Dự báo diện tích đất nông nghiệp bị khô hạn do tác động của biến đổi khí hậu vùng duyên hải Nam Trung Bộ

KHOA HOC C O N G N G H t

DIJ B A O DIEM TiCH D A T IVOIVG IXIGHIEP HI KHO HAIV
DO T A C DOIXIG C U A BIEIXI DOI KHt H A D VIJIXIG
DUYEIXI HAI IXIAM TRUIVG B O
37 -i-5rj
Mai Hsnh Nguyin', Trin VSn Thuy^, Vd Tu CanMMai Van Trinh*

T6MTAT

Q'ior-Z^

Bi^n ddi Idii hau vdi bi^u hi§n chinh la su gia tang nhifet do da, dang vk se gSy ra nhi^u tac dong d^n vi§c sir
dung dat ndng nghiep, trong do han han la m^t trong nhung y^u td gioi hgn quan trpng nhat va ngay cang
trd nen nghiem trpng. Viing duy6n hai Nam Trung bfl co di&n tich tir nhien 4.437.653 ha, trong d6 di§n tich
dat nong nghiep chi^m tr^n 76%. Dac di^m khi h^u cua vung vdi 2 miia ro ret, mua kh6 tir thang I d^n thiing
A'ni, mot so noi nhu Nmh Thuan, Binh Thuan thuong phai doi mat voi han han keo d^ trong cac thing mua
kh6. Hien nay diSn tich dj(t hi kh6 h ^ cua viing chiem mpt ty 1$ d^g k^ trong d^t ndng nghiep (1.160.306
ha, chiem 34,21%), dubao vao nam 2020 la 1.360.745 ha, nam 2030 U 1.366.519 ha, nam 2050 la 1.489.193 ha.
TVong sd di§n tich dat nong nghiep bi kho han cCia viing, d^t lam nghiep bi kho han c6 di§n tich va xu
huong tang nhi^u nhat Dt; ki^n di#n tich dat 14m nghiep bi kh6 hjin vac nam 2050 la 1.014.962 ha (tang
62.689 ha so voi nam 2030 va 191.551 ha so vol hien nay). Dat san xu^t nong nghiep (g6m dat trong cay
h ^ g nam vk dat trong c^y lau nam) du bio co di^n tich kho han vao nam 2050 U 469.300 ha (tang 58.393 ha
so vol nam 2030 va 135.250 ha so voi hien nay). Cac lo^ dat lam mudi, dat nong nghiep khac co di&n tich dat
kh6 han vi dir bio xu hudng tang khOng nhl^u. Trong nghlfen cihi nay, chi sd kho han dupe tinh toin tir sd
lieu khi tuong theo ckc kich ban bi^n ddi khi h^u khdc nhau (vdi su ho tro cua phan m^m CROFWAT tinh
kha nang bdc thoat hoi ti^m nang) lam co' sa cho viec du bao di§a tich dat ndng nghifip bi kho h ^ dudi tac
dpng cua bi^n ddi khi hau cho vimg duydn hai Nam Trung bp.
Tukhda: iOti tuong, dat ndng nghi$p, khd han, Duy6nhaiNam Trung bd.

I.IWBAU

Vung duy6n hai Nam Trung bo (DHNTB) co
dien tich tu nhi6n 4.437.653 ha gom 8 tinh, thanh ph6
t n ^ thudc Trung uong ^ a Ning, Quang Nam.
Quang Ngai, Binh Dinh, Phii Yen, Khanh H6a, Ninh
Thuan va Binh Thuan), trong do dien tich dlit ndng
nghiep chi^m tren 76% difin tich tu nhiSn. Voi d#c
di&n khi hau co 2 mua ro r^t trong nSm, miia mua va
miia kh6, trong do mua khd tu Ihteg I d^n thang
VIII, mot s6 noi thuoc viing duy^n hai Nam Tnmg bg
(Ninh Thuan, Binh Thuan) thutmg phai d6i mat voi
han han keo dai trong cac Ih^ng miia kho.
Vide danh gia han han rat kho thuc hien nh^t la
v^ dmh luong va tac dpng ciia han hdn. Chuong trinh
CROPWAT ra doi vao nam 1990, duoe T6 chiic
Luang thuc Th^ gioi (FAO) xay dung dl tinh toan
nhu cdu nuoc cho cay tr6ng va lap k l hoach tudi dua
trdn dir lidu dug^ cung cap boi ngtrdi su dyng. Trong
' Vign Nghi£n ciru Quan IJ'flatdai
^ Trudng Dai hoc Khoa hpc tu nhien
^ Hpi Khoa hpc Dlt ViSt Nam
'' Vi?n Mdi trudng Nong Nghiep, Vign Khoa hpc Nong
nghiep Vi^t Nam

nghien cuu nay, chuong trinh CROPWAT dugc su
dung dl tinh toan chi so khd han, lam co so cho viec
du bao didn tich d^t ndng nghiep bi khd han do tac
ddng ciia bien ddi khi hau cho vimg duydn hai Nam
Trung bd.
2. V6T UEU VA PHUONG PHAP NGHIBU CUU

2.1. vat li^u nghidn cihi
Nghien cijtu duge tidn hanh tren cac loai vat lieu
sau:
- Sd hdu khi tuong theo thang trong nhidu nam
(1960 - 2013) ciia 12 tram khi tugng thuy van ti-en
vimg nghien cuu.
- Phan mem CROPWAT 8.0 phuc vy tinh toan
lugng bdc hm tiem nSng.
- Phan mem ArcGIS 10.2 phuc vu phan tich
khong gian.
- Kich ban bien doi khi hau nam 2020,2030,2050
cho vung nghidn cuu theo kich ban BDKH & Nuoc
biln dang cua Bd Tai nguydn va Mdi trudng (2012).
2.2. Phuong phdp nghidn cihi
2.2.1. Phimngphip tinh chi sd kho h^
Chi sd khd ban dugc tinh toan la chi s6 khd han

N O N G NGHIEP V A PHAT TRIEN NONG THON - KY 2 - THANG 9/2015

33


KHOA HOC CdNGNGHl

t h a m d o (EDI) p h u t h u o c vao lircmg b d c h o i k h i
t u o n g v a luong h o c h o i ti^m n a n g CTsakiris v^
Vangelis, 2005; Tsakiris vi

cong

su, 2007; E.

KaneUouetal.,2008).
S6 tinh toan EDI, c i n tinh m o t gia t n b a n dau
c h o m d t k h o a n g thoi gian n h ^ t dinh, a^ tai t h ^ g (k)
n h a t dinh trong m d t n a m , d u o e tinh h o i cdng thiic

T r o n g dd:
P E T : T h o a t hoi ti^m n a n g (mm) diroc tinh theo
p h u o n g p h a p Penman-Monteith (Allen a t al,, 1998).
T : Nhiet dd b i n h quSn n g a y tinh tokn (°C).
A: Dd n g h i d n g cua d u d n g q u a n h $ cua n h i | t do
voi ap suat h o i b a o h d a tai n h i ^ t d o T ( k P a . ° C ' ) , A
d u o e x a c dinh theo hd t h u c : A=

sau:

(T + 237,3f
Ca: a p suat hoi n u d e b a o h o a (kPa) e^ = 0,6108»cp

CD

n,21T
T+ 231,3 J
R^: C h i n h lech giiia biic x a tang va biic x^ giam

T r o n g do: . ^ v a PFT)ik lugng m u a va lugng b d c
hoi tiem nSng tai t h a n g j-th cua n a m thiiy van t u o n g
ling. T r o n g nghien cuu nay, nhidt dd k h d n g k h i h a n g
t h a n g cua t u n g t r a m k h i t u g n g d u g c sir d u n g d e d u

doan l u g n g b d c h o i tiem nSng h a n g t h a n g b a n g
p h u o n g phap Thorthwaite.

cua

sdng

ngan

va

song

dai

QAJ/m^-ngky)

Rn="Rns-RnLRns! biic x a ciia m a t trdi dirge giu l?ii sau khi phan
x a ddi voi m a t d^t ti-6ng ti-gt QA]/m^-i\gky)
R„.= Cl-a)R,.
a: Hd so p h a n x a b e m | t didn tich trdng tigt,
H e sd k dugc coi b a n g 1 c h o t h a n g dau tidn ciia tiieo FAO till a = 0 ^ 3 .
R^: Biic x a m a t trdi (MJ/m^-ngay) R,
n a m khi tugng. B6i vdi k h u vuc Dia T r u n g hai k = 1
(0.25+0,5n/N)R,.
vao t h a n g 10 vi cac n a m khi t u g n g bdt dau vao t h a n g
n / N : T y sd giua g i d n a n g m a t trdi t h u c do n va
nay. H e so ajj cd 1h^ dugc tinh cho giai doan b a t ky
ciia n a m , d i l u nay c6 nghia la h e sd nay cd t h i dugc sd gid n a n g cd k h a n S n g Idn n h ^ t N.
R^: Biic x a 6 lop bidn k h i q u y e n (MJ/m^-ngay).

tinh tir b a t k j m d t t h a n g nao, k h d n g phai t h a n g 10
Ra=37,6dr (cOjSinl'sinS+cos'i'cosSsintiJs).
ciia n a m . T r d n t h u c t l , t h u o n g s u d u n g thoi ky t h a n g
©s =arccos(-tan¥tan5).
3, 6, 9 , 1 2 . N l u lua c h p n tiidi ky 12 thdng, k i t q u a co
4*: g d c VI dd dia ly (rad).
t h i dugc so s a n h t r u e tilp vdi chi sd k h d han d i a k h u
5: Gdc l | c h t h e o n g a y (rad) 6=0,409sin(0,0172Jv u c nghidn ciiu. M d t k h u v u c dugc coi la k h d b a n
1,39).
n l u a l 2 c h o m d t nam n h a t dinh thap h o n chi sd k h d
dr: k h o a n g each t u o n g ddi t h e o ngay
han.
dr=l-K),033cos(0,0172D0.408i(J^-G)+Y;z\^i(e^ - « J
J: Sd thii' t u theo n g a y tinh toan.
A+7(1+0.34112)
RnL: biic x a t d a r a bdi n a n g l u g n g hiit dugc ban
dau (MJ/m^-ngay).
(T +237.3)^

4.903.10-^^--^^^^'^^>^:^^-.-^^^^'^^)\0,34^0,14Vi;)(Q,1.0.9A)
2

AT
Hr! D d im t u o n g ddi t r u n g binh ciia k h d n g khi

T n ^ ; T ^ : N h i e t dd Idn nhat, nho n h ^ t C O .
e^: ap su^t hoi n u o c thuc t e d nhidt dp k h d n g khi
t r u n g binh (mbar)

e^^e^—-

63: a p su^t h o i n u d e b a o h d a , cd quan h d vdi
nhidt dd k h d n g khi.

34

(%).
N: Sd gid n d n g c u e dai

N=7,64 (o^ ( h ) .

G: T h d n g l u g n g n h i e t c u a d^t (MJ/m^-ngay),.
n l u tinh G t h e o nhiet dd b i n h q u a n tiiang thi;
G=0,14Crni-T^i).

NONG NGHIEP VA PHAT TRIEN NONG T H 6 N - KY 2 - THANG 9/2015


KHOA HOC CdNG N G H |
TmjTnti. Nhidt dd binh quan cua thing thii m va
m-1 CQ.
y: hang s6 bieu nhiet do
y=0,00163A
^^^^
293-00065.
293
z: (3ao dp so vdi muc nude biln (m).
X^2,501-2,361.10^.
U2: tdc dd gid b dd cao 2 m, khi dd eao khac 2 m
thi phai hieu chinh. Do dd, khi tinh toan su dung hd

thiic U2= KUh
RDI„ik) =

(2)

Chi s6 khd han tiiong thudng RDI (RDI^) dugc
tinh theo edng thiic sau:
RDI^,(^k) = ^

(3}

Trong dd aj^la gia tri tnmg binh theo tung giai
doan.
Chi sd khd han tieu chuan RDI (RDIgrt dugc
tinh tuong tu (3), duge dung de tinh SPI: Trong dd
yk la In ak, ok la gdc Ideh c h u ^ . Miic khd han dugc
phan loai dua tren gia tri cua RDI.
2.2.2. Cac bude thu thap so lieu va thinh lap bin
dd khd han
aha vao

'

^

•

CSOPWAT 8

- Ban Ah ii^nh chfnh

- Bin dd tufn Inmg kho ban
- BSn Ah luen tr?ng sii dung
dat n6ng nghi$p

Kjch ban bien d^i khi hSu
(nhi^ do, \wfn% mua nam
2026,2030,2050)

Luong boc hoi dem nang

Chi so kho han

B i n d6 d ? bao ikt NN bj kho han
v^o nam 2020, 2030,2050

Sad6. Cacbu6c1haiihl^band6 di|bao d^ndng
nghi^bikhdhfin

+Tdng hgp dii li^u ddu vao.
+ cac dii lieu thoi gian kho han cua cac thang
trong nam cho tung tram dupe xac dinh dl tinh toan
lupng hoc hoi mat rudng (ET).
+ Tinh chi sd khd han KDI (RDI^ va RDI_^^ sau
dd ndi suy vimg anh huong cd tinh din tac ddng ctia
ylu t l mat dim va t6ng hgp dU lieu didn tich Ait bi
khd ban theo sd thang khd hEui trong nam cho toan
khu vuc.
+ Ndi suy bang phuong phap Moving average
{trung binh trupt), su dung sd lidu cua cac trgm va sd
li$u dugc noi suy theo khoang each va gia tri ciia eac

tram do.
+ Tinh toan dii lidu hien trang d^t ndng nghiep
hi anh hudng do biln ddi khi hSu (nhilt dd, lugng
mua) tiieo kich ban nam 2020, 2030, 2050 vdi nhidt
dd, lirong mua theo kich ban trung binh: Su dung
cdng cu Intersect de tich lpe vk gin gia tri khd ban
cho cac vung dat ndng nghiep bi anh huong do nude
bien dang theo cac kich ban.
8. K ^ QUA VA THAO LUAN

3.1. Th^c trang va du bao d^t bi khd h^n do tac
dOng cua biln d6i khi hdu
3.1.L Thuc trang dit bi khd ban
Han ban cd anh huong rd r^t tdi co cau sii dung
d^t ndng nghidp. Thdi gian qua, do ning ndng keo
dai, nhilu noi trong vung DHNTB khdng cd mua lam
eho nhilu di^n tich dat ndng nghiep bi khd ban, vide
san xueit ndng nghidp gap khd khan. Ket qua tinh
toan chi sd khd ban tiidi k^ 1960 - 2013 cho thay: Cac
tinh, thanh Da NSng, Quang Nam, Quang Ngai co
chi s6 khd h ^ b miic ban nh? vao khoang thdi gian
tir thang 1 din thang 7, chi s i khd han vao cac thang
2, 3, 4 thudng thtip hon (chi s6 RDI_st dao ddng tir 0,21 den -1,05) thang 5, 6, 7 (chi sd RDI_st dao ddng
tii 0,03 den -0,41); tinh Binh Dinh. Phii Yen, Khanh
Hda ed ehi sd khd ban thtip hon cac tinh Da Nang,
Quang Nam, Quang Ngai, b miic ban nhe (chi sd
RDI_st dao dpng tii 0,02 den -0,88); tinh Ninh Thuan,
Binh Thuan chi sd khd ban thap bom ban, d miic han
trung binh va han nhieu (chi so RDI_st dao ddng tir 1,31 den -5,55) vao cac thang 1,2,3.
Dien tich d^t ndng nghilp bi khd hgn cua vung

duyen hai Nam Trung bd la 1.160.306 ha, ehilm
34,21% didn tich dat ndng nghilp cua toan vimg.
Trong dd: dat bi khd ban nhe cd dien tich la 762.862

N O N G NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 9/2015

35


KHOA HOC CdNG NGHt
ha (chidm 65,75% didn tich dSt khd han cua toan 43,42%, 43,12% vk 7,17%; dat bi kho h?in nang co di«n
vimg); dat hi khd han tnmg bmh cd diSn tich 232.353 tich 165.091 ha (chiem 14,23% di6n tich dSt ndng
ha (chiem 20,03% diSn tich hr nhidn toan vimg). Cac nghidp), tSp trung or tinh Ninh Thu|n (96.057 ha,
tinh Binh Thujn, Ninh Thuan, Quang Ngai la nhimg chidm 36,09% di$n tich dat ndng nghiep) vk Binh
tinh cd dien tich dat hi kho han trung binh chidm ti 1^ Thuan (69.034 ha, chidm 10,15% didn tich djlt nong
cao so vdi didn tich khd han, cd ty 1^ tuong ling la
Bang 1. D i ^ tich cac lo^i hinh su dung d ^ b} khd luui cua cac tinh vimg Duydn hai Nam Tnmg bd nam 2013
Bon vi tinh: ha
Dat san xuat nong nghiep
Dat trong cay hang nam
Tmh/Thanh
Dat Dat t d n g
phd
Tdng
Tdng
trdng
cayHN
lua
khac
Da Nang

9.463
540
3.438
2.867
2.327
Quang Nam 126.834
20.947 10.632
6.482
4.150
Quang Ngai
61.924
27.987 16.596 11.453
5.143
Bmh Dinh
194.331
36.014 16.339
6.573
9.766
PhiiYSn
146.713
25.464 17.356
7.294
10.062
Khinh Hda
130.137
30.939 11.519
2.871
8.648
Ninh Thuan
175.311

47.212 39.500
7.548
31.952
Binh Thuan
315.593
142.049 27.940
8.664
19.276
Tdng
1.160.306 334.050 142.749 53.212
89.537
Coc^u
100,00
28,79
42,73
37,28
62,72
Tong
di^n tich
dat hi
khd ban

Dit
trdng
ciyliu
nim
571
10.315
11.391
19.675

8.108
19.420
7.712
114.109
191.301
57,27

Dit lim
nghiep
4.798
105.669
33.894
158.223
121.220
99.043
127.206
173.358
823.411
70,96

Dat
Sat
ndng
lam
nghifp
mudi
khac
2
17
9

6
59
702
80
875
0,08

1.227
216
26
85
23
96
191
106
1.970
0,17

Ngudn: Kdt qui nghidn ciiu
3.1.2. Bu bio dat hi khd han do tic ddng ciia
bien ddiktiihau
(i)Brib^onSm2020
Kit qua tinh toan chi sd khd ban (RDI_st) cho
thay tinh Quang Nam (tram do Tam Ky, Tra My) co
ban khdng giam; cac tinh, thanh Da NIng (tram do
Da Nang), Quang Ngai (h^im do Quang Ngai) giam
khdng nhilu; tai Binh Dinh (tram do Quy Nhon,
Hoai Nhon) nhin chung giam, tram do Hoai Nhon
giam nhieu hon d tram do Quy Nhon giam khoang -0,3
din -0,5 (dac bidt vao cac thang 1,2,3,4), vao cac thang

3, 4 chi sd kho han giam tir miic han nhe sang han
tiling binh. Cac tinh Phii Yen (tram do Tuy Hoa),
Khanh Hda (ti^im do Nha Tran^, Ninh Thuan (tram
do Phan Ran^, Binh Thuan (hmn do Phan Thilt, Ham
Tan) giam xudng rat manh, dae biet vao cac thang 1,2,
3 chi sd khd ban b miic r^t Ihap (d Binh Thuan chi so
khd ban dao ddng tir -2,3 den -10,53; b Ninh Thuan
chi sd nay tir - 2,18 din -10,54), xuat hien miic han
nhilu vao tiiang 12 d Binh Thuan. T ^ Khanh Hda,
vao tiiang 2, xuat hidn dien tich ban nhilu. Cu till
diln tich dSt ndng nghidp bi khd ban nhu sau:
Bang 2. Du bao didn tich cac loai hinh sii dung d^t bi khd hjui ciia cac tinh
viing duydn hai Nam Trung bO nSm 2020
Bon vi tinh: hi
Dit san xuit nong nghieo
Tdng
Dit
dien
Dit trong civ hang nam
Dit
Dat
Tmh/Thinh
Dat lim
ndng
tich dat
lam
Dat Dit trdng trong
phd
Tdng

nghijp
nghiep
bikho
Tdng
mudi
trdng cayHN cay lau
khac
han
lua
nam
khic
Da Nang
9.953
3.770
3.167
2.387
780
603
4.875
1.308
Quang Nam 126.834
20.947
10.632 6.482
4.150
10.315 105.669
2
216
Quing Ngai
61.924
27987

16.596 11.453
5.143
11.391 33.894
17
26

NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 9/2015 i


KHOA HOC CdNO NGHt
Binh Dinh
196.190
Phu Yen
162.626
Khanh Hda
142.066
Ninh Thuin 176.849
Binh Thuan
484.303
Tdng
1.360.745
Co cau
100,00

27.883
27.072

7.918

6.876

10.042

18.866
12.721

8.035
2.904

10.831
9.817

40.171
217.832 86.765
406.379 196.836
29,86
48,44

7.606
9.414
55.157

32.859
48.029

28,02

19.965
8.206

159.175
135.522

12
7

20.138
32.565
7.858
68.351 131.067
141.679 209.543
71,98
51,56

109.040
127.852
275.214
951.241
69,91

63
705
86
892
0,07

120
25
104
263

171
2.233
0,16

Ngudn: Kdt qua nghidn cm
vao nam 2020, tdng didn tich dat ndng nghiep bi Due linh va Tanh Linh; mdt sd xa phia Tay Bac cua
khd ban ciia ca vimg du bao la 1.360.745 ha, tang Ham Thuan Bac va Ham Thu$n Nam cd ban trung
tiidm 200.439 ha so vdi hiln nay. Trong dd ban nhe binh cdn lai hi ban nang; huyIn Ham Tan phan Ion
du bao tang them g ^ 134 nghin ha, ban tiling binh dien tich hi ban trung binh. Mdt phan diln tich phia
tang thdm hon 3 nghin ha, ban nang tang Idn hon 62 Ddng thanh pho Pban Thilt va phan Ion dien tich phia
nghin ha. Dien tich d& ndng nghilp bi khd ban tang Tay bi han nang. O huydn Bac Binh va Tuy Phong,
phan Idn trin dat lam nghilp, dat trong cay hang dien tieh ban nghiem trong md rdng hon vl phia Bac,
nam, cae loai dat ndng nghilp khac tang Idn khdng dien tich ban nang cung tien vd phia Tay, hdu nhu
nhilu. Ridng a hai tinh Quang Nam, Quang Ngai khdng cdn dien tieh cd ban trung binh.
didn tich dat ndng nghiep bi khd ban vao nam 2020
(iii) Bu bao nam 2030
g ^ nhu khdng tang so vdi hidn nay. Didn tich dat
Theo kit qua tinh toan, chi sd khd ban vao nam
khd ban chii yeu ma rdng trdn cae nhdm dat bai cat, 2030 so vdi nam 2020 tai cac tinh, thanh Da Ning,
con cat va dat cat, djit man, dat xam bac mau, dat do Quang Nam, Quang Ngai khdng co thay ddi nhieu.
vang.
Tinh Binh Dinh tuy giam khdng nhilu, nhung vao
Dien tich khd han cua viing tang thdm vao nam tiiang 3 chi s6 khd han da virgt qua nguong trung
2020 chu yeu la tang 6 tinh Binh Thugn (tang 168.710 binh sang khd han nhilu. Ttnh Phii Yin, Khanh Hda,
ha so vm hien nay), tilp den la cac tinh Phii Ydn, Ninh TTiuan, Binh TTiuan din nam 2030, chi so khd
Khanh Hda (tang tir 11 din 15 nghin ha). Tgi Binh ban van tilp tuc giam, nhung miic giam rat it so vdi
TTiuan, didn tieh khd ban md rdng vl phia Bdc huyIn nam 2020.
BSng 3. Di; bao di^n tich ckc loai hinh sur dung dat hi Idid han c i ^ cdc tinh
vimg duygn hai Nam Trung bd nSm 2030
Bon vi tinh: ha

Dit san xu^t ndng nghiep
Dat
Dit trdng ciy hang nam
Dat
Tdng didn
Dat
Dit lim
ndng
Tmh/Thanh
lam
tich dit bi
trdng
Dit
Dit
trdng
nghiep
nghiep
phd
Tdng
mudi
kho ban
Tdng
trdng
ciyHN ciyliu
khic
nam
lua
khac
3.944
10.166

Da Nang
127.096
21.175
Quang Nam
Quang Ngai
62.528
28.513
Binh Dinh
197.443
38.048
Phii Ydn
163.045
27.491
Khanh Hda
142.572
33.365
Ninh Thuan
178.878
49.215
Bmh Thuan
484.791 209.156
1.366.519 410.907
Tdng
Co can
100,00
30,07
Ngudn: Ket qui nghien aiu

3.220
2.426

10.757 6.531
16.977 11.663
17.510 7.195
19.285 8.280
13.227 2.904
40.568 7.793
78.074 9.502
199.618 56.294
48,58
28,20

794
724
4.226
10.418
5.314
11.536
10.315 20.538
11.005
8.206
10.323 20.138
32.775
8.647
68.572 131.082
143.324 211.289
71,80
51,42

4905
105.688

33.962
159.242
135.522
109.040
128.550
275.364
952.273
69,69

NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 9/2015

2
19
14
7
63
738
115
958
0,07

1.317
231
34
139
25
104
335
196
2.381

0,17


KHOA HOC C 6 N G NGHt
Di?n tich dat ndng nghiep bi khd ban chu yeu xuit hidn thdm mdt sd didn tich dat ndng nghidp (125
^
md rdng trdn cac nhdm dit bai cit, cdn cit vi dit cat, ha) hi khd ban nang.
(iii) Da bio nam 2050
dat min, dit xam biic mau, dit do vang, nhdm dit
xam bac mau. Du bio den nim 2030, didn tich dit
Chi sd khd han t?i cac tinh trong vung vio nim
ndng nghiep hi khd han cua toin viing la 1.366.519 ha, 2050 so vdi nam 2030 nhin chung ddu giam nhung
tang 5.774 ha so vdi nam 2020, tang 206.213 ha so vdi muc dd khac nhau. Cac tinh/thanh Da Nang, Quang
hidn nay. Trong dd, du kidn didn tich dat ndng nghidp Nam, Quang Ngii cd chi sd khd hiin giam khdng
hi khd han nhe la 899.336 ha (chidm 65,81%), kho han nhidu (dao ddng trong khoang -0,1). Cic tinh Binh
trung binh 237.752 ha (chidm 17,40%), khd ban nang Dinh, Phii Ydn, Khanh Hda cd xu huong giam manh
229.431 ha (chidm 16,79%). Didn tich dat ndng nghiep hon, die bidt vao cic thing 2,3,4 cd thing giam trdn
bi khd h?n tang vio nam 2030 chu yeu trdn dit trdng -0,3. So vdi hidn nay, dvt bio den nam 2050, chi sd
ciy hing nam, dit trdng ciy liu nam va dit lam khd ban ciia cic tinh trdn dia ban duydn hai Nam
nghiep. So vm nim 2020, dien tich dit ndng nghiep bj trung bp cd sir thay ddi nhu sau: Tai cac tinh/thanh
kho ban nam 2030 tang khdng nhidu, drr kidn didn Da Ning, Quang Nam, Quang Ngai chi sd khd hjii
tich dit ndng nghidp bi kho han ting nhidu a tinh nhin chung giam, miic giam khdng nhidu ttr 0,01 ddn
Binh Dinh, Ninh Thuan (tang 1.253 ha va 2.029 ha), o -0,2; tai cac tinh Binh Dinh, Phii Ydn, Khanh Hda chi
ckc Hnh cdn lai ting khoang t i 200 ddn 600 ha. So voi sd khd ban cd miic giam dang kd, giam tat ca cac
hien nay, di6n tich dit bi khd hgn tang tip hung chii thing trong nim; tai Ninh Thuin va Binh Thuan mjc
ydu a tinh Binh Thuin (tang 169.198 ha, chidm 82,05% dii hien nay chi sd khd han da d miic cao, die bidt
didn tich dat nong nghidp bi khd ban tang thdm cua ca vio cic thing 1, 2, 3, tuy nhi6n theo tinh toin thi vio
viing). Tidp den li cic tmh Phii Yen, Khanh Hda cd nim 2050 chi sd niy cd miic thay ddi rat Idn theo
didn tich dit ndng nghiep hi khd ban ting th^m chidu hudng giam ding ke, giam tdi trdn -10. Tai
khoang 12,5 den 16 nghin ha; Binh Dinh, Ninh Thuan Binh Thuin xuit hien miic ban nhidu vao thing 12.

cd dien tich ting thdm khoing U-dn 3 nghin ha; cic
tinh cdn lai chi ting 260 - 700 ha, riSng tinh Binh Djnh
Bing 4. Du bio didn tich cicloai hinh sii dung d^t bi khd han cua cic tinh thuOc
vdng Duydn bii Nam Tnmg bO nim 2050
Ban vi tinh: lis
Tmh/ Thinh
phd

Da Ning
Quang Nam
Quang Ngii
Binh Dinh
Phii Yen
Khanh Hda
Ninh Thuin
Binh Thuan

rdng
Cacau

Dat san xuit ndng nghiep
Tdng dien Tong
tich dit bi
khd ban
10.865
127.425
63.165
199.845
163.945
143.791

239.444
540.713
1.489.193
100,00

10.248
127.425
57.956
195.738
155.529
137.386
11.036
211.845
907.163
60,92

Dit trdng cay hang nim
Dat trdng
Dit
CiyHN
Tdng
trdng Ilia
khic
2.507
617
6.592
5.209
11.718
3.670
437

7.958
8.416
8.280
6.024
3.284
381
100.938 127.470 12.648
132.076 158.792 16.928
256.950 287.080 69.915
28,32 111,73 27,21

Dit
Dat trdng Dat lam Dat lim nong
mudi nghidp
cay liu nghidp
khac
nam
909
4.297
5.618
10.872
11.351
10.671
39.615
84.176
167.509
18,47

807
10.507

11.638
21.067
8.317
20.218
8.708
150.614
231.876
15,57

2
31
34
28
75
943
541
1.654
0,11

1.432
264
39
152
176
245
497
472
3.277
0,22

Ngudn: KSt qua nghiin cuu
Du bao ddn nim 2050, didn tich dit ndng nghiep
bi kho ban cua ci viing Ii 1.489.193 ha, chidm 43,91%
didn tich dit ndng nghidp. Trong do di^n tich dit bi
38

han nhe li 907.163 ha (chiem 60,92% didn tich dat
ndng nghidp bi khd han), ban trung bmh la 294.950
ha (chidm 19,81%), han nang li 287.080 ha (chidn)

NONG NGHIEP VA PHAT TRIEN N 6 N G THON - KY 2 - THANG 9/2015


KHOA HOC CONG N G H £
19,27%). Didn tieh dat khd h?n tap trung it ckc tinh
Binh Thuan (540.713 ha, chilm 34,64% dien tich dat
ndng nghidp bi khd ban cua ca vimg, chilm 73,88%
diln tich dat ndng nghidp cua tinh), Ninh Tliuan
(239.444 ha, chilm 16,50% dien tich dat ndng nghiep
hi khd ban cua ca vimg, chilm 89,96% dien tich d^t
nong nghiep cua tinh). Rieng 2 tinh/thanh Da Nang,
Quang Ngai ed di$n tich dat ndng nghi?p bi khd hgn
thap, diln tieh d^t hi khd han tirong ling la 10.865 ha
va 63.165 ha; cac tinh con lai cd diln tich dat ndng
nghiep hi khd han tir 130 nghm den 200 nghm ha.
3.2. Giai p h ^ ling phd tdc ddng djia biln d6i khi
hau trong quan ]y, su dung d^t ndng nghidp hi khd
han
3.2.1. Bidn phip cdng trinh
- Ddu tu xay dimg he thdng h6 dap du tru nude,

kinh muong din nude tuoi va sii dung hgp ly cac
nguon nirde. He thong tiiuy loi duge dau tu, kit nii
vdi nhau thanh mang thuy Igi lien thdng, se bd sung
kip thdi cho nhirng noi tiiieu nude cue bp- Sir dung cac bien phap thu trir nude nhu ddp
dap, xay b l tru nude, tao ho tru nuoc trdn cat, trdn
sirdn ddc... Song song vdi vide thu trii nude, viee bao ve
nguon nude va dat chdng hoang mac hda bude dau
cung da dugc quan tam nhuiam dat tdi thieu dviing dat
doe, tang dd nham be mat dat b^ng each tao tham phu
thuc vat, che phu goc cay, mat dat bang xac thue vat,
bdn phan hiiu co sinh hoc, phan xanh, chpn va bd tii
cay trong hop ly trong miia khd ittiduthu nude.
- cac bien phap chdng ban, nhu td chiie nao vet
khoi thdng ddng chay hd thong kdnh muong thuy
lpi, hudng dan ndng dan ap dung nhiing phuong
phap tudi phun mua, nhd gigt trong san xuat dl tilt
kilm nguon nirdc, gieo tr6ng cae cay chiu han; to
chiie dao gieng, ao ho du tru nude sinh boat eho
ngtrdi dan va nude uong cho dan gia siic...

mang cau xidm (na); mdt vm loai rau, dt.. diu duge
tuyen chpn da chiu dugc ban. Dli vdi 2 tinh chiu han
nang la Ninh Thuan va Binh Thuan, cdn thay liia
bang nhimg loai cay chiu ban, ed hilu qua kinh te
cao hon.
- Phat triln Idp phii tiiuc vat tren dat thdng qua
vile trdng rung va bao vd rimg, khai thac sii dung dat
hgp ly, dae bidt la vimg dat ddc, rimg dau nguon.
3.2.3. Bi$nphap bdn phan
• Cai tao dd phi nhilu, tang eudng sir dung phan

bihi CO (phan xanh, phan chuong, phan ti), su dung
chat thai ndng nghilp (rom, ra...) che phu M tang
kha nang giu am ciia dat, ban chi kha nang bdc hoi
nude.
- Tang chat hiru ca cho dat bdn phan chuong sii
dung tai tao tir dan gia siic, phan hiru ca sinh hgc...
3.2.4. Tich hop yeu td BBKH vio quy hoach, kd'
hoach su dung dit
Tien hanh lap quy hoach su dung dat cae cap
mdt each ddng bd tr6n co sd kit qua danh gia tiem
nang dat dai, xac dinh dien tich dat bi khd ban va bi
thoai hda de tii do tinh toan bd tri quy dat cho cac
muc dich tiong phuong an quy hoach. Danh gia toan
didn ve kha nang thich nghi, du bao su thay ddi ca
cau, didn tich dat theo cac Idch ban BDKH de tir dd
xay dung ke hoach va quy bogch sir dung dat nong
nghiep cho phu hgp vdi cac tilu vung sinh thai. Ndi
dung qui hoach sir dung ddt (cap huyIn, tinh va
viing) DHNTB dugc xay dung trdn ca sd dilu tra
danh gia, phan loai va phuong hudng sir dung hpp ly
tai nguyen daL Day la dieu ki0n thuan Igi de dieu
chinh ca cau kinh t l cua timg tinh, ddi vdi tung tilu
vimg va cac nganh kinh tl, huong tdi dat muc tieu
kinh tl, xa hdi va bin virng. Trong do:

- Bd tri quy hoach thanh cac tilu vimg gdn vdi
ydu cdu ddu tu thuy loi dl san xudt cae vimg chuyen
canh, thSm eanh, viing san xuat ndng san hang boa
3.2.2. Bidnphip cay trdng
quy md Ion viia dam bao tidu thu ndi dia vira dam bao

- Chuyin dich co cau cay tiong phii hop nham sii yeu cau xuat khau. Dau tu phat trien thuy lpi cua tinh
dung tilt Idem, hidu qua nguon nude; sir dung cac phai phii hgp vdi quy hoach thuy Igi, cap nude va
gidng ehm ban, sinh trudng nhanh, dac bidt la cac phong chdng ban ban, lu lut, lii quet, lii dng chung
gidng cay ban dia, eac cay hp dau phii hgp vdi hd eua tinh, gdn chat vdi phat trien dan cu va giao thdng
thdng ndng nghiep cua vimg va cac tinh trong vimg.
ndng thdn;
- Nghien ciiu chgn tuyIn nhiing cay gidng khoe
- Bd tri quy hoach cac vung ed kha nang bi anh
chiu khd ban nhir dieu, ea cao, dliu...; cac cay ndng hudng thien tai do BDKH, gdn liln vdi pbdt trien xa
nghiep ngdn ngay: hanh tim, khoai lang, mi ( s ^ ) , hdi, xay dung ha tdng, phiic Igi cdng edng de phue vu
dau, mia...; cac cay an qua dan xen: thanh long, xoai.

NONG NGHIEP VA PHAT TRIEN N 6 N G THON - KY 2 - THANG 9/2015

39


KHOA HOC C6M0 NOHfe
san xuat, dan sinh, h^in ehl, giam tiiilu tdc ddng do
han ban, lu lut, lu quit, vdi nhung giai pbdp ca ban
d i bao dam k l sinh nhai, khai tiiac nhiing mat cd Igi
nhdm san xuat an toan trong mua lii va mua khd.
- Ddi vdi dat san xuat ndng nghilp: Quy hoach va
tang cudng quan ly, sii dung ddt san xudt ndng
nghidp p h i hpp voi tilm nang dat dai, tiiich ling voi
biln ddi khi hau, khai tiiac ttidt d l cac vimg ddt
trdng cd tilm nSng san xuat ndng nghidp. Khi bd tri
su dimg dat can gdn vdi vide phat triln ndng thdn
theo hudng cdng nghilp hda, hien dai hda va bd tri
eo cdu cay trdng vat nudi phii hgp vdi dac diem tu

nhien, dilu kidn dat dai, ngudn nude dl cai tao, nang
cao chdt lirgng ddt, giam tiiilu tac ddng cua biln ddi
khi hau; cdn can nhdc lua chgn vi tri, didn tich dat bi
khd ban, thoai hda, it ed kha nang phuc hdi chuyin
sang muc dich dat phi ndng nghiep khi cd nhu cau.
- Ddi vdi ddt lam nghidp: Quy hoach va quan ly
tdng hgp ddt Utm nghidp tien co sa ddy manh thirc
hidn cac chirong trinh, du an trdng rimg mdi, khoanh
nudi tdi sinh rimg, phuc hdi rung, tai tao Idp phii thuc
vat bang cay rung tai nhftng khu vuc ddt trdng ddi
trgc. Bao ve nghidm ngat, tang dien tich rung phdng
hd dau ngudn vd nang cao do che phu ciia rimg (dac
bidt la khu vuc ddu ngudn sdng Thu Bdn, sdng Tra
Bdng, Tra Khiic...). Tilp tuc ddy mgnh vi^c giao ddt,
khodn rimg cho cdc td chiic, hd gia dinh, ca nhan
theo quy dinh ciia Luat Ddt dai; Luat Bao vd va Pbdt
triln rimg; cung cd h i thdng cac ca quan quan ly nha
nude de hirdng ddn khai thac, su dung bin vung va
bao vd tai nguydn rimg, ket hgp vdi su tham gia tich
cue cua cdng ddng dan cu.
- Ddi vdi ddt nudi trdng thuy san: Pbdt triln nuoi
trdng thiiy san trdn mat nude hoang hda, khi bd tri sii
dung dat can xem xet chat che ylu td tac ddng den
mdi trudng, dae bidt Id cae khu vuc nudi trdng thuy
san nude Igf, man viing ven biln (nhu nudi tdra frin
cdt b Binh Dinh va Quang Nam). Pbdt triln nudi trdng
thi^ san gdn vdi vide ngan ngira va cd giai phap ky
thuat dl bao vd mdi trudng ven biln. Khuyin khich cac
hinh thiic nudi tham canh cdng nghidp, ban chi cac
hkih thuc nudi quang canh, thilu bin viing. Dac biet la

Idem soat chat chd vide phat triln, md rdng dien tich
nudi trdng thuy san nuoc man, Igr, ban ehl su suy thoai
dat Hoan nguyen vimg kem hidu qua. Nudi tha cac bai
chiu dugc bien ddi mdi trudng (thich nghi vdi libiet dp
tang, tang dd sau cila ao hd dl tao nhidt dd thich hgp
va giam tdn hai do qua trinh tang nhilt dd va bdc hoi
40

nhanh ciia mat nude).
4.K^LUAN

«

- Didn tich dat ndng nghidp bi khd hgn cua toan
vung DHNTB hien nay la 1.160.306 ha (chilm 34,21«
diln tich dat ndng nghilp cua vtmg), du bao vao nam
2020 la 1.360.745 ha, nam 2030 la 1.366.519 ha, nam
2050 la 1.489.193 ha. Mac dii cd su tang khdc nhau
t?u cac dia ban ti-ong todn vimg, nhung theo kit qu5
nghiln cuu hiln trang cQng nhu du bao, didn tich ddt
ndng nghilp hi khd ban phan bd tap tiling d 2 tinh
Ninh Tliuan va Bmh IhuSn.
- Trong sd di|n tieh ddt ndng nghidp bi khd han
ciia vimg, ddt lam nghilp hi khd h ^ cd di|n tich va
xu hudng tang nhilu nhdt. Du kiln diln tich ddt iSra
nghidp bi khd ban vao nam 2050 la 1.014.962 ha
(tang 62.689 ha so vdi nam 2030 va 191.551 ha so vdi
hidn nay). Trong dd a tinh Binh Thuan, diln tich
tang tiidm chilm 59,84% didn tich dat lam nghidp bi
khd h ^ tang them cua vimg (tang 114.624 ha). Ddi

vdi ddt san xudt ndng nghidp fedm dat tidng cay
hdng nam va ddt trdng cay lau nam) du bao didn tich
khd ban vao nam 2050 Id 469.300 ha (tang 58.393 ha
so voi nam 2030 va 135.250 ha so voi hidn nay). D6I
voi cac loai dat lam mudi, dat ndng nghidp khac co
di^n tich dat khd hgn va du bao cd xu hudng tang
khdng nhieu.

TAI UEU THAM KHAO

1. Bd Tai nguyen va Mdi trudng, 2013. Bdo cao
cap nhat hai nam mOt lan Idn thii nhat cua Vi^t Nam
eho edng irde khung ciia Liln hpp qudc vl biln ddi
khi hau.
2. Bd Tai nguydn vd Mdi tiirdng, 2006 Bdo cdo
thuylt minh tdng hgp quy hoach sit dyng ddt din
nam 2010 va dinh huong quy hoach sir dung ddt din
nam 2020 vimg Duydn hai Nam Tnmg bO.
3. Bd Tdi Nguyin vd Mdi hiidng, 2012. Dilu tra,
danh 0 a thoai hda ddt vimg duyen hai Nam Trung
bg phuc vu quan ly su dung dat bin viing.
4. Ngan hang T h i gidi, 2008. Tai Ueu tham khao
quan l;y bin virng dat dai.
5. Ngd Dinh Tudn, Ngd Ld An, 2012. Nghidn ciiu
cac ylu td gay ban han, chi tidu, phan cdp h?n a tinh
Ninh Thuan, Bmh Thuan va giai phap phdng, chdng,
giam thilu.
6. Mai Hanh Nguydn, 2012. Viln Nghiln ciiu

NONG NGHIEP VA PHAT TRIEN N 6 N G THON - KY 2 - THANG 9/2015

KHOAHQC C 6 N G NGHfe
Quan ly dat dai. Danh gid tdng qudt tac ddng ciia
biln ddi khi hau ddi vdi tdi nguydn ddt dai va cdc
biln phap ling phd. TuyIn tap bao cdo Hpi thao khoa
hgc lan tiiii 10
Viln Khoa hpc Khi hipng
Tlmy van va Mdi bnidng.
7. D. Tigkas, H. Vangelis and G. Tsakiris. The
RDI as a composite chmatie index. Lab. Of
Reclamation Works and Water Resoureces
Management National Techmcal University of
Atiiens, Greece.
8. D. Tigkas, Nationnal Technical University of
Athens. Drought Characterisation anf Monitoring in

Regions of Greece.
g g KaneUou, C. Domenikiotis, A. Blanta, E.
Hondronikou and N. R. Dalezios, 2008, hidex-based
Drought Assessment in Semi-Arid Areas of Greece
^^^^^ ^„ Conventional Data. European Water 23/24:
87-98.
^Q G Tsakiris, H. Vangelis and D. Tigkas.
Drought impacts on yield potential in rainfed
agncultiire. Centre for tiie Assessment of Nahu-al
Hazards & Proactive Planning. National Technical
University of Athens, Iroon Polytechniou 9, 15773,
Athens (Greece) e-mail:

PREDICTION OF DROUGHT AGRICULTURAL LAND AREA DUE TO THE IMPACT OF
CLIMATE CHANGE IN THE COASTAL REGION OF SOUTH CENTRAL OF VIETNAM
Nguyen Mai Hanh, TTiuy Tran Van, Can Vo Tu, Trinh Mai Van
Summary
'•>
E
ji

^

\t
;jIJ.-

Climate change have manifested temperature increase causing mucli impact on the usage of agncultural
land, in which, drought is one of the limitingfectorsand becoming more severe. The South Cential Coast
has the natural area of 4,437,653 ha, agncultural land accounts for over 76% of the natural area.
Characteristics of regional climate with two seasons m the year, the rainy season and dry season, in the dry
months from May to August, some areas Lke Nmh Thuan, Binh Thuan oftenfecedwith prolonged drought.
Currentiy drought land area of the region occupies a significant area of agncultural land (1,160,306
hectares, accounting for 34.2190 and forecast to be increased due to the effects of climate change in 2020 is
1,360,745 ha, in 2030 is 1,366,519 ha, m 2050 is 1,489,193 ha. Of which, drought forest land area is increased
the most and forecasted is 1,014,962 ha in 2050 (an increase of 62,689 hectares in comparation with the year
2030 and 191,551 hectares m comparation with the present). Drought agricultural land area (including
annual crops and perennial crops) is forecasted to be increased 469,300 ba in 2050 (increase 58,393 hectares
m comparation with the year 2030 and 135,250 hectares in comparaUon with the present). Drought index
was calculated based on the Reconnaissance Drought Index (RDI) and forecasting for drought agncultural
land area due to the impact of climate change for the South Central Coast This is a really necessary
research, proposing solutions for the management and sustainable land use, adaptating to climate change.
Ksy words: Climate, agricultural land area, dry, south central region.

:

Ngudi phan b i ^ : TS. Hodng TXidn Hi^p

''

Ngdy nhan bdi: 29/7/2015
Ngdy tiidng qua phdn bi|n: 3/9/2015

if
Ngdy duy$t dang: 10/9/2015

NONG NGHIEP VA PHAT TRIEN NONG THON ~ KY 2 - THANG 9/2015