ca Lin Hip Quc, hin c 160 nc v vng lnh ththnh vin. Trm kh hu - Climatological Station: Mt trm thc hin cc quan trc khhu. Trung bnh chun kh hu - Climatolgical Standard Normals: Tr s trungbnh ca s liu kh hu tnh cho tng thi k 30 nm k tip nhau: 01 thng 01 nm1901 n 31 thng 12 nm 1930, 01 thng 01 nm 1931 n 31 thng 12 nm 1960,01 thng 01 nm 1961 n 31 thng 12 nm 1990. Tng tc kh quyn/i dng - Atmosphere/Ocean Interactions: Ngita mi ch hiu mt phn ng lc hc ca cc tng tc kh quyn - i dng vcn tnh n cc mi lin h gia cc lp trn v di ca i dng, khi cn hiu tv cc lin h ny. Tuy nhin, tng tc kh quyn - i dng t ra l nhn t quantrng i vi cc bin thin kh hu vi mi quy m thi gian, v c nhng biu hinr rng v mi lin quan ca n vi nhng bin i theo quy m thi gian vi nm. Xu th kh hu - Climatic Trend: S bin i kh hu c c trng bngvic tng hay gim n iu v trn tru ca gi tr trung bnh trong thi k chui sliu. Khng ch gii hn s thay i tuyn tnh theo thi gian, m c trng bngch mt cc i v mt cc tiu cc u, cui chui s liu. Yu t kh hu - Climatic Element: Mt trong nhng tnh cht hay iu kinca kh quyn (nh nhit khng kh) c trng cho trng thi vt l ca thi tithay kh hu ti mt ni, vo mt khong thi gian nht nh.Kch bn bin i kh hu, nc bin dng cho Vit Nam 9 10. B TI NGUYN V MI TRNGDANH MC BNGBng 1.1. Mc tng nhit v mc thay i lng ma trong 50 nm qua ccvng kh hu ca Vit Nam ........................................................................................23Bng 2.1. Cc h thng m hnh c tham kho trong xy dng kch bn nc bindng cho Vit Nam .....................................................................................................35Bng 3.1. Mc tng nhit (oC) trung bnh nm so vi thi k 1980-1999 theo kchbn pht thi trung bnh (B2) ......................................................................................55Bng 3.2. Mc thay i (%) lng ma nm so vi thi k 1980-1999 theo kch bnpht thi trung bnh (B2) .............................................................................................69Bng 3.3. Mc thay i lng ma ngy ln nht (%) vo cui th k 21 so vi thik 1980-1999..............................................................................................................70Bng 3.4. Mc nc bin dng theo kch bn pht thi thp (cm) .............................71Bng 3.5. Mc nc bin dng theo kch bn pht thi trung bnh (cm) ...................72Bng 3.6. Mc nc bin dng theo kch bn pht thi cao (cm) ..............................72Bng 4.1. Din tch c nguy c b ngp theo cc mc nc bin dng (% din tch) ....74Bng 4.2. T l chiu di quc l c nguy c b nh hng theo cc mc nc bindng (%) .....................................................................................................................74Bng 4.3. T l chiu di tnh l c nguy c b nh hng theo cc mc nc bin dng(%) ..............................................................................................................................75Bng 4.4. T l chiu di ng st c nguy c b nh hng theo cc mc nc bindng (%) .....................................................................................................................76Bng 4.5. T l s dn c nguy c b nh hng trc tip (so vi tng dn s vng)theo cc mc nc bin dng (%) .............................................................................76Kch bn bin i kh hu, nc bin dng cho Vit Nam10 11. B TI NGUYN V MI TRNGDANH MC HNHHnh 1.1. Din bin chun sai nhit trung bnh ton cu ...................................... 17Hnh 1.2. Din bin nhit quy m ton cu v khu vc ..................................... 18Hnh 1.3. Chun sai nhit ton cu thng 6 nm 2010 so vi thi k 1971 2000.................................................................................................................................. 18Hnh 1.4. Din bin lng ma nm cc vng khc nhau trn th gii ................. 19Hnh 1.5. Bin ng mc nc bin trung bnh ton cu ......................................... 19Hnh 1.6. Xu th bin ng mc nc bin trung bnh ti cc trm quan trc ncbin trn ton cu...................................................................................................... 20Hnh 1.7. Xu th bin ng mc nc bin trung bnh ton cu t s liu v tinh ... 21Hnh 1.8. Xu th mc nc bin trung bnh ton cu theo s liu v tinh ................ 21Hnh 1.9. Mc tng nhit trung bnh nm (oC) trong 50 nm qua ......................... 22Hnh 1.10. Mc thay i lng ma nm (%) trong 50 nm qua .............................. 22Hnh 1.11. Bn tn sut XTN hot ng (a), hnh thnh Bin ng (b) v nhhng n t lin Vit Nam (c) ............................................................................... 24Hnh 1.12. Din bin ca s cn xoy thun nhit i hot ng Bin ng, nhhng v b vo t lin Vit Nam trong 50 nm qua ......................................... 24Hnh 1.13. Din bin mc nc bin theo s liu cc trm thc o ......................... 25Hnh 1.14. Din bin mc nc bin theo s liu v tinh (1993-2010) ..................... 25Hnh 1.15. So snh mc nc bin t s liu ti trm hi vn v v tinh ................. 25Hnh 2.1. S tnh ton pht thi kh nh knh theo cc kch bn v mc tng nhit trung bnh ton cu .............................................................................................. 28Hnh 2.2. Giao din ca phn mm SDSM ............................................................... 28Hnh 2.3. Giao din ca phn mm SIMCLIM ........................................................... 29Hnh 2.4. S xy dng hm chuyn theo phng php PP v MOS .................. 30Hnh 2.5. H thng M phng tri t v kch bn BKH ca m hnh AGCM/MRI .. 31Hnh 2.6. S tnh v min tnh ca m hnh PRECIS ........................................... 32Hnh 2.7. Cc qu trnh vt l c xt n trong m hnh PRECIS ........................ 32Hnh 2.8. Phng php tnh v kch bn nc bin dng ca Rahmstorf, 2007 ...... 33Hnh 2.9. Kch bn mc nc bin dng nm 2100 quy m ton cu (NCAR) ..... 34Hnh 2.10. Mt kch bn nc bin dng theo phng php ca Doyle ................... 34Hnh 2.11. Phng php chi tit ha thng k cho mc nc bin dng ................. 34Hnh 2.12. Mc nc bin dng cui th k 21 theo kch bn trung bnh ca cc mhnh s tr................................................................................................................... 36Hnh 2.13. So snh kch bn mc nc bin dng (IPCC) v s liu o c ............ 36Hnh 2.14. Mc nc bin dng cui th k XXI t cc nghin cu khc nhau ....... 36Hnh 2.15. Kch bn mc nc bin ton cu theo cc kch bn pht thi ............... 36Hnh 3.1. Mc tng nhit trung bnh ma ng (oC) vo cui th k 21 theo kchbn pht thi thp...................................................................................................... 40Hnh 3.2. Mc tng nhit trung bnh ma ng (oC) vo gia th k 21 theo kchbn pht thi trung bnh ............................................................................................ 40Hnh 3.3. Mc tng nhit trung bnh ma ng (oC) vo cui th k 21 theo kchbn pht thi trung bnh ............................................................................................ 41Hnh 3.4. Mc tng nhit trung bnh ma ng (oC) vo cui th k 21 theo kchbn pht thi cao ....................................................................................................... 42Hnh 3.5. Mc tng nhit trung bnh ma xun (oC) vo cui th k 21 theo kchbn pht thi thp...................................................................................................... 42Hnh 3.6. Mc tng nhit trung bnh ma xun (oC) vo gia th k 21 theo kchbn pht thi trung bnh ............................................................................................ 42Kch bn bin i kh hu, nc bin dng cho Vit Nam 11 12. B TI NGUYN V MI TRNGHnh 3.7. Mc tng nhit trung bnh ma xun (oC) vo cui th k 21 theo kchbn pht thi trung bnh ............................................................................................ 43Hnh 3.8. Mc tng nhit trung bnh ma xun (oC) vo cui th k 21 theo kchbn pht thi cao ....................................................................................................... 44Hnh 3.9. Mc tng nhit trung bnh ma h (oC) vo cui th k 21 theo kch bnpht thi thp............................................................................................................. 44Hnh 3.10. Mc tng nhit trung bnh ma h (oC) vo gia th k 21 theo kchbn pht thi trung bnh ............................................................................................ 44Hnh 3.11. Mc tng nhit trung bnh ma h (oC) vo cui th k 21 theo kchbn pht thi trung bnh ............................................................................................ 45Hnh 3.12. Mc tng nhit trung bnh ma h (oC) vo cui th k 21 theo kchbn pht thi cao ....................................................................................................... 46Hnh 3.13. Mc tng nhit trung bnh ma thu (oC) vo cui th k 21 theo kchbn pht thi thp...................................................................................................... 46Hnh 3.14. Mc tng nhit trung bnh ma thu ( oC) vo gia th k 21 theo kchbn pht thi trung bnh ............................................................................................ 46Hnh 3.15. Mc tng nhit trung bnh ma thu (oC) vo cui th k 21 theo kchbn pht thi trung bnh ............................................................................................ 47Hnh 3.16. Mc tng nhit trung bnh ma thu (oC) vo cui th k 21 theo kchbn pht thi cao ....................................................................................................... 48Hnh 3.17. Mc tng nhit trung bnh nm (oC) vo cui th k 21 theo kch bnpht thi thp............................................................................................................. 48Hnh 3.18. Mc tng nhit trung bnh nm (oC) vo gia th k 21 theo kch bnpht thi trung bnh ................................................................................................... 48Hnh 3.19. Mc tng nhit trung bnh nm (oC) vo cui th k 21 theo kch bnpht thi trung bnh ................................................................................................... 49Hnh 3.20. Mc tng nhit trung bnh nm (oC) vo cui th k 21 theo kch bnpht thi cao .............................................................................................................. 50Hnh 3.21. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) trongma ng vo gia th k 21 theo kch bn pht thi trung bnh .............................. 50Hnh 3.22. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) trongma ng vo cui th k 21 theo kch bn pht thi trung bnh............................... 51Hnh 3.23. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) trongma h vo gia th k 21 theo kch bn pht thi trung bnh .................................. 52Hnh 3.24. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) trongma h vo cui th k 21 theo kch bn pht thi trung bnh................................... 52Hnh 3.25. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) nm vogia th k 21 theo kch bn pht thi trung bnh ...................................................... 53Hnh 3.26. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) nm vocui th k 21 theo kch bn pht thi trung bnh ...................................................... 53Hnh 3.27. Mc tng s ngy c nhit cao nht trn 35oC vo cui th k 21 theokch bn pht thi trung bnh ..................................................................................... 54Hnh 3.28. Mc thay i lng ma ma ng (%) vo gia (a) v cui th k 21 (b)theo kch bn pht thi thp ...................................................................................... 56Hnh 3.29. Mc thay i lng ma ma ng (%) vo gia th k 21 theo kch bnpht thi trung bnh ................................................................................................... 57Hnh 3.30. Mc thay i lng ma ma ng (%) vo cui th k 21 theo kch bnpht thi trung bnh ................................................................................................... 58Hnh 3.31. Mc thay i lng ma ma ng (%) vo gia (a) v cui th k 21 (b)theo kch bn pht thi cao........................................................................................ 57Kch bn bin i kh hu, nc bin dng cho Vit Nam 12 13. B TI NGUYN V MI TRNGHnh 3.32. Mc thay i lng ma ma xun (%) vo gia (a) v cui th k 21 (b)theo kch bn pht thi thp ...................................................................................... 59Hnh 3.33. Mc thay i lng ma ma xun (%) vo gia th k 21 theo kch bnpht thi trung bnh ................................................................................................... 59Hnh 3.34. Mc thay i lng ma ma xun (%) vo cui th k 21 theo kch bnpht thi trung bnh ................................................................................................... 60Hnh 3.35. Mc thay i lng ma ma xun (%) vo gia (a) v cui th k 21 (b)theo kch bn pht thi cao........................................................................................ 61Hnh 3.36. Mc thay i lng ma ma h (%) vo gia (a) v cui th k 21 (b)theo kch bn pht thi thp ...................................................................................... 61Hnh 3.37. Mc thay i lng ma ma h (%) vo gia th k 21 theo kch bnpht thi trung bnh ................................................................................................... 62Hnh 3.38. Mc thay i lng ma ma h (%) vo cui th k 21 theo kch bnpht thi trung bnh ................................................................................................... 63Hnh 3.39. Mc thay i lng ma ma h (%) vo gia (a) v cui th k 21 (b)theo kch bn pht thi cao........................................................................................ 62Hnh 3.40. Mc thay i lng ma ma thu (%) vo gia (a) v cui th k 21 (b)theo kch bn pht thi thp ...................................................................................... 64Hnh 3.41. Mc thay i lng ma ma thu (%) vo gia th k 21 theo kch bnpht thi trung bnh ................................................................................................... 64Hnh 3.42. Mc thay i lng ma ma thu (%) vo cui th k 21 theo kch bnpht thi trung bnh ................................................................................................... 65Hnh 3.43. Mc thay i lng ma ma thu (%) vo gia (a) v cui th k 21 (b)theo kch bn pht thi cao........................................................................................ 66Hnh 3.44. Mc thay i lng ma nm (%) vo gia (a) v cui th k 21 (b) theokch bn pht thi thp .............................................................................................. 66Hnh 3.45. Mc thay i lng ma nm (%) vo gia th k 21 theo kch bn phtthi trung bnh ........................................................................................................... 67Hnh 3.46. Mc thay i lng ma nm (%) vo cui th k 21 theo kch bn phtthi trung bnh ........................................................................................................... 68Hnh 3.47. Mc thay i lng ma nm (%) vo gia (a) v cui th k 21 (b) theokch bn pht thi cao ............................................................................................... 67Hnh 3.48. Mc thay i lng ma ngy ln nht (%) vo gia (a) v cui th k 21(b) theo kch bn pht thi trung bnh ........................................................................ 70Hnh 3.49. Mc thay i kh p trung bnh b mt (a) v m tng i trung bnhb mt (b) vo cui th k 21 theo kch bn pht thi trung bnh .............................. 71Hnh 3.50. Kch bn nc bin dng cho cc khu vc ven bin Vit Nam ............... 73Hnh 4.1. Bn nguy c ngp khu vc ven bin Vit Nam ng vi mc nc bindng 1m .................................................................................................................... 77Hnh 4.2. Bn nguy c ngp khu vc ng bng sng Hng v Qung Ninh ngvi mc nc bin dng 1m ..................................................................................... 78Hnh 4.3. Bn nguy c ngp khu vc tnh Thanh Ha ng vi mc nc bindng 1m .................................................................................................................... 79Hnh 4.4. Bn nguy c ngp khu vc tnh Ngh An ng vi mc nc bin dng1m ............................................................................................................................. 80Hnh 4.5. Bn nguy c ngp khu vc tnh H Tnh ng vi mc nc bin dng1m ............................................................................................................................. 81Hnh 4.6. Bn nguy c ngp khu vc tnh Qung Bnh ng vi mc nc bindng 1m .................................................................................................................... 82Kch bn bin i kh hu, nc bin dng cho Vit Nam 13 14. B TI NGUYN V MI TRNGHnh 4.7. Bn nguy c ngp khu vc tnh Qung Tr ng vi mc nc bin dng1m ............................................................................................................................. 83Hnh 4.8. Bn nguy c ngp khu vc tnh Tha Thin - Hu ng vi mc ncbin dng 1m............................................................................................................. 84Hnh 4.9. Bn nguy c ngp khu vc thnh ph Nng ng vi mc nc bindng 1m .................................................................................................................... 85Hnh 4.10. Bn nguy c ngp khu vc tnh Qung Nam ng vi mc nc bindng 1m .................................................................................................................... 86Hnh 4.11. Bn nguy c ngp khu vc tnh Qung Ngi ng vi mc nc bindng 1m .................................................................................................................... 87Hnh 4.12. Bn nguy c ngp khu vc tnh Bnh nh ng vi mc nc bindng 1m .................................................................................................................... 88Hnh 4.13. Bn nguy c ngp khu vc tnh Ph Yn ng vi mc nc bin dng1m ............................................................................................................................. 89Hnh 4.14. Bn nguy c ngp khu vc tnh Khnh Ha ng vi mc nc bindng 1m .................................................................................................................... 90Hnh 4.15. Bn nguy c ngp khu vc tnh Ninh Thun ng vi mc nc bindng 1m .................................................................................................................... 91Hnh 4.16. Bn nguy c ngp khu vc tnh Bnh Thun ng vi mc nc bindng 1m .................................................................................................................... 92Hnh 4.17. Bn nguy c ngp khu vc tnh B Ra Vng Tu ng vi mc ncbin dng 1m............................................................................................................. 93Hnh 4.18. Bn nguy c ngp khu vc thnh ph H Ch Minh ng vi mc ncbin dng 1m............................................................................................................. 94Hnh 4.19. Bn nguy c ngp khu vc ng bng sng Cu Long ng vi mcnc bin dng 1m ................................................................................................... 95Kch bn bin i kh hu, nc bin dng cho Vit Nam 14 15. B TI NGUYN V MI TRNGTM TT KCH BN BIN I KH HU, NC BIN DNG CHO VIT NAM VNHNG IM MI C BN1. Cc phng php v ngun s liu xy dng kch bn bin i kh hu, ncbin dng cho Vit Nam c k tha t cc nghin cu trc y v c cpnht n nm 2010. Thi k 1980-1999 c chn l thi k c s trong xy dngkch bn bin i kh hu, nc bin dng cho Vit Nam n nm 2100.2. V nhit :- Theo kch bn pht thi thp: n cui th k 21, nhit trung bnh nm tngt 1,6 n 2,2oC trn phn ln din tch pha Bc lnh th v di 1,6oC i b phndin tch pha Nam (t Nng tr vo). - Theo kch bn pht thi trung bnh: n cui th k 21, nhit trung bnhtng 2-3oC trn phn ln din tch c nc, ring khu vc t H Tnh n Qung Trc nhit trung bnh tng nhanh hn so vi nhng ni khc. Nhit thp nht trungbnh tng t 2,2-3,0oC, nhit cao nht trung bnh tng t 2,0-3,2oC. S ngy cnhit cao nht trn 35oC tng 10-20 ngy trn phn ln din tch c nc.- Theo kch bn pht thi cao: n cui th k 21, nhit trung bnh nm cmc tng ph bin t 2,5 n trn 3,7oC trn hu ht din tch nc ta.3. V lng ma: - Theo kch bn pht thi thp: n cui th k 21, lng ma nm tng phbin khong trn 6%, ring khu vc Ty Nguyn c mc tng t hn, ch vo khongdi 2%. - Theo kch bn pht thi trung bnh: n cui th k 21, lng ma nm tngtrn hu khp lnh th. Mc tng ph bin t 2-7%, ring Ty Nguyn, Nam TrungB tng t hn, di 3%. Xu th chung l lng ma ma kh gim v lng mama ma tng. Lng ma ngy ln nht tng thm so vi thi k 1980-1999 BcB, Bc Trung B v gim Nam Trung B, Ty Nguyn, Nam B. Tuy nhin cckhu vc khc nhau li c th xut hin ngy ma d thng vi lng ma gp iso vi k lc hin nay.- Theo kch bn pht thi cao: Lng ma nm vo cui th k 21 tng trnhu khp lnh th nc ta vi mc tng ph bin khong 2-10%, ring khu vc TyNguyn c mc tng t hn, khong 1-4%.4. V mt s yu t kh hu khc: - Kh p tng trn phm vi ton lnh th Vit Nam, Bin ng. - m tng i gim trn hu khp c nc, nht l pha ng Bc B vNam B.5. V nc bin dng:- Theo kch bn pht thi thp (B1): Vo cui th k 21, mc nc bin dngcao nht khu vc t C Mau n Kin Giang trong khong t 54-72cm; thp nht khu vc Mng Ci trong khong t 42-57cm. Trung bnh ton Vit Nam, mc ncbin dng trong khong t 49-64cm.- Theo kch bn pht thi trung bnh (B2): Vo cui th k 21, nc bin dngcao nht khu vc t C Mau n Kin Giang trong khong t 62-82cm; thp nht khu vc Mng Ci trong khong t 49-64cm. Trung bnh ton Vit Nam, mc ncKch bn bin i kh hu, nc bin dng cho Vit Nam 15 16. B TI NGUYN V MI TRNGbin dng trong khong t 57-73cm.- Theo kch bn pht thi cao (A1FI): Vo cui th k 21, nc bin dng caonht khu vc t C Mau n Kin Giang trong khong t 85-105cm; thp nht khu vc Mng Ci trong khong t 66-85cm. Trung bnh ton Vit Nam, mc ncbin dng trong khong t 78-95cm.6. Nu mc nc bin dng 1m, s c khong 39% din tch ng bng sng CuLong, trn 10% din tch vng ng bng sng Hng, Qung Ninh, trn 2,5% dintch thuc cc tnh ven bin min Trung v trn 20% din tch Thnh ph H ChMinh c nguy c b ngp; Gn 35% dn s thuc cc tnh vng ng bng sng CuLong, trn 9% dn s vng ng bng sng Hng, Qung Ninh, gn 9% dn s cctnh ven bin min Trung v khong 7% dn s Thnh ph H Ch Minh b nhhng trc tip; Trn 4% h thng ng st, trn 9% h thng quc l v khong12% h thng tnh l ca Vit Nam s b nh hng.7. Nhng im mi ca kch bn bin i kh hu, nc bin dng- Cc kch bn bin i kh hu, nc bin dng cho Vit Nam c xy dngtrn cc c s khoa hc v s liu o c thc t. Cc kch bn c xy dng davo cc phn tch, tnh ton bng cc m hnh kh hu, cng c thng k. Cc mhnh, cng c ny c la chn, xy dng chuyn bit cho Vit Nam v khu vcln cn. Trong tnh ton, khai thc ti a cc ngun s liu v cc loi d liukhc nhau, c th l s dng ton b s liu kh tng, kh hu, thy vn, hi vnquan trc ti gn 200 trm kh tng, 17 trm hi vn, s liu quan trc t v tinh, sliu tnh ton t cc m hnh khc nhau, Cc kt qu phn nh c tnh c thca cc vng kh hu cng nh cc vng bin ca Vit Nam. - Cc kch bn v nhit v lng ma c th hin chi tit cho cc khuvc nh ca Vit Nam, p ng c yu cu nh gi tc ng ca bin i khhu i vi tng khu vc nh. Cc yu t cc tr (nhit cao nht, thp nht, maln) cng c tnh ton phc v cho cng tc quy hoch v thit k ca ccngnh. Cc kch bn nc bin dng c xc nh vi mc chi tit n tng khuvc ven bin. - Theo kch bn cp nht, mc tng nhit dao ng trong phm vi ln hnso vi kch bn nm 2009. Chng hn, theo kch bn pht thi trung bnh, vo cuith k 21, mc tng nhit trung bnh nm c th ti 3,5oC cc khu vc nhthuc Bc Trung B (theo kch bn nm 2009, mc tng chung cho vng kh hu nyl 2,8oC vo nm 2100). Tng t i vi ma, lng ma ma kh c th gimn 30% vo nm 2100 mt vi ni thuc Nam B, trong khi theo phin bnnm 2009 th ch gim 18%. Cc yu t cc tr nh nhit cao nht, nhit thpnht, lng ma ngy ln nht v mt s yu t khc c tnh ton v trnh bytrong bn cp nht kch bn bin i kh hu.- So vi kch bn nc bin dng nm 2009, kch bn cp nht tnh chi tithn cho cc khu vc ven bin Vit Nam. Theo cc kch bn, n nm 2100 ncbin dng cao nht khu vc t C Mau n Kin Giang, thp nht vng MngCi n Hn Du. - Cng vi cc bn nguy c ngp cho khu vc ng bng sng Cu Longv Thnh ph H Ch Minh, kch bn cp nht tnh ton v trnh by cc bn nguy c ngp cho ng bng sng Hng, Qung Ninh v tng tnh thuc khu vcven bin min Trung.Kch bn bin i kh hu, nc bin dng cho Vit Nam16 17. B TI NGUYN V MI TRNG1. BIU HIN CA BIN I KH HU, NC BIN DNG1.1. Biu hin ca bin i kh hu, nc bin dng trn th gii S nng ln ton cu l rt r rng vi nhng biu hin ca s tng nhit khng kh v i dng, s tan bng din rng v qua l mc tng mc nc bintrung bnh ton cu. Cc quan trc cho thy rng nhit tng trn ton cu v tng nhiu hn cc v cc Bc. Trong 100 nm qua(1906-2005), nhit trung bnh toncu tng khong 0,74oC, tc tngca nhit trong 50 nm gn y gngp i so vi 50 nm trc (Hnh1.1, 1.2). Theo bo co gn y ca WMO,2010 l nm nng nht trong lch s, vimc tng t nh cc nm 1998 v2005. Ngoi ra, trong mi nm qua tnht nm 2001, nhit trung bnh ton Hnh 1.1. Din bin chun sai nhit cu cao hn na so vi giai on trung bnh ton cu (Ngun: IPCC/2007)1961-1990, mc cao nht tng c ghi nhn i vi bt k mt giai on 10 nm nok t khi bt u quan trc kh hu bng thit b o c (Michel Jarraud, 2011). Theos liu ca NOAA (Hoa K), thng 6 nm 2010 c ghi nhn l thng nng nht trnton th gii k t nhng nm 1880, khi cc quan trc kh tng c thc hin mtcch tng i h thng (Hnh 1.3).Trn phm vi ton cu lng ma tng ln cc i pha Bc v 30oB thik 1901-2005 v gim i cc v nhit i, k t gia nhng nm 1970 (Hnh 1.4). khu vc nhit i, ma gim i Nam v Ty Phi vi tr s xu th l 7,5% cho cthi k 1901-2005. i v trung bnh v v cao, lng ma tng ln r rt min Trung Bc M, ng Bc M, Bc u, Bc v Trung . Tn s ma ln tngln trn nhiu khu vc, k c nhng ni lng ma c xu th gim i (IPCC, 2007). Trn phm vi ton cu, bin i ca xoy thun nhit i (XTN) chu s chiphi ca bin i nhit nc bin, ca hot ng ENSO v s thay i qu o cachnh XTN. Xu th tng cng hot ng ca XTN r rt nht Bc, Ty Nam ThiBnh Dng v n Dng (IPCC, 2010).Trong th k 20 cng vi s tng ln ca nhit mt t c s suy gim khilng bng trn phm vi ton cu. T nm 1978 n nay, lng bng trung bnh hngnm Bc Bng Dng gim khong 2,1-3,3% mi thp k (IPCC, 2007).Kch bn bin i kh hu, nc bin dng cho Vit Nam17 18. B TI NGUYN V MI TRNGChu uBc MChu Nm Chu PhiNm Nam M NmChu c NmNm Nm Ton cu tBin D thng nhit ( C)D thng nhit (oC) D thng nhit (oC) oNm Nm Nm Hnh 1.2. Din bin nhit quy m ton cu v khu vc(Ngun: IPCC AR4 WG-I Report, 2007)Hnh 1.3. Chun sai nhit ton cu thng 6 nm 2010 so vi thi k 1971 2000 (Ngun: NOAA/2010)Kch bn bin i kh hu, nc bin dng cho Vit Nam18 19. B TI NGUYN V MI TRNGXu th ging thy nm, t 1901 n 2005% trn th k Hnh 1.4. Din bin lng ma nm cc vng khc nhau trn th gii (Ngun: IPCC/2007)S nng ln ca h thng kh hu r rng c minh chng thng qua sliu quan trc ghi nhn s tng ln ca nhit khng kh v nhit nc bintrung bnh ton cu, s tan chy nhanh ca lp tuyt ph v bng, lm tng mcnc bin trung bnh ton cu (IPCC, 2007). Mc nc bin tng ph hp vi xu thnng ln do c s ng gp ca: (a) hin tng gin n nhit ca i dng; (b) tanbng Greenland, Nam Cc v cc khu vc khc; (c) thay i kh nng gi nc t lin. Trong cc nhn t ny, hin tng n v nhit ca i dng tng cxem l nhn t ch yu dn n sdng ln ca mc nc bin. Tuynhin, s liu mi v t l tan bng Greenland v Nam Cc cho thy rngnh hng ny ln hn. Bi v cctng bng Greenland v Nam Cccha nc lm tng mc ncbin ln 70m.Theo cc nh khoa hc v bini kh hu (BKH) ton cu v ncbin dng cho thy, i dng nng Hnh 1.5. Bin ng mc nc binln ng k t cui thp k 1950. Cc trung bnh ton cu (Ngun: IPCC/2007)Kch bn bin i kh hu, nc bin dng cho Vit Nam19 20. B TI NGUYN V MI TRNGnghin cu t s liu quan trc trn ton cu cho thy, mc nc bin trung bnhton cu trong thi k 1961-2003 dng vi tc 1,8 0,5mm/nm, trong ,ng gp do gin n nhit khong 0,42 0,12mm/nm v tan bng khong 0,700,50 (IPCC, 2007 - Hnh 1.5). Nghin cu cp nht nm 2009 cho rng tc mcnc bin trung bnh ton cu dng khong 1,8mm/nm (Chuch v White, 2009).Mc nc bin thay i khng ng u trn ton b i dng th gii: mt svng tc dng c th gp mt vi ln tc dng trung bnh ton cu trong khimc nc bin mt s vng khc li c th h thp. Xu th tng ca mc nctrung bnh xut hin hu ht ti cc trm quan trc trn ton cu, mc d, vn xuthin mt s khu vc c xu hng gim nh b bin pha ng ca Nam M vkhu vc ven bin pha Nam Alaska v ng Bc Canada, vng bin Scandinavia(Hnh 1.6). Theo mt s bo co ca cc nh khoa hc, trong thp k va qua, mcnc bin dng nhanh nht vng pha Ty Thi Bnh Dng v pha ng n Dng. Hnh 1.6. Xu th bin ng mc nc bin trung bnh ti cc trm quan trc ncbin trn ton cu (Ngun NOAA/2010) Hin nay, c hai phng php ch yu o c mc nc bin l o titrm hi vn v bng v tinh. Cc s liu t cc trm hi vn cho bit mc thay imc nc so vi mc cao ca trm. c th bit c thay i mc nc doth tch khi nc v cc yu t vt l bin khc, s liu trm hi vn cn phi loi bc yu t do vn ng a cht ca mt t. S c tnh nh hng vn ng acht ni chung s khng thc hin c nu khng c v tr o c hay s liu acht. Tuy nhin, vic la chn cn thn v tr t trm c th loi b c nh hngnhng hot ng kin to v ly trung bnh cc s liu c th thu c sai s nhtrong c tnh mc nc bin ton cu. S bin i mc nc bin da vo s liuKch bn bin i kh hu, nc bin dng cho Vit Nam 20 21. B TI NGUYN V MI TRNGv tinh c o vi khi tm ca Tri t,do khng b nh hng ca vn nga cht. T nm 1992, mc nc bintrung bnh ton cu c tnh ton, cpnht theo chu k 10 ngy t v tinhTOPEX/Poseidon (T/P) v v tinh JASONt 66 Nam n 66 Bc (Nerem vMitchum, 2001). S liu o c ctng hp v hiu chnh t cc v tinhHnh 1.7. Xu th bin ng mc nc(Topex/Poisedon, Jason - 1/2, ERS - 1/2, bin trung bnh ton cu t s liu v tinhEnvisat) t thng 10/1992 n 12/2010 (Ngun: AVISO)cho rng mc nc bin dng vi tc l 3,27mm/nm (CNES, LEGOS, CLS -Hnh 1.7). Trn quy m ton cu, xu th bin i ca mc nc bin tng mnh ven b Ty Thi Bnh Dng trong khi xu th gim b ng Thi Bnh Dng(Hnh 1.8). Hnh 1.8. Xu th mc nc bin trung bnh ton cu theo s liu v tinh(Ngun: CNES/LEGOS/CLS,2010)1.2. Biu hin ca bin i kh hu, nc bin dng Vit Nam Vit Nam, xu th bin i ca nhit v lng ma l rt khc nhau trncc vng trong 50 nm qua. Nhit trung bnh nm tng khong 0,5oC trn phm vic nc v lng ma c xu hng gim pha Bc, tng pha Nam lnh th.Kch bn bin i kh hu, nc bin dng cho Vit Nam 21 22. B TI NGUYN V MI TRNG Nhit thng I (thng c trng 24Ncho ma ng), nhit thng VII (thng Trung quc 22Nc trng cho ma h) v nhit trungbnh nm tng trn phm vi c nc trong 20N50 nm qua. Nhit ma ng tngLnhanh hn so vi ma h v nhit 18N ovng su trong t lin tng nhanh hnQ. Hong Sanhit vng ven bin v hi o. 16NThi Lan Vo ma ng, nhit tng 2Cnhanh hn c l Ty Bc B, ng Bc 14N1CB, ng bng Bc B, Bc Trung B Cm pu chia 0.5C 12N(khong 1,3-1,5oC/50 nm). Nam Trung 0CB, Ty Nguyn v Nam B c nhit -0.5C 10Nthng I tng chm hn so vi cc vng-1Cn g Sa Tr--2Ckh hu pha Bc (khong 0,6-0,9oC/50 8NQ.nm). Tnh trung bnh cho c nc, nhit 102E 104E 106E 108E110E 112E114E ma ng nc ta tng ln 1,2 oC Hnh 1.9. Mc tng nhit trung bnhtrong 50 nm qua. Nhit thng VII tng nm (oC) trong 50 nm qua (Ngun: IMHEN/2010)khong 0,3-0,5oC/50 nm trn tt c cc 24Nvng kh hu ca nc ta. Nhit trungTrung qucbnh nm tng 0,5-0,6oC/50 nm Ty 22NBc, ng Bc B, ng bng Bc B,Bc Trung B, Ty Nguyn v Nam B 20NLcn mc tng nhit trung bnh nm 18NNam Trung B thp hn, ch vo khongo0,3oC/50 nm (Hnh 1.9 v Bng 1.1). Q. Hong Sa 16N Thi Lan Xu th chung ca nhit l tngtrn hu ht cc khu vc trn c nc, tuy 14N 40%nhin c nhng khu vc nh thuc vng Cm pu chia20%ven bin Trung B v Nam B nh Tha 12N 0%Thin Hu, Qung Ngi, Tin Giang c-20%xu hng gim ca nhit . ng lu l 10N-40% nhng ni ny, lng ma tng trongQ.Tr- ng Sa8Nc hai ma: ma kh v ma ma.102E 104E106E 108E110E 112E114E Mc thay i nhit cc i trnton Vit Nam nhn chung dao ng trong Hnh 1.10. Mc thay i lng manm (%) trong 50 nm quakhong t -3oC n 3oC. Mc thay i(Ngun: IMHEN/2010)nhit cc tiu ch yu dao ng trongkhong -5oC n 5oC. Xu th chung ca nhit cc i v cc tiu l tng, tc tng ca nhit cc tiu nhanh hn so vi nhit cc i, ph hp vi xu thKch bn bin i kh hu, nc bin dng cho Vit Nam 22 23. B TI NGUYN V MI TRNGchung ca bin i kh hu ton cu. Lng ma ma kh (thng XI-IV) tng ln cht t hoc khng thay i ngk cc vng kh hu pha Bc v tng mnh m cc vng kh hu pha Namtrong 50 nm qua. Lng ma ma ma (thng V-X) gim t 5 n hn 10% trn aphn din tch pha Bc nc ta v tng khong 5 n 20% cc vng kh hu phaNam trong 50 nm qua. Xu th din bin ca lng ma nm tng t nh lngma ma ma, tng cc vng kh hu pha Nam v gim cc vng kh hu phaBc. Khu vc Nam Trung B c lng ma ma kh, ma ma v lng ma nmtng mnh nht so vi cc vng khc nc ta, nhiu ni n 20% trong 50 nmqua (Hnh 1.10 v Bng 1.1). Lng ma ngy cc i tng ln hu ht cc vng kh hu, nht l trongnhng nm gn y. S ngy ma ln cng c xu th tng ln tng ng, nhiubin ng mnh xy ra khu vc min Trung. Tn ti mi tng quan kh r gias nng ln ton cu v nhit b mt bin khu vc ng xch o Thi Bnhdng vi xu th bin i ca s ngy ma ln trn cc vng kh hu pha Nam.Bng 1.1. Mc tng nhit v mc thay i lng ma trong 50 nm qua ccvng kh hu ca Vit Nam (Ngun: IMHEN/2010) Nhit (OC) Lng ma (%) Vng kh huThi k Thi kThng IThng VII Nm NmXI-IVV-X Ty Bc B1,4 0,50,5 6 -6-2 ng Bc B 1,5 0,30,6 0 -9-7 ng bng Bc B1,4 0,50,6 0-13 -11 Bc Trung B1,3 0,50,5 4 -5-3 Nam Trung B0,6 0,50,320 2020 Ty Nguyn0,9 0,40,619911 Nam B0,8 0,40,6276 9 V xoy thun nhit i, trung bnh hng nm c khong 12 cn bo v pthp nhit i hot ng trn Bin ng, trong khong 45% s cn ny sinh ngaytrn Bin ng v 55% s cn t Thi Bnh Dng di chuyn vo. S cn bo v pthp nhit i nh hng n Vit Nam vo khong 7 cn mi nm v trong c 5cn b hoc nh hng trc tip n t lin nc ta. Ni c tn sut hot ngca bo, p thp nhit i ln nht nm phn gia ca khu vc Bc Bin ng,trung bnh mi nm c khong 3 cn i qua li 2,5 x 2,5 kinh v. Khu vc bbin min Trung t 16 n 18oN v khu vc b bin Bc B t 20oN tr ln c tnsut hot ng ca bo, p thp nhit i cao nht trong c di ven bin nc ta, ckhong 2 nm li c 1 cn bo, p thp nhit i i vo khu vc 1 v b bin(Hnh 1.11). S lng xoy thun nhit i hot ng trn khu vc Bin ng c xuKch bn bin i kh hu, nc bin dng cho Vit Nam 23 24. B TI NGUYN V MI TRNGhng tng nh, trong khi s cn nh hng hoc b vo t lin Vit Namkhng c xu hng bin i r rng (Hnh 1.12). a) b)c)Hnh 1.11. Bn tn sut XTN hot ng (a), hnh thnh Bin ng (b)v nh hng n t lin Vit Nam (c) (Ngun: IMHEN/2010) Hnh 1.12. Din bin ca s cn xoy thun nhit i hot ng Bin ng, nhhng v b vo t lin Vit Nam trong 50 nm qua (Ngun: IMHEN/2010)Khu vc b ca cc cn bo v p thp nhit i vo Vit Nam c xuhng li dn v pha Nam lnh th nc ta; s lng cc cn bo rt mnh c xuhng gia tng; ma bo c du hiu kt thc mun hn trong thi gian gn y.Tuy nhin, mc nh hng ca bo n nc ta c xu hng mnh ln.Hn hn, bao gm hn thng v hn ma c xu th tng ln nhng vi mc khng ng u gia cc vng v gia cc trm trong tng vng kh hu. Hintng nng nng c du hiu gia tng r rt nhiu vng trong c nc, c bit l Trung B v Nam B. Vit Nam, s liu mc nc quan trc ti cc trm hi vn ven bin VitNam cho thy xu th bin i mc nc bin trung bnh nm khng ging nhau. Huht cc trm c xu hng tng, tuy nhin, mt s t trm li khng th hin r xuhng ny. Xu th bin i trung bnh ca mc nc bin dc b bin Vit Nam lkhong 2,8mm/nm (Hnh 1.13).Kch bn bin i kh hu, nc bin dng cho Vit Nam24 25. B TI NGUYN V MI TRNGS liu mc nc o c t v 10.0 5.0Xu th mc nc bin trung bnh nm trm Bi ChyMc nc (cm) 0.0tinh t nm 1993 n 2010 cho thy, xu -5.0-10.0-15.0-20.019621966 1970 197419781982198619901994199820022006th tng mc nc bin trn ton bin Nm Xu th mc nc bin trung bnh nm trm Hn Du 20 15Mc nc (cm) 10ng l 4,7mm/nm, pha ng ca50 -5-10 1966 1970 197419781982 198619901994 1998 20022006 Nmbin ng c xu th tng nhanh hn Xu th mc nc bin trung bnh nm trm Cn C 10864Mc nc (cm)20pha Ty. Ch tnh cho di ven b Vit -2 -4 -6 -8-101991199519992003 2007 NmNam, khu vc ven bin Trung Trung BXu th mc nc bin trung bnh nm trm Ca Vit10 8 6 Mc nc (cm) 4 2 0 -2v Ty Nam B c xu hng tng mnh -4 -6 -8-10197719811985 19891993199720012005 Nm Xu th mc nc bin trung bnh nm trm Sn Trhn, trung bnh cho ton di ven bin 105Mc nc (cm)0 -5-10Vit Nam tng khong 2,9mm/nm-15-20 1978 19821986 1990 19941998 20022006 Nm Xu th mc nc bin trung bnh nm trm Quy Nhn 20 15(Hnh 1. 14).10 Mc nc (cm)50 -5-10 Nh vy, xu th mc nc bin-15-201993 199619992002 2005 2008 NmXu th mc nc bin trung bnh nm trm Ph QUhy2015cho khu vc ven bin t s liu thc o10Mc nc (cm)50 -5-10-15ti trm quan trc hi vn v t v tinh-20 1986199019941998 2002 2006 NmXu th mc nc bin trung bnh nm trm Vng Tu 20 15l gn bng nhau. iu ny cng c 10Mc nc (cm)50-5-10-15-20kim chng khi so snh gia s liu 19781982 1986 1990 1994 1998 20022006 NmXu th mc nc bin trung bnh nm trm Ph Quc 10864 Mc nc (cm)thc o ti trm hi vn v t v tinh.20 -2 -4 -6 -8-101986 1990 1994 199820022006Kt qu so snh cho thy c s tng NmXu th mc nc bin trung bnh nm trm Rch Gi 10.05.0Mc nc (cm)0.0ng cao v pha v bin dao ng-5.0-10.0-15.0-20.0 19781982198619901994 19982002 2006 Nmca mc nc trung bnh cng nhHnh 1.13. Din bin mc nc bin theotng quan gia chng (Hnh 1.15).s liu cc trm thc o (Ngun: IMHEN/2010) 60 50 D thng mc nc (cm) Thy triu 40 V tinh 30 20 100 -10 -20 -30 -401993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Tng quan gia hai chui s liu -Trm Hn Du40 H s tng quan R=0.7302010V tinh 0-10-20-30-40-20-15-10 -5 05 1015 20 25 30Thy triu7050 Thy triuD thng mc nc (cm) V tinh3010-10-30-501993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Tng quan gia hai chui s liu -Trm Sn Tr 40H s tng quan R=0.91 30 20 10 V tinh0 -10 -20 -30 -40-30-20-10010 203040 Thy triu6050D thng mc nc (cm) Thy triu40 V tinh302010 0-10-20-30-40 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Tng quan gia hai chui s liu -Trm Quy Nhn40H s tng quan R=0.83302010V tinh0 -10 -20 -30-30 -20 -100 Thy triu 1020 3040 50 Thy triuD thng mc nc (cm) V tinh 30 10 -10 -30 -501993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007Tng quan gia hai chui s liu -Trm Vng Tu40H s tng quan R=0.88302010V tinh0-10-20-30-40 -30-20 -100 Thy triu 1020 30 40Hnh 1.14. Din bin mc nc bin theoHnh 1.15. So snh mc nc bin t s liu v tinh thi k 1993 - 2010 s liu ti trm hi vn v v tinh (Ngun: IMHEN/2010) (Ngun: IMHEN/2010)Kch bn bin i kh hu, nc bin dng cho Vit Nam 25 26. B TI NGUYN V MI TRNG2. PHNG PHP XY DNG KCH BN BIN I KH HU, NC BINDNG CHO VIT NAM2.1. Yu cu cp nht kch bn bin i kh hu, nc bin dng cho Vit NamNhn thc r tc ng ca bin i kh hu n Vit Nam, Chnh ph phduyt Chng trnh mc tiu quc gia ng ph vi bin i kh hu. Mt trong nhngni dung quan trng ca Chng trnh l xy dng v cp nht kch bn bin i khhu. Kch bn BKH l c s cc B, ngnh, a phng nh gi tc ng cabin i kh hu, xy dng v trin khai k hoch hnh ng ng ph.B Ti nguyn v Mi trng c Chnh ph giao: Da trn c s ccnghin cu c trong v ngoi nc, u nm 2009 hon thnh vic xy dng cckch bn bin i kh hu Vit Nam, c bit l nc bin dng, Cui nm 2010,hon thnh vic cp nht cc kch bn bin i kh hu v n nm 2015,tip tc cp nht cc kch bn bin i kh hu, c bit l nc bin dng cho ccgiai on n nm 2100. Cc kch bn BKH, nc bin dng cho Vit Nam cng b nm 2009 cxy dng ch yu da trn c s cc nghin cu trong v ngoi nc v BKH nthi im v vi mc chi tit n vng kh hu v chung cho c vng bin caVit Nam. Vic cp nht cc kch bn BKH cn phi c thc hin trn c s ngdng cc m hnh kh hu, phn mm thng k, phng php lun c la chn,xy dng chuyn bit cho Vit Nam v khu vc ln cn. Cc loi s liu khc nhaucng cn c khai thc ti a trong qu trnh xy dng cc kch bn BKH, ncbin dng nh s liu quan trc ti cc trm kh tng, kh hu, cc trm hi vn, dliu v tinh, s liu m phng ca m hnh, Cc kch bn BKH, nc bin dngcho Vit Nam phi c c s khoa hc v thc tin. Nhm p ng c cc yu cu nh gi tc ng ca BKH i vi cclnh vc v cc a phng khc nhau ca Vit Nam, kch bn BKH, nc bindng cho Vit Nam cn c chi tit ho n n v hnh chnh cp tnh v nh hn.2.2. La chn kch bn pht thi kh nh knh Bin i kh hu hin nay cng nh trong th k 21 ph thuc ch yu vomc pht thi kh nh knh, tc l ph thuc vo s pht trin kinh t - x hi. Vvy, cc kch bn bin i kh hu c xy dng da trn cc kch bn pht trinkinh t - x hi ton cu.Con ngi pht thi qu mc kh nh knh vo kh quyn t cc hot ngkhc nhau nh cng nghip, nng nghip, giao thng vn ti, ph rng, Do , cs xc nh cc kch bn pht thi kh nh knh l: (1) S pht trin kinh t quym ton cu; (2) Dn s th gii v mc tiu dng; (3) Chun mc cuc sng vKch bn bin i kh hu, nc bin dng cho Vit Nam 26 27. B TI NGUYN V MI TRNGli sng; (4) Tiu th nng lng v ti nguyn nng lng; (5) Chuyn giao cngngh; (6) Thay i s dng t; Trong Bo co c bit v cc kch bn pht thi kh nh knh nm 2000,IPCC a ra 40 kch bn, phn nh kh a dng kh nng pht thi kh nh knhtrong th k 21. Cc kch bn pht thi ny c t hp thnh 4 kch bn gc l A1,A2, B1 v B2 vi cc c im chnh sau:- Kch bn gc A1: Kinh t th gii pht trin nhanh; dn s th gii tng tnh vo nm 2050 v sau gim dn; truyn b nhanh chng v hiu qu cccng ngh mi; th gii c s tng ng v thu nhp v cch sng, c s tngng gia cc khu vc, giao lu mnh m v vn ho v x hi ton cu. H kchbn A1 c chia thnh cc nhm da theo mc pht trin cng ngh, nh: + A1FI: Tip tc s dng thi qu nhin liu ha thch (kch bn pht thicao); + A1B: C s cn bng gia cc ngun nng lng (kch bn pht thi trungbnh);+ A1T: Ch trng n vic s dng cc ngun nng lng phi ho thch (kchbn pht thi thp).- Kch bn gc A2: Th gii khng ng nht, cc quc gia hot ng c lp, tcung t cp; dn s tip tc tng trong th k 21; kinh t pht trin theo nh hngkhu vc; thay i v cng ngh v tc tng trng kinh t tnh theo u ngichm (kch bn pht thi cao, tng t nh A1FI).- Kch bn gc B1: Kinh t pht trin nhanh ging nh A1 nhng c s thayi nhanh chng theo hng kinh t dch v v thng tin; dn s tng t nh vonm 2050 v sau gim dn; gim cng tiu hao nguyn vt liu, cc cngngh sch v s dng hiu qu ti nguyn c pht trin; ch trng n cc giiphp ton cu v n nh kinh t, x hi v mi trng (kch bn pht thi thp,tng t nh A1T). - Kch bn gc B2: Dn s tng lin tc nhng vi tc thp hn A2; chtrng n cc gii php a phng thay v ton cu v n nh kinh t, x hi v mitrng; mc pht trin kinh t trung bnh; thay i cng ngh chm hn v manhmn hn so vi B1 v A1 (kch bn pht thi trung bnh, c xp cng nhm viA1B). Nh vy, IPCC khuyn co s dng cc kch bn pht thi c sp xp tthp n cao l B1, A1T (kch bn thp), B2, A1B (kch bn trung bnh), A2, A1FI(kch bn cao) vi cc mc pht thi kh nh knh trong th k 21 v d tnh mctng nhit trung bnh ton cu c th hin trn Hnh 2.1. Tuy nhin, ty thucvo nhu cu thc tin v kh nng tnh ton ca tng nc, IPCC cng khuyn cola chn cc kch bn pht thi ph hp xy dng kch bn bin i kh hu.Kch bn bin i kh hu, nc bin dng cho Vit Nam27 28. B TI NGUYN V MI TRNGCc kch bn bin i kh hu, nc bin dng cho Vit Nam c xydng v cng b nm 2009 theo cc kch bn pht thi kh nh knh mc thp(B1), trung bnh (B2) v cao (A2, A1FI), trong kch bn trung bnh B2 c khuynngh cho cc B, ngnh v a phng lm nh hng ban u nh gi tcng ca bin i kh hu, nc bin dng v xy dng k hoch hnh ng ngph vi bin i kh hu. K tha cc nghin cu c v trn c s cc kt qutnh ton ca cc m hnh kh hu Vit Nam, cc kch bn pht thi kh nh knhc chn nhm cp nht kch bn BKH, nc bin dng cho Vit Nam trong boco ny bao gm: B1 (kch bn thp) , B2, A1B (kch bn trung bnh), A2 v A1FI(kch bn cao).Hnh 2.1. S tnh ton pht thi kh nh knh theo cc kch bn v mc tng nhit trung bnh ton cu (Ngun: IPCC)2.3. La chn phng php xy dng kch bn bin i kh hu, nc bindng cho Vit Nam2.3.1. Cc phng php xy dng kch bn bin i kh hu Nhiu phng php c sdng xy dng kch bn BKH choVit Nam nh: ng dng cc phn mmSDSM, SIMCLIM, ng dng phngphp chi tit ho thng k, khai thc snphm ca cc m hnh ng lc toncu v khu vc, Cc phng phptnh cng nh cc sn phm minh hoca cc phng php c gii thius lc sau y:Hnh 2.2. Giao din ca phn mmSDSM ng dng phn mm SDSM Phn mm SDSM l mt cng c h tr, nh gi s thay i kh hu quym a phng bng cch s dng k thut chi tit ha thng k (Hnh 2.2). Cu trc hot ng ca SDSM nh sau:Kch bn bin i kh hu, nc bin dng cho Vit Nam28 29. B TI NGUYN V MI TRNG - Kim sot cht lng v chuyn i d liu thng k; - Kim tra cc nhn t d bo; - Hiu chnh m hnh; - T hp cc d liu hin ti bng cc nhn t trong quan trc; - a kt qu ca m hnh ln cng c ha; - T hp cc d tnh kh hu tng lai (kch bn BKH). ng dng phn mm SIMCLIMPhn mm SIMCLIM c 2 chc nng chnh l tnh ton xy dng cc kch bn(Scenarios Generation) v nh gi tc ng theo cc kch bn (Impact model). Chc nng xy dng kch bn: Da trn sn phm ca cc m hnh ton cu(GCM) theo tng kch bn v chui s liu ca cc yu t kh hu, mc nc bindng cc a phng, phn mm SIMCLIM c th tnh ton cc kch bn v ccyu t kh hu v mc nc bin dng cho cc a phng . Phng php chnhc s dng l thng k kt hp vi cc cng c ha. Cc yu t kh hu baogm: lng ma, nhit (trung bnh, cc tr) v cc yu t khc nh m, gi,Sn phm ca hn 20 m hnh hon lu chung kh quyn c tch hp trongSIMCLIM v c sn trong c s d liu ca t chc PCMDI (http://www-pcmdi.llnl.gov/). Chc nng nh gi tc ng bao gm: - nh gi tc ng ln ti nguyn nc: c th hin thng qua cc tnhton cn bng nc. Phn mm tnh ton s khc nhau gia lng ma v bc hitim nng. u vo ca m hnh l nhit trung bnh, lng ma v bc x mttri, v u ra l gi tr cn bng nc.Hnh 2.3. Giao din ca phn mm SIMCLIM- nh gi tc ng ln nng nghip: S dng cc tnh ton nhit ngy(degree - day) nh gi tc ng ca bin i kh hu ln nng nghip.Kch bn bin i kh hu, nc bin dng cho Vit Nam 29 30. B TI NGUYN V MI TRNG - nh gi tc ng xi l ng b v cn bng nc. Phng php chi tit ha thng kPhng php chi tit ha thng k (Statistical Downscaling) s dng nhngthng tin kh hu v BKH t m hnh kh hu ton cu (GCMs) c phn giitng i th tnh ton chi tit v c phn gii cao hn cho mt khu vc. Mcd GCM ngy cng c hon thin trn phm vi khng gian v thi gian, tuy nhinkt qu ca cc m hnh vn cha chi tit nh gi tc ng ca BKH chomt khu vc nh v cc iu kin nh a hnh, mt m c nh hng ln n khhu a phng nhng cha c th hin trong GCM.M hnh chi tit ha thng k xy dng mi quan h nh lng gia cc binkh quyn quy m ln, ng vai tr l cc nhn t d bo (NTDB) v cc bin lp bmt ca a phng - i tng d bo (TDB). Cc m hnh chi tit ha thng k pht trin kh mnh trong d bo ni chung, d bo hn di (DBHD) ni ring.ng dng phng php chi tit ha thng k xy dng kch bn v BKH ltrng hp c bit trong d bo hn di. C 3 phng php c p dng trongchi tit ha thng k: Cc m hnh hi quy (Regression models); Cc s phn loi thi tit (Weather Classification schemes hoc Weather Typing); Cc "my" to thi tit (Weather Generators).Trong cc nghin cu xy dng m hnh d bo v xy dng kch bn BKH,hai phng php thng c dng l phng php thng k u ra ca m hnh(MOS) v phng php s dng s liu "phn tch li" kt hp vi ngun s liuquan trc tng ng thit lp m hnh (PP), nh c trnh by trong Hnh 2.4.Phng php PP/MOS S liu phn tch li theo li / S liu mXc nhphng ca m hnh trong qu khhm chuyn S liu quan trc ti a phngLa Kch bnchnBKH t cc Kch bn BKHhm m hnh khcho khu vc nh chuyn hu ton cuHnh 2.4. S xy dng hm chuyn theo phng php PP v MOS - Phng php "Thng k t u ra ca m hnh" (Model Output Statistics -MOS). Phng php ny s dng kt qu u ra ca m hnh trong qu kh, ktKch bn bin i kh hu, nc bin dng cho Vit Nam30 31. B TI NGUYN V MI TRNGhp vi s liu quan trc tng ng ti cc trm xy dng m hnh hi quy,chuyn cc kch bn c c t cc m hnh ny cho tng lai v cc khu vcnghin cu. - Phng php s dng s liu "phn tch li" kt hp vi ngun s liu quantrc tng ng thit lp m hnh (Perfect Prognosis - PP). Do ngun s liu tiphn tch c coi l ngun s liu gn thc t, tng t nh s liu quan trc nnmi quan h to ra gia chng c coi l gn vi quan h thc. Vic nh gi mc tin cy v tiu ch la chn c thc hin khi xydng v la chn hm chuyn. Cc phng php dng xy dng v kim chngm hnh c la chn cho ph hp vi di v c im ca cc chui s liu. ng dng kt qu ca m hnh AGCM/MRI (Nht Bn) M hnh AGCM/MRI do Vin Nghin cu Kh tng Nht Bn v Cc Khtng Nht Bn (JMA) xy dng, kt hp gia m hnh d bo thi tit thi onngn vi m hnh kh hu th h mi m phng kh hu thi gian di. M hnh phn gii 20 km v 60 km, chy bng h thng m phng tri t(Earth Simulator) ti Cc Cng ngh v khoa hc Tri t - i dng, Nht Bn. AGCM/MRI dng s liu 25 nm t nm 1979 - 2003 m phng kh huqu kh nhm tnh ton cc c trng kh hu cho thi k c s. Tng lai gnc m t t 2015 n 2039 (25 nm) v tng lai xa c m phng t 2075 n2099 (25 nm). Sn phm ca m hnh gm khong 70 yu t kh hu theo kch bnpht thi trung bnh A1B.Hnh 2.5. H thng M phng tri t v kch bn BKH ca m hnh AGCM/MRI ng dng m hnh PRECIS ca Trung tm Hadley Vng quc Anh PRECIS (Providing Regional Climates for Impacts Studies) l m hnh nglc kh hu khu vc c xy dng bi Trung tm Nghin cu Kh hu ton cuHadley. M hnh c dng xy dng cc kch bn BKH cho khu vc nh v cth chy trn my tnh c nhn. S tnh v min tnh ca m hnh PRECIS ctrnh by trong Hnh 2.6. M hnh s dng h ta lai (Hybrid, ) gm 19 mc thng ng vi miKch bn bin i kh hu, nc bin dng cho Vit Nam31 32. B TI NGUYN V MI TRNGmc , k (k = 1, ..., 19) xc nh bi s kt hp tuyn tnh gia cao a hnh vcc mc kh p. Li ngang l li xen k, cc bin v hng nh nhit , kh p, m c xc nh ti tm li cn cc thnh phn hu hng c xc nhti cc im nt li. PRECIS s dng php chiu cc quay, m bo cho s nnh m hnh m khng cn ti php lc phi vt l. Cc s tham s ha vt l c xt n l: S my v ging thy; S bc x; S sol kh; S lp bin; S b mt t; S sng trng trng(Hnh 2.7). iu kin bin xung quanh c ly t m hnh ton cu hoc d liu phntch, bao gm gi, nhit , m, p sut b mt, Kt qu ca m hnh gmkhong hn 100 bin kh tng, trong nhit trung bnh, cao nht, thp nht bmt v lng ma theo ngy, thng, nm c dng trong xy dng kch bn BKH.Hnh 2.6. S tnh v min tnh ca m hnh PRECIS Hnh 2.7. Cc qu trnh vt l c xt n trong m hnh PRECIS Min tnh cho Vit Nam c xy dng vi phm vi khng gian trong khong:Kch bn bin i kh hu, nc bin dng cho Vit Nam 32 33. B TI NGUYN V MI TRNG4N-36oN, 93-120oE, phn gii ngang 25 x 25km, bao gm 140 x 160 nt li.M hnh c s dng tnh ton cho 2 thi k: (1) Thi k c s c lachn theo 2 phng n l 1961-1990 v 1980-1999, v (2) Thi k tng lai, cla chn l thi k 2000-2100 i vi cc kch bn pht thi trung bnh v cao. Ccmc thi gian trong tng lai c xc nh theo khong 20 nm mt: 2000-2019,2020-2039, 2040-2059, 2060-2079 v 2080-2100.La chn phng php xy dng kch bn bin i kh hu cho Vit Nam Vic la chn phng php xy dng kch bn BKH cho Vit Nam cda trn mc ph hp ca cc phng php vi iu kin kh hu Vit Nam,mc chi tit v tnh y ca kch bn, tnh k tha v cc phng php c s dng trong kch bn cng b nm 2009 v kh nng ch ng cp nhttrong tng lai. Cc phng php c dng xy dng kch bn BKH cho VitNam bao gm: Phng php chi tit ha thng k c dng tnh ton cho kchbn nhit , lng ma trung bnh ma, nm i vi cc kch bn thp, trung bnhv cao; M hnh AGCM/MRI c dng tnh ton cho kch bn nhit , lngma trung bnh ma, nm i vi kch bn trung bnh v m hnh PRECIS cdng tnh ton cho kch bn nhit , lng ma trung bnh ma, nm v cc tri vi kch bn trung bnh. Cc phn mm SDSM, SIMCLIM c dng thamkho.Thi k c s so snh s thay i ca kh hu l giai on 1980-1999, ycng giai on c IPCC dng trong bo co ln th t.2.3.2. Cc phng php xy dng kch bn nc bin dngCc phng php chnh nhm xy dng kch bn nc bin dng ton cucng nh khu vc bao gm: Phng php chi tit ho thng k (MAGICC, SIMCLIM,SLRPP) v ng dng sn phm ca cc m hnh s tr. quy m to cu, Rahmstorf(2007) xy dng phng php thngk bn thc nghim tnh mc ncbin dng. Phng php ny da vomi quan h gia nhit trung bnh vmc nc bin ton cu trong qu kh c tnh cho tng lai. Kt qu tnhton c so snh vi s liu thc o(Hnh 2.8). Aslak Grinsted (2009) dngphng trnh phi tuyn bn tham s xy dng quan h gia nhit v mcnc bin ton cu trong 2000 nm v Hnh 2.8. Phng php tnh v kch bntnh ton mc nc trong qu kh v nc bin dng ca Rahmstorf, 2007Kch bn bin i kh hu, nc bin dng cho Vit Nam33 34. B TI NGUYN V MI TRNGtng lai. Nhiu m hnh s tr cpht trin tnh ton xy dng kchbn nc bin dng vi s kt hp giagia m hnh kh hu v m hnh idng i vi cc kch bn pht thi khnh knh khc nhau, v d trn hnh 2.9l kch bn mc nc bin dng nm2100 quy m ton cu ca Trung tmNghin cu Kh quyn Quc gia, Hoa K(NCAR). Hnh 2.9. Kch bn mc nc bin dng nm 2100 quy m ton cu (NCAR)Trong nghin cu xy dng kchbn nc bin dng cho cc khu vc,Joanne (2008) s dng ch(SLRRP)ti s dng lcc kch bn nc bin dng cho cckhu vc dHnh 2.10. Mt kch bn nc bin dngtheo phng php ca Doyle i a cht ti khuvc . Thomas W. Doyle (2010) tnh tonkch bn nc bin dng cho vng ngbng sng M Kng trn c s tng hpcc yu t: (1) Bin thin mc nc bintrong qu kh ti khu vc; (2) Mc stln ca khu vc; (3) Xu th mc ncbin dng theo s liu quan trc; (4) Kchbn mc nc bin ton cu ca IPCCtheo cc kch bn pht thi A1FI v B1(Hnh 2.10).Trong kch bn nc bin dng Hnh 2.11. Phng php chi tit ha thng k cho mc nc bin dngca Vng quc Anh nm 2009(UKCP09), kch bn mc nc bin cho 4 khu vc mc nc bin trung bnh toncu c chit xut t 11 m hnh s tr kt hp vi c tnh ca IPCC (2007) vKch bn bin i kh hu, nc bin dng cho Vit Nam 34 35. B TI NGUYN V MI TRNGnc bin dng do qu trnh tan bng v nhng nghin cu v bin i, st ln acht cho 4 khu vc khc nhau.Nhn chung, khi tnh ton kch bn mc nc bin dng cho khu vc nh, ccnghin cu trn th gii thng s dng cc yu t a phng nh tc bin imc nc trong qu kh v s dch chuyn a cht ti khu vc nhm hiu chnh cckch bn nc bin dng quy m ton cu t phng php thng k hoc cc m hnhs tr.La chn phng php u im ca phng php s tr l c th m t c qu trnh mc nc bindng ti tng khu vc c th vi cc thi k dng rt theo chu k kh hu. Nhcim ca phng php ny l cha m t ng c qu trnh tan bng nn cc ktqu thng thin thp khi kim chng vi s liu thc o. Mt khc, do m hnh l quy m ton cu nn i hi khi lng tnh ton qu ln, yu cu phi c h thngsiu my tnh chy trong thi gian kh di. Trn c s k tha kch bn nc bindng do bin i kh hu c cng b nm 2009 v yu cu chi tit ho ca kchbn cp nht cng nh kh nng p dng cc phng php tnh ton kch bn ncbin dng trong iu kin hin nay Vit Nam, phng php chi tit ha thng k c la chn. Kch bn mc nc bin dng c xy dng trn c s mi quanh thng k gia mc nc bin thc o, c tnh t v tinh trong qu kh tngkhu vc ca Vit Nam vi mc nc bin ton cu (Hnh 2.11). Kt qu c chit xut t 10 m hnh s tr ton cu (Hnh 2.12, Bng 2.1) vcc phng php khc, nh m hnh SIMCLIM, c s dng tham kho. Bng 2.1. Cc h thng m hnh c tham kho trong xy dng kch bnnc bin dng cho Vit Nam phn gii ti khuTTTn M hnh Quc gia vc Vit Nam 1BCCR-BCM2.0Na Uy1 x 1 2 ECHAM5/MPI-OM c1 x 1 3MIUB-ECHO-Gc - Hn Quc2,5 x 1 4 GFDL-CM2.0M 1 x 1 5 GFDL-CM2.1M 1 x 1 6GISS-ERM 4 x 5 7MIROC3.2 Nht Bn 1,4 x 1,4 8MRI-CGCM2.3.2Nht Bn2,5 x 2 9 NCAR - PCMM 1 x 110UKMO-HadCM3Anh 1,25 x 1,25Kch bn bin i kh hu, nc bin dng cho Vit Nam 35 36. B TI NGUYN V MI TRNGBo co ln th t ca IPCC c tnh mc nc bin dng khong26-59cm vo nm 2100, tuy nhinkhng loi tr kh nng tc cao hn.Cc nghin cu gn y cho thy mcnc bin dng nhanh hn so vinhn nh ca IPCC. Hnh 2.12. Mc nc bin dng cui th Hnh 2.13 cho thy mc nck 21 theo kch bn trung bnh ca ccthc o nhng nm gn y nm cnm hnh s trtrn ca kch bn nc bin dng caIPCC trong cng thi k. Nhiu nghincu cho thy vo cui th k 21 mcnc bin c th dng t 1m (Horton,2007); 1,4m (Rahmstof, 2007) n 2,1m(Grinsted, 2009) nh th hin trongHnh 2.14. T nhng phn tch, nhn nhtrn, kt qu tnh ton kch bn ncHnh 2.13. So snh kch bn mc nc bin dng (IPCC) v s liu o cbin dng ton cu theo m hnhMAGICC (Hnh 2.15) c la chnlm u vo tnh ton kch bn ncbin dng cho Vit Nam.Xc nh cc khu vc ven bin cmc nc bin dng khc nhau S liu mc nc thc o ti cctrm hi vn, s liu quan trc t v tinhv kt qu tnh ton nc bin dng t Hnh 2.14. Mc nc bin dng cui thcc m hnh s tr cho vng ven bin k XXI t cc nghin cu khc nhauVit Nam c s dng xc nh cckhu vc ven bin c s ng nht v xu 100Kch bn A1FI_Cn trnKch bn A1FI_Cn diKch bn B2_Cn trnKch bn B2_Cn dith bin i mc nc bin trong quMc tng mc nc (cm)80Kch bn B1_Cn trnKch bn B1_Cn dikh v d on cho tng lai. 60 Kt qu cho thy c 7 khu vc40ven bin c s ng nht v xu th bin20i mc nc bin nh sau: 0 2000 20102020 203020402050 20602070 2080 2090 2100 Nm 1) Khu vc ven bin bc Vnh Hnh 2.15. Kch bn mc nc bin tonBc B, t Mng Ci n Hn Du (gmcu theo cc kch bn pht thiKch bn bin i kh hu, nc bin dng cho Vit Nam36 37. B TI NGUYN V MI TRNGtnh Qung Ninh v pha Bc thnh ph Hi Phng); 2) Khu vc ven bin ng bng sng Hng v Bc Trung B, t Hn Du no Ngang (gm pha Nam thnh ph Hi Phng, cc tnh Thi Bnh, Nam nh, NinhBnh, Thanh Ha, Ngh An v H Tnh);3) Khu vc ven bin pha Nam Vnh Bc B, t o Ngang n o Hi Vn(gm cc tnh Qung Bnh, Qung Tr v Tha Thin - Hu;4) Khu vc ven bin pha Bc ca Nam Trung B, t o Hi Vn n Mi iLnh (gm Thnh ph Nng, tnh Qung Nam, Qung Ngi, Bnh nh v PhYn);5) Khu vc ven bin pha Nam ca Nam Trung B, t Mi i Lnh n Mi KG (gm cc tnh Khnh Ha, Ninh Thun v Bc Bnh Thun);6) Khu vc ven bin ng Nam B, t Mi K G n Mi C Mau (gm NamBnh Thun v cc tnh B Ra Vng Tu, TP H Ch Minh, Tin Giang, Tr Vinh,Bn Tre, Sc Trng, Bc Liu, C Mau);7) Khu vc ven bin Ty, t Mi C Mau n H Tin (gm cc tnh C Mau vKin Giang).2.3.3. Phng php xy dng cc bn nguy c ngpBn nguy c ngp theo cc mc nc bin dng c xy dng ch racc khu vc c nguy c b tc ng trc tip do nc bin dng. D liu c dng xy dng bn nguy c ngp bao gm :- Bn s a hnh cc tnh ven bin t l 1:10.000, Cc o c v Bn -B Ti nguyn v Mi trng (2010).- Bn a hnh t l 1:5.000 vng ng bng sng Cu Long thuc d ncp nh nc "Xy dng c s d liu h thng thng tin a hnh - thu vn c bnphc v phng chng l lt v pht trin kinh t - x hi vng ng bng sng CuLong", Trung tm Vin thm Quc gia - B Ti nguyn Mi trng (2008).- D liu nn a l v giao thng cc tnh ven bin t l 1:25.000, Nh xutbn Bn - B Ti nguyn v Mi trng. - S liu v din tch v dn s cc tnh ven bin, Tng cc Thng k (2009). Mi bn cho mt khu vc c xy dng da trn mt gi tr duy nht camc nc p dng trn ton vng th hin ca bn . V c bn, phng phpny l nng b mt nc theo mt gi tr c la chn. Cch tip cn ny cs dng ph bin nht trong xy dng bn nguy c ngp do nc bin dng.Cc lp thng tin c nhp vo h thng GIS, th hin bn nguy c ngpv c trnh by theo quy nh ca bn chuyn ban hnh.Kch bn bin i kh hu, nc bin dng cho Vit Nam 37 38. B TI NGUYN V MI TRNG2.4. Mt s lu v cc kch bn bin i kh hu, nc bin dng v bn nguy c ngp Cc kch bn ni chung v kch bn BKH lun tn ti nhng im cha chcchn, v th tnh cha chc chn ca cc kch bn BKH cn c xt n trongnh gi tc ng, tnh d b tn thng v xc nh cc gii php thch ng viBKH. V c bn, tnh cha chc chn trong cc kch bn BKH lin quan n tnhcha chc chn trong xc nh cc kch bn pht thi kh nh knh, nng kh nhknh trong kh quyn trong tng lai, nhng hiu bit cn hn ch v h thng khhu ton cu v khu vc, phng php xy dng cc kch bn.V cc kch bn pht thi kh nh knhTnh cha chc chn ca cc kch bn pht thi kh nh knh c cho lnguyn nhn chnh gy ra nhng im khng chc chn ca cc kch bn BKH.Nhng im cha chc chn ca cc kch bn pht thi kh nh knh lin quan ncc mi quan h rng buc gia s tng dn s, pht trin kinh t - x hi v thayi cng ngh trong tng lai. khc phc vn ny cc kch bn bin i khhu, nc bin dng c xy dng da theo cc kch bn pht thi kh nh knhkhc nhau, t kch bn thp n cc kch bn cao (theo cc h kch bn chnh A1,A2, B1 v B2).V nng kh nh knh trong kh quyn Tnh cha chc chn v nng kh nh knh trong kh quyn lin quan nnhng hn ch trong hiu bit v cc qu trnh vt l v ha hc trong kh quyn. Dovy, s tn ti nhng im cha chc chc tim n trong cc kt qu xy dng kchbn BKH, nc bin dng. Ngoi ra, tnh cha chc chn cn lin quan n viccha tnh n nhng nh hng ca bc x n nng sol kh lm thay i nng kh quyn. Cc m hnh ng lc ton cu ngy cng c gng m phng y hn cc qu trnh vt l v ha hc trong kh quyn.V kh nng m phng ca cc m hnh kh hu ton cu Cc m hnh ton cu thng kh c th m phng y v chnh xc ccqu trnh trong kh quyn, v th c nhng sai s nht nh, cc m hnh khc nhauc th cho kt qu khc nhau. khc phc, cn s dng kt qu ca nhiu mhnh a ra cc khong gi tr. Ngoi ra, phng php t hp cng c th cp dng i vi cc kt qu khc nhau, trong cc kch bn thnh phn c thc to ra bng cch thay i iu kin u vo ca m hnh ton cu hoc sdng cc m hnh ton cu khc nhau.V cc phng php khu vc ha kh huNhn chung, cc phng php khu vc ha thng c cc sai s tnh ton.i vi phng php ng lc, sai s l do tnh cha hon ho ca cc s vt l,ng lc v nhng thay i bn trong ca m hnh. Bn cnh , nhng im chaKch bn bin i kh hu, nc bin dng cho Vit Nam 38 39. B TI NGUYN V MI TRNGchc chn ca m hnh ton cu cng gp phn lm tng thm mc sai s cam hnh khu vc.i vi phng php chi tit ha thng k: S ph hp ca cc hm chuync nhn nh thng qua ln ca h s tng quan tuyn tnh gia nhit ,lng ma m phng, phn tch bng m hnh ton cu v quan trc Vit Nam.i vi nhit , h s tng quan dao ng trong khong 0,65-0,95. Cc hmchuyn l ng tin cy, nht l vo cc thng ma ng. i vi lng ma, h stng quan dao ng trong khong t 0,4-0,7 vo ma kh v khong 0-0,2 vo ccthng ma ma. Cc hm chuyn tin cy vo ma kh v cha ng tin cy voma ma. i vi sn phm ca m hnh AGCM/MRI: Kt qu kim nh m hnh chothi k 1979-2003 cho thy m hnh m phng kh tt bin trnh nm ca nhit ,tuy nhin vn tn ti sai s gia gi tr nhit tnh ton v thc o i vi cc trmthuc khu vc Trung B v Nam B. Bin trnh nm ca lng ma c m phngkh tt i vi cc trm thuc Bc B, Trung B, Ty Nguyn v Nam B, nhnglng ma vo thi k cao im ma ma Nam Trung B c nhiu sai s. i vi m hnh PRECIS: S liu ti phn tch vi phn gii 0,5 x 0,5 kinh v v s liu thc o ti cc trm Vit Nam c dng kim nh m hnh.M hnh m phng kh tt nhit (gi tr, bin trnh nm v phn b theo khnggian). M hnh m phng tt bin trnh nm ca lng ma Bc B v Nam B, mphng c cc tm ma ln pha Bc, nhng thin thp i vi lng ma chokhu vc Trung B v Nam B, m phng khng tt lng ma vo cc thng cao imma ma Trung B.V cc kch bn nc bin dng S cha chc chn trong tnh ton nc bin dng cho tng lai quy mton cu do hai nguyn nhn c bn sau: (1) S cha chc chn ca m hnh khhu v y l u vo cho cc m hnh tnh ton nc bin dng; (2) Hiu bit chay v cc qu trnh tan bng.V chnh xc ca cc bn nguy c ngpMc chnh xc ca bn nguy c ngp ph thuc vo mc chnh xcca bn a hnh.Kch bn bin i kh hu, nc bin dng cho Vit Nam 39 40. B TI NGUYN V MI TRNG3. KCH BN BIN I KH HU, NC BIN DNG CHO VIT NAM3.1. Kch bn bin i kh hu i vinhit 3.1.1. Nhit trung bnha) Ma ng (thng XII-II)Theo kch bn pht thi thp, ncui th k 21, trn a phn din tchnc ta, nhit ma ng tng t 1,6n 2,2oC so vi thi k c s 1980-1999. phn ln din tch Ty Nguyn,cc nam Trung B v Nam B c nhit tng t hn, t 1 n 1,6oC. Khu vc tnhSn La c nhit tng nhiu nht, trn2,5oC (Hnh 3.1). Theo kch bn pht thi trungbnh, vo gia th k 21, nhit tng Hnh 3.1. Mc tng nhit trung bnht 1,4 n 1,8oC trn i b phn din ma ng (oC) vo cui th k 21 theotch pha Bc (t Nng tr ra). Hu kch bn pht thi thpkhp din tch pha Nam (t QungNam tr vo) c mc tng t nh hn1,0 n 1,4oC (Hnh 3.2). Vo cui th k 21, nhit tngt 2,5 n 3,1oC trn a phn din tchnc ta. Ring khu vc pha Ty tnhLo Cai, pha Nam tnh in Bin vhu ht din tch cc tnh Sn La,Qung Bnh v Qung Tr c mc tngcao hn 3,1oC. Phn ln din tch pha Nam (t Qung Nam tr vo) cmc tng nhit t 1,6 n 2,5oC. Mtphn nh din tch tnh Lm ng vkhu vc pha Bc ca Ty Nam B cmc tng t 1,0 n 1,6oC (Hnh 3.3).Nh vy, mc tng nhit pha BcHnh 3.2. Mc tng nhit trung bnhcao hn pha Nam.ma ng (oC) vo gia th k 21 theokch bn pht thi trung bnhKch bn bin i kh hu, nc bin dng cho Vit Nam 40 41. B TI NGUYN V MI TRNG Theo kch bn pht thi cao, vo cui th k 21, trn phn ln din tch nc tanhit ma ng tng t 2,8 n trn 3,7oC. Ring khu vc tnh Lo Cai, Nam inBin, Sn La v khu vc t Nam H Tnh n Qung Tr c nhit tng trn 3,7oC.Phn ln din tch khu vc t Khnh Ha tr vo c mc tng thp hn, t 1,6 n2,8oC (Hnh 3.4).Hnh 3.3. Mc tng nhit trung bnh ma ng (oC) vo cui th k 21 theo kch bn pht thi trung bnhKch bn bin i kh hu, nc bin dng cho Vit Nam41 42. B TI NGUYN V MI TRNGb) Ma xun (thng III V)Hnh 3.4. Mc tng nhit trung bnh Hnh 3.5. Mc tng nhit trung bnhma ng (oC) vo cui th k 21 theoma xun (oC) vo cui th k 21 theokch bn pht thi cao kch bn pht thi thp Theo kch bn pht thi thp, vocui th k 21, nhit ma xun tng t1,6 n 2,2oC a phn din tch nc taso vi thi k c s 1980-1999. Khu vcQung Bnh n Qung Tr c mc tngt 2,2 n trn 2,8oC. Mt vi ni thucBc B, mt phn din tch Nam TrungB, a phn din tch Ty Nguyn v TyNam B c mc tng nhit thp nht,t 1,0 - 1,6oC (Hnh 3.5). Theo kch bn pht thi trung bnh,vo gia th k 21, nhit tng t 1,2n 1,6oC a phn din tch nc ta.Khu vc Qung Bnh n Qung Tr cmc tng t 1,6 n trn 2,2oC. a phndin tch Ty Nguyn v Ty Nam B cmc tng t di 1,0 n 1,2oC (Hnh Hnh 3.6. Mc tng nhit trung bnh3.6). Vo cui th k 21, nhit tng t ma xun (oC) vo gia th k 21 theo2,2 n 3,1oC i b phn din tch kch bn pht thi trung bnhKch bn bin i kh hu, nc bin dng cho Vit Nam 42 43. B TI NGUYN V MI TRNGnc ta. Khu vc t Nam H Tnh n Qung Tr c mc tng cao nht, t 3,1 ntrn 3,4oC. Mt phn din tch Ty Nguyn v a phn din tch Ty Nam B c nhit tng thp nht, t 1,3 n 2,2oC (Hnh 3.7).Hnh 3.7. Mc tng nhit trung bnh ma xun (oC) vo cui th k 21 theo kch bn pht thi trung bnh Theo kch bn pht thi cao, tnh n cui th k 21, nhit ma xun tngt 2,8 n trn 3,7oC trn i b phn din tch nc ta. Mt phn din tch TyNguyn v Ty Nam B c mc tng t trn 1,3 n 2,8oC (Hnh 3.8).Kch bn bin i kh hu, nc bin dng cho Vit Nam43 44. B TI NGUYN V MI TRNGc) Ma h (thng VI-VIII) Theo kch bn pht thi thp, ncui th k 21, nhit ma h tng t 1,0n 1,6oC phn ln din tch nc ta;tng t 1,6 n 2,5oC trn khu vc t HTnh n Qung Tr, mt phn din tchthuc Ty Nguyn v Nam Trung B v aphn din tch Nam B (Hnh 3.9). Theo kch bn pht thi trung bnh,vo gia th k 21, trn a phn din tchnc ta nhit tng t 1,0 n 1,4oC.Khu vc t H Tnh n Qung Tr, mtphn nh din tch Ty Nguyn, cc namTrung B v ng Nam B c nhit tng t 1,4 n trn 1,8oC (Hnh 3.10). Vocui th k 21, nhit tng t 1,6 n3,1oC trn i b phn din tch c nc. Hnh 3.8. Mc tng nhit trung bnhKhu vc t H Tnh n Qung Tr, mt ma xun (oC) vo cui th k 21 theophn din tch thuc Ty Nguyn v ng kch bn pht thi caoHnh 3.9. Mc tng nhit trung bnh Hnh 3.10. Mc tng nhit trung bnh ma h (oC) vo cui th k 21 theoma h (oC) vo gia th k 21 theokch bn pht thi thp kch bn pht thi trung bnhKch bn bin i kh hu, nc bin dng cho Vit Nam44 45. B TI NGUYN V MI TRNGNam B c mc tng t 3,1 n trn 3,7oC; mc tng nhit t 1,0 n 1,6oC xy ra pha Bc Ty Bc B v hu ht din tch t Tha Thin - Hu n Kon Tum (Hnh 3.11).Hnh 3.11. Mc tng nhit trung bnh ma h (oC) vo cui th k 21theo kch bn pht thi trung bnh Theo kch bn pht thi cao, vo cui th k 21, nhit tng t 2,2 n trn o3,7 C trn i b phn din tch nc ta. Khu vc pha Bc Ty Bc B v t ThaThin Hu n Kon Tum c mc tng t 1,0 n 2,2oC (Hnh 3.12).Kch bn bin i kh hu, nc bin dng cho Vit Nam 45 46. B TI NGUYN V MI TRNGd) Ma thu (thng IX-XI) Theo kch bn pht thi thp, vocui th k 21, trn hu khp din tchnc ta, nhit ma thu tng t 1,3n 2,2oC, trong pha Bc (tQung Nam tr ra) v khu vc Nam B,tng ch yu t 1,6 n 2,2oC; khu vcNam Trung B v Ty Nguyn c mctng ch yu t 1,0 n 1,6oC (Hnh3.13). Theo kch bn trung bnh, vo giath k 21, nhit ma thu trn hu htdin tch nc ta tng t 1,0 n 1,6oC,trong mt phn din tch thuc TyNguyn, Nam Trung B v Ty Nam Bc nhit tng t 1,0 n 1,2oC (Hnh3.14). Hnh 3.12. Mc tng nhit trung bnh ma h (oC) vo cui th k 21 theo kchbn pht thi caoHnh 3.13. Mc tng nhit trung Hnh 3.14. Mc tng nhit trung bnh ma thu (oC) vo cui th k 21 bnh ma thu (oC) vo gia th k 21 theo kch bn pht thi thp theo kch bn pht thi trung bnh Vo cui th k 21, trn hu khp din tch c nc c nhit tng t 1,6Kch bn bin i kh hu, nc bin dng cho Vit Nam 46 47. B TI NGUYN V MI TRNGn 2,8oC. mt vi ni thuc Bc B, khu vc t nam H Tnh n Qung Tr vmt phn nh din tch Nam B c mc tng t 2,8 n trn 3,1 oC. Mt phn nhdin tch thuc Ty Nguyn v Ty Nam B c mc t 1,0 n 1,6oC (Hnh 3.15). Hnh 3.15. Mc tng nhit trung bnh ma thu (oC) vo cui th k 21 theo kch bn pht thi trung bnh Theo kch bn pht thi cao, vo cui th k 21, nhit ma thu tng t 2,5n trn 3,7oC so vi thi k c s 1980-1999 hu khp din tch nc ta, mtKch bn bin i kh hu, nc bin dng cho Vit Nam 47 48. B TI NGUYN V MI TRNGphn din tch Ty Nguyn c tng t 1,3 n trn 2,5 oC (Hnh 3.16).e) Trung bnh nm Theo kch bn pht thi thp, ncui th k 21, nhit trung bnh nmtng t 1,6 n ln hn 2,2oC trn ib phn din tch pha Bc (t ThaThin Hu tr ra). Mc tng nhit t1,0 n 1,6oC i b phn din tchpha Nam (t Qung Nam tr vo -Hnh 3.17). Theo kch bn pht thi trungbnh, vo gia th k 21, trn a phndin tch nc ta, nhit trung bnhnm c mc tng t 1,2 n 1,6oC.Khu vc t H Tnh n Qung Tr cnhit tng cao hn, t 1,6 n trn1,8oC. a phn din tch Ty Nguyn,cc nam Trung B v Nam B c mcHnh 3.16. Mc tng nhit trung bnhtng thp hn, t di 1,0 n 1,2oCma thu (oC) vo cui th k 21 theo(Hnh 3.18). kch bn pht thi cao Hnh 3.17. Mc tng nhit trung bnh Hnh 3.18. Mc tng nhit trung bnhnm (oC) vo cui th k 21 theo kch nm (oC) vo gia th k 21 theo kchbn pht thi thp bn pht thi trung bnhKch bn bin i kh hu, nc bin dng cho Vit Nam 48 49. B TI NGUYN V MI TRNG n cui th k 21, nhit tng t 1,9 n 3,1oC hu khp din tch cnc, ni c mc tng cao nht l khu vc t H Tnh n Qung Tr vi mc tngtrn 3,1oC. Mt phn din tch Ty Nguyn v Ty Nam B c mc tng thp nht, t1,6 n 1,9oC (Hnh 3.19). Hnh 3.19. Mc tng nhit trung bnh nm (oC) vo cui th k 21 theokch bn pht thi trung bnhTheo kch bn pht thi cao, n cui th k 21, nhit trung bnh nm cmc tng ch yu t 2,5 n cao hn 3,7oC trn hu ht din tch nc ta. Ni cKch bn bin i kh hu, nc bin dng cho Vit Nam49 50. B TI NGUYN V MI TRNGmc tng thp nht, t 1,6 n 2,5oC l mt phn din tch thuc Ty Nguyn vTy Nam B (Hnh 3.20).3.1.2. Nhit cc tra) Nhit cc tr ma ng (thng XII-II)Theo kch bn pht thi trung bnh,vo gia th k 21, nhit thp nhttrung bnh ma ng tng t 1,0 n1,2oC trn hu ht din tch t Khnh Hatr ra; tng t 1,2 n 1,5oC trn khu vct Ninh Thun tr vo (Hnh 3.21a). Nhit cao nht trung bnh tng t 1,2 n2,2oC trn hu ht din tch pha Bc (tNgh An tr ra), khu vc tnh Bnh Thunv Nam B; tng t 0 n 1,2oC hukhp din tch Trung B v Ty Nguyn Hnh 3.20. Mc tng nhit trung bnh(Hnh 3.21b). nm (oC) vo cui th k 21 theo kchbn pht thi cao a)b)Hnh 3.21. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) trongma ng vo gia th k 21 theo kch bn pht thi trung bnh Vo cui th k 21, trn i b phn din tch khu vc t Bc Ph Yn tr ra,nhit thp nht trung bnh ma ng tng t 2,0 n 2,2oC; mt phn din tchng Bc B, Nam Ty Nguyn, cc nam Trung B v Nam B c mc tng t 2,2n trn 3,0oC. Nhit cao nht trung bnh tng t 2,2 n 3,2oC trn a phn dintch t Ngh An tr ra v khu vc Nam B; tng t 2,0 n 2,2oC trn hu ht dinKch bn bin i kh hu, nc bin dng cho Vit Nam 50 51. B TI NGUYN V MI TRNGtch Trung B v Ty Nguyn (Hnh 3.22). a)b) Hnh 3.22. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) trongma ng vo cui th k 21 theo kch bn pht thi trung bnhb) Nhit cc tr ma h (thng VI-VIII) Theo kch bn pht thi trung bnh, vo gia th k 21, nhit thp nht trungbnh ma h c th tng t 1,7 n trn 2,0oC ng Bc B, i b phn din tcht Tha Thin Hu n Ninh Thun; tng t 1,2 n 1,7 oC Ty Bc B, Bc TrungB, Ty Nguyn v Nam B. Nhit cao nht trung bnh ma h ch yu tng t 1,2 n trn 2,0oC ng Bc B v hu ht din tch pha Nam (t Tha Thin Hu tr vo); tng t1,0 n 1,2oC Ty Bc B, phn ln din tch thuc Bc Trung B v Ty Nguyn. Vo cui th k 21, nhit thp nht trung bnh ma h tng t 2,7 n trn3,2 C ng Bc B v i b phn din tch Trung B; tng t 2,0 n 2,7oC Ty oBc B, mt phn din tch Trung B, Ty Nguyn v Nam B. Nhit cao nhttrung bnh tng t 2,2 n 3,2oC ng Bc B v Trung B; tng t 2,0 n 2,2oC Ty Bc B, Ty Nguyn v Nam B (Hnh 3.24).c) Nhit cc tr nm Theo kch bn pht thi trung bnh, vo gia th k 21, nhit thp nhttrung bnh nm tng t 1,0 n 1,7oC trn i b phn din tch nc ta; tng t 1,7n 2,0oC mt phn nh din tch Nam Ty Nguyn v Nam B. Nhit cao nhttrung bnh nm tng t 1,0 n 1,7oC trn phn ln din tch lnh th; tng t 1,7n 2,2oC ng Bc B, mt phn din tch Nam Ty Nguyn v Nam B (Hnh3.25).Kch bn bin i kh hu, nc bin dng cho Vit Nam 51 52. B TI NGUYN V MI TRNG a)b) Hnh 3.23. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) trong ma h vo gia th k 21 theo kch bn pht thi trung bnha) b) Hnh 3.24. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) trong ma h vo cui th k 21 theo kch bn pht thi trung bnh Vo cui th k 21, nhit thp nht trung bnh nm tng t 2,2 n 3,0oC;trong , a phn din tch Bc B, Nam Ty Nguyn v Nam B c mc tng caohn so vi cc khu vc khc (t 2,7 n 3,0 oC). Nhit cao nht trung bnh nmtng t 2,0 n 3,2oC, trong khu vc ng Bc B v a phn din tch Nam BKch bn bin i kh hu, nc bin dng cho Vit Nam52 53. B TI NGUYN V MI TRNGc mc tng cao nht, t 2,7 n 3,2oC (Hnh 3.26).a)b)Hnh 3.25. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh (b) nm vo gia th k 21 theo kch bn pht thi trung bnha) b) Hnh 3.26. Mc tng nhit ti thp trung bnh (a) v ti cao trung bnh(b) nm vo cui th k 21 theo kch bn pht thi trung bnhVo cui th k 21, s ngy nng nng (nhit cao nht trn 35oC) tng t10 n 20 ngy trn phn ln din tch c nc. a phn din tch Bc B v mtphn nh din tch Ty Nguyn c mc tng t 1 n 10 ngy (Hnh 3.27).Kch bn bin i kh hu, nc bin dng cho Vit Nam53 54. B TI NGUYN V MI TRNGHnh 3.27. Mc tng s ngy c nhit cao nht trn 35oC vo cui th k 21 theo kch bn pht thi trung bnhBng 3.1 trnh by mc tng nhit (oC) trung bnh nm ca tng thp kca th k 21 so vi thi k 1980-1999 theo kch bn pht thi trung bnh (B2) cho 63tnh, thnh ph trc thuc trung ng. i vi cc mc thi gian vo gia v cui thk 21 c b sung khong dao ng ca mc tng nhit , v d vo nm 2050, Lai Chu, mc tng nhit dao ng trong khong t 1,0 n 1,6 oC, nhng khnng cao nht c th xy ra l 1,2oC.Kch bn bin i kh hu, nc bin dng cho Vit Nam54 55. B TI NGUYN V MI TRNGBng 3.1. Mc tng nhit ( oC) trung bnh nm so vi thi k 1980-1999 theo kch bn pht thi trung bnh (B2)Cc mc thi gian ca th k 21 STT Tnh, thnh ph 2020 2030 2040 20502060 2070 2080 20902100 1 Lai Chu 0,5 0,7 1,0 1,2 (1,0 - 1,6)1,5 1,8 2,0 2,2 2,4 (1,9 - 2,8) 2 in Bin0,5 0,8 1,1 1,4 (1,0 - 1,6)1,7 2,0 2,3 2,5 2,7 (1,9 - 2,8) 3 Sn La 0,6 0,8 1,2 1,5 (1,2 - 1,8)1,8 2,1 2,4 2,7 2,9 (2,2 - 3,4) 4 Ha Bnh 0,5 0,7 1,0 1,3 (1,2 - 1,4)1,6 1,9 2,1 2,4 2,6 (2,2 - 2,8) 5 H Giang 0,5 0,7 1,0 1,3 (1,2 - 1,4)1,5 1,8 2,0 2,2 2,4 (2,2 - 2,8) 6 Cao Bng 0,5 0,7 1,0 1,3 (1,2 - 1,4)1,5 1,8 2,0 2,2 2,4 (2,2 - 2,8) 7 Lo Cai0,5 0,8 1,1 1,4 (1,2 - 1,6)1,7 2,0 2,3 2,5 2,7 (2,2 - 3,1) 8 Yn Bi0,5 0,7 1,0 1,3 (1,2 - 1,6)1,5 1,7 2,0 2,2 2,4 (2,2 - 3,1) 9 Tuyn Quang0,5 0,7 1,0 1,3 (1,2 - 1,4)1,6 1,8 2,1 2,3 2,5 (2,2 - 2,8) 10Bc Kn0,5 0,7 0,9 1,2 (1,0 - 1,4)1,5 1,7 1,9 2,1 2,3 (2,2 - 2,8) 11Thi Nguyn0,5 0,8 1,1 1,4 (1,2 - 1,6)1,7 2,0 2,2 2,4 2,7 (2,2 - 2,8) 12Lng Sn 0,5 0,7 1,0 1,3 (1,2 - 1,4)1,6 1,9 2,1 2,3 2,5 (2,2 - 2,8) 13Ph Th0,5 0,8 1,1 1,4 (1,2 - 1,6)1,7 2,0 2,2 2,5 2,7 (2,2 - 2,8) 14Bc Giang0,5 0,8 1,1 1,4 (1,2 - 1,6)1,7 2,0 2,3 2,5 2,7 (2,5 - 2,8) 15Qung Ninh 0,5 0,7 1,0 1,3 (1,2 - 1,4)1,6 1,9 2,1 2,3 2,5 (2,2 - 2,8) 16Vnh Phc0,5 0,7 1,0 1,3 (1,2 - 1,6)1,6 1,8 2,1 2,3 2,6 (2,5 - 2,8) 17Bc Ninh 0,5 0,8 1,1 1,4 (1,2 - 1,6)1,7 1,9 2,2 2,4 2,6 (2,5 - 2,8) 18H Ni 0,5 0,8 1,1 1,4 (1,2 - 1,6)1,7 1,9 2,2 2,4 2,6 (2,5 - 2,8) 19Hng Yn 0,5 0,8 1,1 1,4 (1,2 - 1,6)1,7 1,9 2,2 2,4 2,6 (2,5 - 2,8) 20Hi Dng0,5 0,7 1,1 1,4 (1,2 - 1,6)1,6 1,9 2,2 2,4 2,6 (2,2 - 2,8) 21Hi Phng0,5 0,7 1,0 1,3 (1,2 - 1,4)1,6 1,9 2,1 2,3 2,5 (2,2 - 2,8) 22H Nam 0,4 0,6 0,9 1,1 (1,0 - 1,4)1,4 1,6 1,8 2,0 2,3 (2,2 - 2,8) 23Thi Bnh0,5 0,7 0,9 1,2 (1,0 -1,4 )1,5 1,7 1,9 2,1 2,3 (2,2 - 2,8) 24Nam nh 0,5 0,8 1,1 1,4 (1,2 - 1,6)1,7 2,0 2,3 2,5 2,7 (2,5 - 2,8) 25Ninh Bnh0,5 0,7 1,0 1,3 (1,2 - 1,4)1,6 1,9 2,1 2,3 2,5 (2,2 - 2,8) 26Thanh Ha0,5 0,7 1,0 1,2 (1,0 - 1,4)1,5 1,7 2,0 2,2 2,4 (2,2 - 2,8) 27Ngh An0,5 0,7 1,1 1,4 (1,2 - 1,6)1,6 1,9 2,2 2,4 2,6 (2,2 - 2,8) 28H Tnh0,6 0,9 1,3 1,7 (1,4 - 1,8)2,0 2,4 2,7 2,9 3,2 (2,5 - 3,4) 29Qung Bnh 0,7 1,0 1,4 1,8 (1,6 - 2,0)2,2 2,5 2,8 3,1 3,4 (3,1 - 3,7) 30Qung Tr0,6 1,0 1,3 1,7 (1,6 - 2,0)2,1 2,5 2,8 3,1 3,3 (2,8 - 3,7) 31Tha Thin - Hu 0,5 0,7 1,0 1,3 (1,0 - 1,6)1,5 1,8 2,0 2,2 2,4 (2,2 - 3,1) 32 Nng0,5 0,7 1,0 1,3 (1,2 - 1,4)1,6 1,8 2,1 2,3 2,5 (2,2 - 2,8) 33Qung Nam0,4 0,6 0,8 1,1 (1,0 - 1,4)1,3 1,5 1,7 1,9 2,0 (1,9 - 2,2) 34Qung Ngi 0,5 0,7 0,9 1,2 (1,0 - 1,4)1,5 1,7 1,9 2,1 2,3 (1,9 - 2,5) 35Bnh nh0,4 0,7 0,9 1,2 (1,0 - 1,4)1,5 1,7 1,9 2,1 2,3 (2,2 - 2,8) 36Ph Yn0,5 0,7 1,0 1,3 (1,0 - 1,6)1,6 1,9 2,1 2,4 2,5 (2,2 - 3,1) 37Khnh Ha0,5 0,7 1,0 1,2 (1,0 - 1,4)1,5 1,8 2,0 2,2 2,4 (1,9 - 2,8) 38Ninh Thun 0,5 0,7 1,0 1,2 (1,0 - 1,4)1,5 1,8 2,0 2,2 2,4 (1,9 - 2,8) 39Bnh Thun 0,5 0,7 1,0 1,3 (1,2 - 1,4)1,6 1,8 2,0 2,3 2,5 (2,2 - 2,8) 40Kon Tum0,3 0,5 0,6 0,8 (0,5 - 1,2)1,0 1,2 1,3 1,5 1,6 (1,3 - 2,2) 41Gia Lai0,5 0,7 0,9 1,2 (1,0 - 1,6)1,5 1,7 1,9 2,1 2,3 (1,6 - 3,1) 42k Lk0,5 0,7 1,0 1,2 (0,5 - 1,6)1,5 1,8 2,0 2,2 2,4 (1,9 - 2,8) 43k Nng 0,4 0,5 0,8 1,0 (0,5 - 1,4)1,2 1,4 1,6 1,7 2,0 (1,9 - 2,8) 44Lm ng 0,3 0,5 0,7 0,9 (0,5 - 1,6)1,1 1,3 1,5 1,6 1,8 (1,6 - 2,8) 45Ty Ninh 0,5 0,8 1,1 1,4 (1,2 - 1,6)1,8 2,1 2,3 2,6 2,7 (2,5 - 2,8) 46Bnh Dng 0,6 0,8 1,2 1,5 (1,4 - 1,6)1,8 2,1 2,4 2,6 2,7 (2,5 - 2,8) 47Bnh Phc 0,6 0,8 1,2 1,5 (1,2 - 1,6)1,8 2,1 2,4 2,6 2,9 (2,5 - 3,1) 48Tp. H Ch Minh0,5 0,8 1,1 1,3 (1,2 - 1,4)1,7 2,0 2,2 2,4 2,7 (2,5 - 2,8) 49ng Nai 0,5 0,7 1,0 1,3 (1,2 - 1,6)1,6 1,8 2,1 2,3 2,6 (2,5 - 2,8) 50B Ra - Vng Tu0,4 0,6 0,9 1,1 (1,0 - 1,6)1,4 1,6 1,8 2,0 2,3 (2,2 - 2,8) 51Long An0,4 0,6 0,8 1,1 (1,0 - 1,4)1,3 1,5 1,7 1,8 2,0 (1,9 - 2,8) 52ng Thp0,3 0,5 0,7 0,8 (0,5 - 1,2)1,0 1,2 1,3 1,5 1,7 (1,6 - 2,2) 53Tin Giang 0,5 0,7 1,0 1,1 (1,0 - 1,4)1,5 1,8 2,0 2,2 2,4 (1,9 - 2,5) 54Bn Tre0,4 0,6 0,9 1,1 (1,0 - 1,2)1,4 1,6 1,8 2,0 2,2 (1,9 - 2,5) 55Vnh Long0,4 0,6 0,8 1,1 (1,0 - 1,2)1,3 1,5 1,7 1,9 2,1 (2,2 - 2,5) 56Tr Vinh 0,4 0,6 0,8 1,1 (1,0 - 1,4)1,2 1,4 1,6 1,8 2,0 (1,9 - 2,2) 57An Giang 0,3 0,5 0,7 0,9 (0,5 - 1,2)1,0 1,2 1,4 1,5 1,6 (1,3 - 1,9) 58Cn Th0,3 0,5 0,7 0,9 (0,5 - 1,2)1,1 1,2 1,4 1,5 1,7 (1,6 - 2,5) 59Hu Giang0,4 0,6 0,8 1,1 (1,0 - 1,4)1,3 1,5 1,7 1,9 2,1 (1,9 - 2,5) 60Sc Trng0,5 0,7 1,0 1,2 (1,0 - 1,4)1,5 1,7 2,0 2,2 2,3 (1,9 - 2,5) 6