VIEN DIA LY - VIEN KH&CN VIET NAM HOI DIA LY VIET NAM
NGHIEN CUU DU BAG ANH HUONG THEO CAC
KjCH BAN BIEN DOI KHJ HAU DEN HAN HAN, SA M.AC HOA VUNG NAM TRUNG BO DEN NAM 2020
Nguyen Trgng Hieu ', Nguyen Lilp Ddn ', Pham Thj Thanh Huang ' S U M M A R Y
Provinces of South Central Coast (including Quang Nam, Da Nang, Quang Ngai, Bmh Dinh, Phu Yen, Khanh Iloa. Ninh Thuan, Binh Thuan) have an area of 40,655.7 km' (equivalent to 12.5 % of total area of whole country). Population of this region is more than 8.6 millions of people; make up 10.6% of toted population. There are over 264.981 ha of sand-bank, white-red-yello\y sank expanse, make up 6% of total area of whole country. In some places sand filled up field and construction works. More than 51,000 ha of salty soil is next lo sand-bank, 71,000 ha of alum soil is expanded by drought, flood-tide. In the hills, there are over 65,000 ha of infertile soil, more than 41,000 ha of erosion soil, especially 36,847 ha of bare rocky mountain. Wild land and hare hill of whole country has an area of 1,000,110 ha; make up 22.61'Xi of the total natural area.
The Central Southern of Vietnam affected by the the monsoon of the tropical climate with the high temperature, .high radiation, many rainfall. In this area has many high mountains protruding to the near sea that coasted plain divided by the cells separated, these characteristics have impact on the climate distribution, formation of sub-regional climate, many areas more rains but that are the arid. Amount evaporated in the area from 800-1000mm. In Ninh Thuan, evaporation of 1600inm while the average rainfall is only 700mm value. As a result, the study predicts the impact of climate change scenarios to drought - desertificalion in the Centred Southern of
Vietnam in 2020 to help making the .system for disaster management of drought - desertification to overcome and mitigation the damage caused by natural calamities of drought, desertification is essential.
DAT VAN DE
cac tinh duyen hai Nam Trung Bd tir Quang Nam- Da Nang den Binh Thuan cd dien tich lu nhien 40.655,7kiii" (tuong duang 12,5% dien tich ca nude). Dan sd trong vimg den nam 2004 hi tren 8,6 trieu ngudi chiem 10,6% dan sd ca nude. Dgc theo ddi bd bien cd tren 264,981 ba cac cdn cat, bai cat trang - dd - vang chiem gan 6% didi tich dat tu nhien ciia ca nude. Nhieu noi cat di ddng lam lap rugng vudn va cac cdng trinh dan sinh. Ben canh vimg dat cat la tren 51.000ha dat man, 71.000 ba dat phen ludn md rdng do ban ban, trieu cudng. Tren vimg ddi xuat hien dat bac mau chiem tren 65.000ha, dit xdi mdn tra da chiem trdi 41.000ha va dac biet cd tdi 36.847 ha cac nui da trgc. Dat trong ddi trgc hoang hda loan viing la 1.000.1 lOba chiem 22,61% tdng dien tich tir nhien. Vimg Nam Trung Bd chju anh hudng ciia che do khi hau nhiet ddi gid nnia cd nIn nliid do cao, khi hau ndng am, birc xa cao, mua nhieu. Trong viing cd ' Trung ldm Khoa hgc cong nghe Khi Iwong - ihiiy van vd Moi Irirdng
Vien Dia ly
Hdi nghi Klioa hgc Dia ly Todn qud'c la'n th&S - Ha Ndi. 2010 795
VTEN DIA LY VIEN KH&CN VIET NAM HOI DIA LY VTET NAM
nhilu da\ nui cao chay nhd ra sat bien da chia cat dai ddng bang ven bien thanh nhfrng d ngan each bin \di nhau, dac diem na\ da tac ddng den sir phan hda khi hau, hinh thanh cac \'ung tilu khi hau, nhieu khu vuc mua Idn nhung nhieu khu vuc lai rat kho ban. Lugng bic hai trong khu vuc tir 800-lOOOinni. Tai Ninh Thuan lugng hoc hoi 1600inni trong khi dd lugng mua trung binh chi dat gia trj 700inm. Nhu vay, viec nghien ciru du bao anh hirdng theo cac kjch ban bien ddi khi bau den ban ban - sa mac hda \ung Nam Trung Bd din nam 2020 giiip cho viec xay dung be thdng quan ly thien tai ban ban - sa mac hda viing Nam Trung Bd nham khac phuc va giam thieu cac thiet hai do thien lai ban ban, sa mac hda la rat can thid.
I. NOI DUNG CHU YEN CUA KICH BAN BIEN DOI KHI HAU 6 NTB TRONG THE KY 21
Kich ban bien ddi khi bau nam 2007 dirge Vien Khoa bgc Kbi tugng Thiiy van va Mdi trudng xay dung theo phuo'ng phap to hgp MAGIC - SCENGEN tir cac md hinh khi bau cua nhieu nude khac nhau tren the gidi. Kjch ban bien ddi khi hau nay dugc xay dung chi tiet cho 7 vimg khi ban d Vid Nam: Tay Bac. Ddng Bac, ddng bang Bac Bd, BIC Trung Bd, Nam Trung Bd, Tay Nguyen va Nam Bd, Ndi dung chu yeu ciia kjch ban bao gdm: Muc tang nbid do trung binh (°C), miic thay ddi ty le lugng intra va muc nude bien dang vao cac nam: 2020, 2030,.,., 2100 so vdi thdi ky 1980 - 1999.
1.1. Kjch ban nhiet do
Ngi dung cbii yeu trong kjch ban nbid do la muc tang nhiet do trung binh nam cac miia: xuan (III - V). ha (VI - VIII), thu (IX - XI), ddng (XII - II).
0 NTB, theo kjch ban cao mirc tang nbid do trung binh nam so vdi thdi ky 1980 - 1999 vao cac nam 2020, 2050, 2070, 2100 la: 0,4; 1,0; 1,5; 2.4°C, Tuy nhien, mirc tang nhiet do lai khac nhau trong cac miia, trong dd niiia he cao bon trung binh nam con trong miia xuan, miia thu va miia ddng thi ngugc lai, thap ban hoac xap xi trung binh nam.
Theo kjch ban vira, mirc tang nhiet do trung binh so vdi thdi ky 1980 - 1999 vao cac nam ndi tren lan lugt la 0,4; 0,9; 1,4; 1,9°C cao ban chiit it so vdi mirc tang ciia kjch ban thip: 0,4; 0,9; 1,2; 1,2°C.
Khac kjch ban cao, trong kjch ban viia va thip cua nhiet do trung binh miia xuan, miia thu va miia ddng cao ban cua nam va mirc tang cua nhiet do trung binh miia he thi ngugc lai, thap ban ciia nam,
1.2. Kjch ban luong mua
Ngi dung ca ban ciia kjch ban lugng mua la mirc tang hay giam hay con ggi la mirc tha\ ddi ty le lugng mua nam vao cac miia: xuan, ba, thu, ddng,
0 NTB, theo kjch ban cao, mirc tang lugng mua nam so vdi thdi ky 1980 -1999 vao cac nam 2020, 2050, 2070 va 2100 lln lugt la 0,8; 1,9; 3,1; 5,0%, Tuy nhidi, mirc thay doi tuong img trong cac miia rat khac nhau: giam di trang miia ddng, miia xuan va ngirgc lai la tang len trong miia he va miia thu.
Theo kjch ban viia, muc tang ciia lugng mua nam so vdi thdi ky 1980 - 1999 vao cac nam ndi tren lln lugt la 0,3; 0,8; 1,1; 1,5%, Cung nhu kjch ban cao, mirc thay dii
796 Hdi nghi Khoa hgc Dia ly Todn qud'c lan th&S - Ha Ndi, 2010
VTEN DIA LY - VIEN KHfcfCN VIET NAM KOI DIA LY VTET NAM
ciia lugng mua trong kjch ban vii'a la giam di trong miia ddng, nuia xuan va tang len trong nuia be va nuia thu nhirng vdi ty le thap ho'ii.
Theo kjch ban thap, mirc tang cua lugng mua nam so vdi thai ky 1980 - 1999 vao cac nam ndi tren lan lugt la 0,3; 0,7; 0,9; 1,0%, Tuo'ng tu kjch ban cao va kjch ban vira, lugng mua miia ddng va miia xuan giam di trong khi lugng mua miia be va miia thu tang len vdi ty Ic cdn thap ban kjch ban vira.
1.3. Kjch ban nude bien dang
Tren cac doan bd bien Viet Nam, tir Bac Bd, Trung Bd den Nam Bd deu cd chung kjch ban nude bien dang. Theo kjch ban cao, muc nude bien dang vao cac nam 2020, 2050, 2070 va 2100 la 12; 33; 57; 100 cm trong khi kjch ban vira dir kien muc nude bien dang trong cac nam ndi tren la 12; 30; 46; 75 cm. Theo kjch ban thap, muc nude bien dang vao nam 2050 la 28 cm va nam 2100 la 65 cm.
II. LU^A CHON C l l i SO HAN HAN PHUC VU XAY DUNG KICH BAN HAN HAN CHO NAM TRUNG BO
11.1. Cac loai han iian
Tir nam 1983 mdt sd chuyen gia ciia Td chuc Khi tugng the gidi (WMO) da phan djnh 4 loai ban ban sau day:
1) Hgn khi tugng
Thieu but nude trong can can lugng mua - lugng bdc bai, nhat la trong cac trudng hgp lien luc it mua hoac khdng mua. O day, lugng mua tieu bieu cho phan thu va lugng bdc hoi tieu bieu cho phan chi ciia can can nude.
2) Hgn ndng nghiep
Thilu but mua dan tdi mat can bang gifra ham lugng nude thuc te trong dat va nhu cau nude ciia cay trdng. Han ndng nghiep tbirc chat la ban sinh ly dugc xac djnh bdi dieu kien nude khdng thich nghi ciia cay trdng, he canh tac ndng nghiep,...
3) Hgn thiiy vdn
Ddng chay sdng sudi thap ban trung binh nhieu nam rd r d va muc nude trong cac tang chua nude dudi dat ba thap.
4) Hgn kinh te - xd hdi
Nude khdng dii cho nhu cau ciia cac hoat ddng kinh te - xa hdi.
11.2. Yeu cau ve chi so ban ban phuc vu xay dung kjch ban han han
D I CO mdt chi sd ban ban phuc vu die lire cho viec xay dung kjch ban ban ban, chiing tdi xac djnh mdt sd yeu cau chung ve chi sd ban ban nhu sau:
1) Chju su tac dgng rd ret ciia biln ddi kbi hau va cd lien quan mat thiet vdi cac ylu to chinh trong kjch ban biln ddi khi hau la nhiet do va lugng mua.
2) Phan anh dugc ban chit ban ban la thieu but mua so vdi yeu cau ciia thuc te san xuat ndng nghiep.
3) Phan anh dugc dao ddng am ciia lugng mua tai thdi diem bidi tai.
4) Phan anh dugc ca mirc do thilu hut mua tai thdi gian hidi tai va ca anh hudng kl thira ciia tinh trang thilu hut mua thdi gian trudc do.
Hdi nghi Khoa hgc Dia ly Todn qud'c Id'n th&o - Ha Ndi, 2010 797
VIEN DIA LY - > IEN KH&CN VIET NAM HOI DIA LY VIET NAM
5) Phan anh dugc nuic do ban ban llurc te nhat la nhiing nam ban nang.
6) Cac so lidi dl tinh chi sd ban cd the thu thap dugc.
11.3. Danh giii ciic chi so han da co
Dua tren kit qua phan lich kha nang dap irng 6 yeu cau tren cho tiing chi so ban khi tirgnc. ban nong nghiep da cd cho phep phat hidi 4 chi sd dugc coi la co sd cho
\ iec xa\ dung chi so ban ban phuc \ u xa\' dung kjch ban.
1) Chi so aj
Y^R<15%YA
2) \a 3) Cac chi sd a?, as Z y? < 10: 30; 50 mm llidng
4) Chi sob,?
" - I
Kii = kn + Y,ik,-l)
11.4. Xac djnh chi sd han phuc vu xay dung kjch ban han han
Tac ddng ciia bien ddi khi hau den ban ban va sa mac hda d NTB dugc nghidi ciru thdng qua viec xay dung kjch ban ban ban cho khu vuc nay. De lien hanh cdng vice he trgng luiy, trudc het phai xac djnh chi sd ban cho khu virc,
can cir vao linh chat trien mien ciia ban ban d viing khi bau NTB va ket qua doi chieu cac chi sd ban da cd vdi cac yeu cau ve chi sd ban hoac phuc vu xay dung kjch ban bien ddi khi hau, chimg tdi da xac djnh chi sd ban ban vdi cac thanh td sau day:
(1) Ten chi sd: Do dai miia ban
(2) Don vj trac lugng: Thdi gian keo dai, tinh bang thang hoac bang ngay (3) Diet! kien xuat hien va ton tai ban
- Han xuat bien va tdn tai trong ca miia vu dugc xac djnh thdng qua cac tieu chi sau da\:
(a) Trong ihdi gian tir thang XI din thang IV tong lugng mua 3 thang lien tiep khong qua 60 mm.
(b) Trong thdi gian tii' thang IV den thang V long lugng mua khdng qua 70 mm.
(c) Trong thdi gian tu thang V den thang IX long lugng mua 2 thang lien tiep khong qua 100 mm.
Doi \di bat cii' dja phuong nao trong khu vuc, dugc coi la tdn tai ban khi thoa man cac dieu kidi sau day:
- Ton tai ban dong xuan vdi dilu kidi (a), (b) - Tdn tai ban miia lii vdi dilu kien (c)
- Ton tai ban 2 vu vdi dieu kien (a) va (c) hoac (b) va (c).
798 Hdi nghi Klioa hgc Dia ly Todn qud'c lan th&S- Ha Ndi, 2010
VIEN DIA LY • VIEN KH&CN VIET NAM HOI DIA LY VIET NAM
111. XAY DUNG KICH BAN H.\N 6 NTB 111.1. Muc dich
1) Dir kien tinh hinh ban d NTB Irong cac ihap ky sap tdi.
2) Daub gia tac dgng cd the cd cua ban ban vdi mgt sd dieu kidi kinh le .xa hgi trong thdi gian sap tdi.
111.2. Ngi dung cdng tiic
Ndi dung cdng lac xay dung kjch ban ban d NTB bao gdm cac budc cong lac sau
• d a y :
Budc T. Xac djnh thdi ky ban cao diem tuong irng vdi miia khi hau trong kjch ban bien doi kbi ban.
Budc 2: Xac djnh cac diic trung yeu td khi hau trong kjch ban khi hau lien quan vdi ihdi ky ban cao diem.
Bircrc 3: Xac djnh mdi quan he gifra do dai miia ban vdi cac dac trung >cii td khi hau trong kjch ban bien ddi khi hiiu.
Budc 4: Xac djnh mirc thay ddi do dai miia ban tuong irng vdi mirc tang nbid do theo kich ban bicn ddi khi bau.
Budc 5: Xac djnh mirc thay ddi do dai miia ban tuong irng vdi mirc tang ciia lugng mua lbeo kjch ban bicn doi khi ban.
Budc 6: Lira chgn kjch ban ban trong cac thap ky sap tdi.
111.3. Thdi ky han cao diem
Miia ban d NTB xay ra tir thang I den thang VI, thing Vll d luiu het khu vuc.
Ridig d phia Nam Binh Thuan nuia ban xay ra tir thang 1 den thang VII, thang Vlll.
Thdi gian chii }'cu cao diem ciia miia ban d NTB ki lir Uuing VI den thang Vlll tren hau bet cac tinh va tir thang 111 den thing V d Nam Binh Thuan. Dd cfmg li co' sd de xac djnh dac trung luang irng phd bien trong kjch ban la nbid do miia be (VI - VIII), rieng d Nam Binh Thuan la nbid do trung binh miia xuan va lugng mua miia xuan (111-V).
111.4. Moi quan he giua han vdi nhiet do va mua
De hinh dung dugc mdi quan he gifra ban vdi nhiet do va lugng mua, chimg toi khao sat chuan sai ciia ban, nbid do trung binh nuia he va lugng mua nuia he tren cic dja dilm lieu bilu vao 10 nam ban nang nhll: 1963, 1969, 1977, 1979, 1983. 1987, 1993, 1998, 2002, 2005 va 10 nam ban it nhll hoac khdng ban: 1961, 1971, 1976, 1978, 1982,1985, 1989, 2000, 2001, 2007.
Cd Ihl nhan djnh nhu sau ve k d qua trinh bay trong bang 1.
1) vao nhfrng nam ban nang ciia khu vuc, phan Idn chuan sai thang ban AH ciia cac noi diu duong, ty trgng chuan sai duang thay ddi cao d 3 tinh trung tam: Binh Djnh, Phil Yen, Khanh Hda va tuong doi thip d cac tinh khac. Tuong tu, vao nbiing nam ban nhe ciia khu vuc, phan Idn chuan sai ban ciia cac nai deu am, ty trgng chuan sai am Cling cao nhit d 3 linh trung tam va tuong ddi thap a Da Nang, Quang Nam va Binh Thuan.
Hdi nghi Klioa hoc Dia ly Todn qud'c Id'n th&S - Hd Ndi, 2010 799
VIEN DIA LY - VIEN KH&CN VIET NAM HOI DIA LY VIET NAM
2) T\ trgng chuln sai duong \ a khdng ciia nhiet do AT vao nhung nam ban nang cfina nhu t\ trgng chuan sai am va khong ciia nhiet do vao nhfrng nam ban nhe phd biln tren 80%.
3) Tv trgng chuln sai am ciia lugng mua AR vao nhfrng nam ban nang cfmg nhu tv trgna dironc ciia lugng mua vao nhfrng nam ban nhe phd bien tren 50%.
Mdi quan he giiia do dai miia vdi thdi gian (t). nhiet do (T) va lugng mua (R) trong thdi ky chii yeu ciia miia ban dugc diic k d trong bang 2.
D I dang nhan thay, do dai miia ban tang len theo nbid do vdi tdc do tir 0,03 thang/°C d Phan Thilt len 0,80-0,88 thang/°C d Da Nlng, Quy Nhon va 1,45- 2,11 thang/'C d Tuy Hda, Nha Trang, Trong khi do. do dai miia ban giam di theo lugno mua vdi tdc do 0,016 - 0,155lhang/10min,
Day chinh la co sd de du tinh mirc do keo dai hay nit ngan miia ban kbi nhiet do tang len va lugng mua thay ddi theo kjch ban bien ddi kbi bau d NTB,
Bdng 1: Chuan sai so thdng hgn, nhiet do trung binh vd lugng mira trong 10 hgn nang vd 10 ndm han nhe.
Mirc do han
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boo Hdi nghi Khoa hgc Dia ly Toan qud'c lan th&S-Ha Ndi, 2010
VIEN DIA L'i" - VIEN KH&CN V I E T NAM i r o i DIA LY VIET NAM
Bang 2: MCit sd d(tc trung ve tdc ltd xu the cua hgn
Uac irung yen l6
[)6 dai miia han Do lech tieu chuiin ciia do dai miia han Nhiel do trung binh Uong miia han
Do lech tieu chuan ciia T trong niCia han Luong mua Irong niiia han Do lech lieu chuan ciia R trong niiia han Toe do xu the ciia H tinh theo ihiri gian 1 He so tuong quan gifra H va 1 Toe do \ii iht;
ciia H theo T He so tuong quan giii'a H va T
Toe do xu the ciia 11 Iheo R He so tirang quan giira H va R
Toe do xu the cua T theo ihdi eian 1
He so Urang quan gifra T va t Toe do xu the ciia R theo thoi gian 1
He so tirong quan gi&a R va t
ICy hieu
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ST R SR
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b , ( r t ) r ( i t ) b,(RO r(Rt)
Dan vi linh
thang Ihiing
°C
»C mm mm
thang/nam lhang/°C
ihang/lOmm
"C/nam mm/nam
T'ram khi urgng tieu bieu Da Nang
2,89 2,12
29,1
0,37 314 100
0,0069 0,0444 0,8018 0,1430 -0.016 -0.3037
0.0005 0,0111 2,1185 0,1993
Quy Nhon 3,66 2,27
29,9
0,41 182 84
-,00126 -0,0753 0,8680 0,1567 -0.050 -0,1843
0,0168 0,5550 0,0969 0.1557
Tuy Hoa 4,28 2,32
29.1
0,60 151 75
0,0030 0,0176 1,4490 0,2250 -0,155 -0,4980
0,0043 0,1624 0,1302 0,0237
Nha Trang 5,36 2,14
28,6
0,60 139 62
0,0219 0,1204 2,1070 0,5167 -0,057 -0,1421
0,01573 0,3386 0,6282 0,1422
Phan Ihiii 5.21 0.90
27.8
0.49 186 89
0.0045 0.0682 0.0306 0,1665 -0.032
0.3210 0.1966 0.5456 1.2779 0.1949
III.5. Miic tang do dai mua han theo cac kich ban bien doi khi hau 3.5.1. Mirc tdng do ddi miia hgn do nhiet do tdng
a) Kich bdn cao
Theo kjch ban cao, mirc tang do dai miia ban do nhiet do tang vao cac mdc chinh ciia the ky 21 nhu sau
a,) Nam 2020
Do dai miia ban tang len 1 0 - 2 0 ngay d cac tinh phia Bac (Da Nang. Quang Nam, Quang Ngai, Binh Djnh), 5 - 1 0 ngay d Nam Binh Thuan va 20 - 40 ngay d cac
Hdi nghi Khoa hgc Dia ly Todn qud'c la'n th&S-Ha Ndi, 2010 801
. . r , ^ « v f P T N & M HOI DIA LY VIET NAM
VIENDIAJ^Y^>25!iJ^5^?^^^5^^5Iil^^ '- =
nnh phia Nam (Phu i'di. Khanh Hda. Ninh Thuan. Bac Binh Thuan) va 5 - 20 ngay d Nam Binh Thuan.
a.) Nam 2050
Dd dai mua ban tang ldi 20 - 30 nga> d cac tinh phia B I C . 30 - 50 ngay d cac inih phia Nam. 30 - 50 ngay d tinh phia Nam va 1 0- 30 ngay d Nam Binh 1 huan.
a-,)Nam 2100
Do dai miia ban tang ldi 60 - 100 nga>' d cac tinh phia B I C . 100-180 ngay d cac tinh phia Nam. 20 - 40 ngiiy d Nam Binh Thuan.
b) Kich ban vira
Theo kich ban xira, mirc tang do dai mua ban do nhiet do tang vao ciic mdc chinh nhu sau:
bi) Nam 2020
Do dai mua ban tang ldi 5 - 1 0 ngay a phia BIC. 1 0 - 3 0 ngay d phia Nam, ridig Nam Binh ibunn cbl 3 - 5 ngay.
b:)Nam 2050
Do dai miia ban tang ldi 1 5 - 20 ngiiy d phia B I C . 25 - 45 ngay d phia Nam, rieng Nam Binh Thuan chi 5 - 7 ngay.
b:,)Nam 2100
Do dai mua ban tang len 30 - 40 nga> a phia B I C . 40 - 90 ngay a phia Nam, ricng Nam Binh Thuan chi 1 0 - 2 0 nga\',
c. Kich ban thdp
Theo kjch ban thip, mirc tang do dai miia ban do nhiet do tang vao cac moc chinh nhu sau
C|)Nam 2020
Tuang tir kjch ban vira c:) Nam 2050
Thap ban mdt it so vdi kjch ban vira c.) Nam 2100
Do dai miia ban tang len 20 - 50 ngiiy a phia B I C . 25 - 60 ngiiy d phia Nam, rieng Nam Binh Thuan chi dudi 10 nga\.
3.5.2. .Mirc thay ddi do ddi miia hgn do thay ddi lugng mua
Tha\ ddi do dai miia ban d ca phia BIC va phia Nam vdi bit cir kich ban nao deu la giam di \di nuic pho biln 1 - 2 ngay vao nam 2020, 2 - 4 ngay vao nam 2050 va 5 - 6 nga\ vao nam 2100. Ricng d Binh Thuan. do Uic dgng ciia lugng mua giam vao thdi ky cao didn, miia ban dai them khoang 3 nga\ \ a o nam 2020, 7 ngay vao nam ^050 \'a 9 - 1 8 nga_\ \ao nam 2100.
5._\5. .Mirc ldng do ddi iniia hgn do hien ddi khi ligii
Do bidi ddi khi hiiu, bao gom nhiel do lang len \ a tha>' ddi lirgng mua, miia ban kco dii them \ai mirc nhu sau trong cac mdc thdi gian cua the ky 21,
~^ Hdi nghi Klioa hgc Dia ly Toan qud'c la'n th&S - Ha Ndi, 2010
VIEN DIA LY - VIEN KH&CN VIET NAM HOI DIA L'r VIET NAM
a. Kicli bdn cao a,) Nam 2020
Do dai miia ban tang ldi 1 0 - 1 5 ngay d phia BIC, 1 5 - 3 5 ngay d phia Nam, rieng Nam Binh Thuiin dudi 10 ngay.
a,) Nam 2050
Do dai miia ban tang len 25 - 30 ngay d phia BIC, 40 - 70 ngiiy d phia Nam.
rieng Nam Binh Tluiaii dudi 15 ngay.
a3)Nam 2100
Do dai nuia ban tang len 60 - 70 ngay a phia BIC, 100 - 180 ngay d phia Nam, ricng Nam Binh Thuiin khoang 40 - 50 ngay.
b) Kich bdn vira b|)Nam 2020
Do dai miia ban tang len 5 - 1 0 nga\ d phia BIC, 1 0 - 2 0 ngay d phia Nam, rieng Nam Binh Thuan chi khoang 5 - 7 ngay.
bj) Nam 2050
Do dai miia ban tang len 1 5 - 2 0 ngay d phia Bac, 20 - 50 ngay d phia Nam, rieng Nam Binh Thuan chi 1 0 - 1 5 ngay.
b3) Nam 2100
Do dai miia ban tang len 30 - 35 ngay d phia Bac, 35 - 90 ngay d phia Nam, rieng Nam Binh Thuan chi 20 - 30 ngay.
c. Kich bdn thdp C|) Nam 2020
Do dai miia ban tang len 5 - 1 0 ngay d phia Bac, 1 0 - 2 0 ngay d phia Nam, rieng Nam Binh Thuan chi khoang 5 ngay.
c.) Nam 2050
Do dai miia ban inng len 1 5 - 2 0 ngay d phia Bac, 20 - 50 ngay d phia Nam, rieng Nam Binh Thuan chi 1 0 - 1 5 ngay.
C3) Nam 2100
Do dai miia ban tang ldi 20 - 25 ngay d phia Bac, 25 - 60 ngay d phia Nam, ricng Nam Binh Thuan chi 1 5 - 2 0 ngay.
IV. TAC DONG CUA BIEN D O I KHI H.4U DEN HAN HAN, HOANG MAC HOA VAO NAM 2020
IV.l. Du kien tac dgng ciia bien ddi khi hau den han han, hoang mac hoa va sa mac hda d NTB trong the ky 21
Tac dgng ciia biln ddi khi hau den tinh trang ban ban, hoang mac boa va sa mac hda khdng bain toan nhu nhau tren dja ban NTB. Cd the phan b i d 3 nhdm dja phuong khac nhau vl mirc tang ciia nbid do, mirc thay doi ciia lugng mua, mirc tang do dai miia ban va nguy ca hoang mac hda.
Hdi nghi Klioa hgc Dia ly Todn qud'c lan th&S-Hd Ndi, 2010 803
VIEN D!A LY - VIEN KH&CN VIET NAM HOI DIA LY VIET NAM
1) Cdc tmh phia Bdc NTB
Cac tinh phia BIC bao gom Da Nang, Quang Nam, Quang Ngai va Binh Djnh vdi hai tram khi tugng tidi bilu la Da Nang, Quy Nhan. C» day ban thudng xay ra trong miia xuan \ a ca miia he vdi do dai trung binh miia ban khoang 2,5 - 3,5 thang. Nhirng nam ban nang. ban bit diu tii' cuoi miia ddng, qua miia xuan va trd nen gay git Irong miia be. Nhfrng nam ban nhe, ban chi bd ggn trong mdt vai thang miia xuan hay miia hd
Theo du kiln, do dai miia ban keo dai thdn khoang 5 - 1 5 ngay vao nam 2020, 15 - 35 nsax Nao nam 2050 va 20 - 70 ngay vao nam 2100, nguy ca hoang mac boa ngay can" tang len \'a trd len tuong ddi nghiem trgng tir nhung nam 2020 va nghiem trgng tu nhfrng nam 2050.
2) Cdc Imh phia Nam
Cac tinh phia Nam bao gdm Phii Yen, Khanh Hda, Ninh Thuan va Bac Binh Thuan \'di hai tram khi tugng tieu bieu la Tuy Hda va Nha Trang.
Trong nhfrng nam qua, ban thudng xay ra tii' cudi miia ddng, qua miia xuan den miia be. Nhung nam nang, ban bat dau tir thang XII, thang I va ket thiic vao cuoi miia he. Nhfrng nam nhe, ban chi duy tri trong miia xuan. Trung binh mdi nam miia ban dai 4 - 6 thang.
Theo du kien do dai miia ban keo dai them 1 0 - 3 5 ngay vao nam 2020, 20 - 70 nga\' vao nam 2050 \'a 25 - 180 ngay vao nam 2100.
0 cac tinh phia Nam, nguy co' hoang mac hda ngay cang tang len va trd len nghiem trgng tir nhfrng nam 2020 va dac bid nghiem trgng tir giQa the ky 21.
3) Nam Binh Thuan
Trong nhirng nam qua ban thudng xay ra vao miia ddng va miia xuan. Nhung nam nang, ban bat dau tii' thang XII keo dai den thang V, thang VI. Nhung nam nhe, ban chi bo hep trong 3 thang, tii' thang I den thang III.
Theo du kien do dai miia ban keo dai them 5 - 1 0 ngay vao nam 2020, 1 0 - 1 5 ngay vao nam 2050 va 1 5 - 5 0 ngay vao nam 2100.
Tiem nang hoang mac hda hien tai d viing nay Idn hon cac tinh phia Bac song thap hon cac tinh Khanh Hda, Ninh Thuan va BIC Binh Thuan. Theo du kiln hoang mac hda nga>' cang tang len, nghiem trgng ban hoac bing cac tinh khac d phia BIC, nghTa la tuang doi nghiem trgng tir nhfrng nam 2020 va nghiem trong tii' nhung nam 2050.
1V.2. Du kien tac dong ciia biin dii khi hau din han han, hoang mac hoa vao nam 2020 Vao khoang nam 2020, tinh hinh ban ban va hoang mac hda dien ra nhu sau trdi cac bd phan lanh tho ciia NTB
1) Cdc tmh phia Bdc NTB
So vdi thdi ky 1980 - 1999, do dai miia ban dai them 1 0 - 1 5 ngay song tiem nang hoang mac boa chi d mu'c tuong doi nghiem trgng tren mdt so huyen ding bing ven bidi hoac trung du nhu Thanh Binh, Niii Thanh (Quang Nam), Md Dire, Dire Phd (Quang Ngai). Phii Cat, Phii My, Tuy Phudc (Binh Djnh),
eo4 Hdi nghi Khoa hoc Dia ly Toan qud'c lan th&S-Hd Ndi, 2010
VIEN DIA LY - VIEN KH&CN VIET NAM HOI D | A LY VIET NAM
2) Cdc tinh phia Nam NTB
So vdi thai ky 1980 - 1999, do dai miia ban dai them 1 0 - 3 5 ngay song tiem nang hoang mac hda trd len nghiem trgng dtinh Ninh Thuan va cac huyen Dien Khanh, Cam Ranh ciia Khanh Hda, Tuy Phong, Bac Binh ciia Binh Thuiin,
3) Bdc Binh 'Thuan
So vdi thdi ky 1980 - 1999, do dii miia ban dai them 5 - 1 0 ngay song tilm nang hoang mac hda d mirc tuong ddi nghiem trgng.
V. KET LUAN
1) Theo kjch ban bien ddi khi hau cho Viet Nam, d N T B nhiet do trung binh nam tang len 0,4"C vao nam 2020; 0,9 - 1,0°C vao nam 2050 va 1,2 - 2,4°C vao nam 2100.
Cd dieu la ,d' NTB theo kjch ban cao mirc tang nhiet do vao miia he cao hon ciia ca nam, cdn theo kjch ban thap thi ngugc lai,
2) Cung nhu kjch ban bicn ddi kbi bau cho Viet Nam, d NTB lugng mua tang khoang 1,5 - 2,0%, Tuy nhien, lugng mua khdng tang trong tat ca cac miia ma giam di trong miia ddng va miia xuan,
3) O NTB cd the phan bid hai che do ban khac nhau:
- Han bat dau tir miia xuan keo dai va bet sire khac ngliid vao miia he tren hau khap cac tinh
- Han bat dau tir miia ddng, keo dai va khac nghid ban trong miia xuan d Nam Binh Thuan.
4) Han ban keo dai, cang ve cudi miia cang nghiem trgng va do dd, dac trung chii yeu de phan anh linh trang ban d NTB la do dai miia ban.
5) Trong gan 50 nam qua, do dai miia ban tang Ien kbi nhiet do tang ciing vdi hrgng mua giam va ngugc lai, giam di khi nhiet do giam va lugng mua tang. Dd la ca sd khoa hgc chii yeu de tinh mirc tang ciia do dai miia ban khi lugng mua thay ddi theo kjch ban bien ddi khi hau d NTB trong the ky 21.
6) Theo dimg kjch ban bien ddi khi hau cho NTB, vao nam 2020, do dai miia ban tang len 1 0 - 3 5 ngay theo kjch ban cao va 5 - 20 ngay theo kjch ban thap; vao nam 2050, tang len 15 -75 ngay theo kjch ban cao va 1 0 - 5 0 ngay theo kjch ban thap. Den nam 2100, mirc tang se la 40 - 180 ngay theo kjch ban cao va 1 5 - 6 0 ngay theo kjch ban thap.
Mirc tang ndi tren trong bat cii' kjch ban nao, thai diem nao cung tuong ddi ihap d cac tinh phia Bac ciing nhu Nam Binh Thuan va tuong ddi cao d cac tinh phia Nam.
7) Nguy CO' hoang mac hda d NTB ngay cang ro ret, nhat la d cac tinh phia Nam:
Khanh Hda, Ninh Thuan, Bac Binh Thuan.
Hdi ng-hi Klioa hgc Dia ly Toan qud'c la'n th&S - Ha Ndi, 2010 805
VIEN DIA LY • VIEN KH&CN VIET NAM
HOI DIA LY VIET NAM
TAI LIEU THAM KHAO
[1], NGUVEN VAN CU'va nnk, 2000. Nguyen nhdn. gidiphdp vd ngdn chgn qua trinh hoang mgc hda d Nam Trung Bg.
[2]. NGUYEN DUC NGU' va nnk, 2002. 77/;; hieu vi hgn hdn vd hoang mgc hda Nha xuat ban Khoa hgc va ky tluial.
[3]. NGUYEN TRONG HIEU, 2000, Nguyen nhdn, giai phdp phdng ngira vd ngdn chgn qua Irinh hoang mgc hda a Trung Trung Bg.
[4], NGUYEN TRONG HIEU, 1995. Phdn bd hgn hdn vd tdc ddng cua elnino
Vidi Khi tugng Thiiy van. "" '^"'' [51. Vidi Khoa hgc Kbi tugng Thiiy van va Mdi trudng, 2009, Di dn .xdy dimg
han do hgn hdn vd mirc do thieu nuac sinh hogt a NTB vd Tdy Nguyen.
[6]. Bg Tai ngu>'di va Moi trudng, 2009. Kich ban biin ddi khi lidii. nude bien ddng cho J'iel .\aiii.
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Hdi "g'hi Klioa hoc Dia Iv Todn aud'c Id'n thi'r.^ - Ha nrA; onm
