Hạn hán, hoang mạc hóa lãnh thổ Tây Nguyên với kịch bản biến đổi khí hậu

35(4), 3/0-377

Tap chi CAC KHOA HOC V£ TRAI B A T

\ ^ A N HAN, HOANG MAC HOA LANH THO
TAY NGUYEN GAN V6l KICH BAN BIEN DOI KHI HAU
NGUYEN LAP D A N ' , NGUYEN TRQNG HIEU^ VU THI THU LAN'
E-mail:
Viin D(a ly, Vien Hdn tdm Khoa hgc vd Cong nghi ^101 Nam
Trung tdm KHCN Khi lufrng, Thdy vdn vd Moi truang
Ngay nhanbai: 8 - 9 - 2 0 1 3
l.Mff dau
Lanh tho Tay Nguyen co ranh gioi gan trimg
voi dia giai hanh chinh ciia 5 tinh Kon Tum, Gia
Lai, Dak Lak, Dak Nong va Lam Dong. Ve phia
bac, giap voi viing ritng niii ciia tinh Quang Nam,
phia nam va tay nam giap cac tinh Binh Thuan,
Dong Nai, Binh Phuoc. Phia dong giap cae tinh
dong bang ven bien Nam Trung Bo: Quang Ngai,
Binh Dinh, Phii Yen, Khanh Hoa, Ninh Thuan,
Phia tay giap Cpng hoa dan chu Nhan dan Lao va
Vuong quoc Cam Pu Chia, Di?n tich t\i nhien toan
Ianh th6 Tay Nguyen la 54.473,79 km^.
Tay Nguyen co 4 h? thong song Ion, thugng
song Se San, thugng song Ba, thugng song Srepok
va thugng song Dong Nai, Theo thong ke, din nSm
2009 dan s6 ciia 5 tinh Tay Nguyen la 5.107.437
nguoi. Tay Nguyen dugc ggi la noc nha Dong
Duong, la dia ban quan trgng ciia ca nuoc ve kinh
t e - x a hgii va an ninh quoc phong.
Tay Nguyen co trii lugng nuoc nam phong phii,

nhung vao thai ky miia kho, ban han vin xay ra lien
tiep. Han han thucmg gay anh huong tren dien rgng.
Tuy it khi la nguyen nhan true li6p gay t6n thit vi
nguai, nhung thiet hai ve kinh te - xa hpi va moi
truang do ban han gay ra la rat Ian [1].
Bai bao se phan tich danh gia thyc trang han
han, hoang mac hoa ISnh tho Tay Nguyen, gin voi
kich ban bien doi khi hau the ky XXI.
Day la m^t phSn ket qua cua de tai "Nghien
ciru CO sa khoa hgc cho giai phap tong thi giai
quyet cac mau thuan Igi ich trong vi^c khai thac sit
d\mg tai nguyen nuoc lanh tho Tay Nguyen", m3

so TN3/T02 thugc Chuang trinh Khoa hgc va
Cong nghe phuc vu phat trien kinh te - xa hgi TSy
Nguyen, ma so TN3/11-15.
2. Thirc t r a n g h^n han, p h a n bo khong gian vk
dien bien ban lanh tho T i y Nguyen
2.1. Thirc trgng hgn hdn
_ Chi trong khoang thoi gian 1990 - 2000 tren ISnh
tho Tay Nguyen, han han da xay ra vao cac n3m
1994, 1995, 1996, 1997 vk 1998 voi dien tieh liia bj
ban mSi vy tir 2000 ha din 130 000 ha. Dgt han n5m
1998 da gay ban cho 10.700ha Iiia nuac vy Dong
Xuan (mat trSng 5.320 ha), 13.330 ha Iua vy miia
(mat trang 2.280 ha). Dicn tieh cSy an qua v^ cSy
eong nghiip bj han la 110 630 ha (bi chdt la 13.760
ha), rieng ca phe di?n tich bi ban la 74.400 ha (bj
chet 13.760 ha). So nguoi bi thieu nuac sinh hoat
trong dgt han nay len den hon 770.000 nguai.

Gan day nhat, nam 2003 tren luu virc s6ng
Srepok da c6 khoang 40.400 ha ea phd bj han, thi?t
hai uac tinh len toi 277 ty d6ng.
Den nam 2008 Tay Nguyen da xay dyng 1.360
cong trinh bao gom: ho chua 760 cong trinh, dap
dang 558 cong trmh, tram bom 42 cong trinh, so voi
nang luc tuoi thiet ke cac c6ng trinh chi dap iing
hieu suat tuoi dugc tren 60% thyc tudi [2].
Theo bao eao thdng 3 nSm 2013 ciia Bg Nong
nghi?p va Phat triSn Nong th6n, tii thing 8/2012,
do khi hau ENSO boat dgng manh da tac dgng xiu
den nguon nuoc cac tinh Tay Nguyen gay thi^u
nuoc, han han anh huang rat Ian din san xuat cufli
vy Dong Xuan 2012-2013, d i u vy He Thu 2013 vi
nuoc sinh boat ciia nhan dan, theo thflng ke [3] bj
anh huong n$ng n i nhat la ckc tinh Dak LSk, Dak
Nong, Gia Lai, Kon Turn.


Da CO 39.607 ha cay trong bj thieu nuoc bao Ion o Tay Nguyen dSu bj tbiia hyt nuoc nghiem
gom: Ilia 11.036 ba, ca phe 23.921 ha, cay khac trgng, nhieu ho chira nho da can hoac gan xuflng
5007 ha; trong d6 han nSng dk Iam mat trSng 3857 den myc nuoc chet khong du tuai suot vy gay ra
ha. Hau het cac ho chua thiiy lgi, thuy dien vira va ban han (bdng 7).
BSng 1 . Di^n tich h^n han cac tinh Tay Nguyen
(Bao cao ngay 12/03/2013 ciia Bq Nong nghigp va Phat trien Nong th6n)
STT
1
2
3
4

5

Tinh

Di$ n tich gieo trdng
t h i / c t l (ha)

Kon Tum
Gia Lai
Ddklik
Dih NOng
Lam DAng
Ting cOng

6920
26.630
31.444
4.027
11.070
50.091

Dig
h^n Mn (ha)
2.044
1.174
22.144
13.186
1.416
39.964

Trong dd (ha)
LCia
605
793
6698
1.124
1,416
11.036

CdPhe

14.525
9.293

cay khac
1.136
361
721
2.769

^3.921

5.007

103

t i l n g (ha)
500
255
3247

4,002

Danh gia ve kinh te, tinh Gia Lai uoc tinh thj|t
hai do ban han gay ra khoang 196,817 ty ddng
trong do cay ca phe thiet hai 144,880 ty dflng [4].

Nguyen vi trung Tiy Nguyen. Tuy nhien, tan suit
ban rat thap, nhieu nhat d Bufln Ma Thugt chi
den 6%.

Tinh dSn ngay 12/04/2013 tinh Dkk Lak co
khoang 3486 ha bi mSt trAng, trong do 3047 ha liia
nuoc, 103 ha ngfl, 278 ha ca phe. Thift hai ve san
xukt uoc tinh hon 1182 ty dflng. Tai thanh phfl
Bufln Ma Thugt viec cdp nudc sinh hoat trong miia
khfl nam 2013 chi dap iing dugc 50% nhu eSu dimg
nuoc [5].

Thing XI: Ii thang cufli ciing ciia miia mua
song d hau het cic nai, trir Bao Lgc, ban lac die
xEiy ra trong mgt sfl nam nhit li d bac Tay NguySn.
Tin suit han tren dudi 20%, chiing to miia han
thyc sy bit diu d Kon Tum, Gia Lai vi chdm bit
dau d cic noi khac.

CAc nguySn nhSn chinh giy hgn hkn d Tiy
Nguyen vira xiy ra n5m 2013 do:
- Miia mua nSm 2012 kit thuc som hon binh
thucmg 1-1,5 thing, tflng lugng mua ci n5m thieu

hyt so vdi trung binh nhieu nam 20-30% trong cac
thing miia mua thilu hyt khoing 40% trong khi dfl
tir thing 8 den cu6i nim 2012 lugng bflc boi dat
150-250 mm, thing 1 va thing 2/2013 lugng bflc
hoi Idn, ISn tai 400-600mm.
- Myc nudc vi dong chay tren cac sflng sufli
thieu hyt so vdi trung binh nhi^u nSm tu 20 dia
60%, nhilu sflng sufli nhfl bj c^n ki?t, myc nudc
ngam bj ha thdp.
2.2. PhSn bo khong gian vd dien biin th&i gian
hgn hdn
2.2.1. Tdn sudt vd miia hgn
Lien quan chjtt che vdi sy hinh thanh miia khfl
d^u d$n hing nim vi stf phSn b6 thdt thudng ciia
lugng mua tren mgt s6 dja diem trong mOt so nim,
tan suat h^n d T3y Nguyen trong cic thing nhu sau
(bdng 2):
Thing X: van Ii mgt trong nhiing thing mua
nhilu song lic die cd ban d mflt sfl noi bdc Tay

Thing XII: ngay khi raiia mua ket tbiic, mua
khfl han 4p den, tin suit han len den tren 75% d
bdc Tay Nguyen, 60% d trung Tay Nguyen vi ph6
bien 40 - 60% d nam Tay Nguyen, trir Bio Lgc chi
12%.
Thing 1: C6 th€ eoi thing 1 li thing han n^g
nhdt d Tiy Nguyen vdi tin suat ban tren 90% d bic
Tiy Nguyen, tren 80% d trung Tay Nguyen vi 60 80% d nam Tay Nguyen, trir Bio Lgc chua din
30%.
Thing II: Han thing II chi thua kem thing 1 dfli

chlit. Tdn sudt len tdi 75 - 90% d bic Tay Nguyen,
trung Tiy NguySn va khoing 30 - 60% d nam Tay
Nguyen, trir Bao Lflc chi 14%.
Thing HI: Tin sudt giim di ro rft d bic TSy
Nguyen, chi 20 - 60%, van rit cao d trung Tiy
Nguyen, 70 - 85% va kha thdp d nam Tiy Nguyen,
kS ci vimg Bao Lgc, chi 15 - 30%,
Thing IV: Mua ban nhanh chdng kSt thiic d bic
Tiy Nguyen, nam Tay Nguyen (tin suat han dudi
15%) vi chi cdn ding kg d trung Tiy Nguyen (25 30%).
Thing V; Miia han ehdm diit hoin toan tren hau
311


het lanh tho Tiy Nguyen, rieng vitng ban noi tieng
nhu Ayunpa, han van xay ra trong suot cac thing
,. i
s ,, . ,n ,„„,
mua mua, voi tan suat khoang 10 - 40%.
**
Nhu v$y, miia han d Tiy Nguyen keo dai tii
thing IX den thing IV, tuong doi dai d bac Tay
Nguyen, trung Tiy Nguyen va tuong dfli ngan d

nam Tay NguyeiL
_i
i^ , ^
.
..
. ,•

, ^
Tan suat han trong tung thang d bic va trung
T- ^i - ~
L-^ L T- vi Tay Nguyen cung nhieu hem o nam Tay Nguyen.
Xuat hien hai viing cd tan suat h ^ dac bi^t d Tiy
NguySn la d ^ biflt cao d Ayunpa vi dac bi^t thip
d Bao Loc.

B i n g 2. T i n sudt hgn cac t h i n g (%)
Trgm

I

l l _

III

IV

V

VI

Vll

VIII

IX

X

XI

Kon Tum

94

76

24

6

6

9

0

0

0

3

21

Xll

79

Pleiku

90

80

58

14

2

4

2

2

0

2

18

76

Ayunpa

100

83

85

30

12

33

2

6

0

3

3

61

BuSn Ma Thu^t

84

S8

70

26

0

0

2

0

0

6

6

60
56

oak Nong

62

32

15

0

0

0

0

0

0

0

12

Da Lgt

70

56

28

0

8

2

0

0

0

0

8

44

BaoLfr;

26

14

18

2

2

2

0

0

0

0

0

12

2.2.2. So thdng hgn trung binh
Trong thdi ky 1960 - 2009, s6 thing ban trung
binh tuong doi nhiSu d bic Tiy Nguyen, trung Tiy
Nguyen, nhieu nhat d Ayunpa va tuang dfli it d
nam Tiy Nguyen, it nhat d phia nam tmh Lim
Dong, tieu bieu la Bio Lgc.
Han dien bien rat phiic tap, ting len hoac giim
di tit niia thap ky niy sang nua thap ky khic. Cd
D|a S\&m
1961 -1965

the nhin thiy dieu nay qua diSn biSn hi mia thap
ky diu, 1961 - 1965, den cac niia thip ky cufli,
2001 -2005vi2006-2010(6dng5).
So vdi trung bmh nhieu nam nita thip ky 1961 1965, ban nang ban d Pleiku, Bufln Me Thu0t, Di
Lat va ban nhg hon rfl r^t d trong hai nita th^p kj'
1966 - 1970, 1971 - 1975 a Budn Me Thuflt, Da
Lat, Bio Ldc, rieng Pleiku nang hem chut it.

Bang 3. s 6 thang h jin trung binh ckc nira t h | p ky va cac thoi kj'
Kon Tum
D i k Nflng

1966-1970

1971-1975
1976-1980

4,0

1981-1985

3,8

1986-1990

3.4

1991-1995

3,6

1996-2000

2,4

2001-2005

3,6

2006-2010

3,5

1980-1999

3,4

0,S
0.9

LiSn tiep hai nua thip ky 1976 - 1980 vi 1981 1985, ban nh? hon so vdi trung binh nhiSu n5m
tren tit ci cie tinh. Trong niia thap ky 1986 - 1990,
ban ning d Kon Tum, Ayunpa, Dik Nflng, Da L^t,
Bao Lgc song nh? han d Pleiku, Buon Me Thugt.
Trong cac niia th§p ky 1991 - 1995, 1996 -

2000, 2001 - 2005 ciing cd tinh trang h^n khflng
tang hay giim dflng nhdt tren cic tinh ciia Tiy
Nguyen. Ding chii J Ii, vio niia thgip kJ gdn diy,
2006 -2010, han ning hon d bdc Tiy NguySn song
nh? hon d trung Tiy NguySn vi nam Tay Nguyfin
so vdi trung binh nhiSu nim.


Theo (bdng 3), so vdi thdi kJ 1960 - 2009 va
thdi ky 1980 - 1999, han nang hon d nhilu noi
thugc bdc Tay Nguyen (Kon Tum, Ayunpa), song
nh? hon d trung Tay NguySn vi nam Tiy Nguyen.
Cd dieu li, muc chenh l?ch giiia hai thdi ky khflng
qui 0,2 thing ban.
3. Han ban, hoang mac hda gin vdi k|ch ban
bidn doi khi hau lanh tho TSy Nguyen
3.L Kich bdn bien doi khi hpu Idnh thi TSy
Nguyen trong thi ky XXI

Vift Nam da tiing xiy dyng va cflng bo nhieu
kjch bin BDKH, nudc bien dang (NBD) khic
nhau: Kich bin BDKH, NBD nam 1994, kjch bin
BDKH, NBD 1998, kjch ban BDKH, NBD 2009
va kjch ban BDKH, NBD 2012.
6 diy, kich bin BDKH, NBD 2012 thyc chit li
phien ban dugc dieu chinh tii kich bin BDKH,
NBD 2009 tren mgt sfl nguyen tic co bin, trudc
het li cap nhit cic thong tin ve BDKH tren thS gidi
ciing nhu trong nudc.
Cic tic gii da xay dyng kjch ban BDKH, NBD
theo 3 miic kjch ban phat thai khic nhau, phit thai
cao, phat thai trung binh, phat thai thap. Tuy nhien,
trong hoin cinh chung ciia the gidi vi Vi?t Nam hi§n
nay cic kjch bin BDKH cdn cd nhCtng dilm chua
chac chdn, do v|y mite kjch bin duge dimg li kjch
bin Irung binh sS co mice dg on dinh nhdt djnh.

dyng trong bai bio la kich bin trung binh, ngi dung
chil yeu la muc tSng nhiSt dg trung buih nim, cic
miia: Xuan (X), he (H), thu (T) vi dflng (D) vio
cac nam cuoi ciia moi thip k;^ trong the ky XXI.
Theo kich bin, nhiet do trung binh nim va nim
2020 tang len 0,5°C so vdi thdi kJ 1980 -1999
tren hiu het cac tinh, trir Dik Nong, Lim Dflng chi
ting 0,4°C; vio nam 2050 d Lim Dong tang tdi
0,8°C, 1,2°C d Kon Tum, Gia Lai, Dik l i k va
1,0°C d Dak Nflng; vio nam 2100 ting Ien 2,3°C d
Kon Turn, Dak Lik, 2,0°C d Dak Ndng va len den
2,5°C d Gia Lai vi 2,8°C d Lam Dflng. Ve ca bin,

muc tang nhiet dg trong cac giai doan tuang doi
cao d Lam Ddng, thu den la Gia Lai, Kon Turn,
Dik Lik va thip nhat d Dik Nflng.
So vdi muc tang cua nhigt dg trung binh nam,
miic tang ciia nhiet dg mua ddng vio nim 2020 chi
sai khic vdi muc tang ci nim O.^C, vio nim 2050
sai khic den 0,2°C va den nam 2100 sai khic den
0,4°C. Dang chu y la, sy sai khac d diy li do mite
ting nhi?t dfl trung binh miia dong thap hon miic
ting nhiet dg trung binh nSm.

So vdi muc tang cua nhi?t dg trung binh nim,
miic ting ciia nhiet dfl trung binh miia xuin vio
nam 2020 chi sai khac den 0,1°C, vio nam 2050
chi sai khac dSn 0,2°C, vio nim 2100 sai khic d^n
0,4°C. Sai khac d diy ph6 bien do mite ting nhi?t
3.2. Ngi dung kjch bdn BBKH lanh thS Toy Nguyen
dg miia xuin thap hon muc ting nhi?t dO trung
Theo kieh ban BDKH, NBD cho ViSt Nam, binh nim.
nhi?t dg trung binh ISnh thfl Tiy Nguyen se ting
So vdi miic ting cua nhigt dg trung bmh nam,
khoing 0,4 - O.S^C vao nim 2020, 1,1 - 1,5^ vio
nSm 2050 vi 2,0 - 2,8°C vio nim 2100. Ding Iuu miic ting ciia nhi?t dfl trung bbih mita he vio nim
y la miic tang nlii?t d0 nhidu nhdt d Lim D6ng, noi 2020 sai khic den 0,2''C, vao nim 2050 sai khic
CO nhigt dg tuong ddi thdp vi han bin tuong doi it. dSn 0,3°C, vio nim 2100 sai khic den 0,7''C.
Nhiing sai khic d day pho bien do miic tang nhiSt
Mire ting nhiSt dg khong dong ddu trong cic
miia, miia ddng, miia xuin it han vi miia he, mCia dg trung binh miia he cao bon mire ting nhi?t dfl
trung
binh nim, ro nhat d Lam Dong, Dik Nflng.

thu tang nhieu ban so vdi miic tang ciia nhiSt dg
trung binh nim.
So vdi miic tang ciia nhi?t dg trung binh nim,
Cfing theo kjch ban BDKH, NBD ndi trSn, lugng miic ting ciia nhiffdfl trung binh miia thu vio nim
mua ianh thfl Tiy NguySn s5 tSng 0,3 - 0.9% vao 2020 chi sai khic 0,rC, vio nim 2050 ciing chi
nim 2020, 0,3 - 2,5% vio nim 2050 vi 0,6 - 4,8% 0,1°C vao nim 2100 chi sai khic 0,2*'C. Thflng
vio nim 2100. Lugng mua ei nim tang len nhd thudng mite ting ciia nhift dfl trung binh mua thu
lugng mua ting trong miia he, miia thu trong khi cao hon miic ting ciia nhift dg trung binh nim.
lugng mua miia dflng, miia xuin vdn giim. Ding
Nhu v§y, mire tang ciia nhift dg miia \ii, m ^
luu ^ Ii, Lam Dong li nai cd lugng mua ting it nhat
thu cao ban miia dflng, miia xuin thap ban miic
so vdi cic tinh khic.
ting ciia nhift dfl trung binh nam. Sy sai khic niy
3.2.1. Kjch bdn tmng binh ve nhi^t dfS
cing ve cuoi thi ky cing rd n^t, nhat Ii d vimg niii
Kjch ban nhi?t dfl cho Tiy Nguyen dugc sii tuong doi cao Lim Dong (bdng 4).


Bang 4. Mt>c tang nhi^t dg trung tiinh nam (N) miia ddng (D), mua xuan (X), miia he (K), miia thu (T)
so v6^ thfri ky 1960 -1999 theo kjch bin phit thai trung binh (B2), (°C)

0.5

0.6

0,5

0.5

D6ng

3.2.2 Kich bdn tmng binh vi lugmg mua
So vdi thdi ky 1980 - 1999, miic tang ciia
lugng mua nam vao nam 2020 chi li 0,3 - 0,4%
tren 4 tinh: Kon Tum, Dik Lik, Dak Nong va Lam
Dflng li 0,9% d tinh Gia Lai, vio nam 2050 la 0,3 1,2% d 4 tinh ndi tren vi 2,5% d tinh Gia Lai, vio
nam 2100 phd bien tren dudi 2%: 2,1% d Kon
Tum; 2,4% d Dak Lak; 1,7% d Dik Nflng song len
den 4,8% d Gia Lai va ngugc Iai chi 0,6% d
Lam Dong.
Khac vdi nhift dfl, mite thay ddi cua lugng mua
cac miia rat khac nhau vi khac vdi miic thay dfli
ciia lugng mua nim. De dang phan bift mite giam
cua lugng mua trong miia khfl noi chung, bao gflm
miia dflng (XII - 11) vi miia xuan (111 - V), ngugc
lai tang trong miia mua, bao gdm miia be (VI VIII) va miia thu (IX - XI).
Mua giim so vdi thdi ky 1980 -1999 cua lugng
mua miia dong vao nim 2020 phd bi6n li 3%; Kon
Tum, Dik Nflng -2,6 - -2,7%, Gia Lai, Dik Lik:
-2,0 -^ -3,0%, Lam Dflng giam 3,8%, vio nam 2050
giam 7-8%, Lam Dflng giam 10,3%; vao nim 2100,
neng Lam Dflng giam 19,7%. Miic giam so vdi
1980 - 1999 ciia lugng mua miia xuan vao nam
2020 la tren dudi 2%; -2,7% d Dik Nflng; -2,1% d

Kon Tum; -2,0% d Gia Lai vi -1,7 - -1,8% d Dik
Lak, Lam Dong, vio nam 2050 la trfn dudi 5%:
-6,6% a Dik Nflng; d Kon Turn, Gia Lai, -4,7% d
Lam Ddng, -4,6% d Dak Lik; vao nim 2100 phd

bien tren dudi 10%,riengDak Ndng giim 12,7%.
Mire tang so vdi thdi ky 1980 - 1999 cua lugng
mua miia be vao nam 2020 khoang 0,2 - 0,6%, vio
nim 2050 khoing 0,1 - 1,7%; vio nim 2100 chua
dSn 1% d Kon Tum, Dik Lik, len ddn 2,9% d Gia
Lai va 3,3% d Dik Nong.
Muc tang so vdi cudi the ky 20 cua lugng mua
miia thu vao nam 2020, phfl biSn trfn dudi 2%:
2,7% d Gia Lai, 2,6% d Kon Tum; 2,1% d Dik
Lak, 2,0% d Dik Nong va chi 1,7% d Lim D^ng;
vio nim 2050 la 7,1% d Gia Lai; 7,0% d Kon
Tum; 5,7% d Dik Lik; 5,4% d Dik Nflng vi chi
4,4% d Lam Dong.
Nhu vay, miic giam ciia lugng mua miia dflng
nhifu hem miia xuan va miic ting lugng mua miia
thu nhieu ban miia he. VS khflng gian, dang chii y
Ii muc giam lugng mua d viing cao Lim D^ng
nhieu hem cac nai khac va ngugc Iai, miic ting ciia
lugng mua d Lim Dong cung it han cic nai khac
(bdng 5).

Bdng 5. MLPC t h a y d o i l u ^ n g nura nam (N) mila d o n g (D), m u a x u a n (X), m u a h e (H), m i l a t h u (T)
s o VPi tho-i k y 1980 - 1 9 9 9 theo kjch ban phat t h a i t r u n g b i n h (B2). %
Tinh
N

0

Kon Tum

0.4 -2,7

-2,1

13.6

-10,6

0,9

13,3

Gia Lai

0,9 -2,9

-2,0

15,0

-10,4

2,9

13,6
10,9

DakLak

0,5 -3,0

-1.7

15.1

-6,9

0.2

DikNfing

0,3 -2,6

-2.5

13,3

-12,7

3.3

10,3

Lam Dflng

0,4 -3,8

-1.6

19.7

-9.0

1.3

8.4


4, Xay d^ng kjch ban h^n hin cho Tay Nguyen
4.1. Cdc bu&c th{rc hifn
DS xay dung kjch ban ban hin cho Tay Nguyen
thyc hifn cic budc sau diy:
Budc 1: Lira chgn chi tieu han thi'ch bgp vdi
myc dich cu the Ii xay dung kjch bin ban hin.
Budc 2: Xic djnh cic mdc ting ciia nhift do vi
mire thay ddi iugng mua tren cic dia difm cua Tay
Nguyen theo kjch bin BDKH, NBD vira dugc
cap nhat.
Budc 3: Tmh toin cic chi sd ban cho thdi ky ca
bin cua kjch ban BDKH, NBD ndi chung.
Budc 4: Xac dinh muc thay dfli cua chi sd ban
theo cic kich ban tren cic tinh ciia Tay Nguyen so
vdi thdi ky ca bin.
Budc 5: N14n dinh ve tic dgng cua bien dfli khi
hau dfli vdi nguy co ban hin hoang mac hoa d Tay
NguySn.
4.2. Ket qua xay difng kjch bdn hgn cho
Tay Nguyen
Kjch bin ban cho Tiy Nguyen dugc xiy dyng
trfn CO sd kjch ban BDKH, NBD tuong iing vdi

phit thii khi nhi kinh d mire trung binh.
Nfli dung kjch ban han la cdp dfl ban d^ kien
cho cic nim cua mflt sfl thip ky trong the ky XXI,
bao gom nam 2020 tieu bi^u cho diu thd ky, 2050
tieu bieu cho giQa thS ky vi 2100 tieu bieu cho
cufli the ky. Dd ciing li cac m6e thdi gian thudng
dugc dS cap den trong nhieu kjch bin ciia IPCC
(Intergovernmental Panel on Climate Change)
ciing nhu cac tfl chiic qudc te khic.

- Cap 5: So thang ban trung bmh khoing 5,0 5,9
- C ^ 6: Sfl thing han tnmg binh khoang 6,0 - Cap 7: Sfl thing ban trung binh khoing 7,0 - Cap 8: So thing ban trung binh khoang > 8,0
Theo kjch bin h^n da dugc xiy dung cap dg
ban cua cic khu vuc vi cac tinh cua Tiy Nguyen
vio cic mgc thdi gian tuong lai nhu sau:
Nam 2020:

Vio nam 2020, so vdi thdi ky 1980 - 1999 han
cao ban 0,2 - 0,7 cdp (it nhdt 0,33 cdp, nbidu nhdt
0,61 cap), cap han phfl bien li 3-4 d bac Tiy
Nguyen, trung Tay Nguyen (4,1 d Kon Tum, 4,0 d
Pleiku, 3,9 Budn Ma Thugt) ca bift cd vimg len
den cap 5 (Ayunpa: 5,1). Trong khi dd, han phd
bien la cip 2 d nam Tay Nguyen (2,2 d Dik Nflng,
2,3 d Da Lat, ei biet cht cap 1 d nam Lim D^ng
(Bio Lgc, 1,3).
Nam 2050:

Vio nim 2050, ban cao ban so vdi thdi ky
1980 - 1999 pho bidn 1 - 2 cdp (h nhdt la 1,2 cdp,

nhieu nhat Ii 1,87 cap), cap ban pho bien li cap 4 d
bic Tiy Nguyfn (4,9 d Kon Tum, 4,7 d Gia Lai),
cdp 5 d trung Tiy Nguyfn (5,0 d Bufln Ma Thuflt),
ci bift cap 6 d Ayunpa (6,0), Trong khi do, cap
ban phd bien d nam Tiy Nguyen li 3 (Dik Ndng:
3,1; Di Lai: 3,2), ca bift cap 2 d Bio Lgc (2,7).

- Cap 0: S6 thing ban trung binh khoang 0,0 -

Vao nim 2100, ban cao han so vdi thdi ky
1980 - 1999, khoang 2,3 - 3,5 cap (2,33 - 3,49).
Cip ban d bic Tiy Nguyen, tnmg Tay Nguyen phfl
bien la cdp 6, ci bift d Ayunpa len den cap 7 (7,6).
Trong khi do, cip han pho bien d nam Tay Nguyen
(ke ca nam Lim Dong li 4, Dak Nong la 4,2, Di
Lgt: 4,4, Bio Lgc: 4,3).

- cdp 1: So thing ban trung binh khoing 1,0 -

4.3. B{r kien tdc dgng cua bien doi khi hgu den
hgn hdn vd hoang mgc hda & Tdy Nguyen

- cdp 2: S6 thing ban trung binh khoing 2,0 -

Nguy CO gia ting ban ban vi xudt hifn hoang
mac hda ting din theo thdi gian tren mflt sfl dja
bin ngay cing rgng Idn d Tiy Nguyfn,

Dc tifn lgi eho vife thuyet minh kjch ban, miic
dfl ban dy kiin duge phin chia thinh 9 cap

sau diy:
0.9

2,9
- cdp 3: So thing ban trung binh khoing 3,0 9
- cdp 4: S6 thing h ^ trung binh khoang 4,0 -

Nam 2020:

Den nim 2020, dg dii ctia miia han dai them 10
- 22 ngay d hau khip noi, ding ke nhat li viing


nam Lam Dflng. Tuy nhiSn, muc do han d Bio Lgc
vin rit thap m^c dia mite dfl ban gia tang nhieu han
so vdi eic vimg khac. O Ayunpa, ban vao thap ky
niy da len den cap 5, xap xi nhiSu noi d Nam
Trung BO vi Bic Trung Bg.
Nam 2050:

Den nam 2050, dg dii miia ban dai them 35 60 ngiy so vdi thdi ky 1980 - 1999, mire tang
nhifu nhit Ii d viing xua nay ban rat it nhu nam
Lim Dflng. Vdi mite tang dfl dai ban nhu tren, miia
ban d nhieu noi, nhat la d trung Tay Nguyen len
den 5-6 thing. DT nhifn, nai han nang nhat van d
viing Ayunpa vi d diy, thuc su xuat hifn nguy co
hoang mac hda do miia ban da chiem nua thdi gian
trong nam.
Nam 2100:

Vio cuoi the ky XXI, miia ban dii bon thdi ky
1980 - 1999 tir 2,3 dfn 3,5 thing khoang 70 - 105
ngay. Miia ban dai them nhieu nhit van d nam Tay
Nguyen va dii them it nhit d bac Tiy Nguyen.
Vdi mire tang nhu tren, miia han d bac Tay
Nguyfn phfl bifn la cap 6, cd noi cap 7, ning ban
mire dfl han hifn t^ii ciia bit ky noi nao d nude ta.
Cung cd the ude doin, vio thdi diem niy, ban d
bdc Tay NguySn va tnmg Tiy Nguyen ciing vdi
cyc nam Trung Bfl, ning nS nhit so vdi cac vimg
khi hau ciia Vift Nam; cie vimg niy trd thanh dia
bin trgng diem ve nguy ca hoang mac hda.
Trong khi dd, d nam Tiy Nguyen Ii tang nhieu
song van d cap 4, tucmg ducmg bic Tay Nguyen vi
Trung Tay NguySn thdi diSm hifn tai. Cd didu Ii,
Nam Tay Nguyen tir tinh trang biu nhu rat hiem
khi ed ban hin hifn nay trd thanh dja bin cd ban
hin dang ke.
5. Dd xudt giai phap ung pho
Df phdng chdng giim thieu ban han, hoang
mac hda cin cd cac giai phap sau:
- Cin xiy dyng co cau cay trflng phii hgp, dac
bift dfli vdi nhiing viing trflng cay cdng nghifp liu
nim nhu ci phe, tieu, ea cao,.., cd difn tich Idn
cdn chii y tr6ng ciy cd bdng mat dS giam hoc thoit
bai nudc, chin gid nhim giii dg dm cho dit lim
giim lugng nudc tudi.
- Phan loai difn tich va cac loai ciy trflng, dS cd
thii ty uu tiSn cap nudc tudi (ciy giong, liia dang
trfl bflng, giiiflndjnh difn tich ciy cong nghifp cd

gii tri).
316

- Phit trien cac giong cay chju han vdi cac dieu
kien khic nghift.
- Dua cflng nghf tudi bien dai dS tiet Idem
nudc, nit ngin thdi gian cic dgt tudi (tudi luan
phiSn, tudi im va phii gflc cay giii im).
- cdn difu tiSt tang Iugng xi nudc qua phit
difn, bfl sung ddng chiy ve ha du cho cac cflng
trinh thuy lgi cd dii ngufln nudc tudi vao vy he thu,
vymiia.
- Kien cd cung hda he thflng kenh muong giam
tdn that mat nudc.
- Nao vet kenh rach, ao ho. Huy dflng vi lip dat
them miy bam di chien, khoi sau gieng dao, khoan
them giSng nudc tudi.
- Tfl chiic quan ly chat che ngudn nudc, lay
nuoc tru vio cic kenh rach van hinh hgp Iy cic
cdng trinh.
- Quan Iy chit che vifc khai thic nudc ngim d
eic dia phuong.
- Cin cd dy bio, thflng bao kjp thdi diln bifn
thdi tiet nguon nudc cbo cac nganh va tren phuong
tifn thflng tin d^i chung df nhin din chii dflng co
giii phip dfli phd vdi han han vi chuyen dich thdi
vu gieo trflng
- cin ting cudng thong tin, tuySn truySn den
cic dja phuong, nhin din tich cue tham gia cac
cflng vifc hifu qui, thiSt thyc de chflng ban, lim

cho cic cdp, cic nganh va mgi ngudi din hiSu rfl
vifc phdng chdng ban.
6. Ket luan
Tay NguySn cd lugng nudc phong phii nhung
vio thdi ky miia khfl ban ban vin xiy ra lien tidp.
Han bin thudng giy inh hudng tren difn rflng. Tuy
it khi li nguyen nhin tryc tiSp giy tdn thdt vi ngudi,
nhung thift hai ve kinh te-xa hgi vi moi trudng do
han han giy ra la rit Idn.
Sy ting lugng mua trong miia mua vi giim
lugng mua trong miia khfl se tang them tinh cyc
doan cho \a lyt va ban hin d Tay NguySn. Theo
thang dfl tii cdp dfl 0 ddn cdp 9 hifn tai ban phd
bidn cdp 3, cdp 4 d bic Tay Nguyen, trung Tiy
NguySn, cdp 2 d nam Tiy Nguyen, ci bift cd nai
ISn dSn cdp 5 nhu Ayimpa nhung ngugc 1^, d Bao
Lflc chi cap 0. Miia ban hifn nay pho biSn tii thing
XII den thing III, noi mua h^n dii han nhu d
Ayui^a til thing XII den thing IV. d Bio Lgc, vio


bat cir thing nao ban cung khdng ding kd, tham chi
cd the coi li khdng cd miia han.
Theo kjch bin trung bmh, so vdi thdi ly 1980 1999 miic tang cdp dg ban khoing 0,3 - 0,7 cip vio
nam 2020; 1,2 - 1,9 edp vio nim 2050 vi 2,3 - 3,5
cap vao nim 2100. Ding luu y Ii, mite tang cdp dfl
h^n nhieu nhat d vimg rat it ban hifn tai - Bao Lgc.
Vdi mire tang nhu tren, cdp dfl han vio nim
2020 phfl bien la 3- 4 d bic Tiy Nguyen, trung Tiy
Nguyen, cip 2 d nam Tiy Nguyen.

Vao nim 2050 phd biSn cip 4 d bic Tiy
NguySn, cdp 5 d trung Tay Nguyen (ca bift cip 6 d
Ayunpa) cdp 3 a nam Tiy Nguyfn, vio nim 2100,
phfl bien cdp 6 d bac Tiy Nguyen, trung Tay
Nguyen; ei bift cap 7 d Ayunpa; cip 4 d nam Tay
NguySn, kS ci trung tam mua Bio Lflc.
Sy gia ting cap dfl ban linh thd Tay Nguyen
chic chin md rgng thdi gian cua miia han, dfl dat
miia ban phd bien keo dai them 10-22 ngay vio
nim 2020, 35 -60 ngay vao nam 2050, 70 - 105
ngiy vio nSm 2100 so vdi thdi kJ-1980 - 1999.

khdng thua kem cic vimg ban ban dien hinh nhu cue
nam Trung Bfl.
TAI UEU DAN
[1] Nguyin Lap Ddn, 2013: Ca sir khoa hgc
cho giii phip giii quyet eac miu thuan lgi ich
trong khai thic su dung tai nguyen nudc phuc vu
phit triSn kinh td - xa hfli Ianh thfl Tiy Nguyen,
Tap chi Khoa hgc Cdng nghe Vift Nam, sfl 8 nam
2013,651tr.
[2] Bfl Nflng nghiep va Phit tridn Nflng thdn,
2010: Ra soit quy hoach thiiy lgi vimg Tiy
Nguyen 2009.
[3] Bfl Nflng nghifp vi Phat trien Ndng thfln,
2013: Bao cio tinh binh ban ban, xim nhap man,
vi cflng tac chi dao phong chflng khic phyc hau
qui tai cic tinh Mien Tmng va Tiy Nguyen.
[4] Uy ban nhan dan tinh Gia Lai, Lien Sd
(Sd Nong nghifp vi Phat triSn Nflng thdn, Tii

Chinh), 2013: Bao cao tinh hinh khfl han vu Ddng
Xuan 2012-2013.

Vdi sy gia ting ban ban nhu treo s6 khflng cdn noi
[5] Uy ban nhin din tinh Dik Lak, Sd Nflng
nio h?n rat it nhu Bio Lgc bifn nay va nguy ca han nghifp va Phat trifn Nflng thdn, 2013: Tinh hinh
hin hoang mac hda d Tay Nguyen, nhat la d bic Tay ban hin vy Dflng xuan 2012-2013 trfn dja ban tinh
NguySn, hiong Tiy Nguyen se rat nghiem trgng. Dak Lik..

Drought, desertification in Tay Nguyen territory associated with climate change scenarios
In recent years, under the impact of climate change, increasing deforestation and leveling soil, the natural flows
regulating ability of nver basins in Tay Nguyen has been declining strongly. Tay Nguyen has four major river systems:
the upstream of Se San nver, the upstream of Srepok nver, the upstream of Ba river and the upstream of Dong Nai
river. Tay Nguyen also has an abundant water resource, however, in dry season drought occurs consecutively having
widespread influences. The drought is rarely the direct cause of human loss but social - economic and environmental
damage caused by drought is significantly, especially it leads to desertification. In this study, the authors will analyze and
assess the current status of drought and desertification in Tay Nguyen associated with climate change scenarios in the
2 1 " century, proposing solutions to minimize and to respond to drought and desertification in Tay Nguyen,
Just in time (1990 - 2000} in Tay Nguyen territory, drought o c c u r e d in 1994, 1995, 1996, 1997 and 1998 droughtprone rice area from 2.000 ha to 130.0DOha each crop. In 1998, drought-prone coffee area was 74.400ha, 770,000
people are the lack of water in this drought.
Drought had a great influence on tha production winter-spring at the end of the 2012-2013, eariy summer-autumn in
2013 and water of the people in the provinces of Dak Lak, Dak Nong, Gia Lai, Kon Tum.
Results of expected impacts of climate change to drought and desertification showed appearance of droughts and
deseriification gradually increase over time in 2020, 2050, 2100 on areas in Tay Nguyen. Thus, proposing solutions to
minimize drought and desertification in Tay Nguyen temtory including: construction of appropnate plant structure.
modem irrigation technologies, water saving, hardened concrete canal systems, increased regulation of water through
generating additional downstream flow of the inigation water source lo meet the summer collection season. Organization
of closely manage water resources and enhancing information, dissemination to local urKferstand Ihe drought response

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