Thực trạng và dự báo đất bị khô hạn do tác động của biến đổi khí hậu, giải pháp ứng phó với tác động của biến đổi khí hậu trong quản lý, sử dụng đất nông nghiệp bị khô hạn.
Trang 1DIJ B A O DIEM TiCH D A T IVOIVG IXIGHIEP HI K H O 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' flat dai
^ 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
33
Trang 2t 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 l u o n g h o c h o i ti^m n a n g CTsakiris v^
Vangelis, 2005; T s a k i r i s vi c o n g su, 2007; E
K a n e U o u e t a l , 2 0 0 8 )
S6 tinh toan EDI, c i n tinh m o t gia t n b a n d a u
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 d i n h t r o n g m d t n a m , d u o e tinh h o i c d n g thiic
sau:
CD
T r o n g do: ^ v a PFT)ik l u g n g m u a va l u g n g b d c
h o i tiem nSng tai t h a n g j-th c u a n a m thiiy van t u o n g
ling T r o n g n g h i e n c u u nay, nhidt dd k h d n g k h i h a n g
t h a n g c u a 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 p h a p T h o r t h w a i t e
H e s d k d u g c coi b a n g 1 c h o t h a n g d a u tidn ciia
n a m k h i tugng B6i vdi k h u vuc Dia T r u n g hai k = 1
vao t h a n g 10 vi c a c n a m k h i t u g n g bdt dau vao t h a n g
nay H e s o ajj cd 1h^ d u g c tinh cho giai doan b a t k y
ciia n a m , d i l u n a y c 6 n g h i a la h e sd n a y cd t h i d u g c
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
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
3, 6, 9 , 1 2 N l u lua c h p n tiidi ky 12 thdng, k i t q u a co
t h i d u g c s o s a n h t r u e tilp vdi c h i s d k h d h a n d i a k h u
v u c nghidn ciiu M d t k h u v u c d u g c c o i la k h d b a n
n l u a l 2 c h o m d t n a m n h a t dinh t h a p h o n chi sd k h d
h a n
0 4 0 8 i ( J ^ - G ) + Y - ;z\^i(e^ - « J
A+7(1+0.34112)
(T +237.3)^
T r o n g dd:
P E T : T h o a t h o i ti^m n a n g ( m m ) diroc tinh theo
p h u o n g p h a p P e n m a n - M o n t e i t h (Allen a t al,, 1998)
T : N h i e t dd b i n h quSn n g a y tinh tokn (°C)
A: D d n g h i d n g c u a d u d n g q u a n h $ c u a n h i | t do voi ap s u a t 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 t h e o hd t h u c : A=
(T + 237,3f Ca: a p s u a t h o i n u d e b a o h o a (kPa) e^ = 0,6108»cp n,21T
T+ 231,3 J
R^: C h i n h lech giiia biic x a t a n g v a biic x ^ giam
c u a s d n g n g a n v a s o n g dai QAJ/m^-ngky)
Rn="Rns-RnL-Rns! biic x a ciia m a t trdi dirge g i u l?ii sau k h i phan
x a d d i voi m a t d^t ti-6ng ti-gt QA]/m^-i\gky)
R„.= Cl-a)R,
a: H d s o p h a n x a b e m | t didn tich trdng tigt, tiieo FAO till a = 0 ^ 3
R^: Biic x a m a t trdi (MJ/m^-ngay) R, (0.25+0,5n/N)R,
n / N : T y sd g i u a g i d n a n g m a t trdi t h u c do n va
sd g i d 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)
Ra=37,6dr (cOjSinl'sinS+cos'i'cosSsintiJs)
©s =arccos(-tan¥tan5)
4*: g d c VI dd dia ly (rad)
5: G d c l | c h t h e o n g a y (rad) 6=0,409sin(0,0172J-1,39)
dr: k h o a n g e a c h t u o n g d d i t h e o ngay
dr=l-K),033cos(0,0172D-J: Sd thii' t u t h e o n g a y tinh toan
RnL: biic x a t d a r a b d i n a n g l u g n g hiit dugc ban dau (MJ/m^-ngay)
4 9 0 3 1 0 - ^ ^ - - ^ ^ ^ ^ ' ^ ^ > ^ : ^ ^ - - ^ ^ ^ ^ ' ^ ^ ) \ 0 , 3 4 ^ 0 , 1 4 V i ; ) ( Q , 1 0 9 A )
2 AT
Hr! D d im t u o n g d d i t r u n g b i n h ciia k h d n g khi
T n ^ ; T ^ : N h i e t dd Idn nhat, n h o n h ^ t C O (%)
e^: ap s u ^ t h o i n u o c t h u c t e d nhidt dp k h d n g khi N: Sd g i d n d n g c u e dai N=7,64 (o^ ( h )
t r u n g b i n h (mbar) e^^e^—- G: T h d n g l u g n g n h i e t c u a d^t ( M J / m ^ - n g a y ) ,
n l u tinh G t h e o n h i e t dd b i n h q u a n tiiang thi;
63: a p s u ^ t h o i n u d e b a o h d a , cd quan h d v d i G=0,14Crni-T^i)
n h i d t dd k h d n g khi
Trang 3TmjTnti Nhidt dd binh quan cua thing thii m va
m-1 CQ
y: hang s6 bieu nhiet do
y = 0 , 0 0 1 6 3
-A
^ ^ ^ ^ 2 9 3 - 0 0 0 6 5
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$p
Kjch ban bien d^i khi hSu
(nhi^ do, \wfn% mua nam
2026,2030,2050)
Luong boc hoi dem nang
Chi so k h o han
B i n d6 d ? bao ikt NN bj kho han
v^o nam 2020, 2030,2050
Sad6 Cacbu6c1haiihl^band6 di|bao d^ndng
nghi^bikhdhfin
+Tdng hgp dii li^u ddu vao
+ cac dii lieu thoi gian kho han cua cac thang trong nam cho tung tram dupe xac dinh d l tinh toan lupng hoc hoi mat rudng (ET)
+ Tinh chi sd khd han KDI (RDI^ va RDI_^^ sau
dd ndi suy vimg anh huong cd tinh din tac ddng ctia
ylu t l mat dim va t6ng hgp dU lieu didn tich Ait bi
khd ban theo sd thang khd hEui trong nam cho toan khu vuc
+ Ndi suy bang phuong phap Moving average {trung binh trupt), su dung sd lidu cua cac trgm va sd li$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
35
Trang 443,42%, 43,12% vk 7,17%; dat bi kho h?in nang co di«n
tich 165.091 ha (chiem 14,23% di6n tich dSt ndng nghidp), tSp trung or tinh Ninh Thu|n (96.057 ha,
chidm 36,09% di$n tich dat ndng nghiep) vk Binh
Thuan (69.034 ha, chidm 10,15% didn tich djlt nong
ha (chidm 65,75% didn tich dSt khd han cua toan
vimg); dat hi khd han tnmg bmh cd diSn tich 232.353
ha (chiem 20,03% diSn tich hr nhidn toan vimg) Cac
tinh Binh Thujn, Ninh Thuan, Quang Ngai la nhimg
tinh cd dien tich dat hi kho han trung binh chidm ti 1^
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
Tmh/Thanh
phd
Da Nang
Quang Nam
Quang Ngai
Bmh Dinh
PhiiYSn
Khinh Hda
Ninh Thuan
Binh Thuan
Tdng
Coc^u
Tong
di^n tich
dat hi
khd ban
9.463
126.834
61.924
194.331
146.713
130.137
175.311
315.593
1.160.306
100,00
Dat san xuat nong nghiep
Tdng
3.438 20.947 27.987 36.014 25.464 30.939 47.212 142.049 334.050 28,79
Dat trong cay hang nam
Tdng
2.867 10.632 16.596 16.339 17.356 11.519 39.500 27.940 142.749 42,73
Dat trdng lua 2.327 6.482 11.453 6.573 7.294 2.871 7.548 8.664 53.212 37,28
Dat t d n g cayHN khac
540 4.150 5.143 9.766 10.062 8.648 31.952 19.276 89.537 62,72
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
Sat lam mudi
2
17
9
6
59
702
80
875 0,08
Dat ndng nghifp khac 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
Tmh/Thinh
phd
Da Nang
Quang Nam
Quing Ngai
Tdng
dien
tich dat
bikho
han
9.953
126.834
61.924
Dit san xuit nong nghieo
Tdng
3.770 20.947
27987
Dit trong civ hang nam
Tdng
3.167 10.632 16.596
Dat trdng lua 2.387 6.482 11.453
Dit trdng cayHN khic
780 4.150 5.143
Dat trong cay lau nam
603 10.315 11.391
Dat lim nghijp
4.875 105.669 33.894
Bon
Dit lam mudi
2
17
vi tinh: hi
Dit ndng nghiep khac
1.308
216
26
Trang 5Binh Dinh
Phu Yen
Khanh Hda
Ninh Thuin
Binh Thuan
Tdng
Co cau
196.190
162.626
142.066
176.849
484.303
1.360.745
100,00
27.883 27.072 32.859 48.029 217.832 406.379 29,86
7.918 18.866 12.721 40.171 86.765 196.836 48,44
6.876 8.035 2.904 7.606 9.414 55.157 28,02
10.042 10.831 9.817 32.565 68.351 141.679 71,98
19.965 8.206 20.138 7.858 131.067 209.543 51,56
159.175 135.522 109.040 127.852 275.214 951.241 69,91
12
7
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
khd ban ciia ca vimg du bao la 1.360.745 ha, tang
tiidm 200.439 ha so vdi hiln nay Trong dd ban nhe
du bao tang them g ^ 134 nghin ha, ban tiling binh
tang thdm hon 3 nghin ha, ban nang tang Idn hon 62
nghin ha Dien tich d& ndng nghilp bi khd ban tang
phan Idn trin dat lam nghilp, dat trong cay hang
nam, cae loai dat ndng nghilp khac tang Idn khdng
nhilu Ridng a hai tinh Quang Nam, Quang Ngai
didn tich dat ndng nghiep bi khd ban vao nam 2020
g ^ nhu khdng tang so vdi hidn nay Didn tich dat
khd ban chii yeu ma rdng trdn cae nhdm dat bai cat,
con cat va dat cat, djit man, dat xam bac mau, dat do
vang
Dien tich khd han cua viing tang thdm vao nam
2020 chu yeu la tang 6 tinh Binh Thugn (tang 168.710
ha so vm hien nay), tilp den la cac tinh Phii Ydn,
Khanh Hda (tang tir 11 din 15 nghin ha) Tgi Binh
TTiuan, didn tieh khd ban md rdng vl phia Bdc huyIn
Due linh va Tanh Linh; mdt sd xa phia Tay Bac cua Ham Thuan Bac va Ham Thu$n Nam cd ban trung binh cdn lai hi ban nang; huyIn Ham Tan phan Ion dien tich hi ban trung binh Mdt phan diln tich phia Ddng thanh pho Pban Thilt va phan Ion dien tich phia Tay bi han nang O huydn Bac Binh va Tuy Phong, dien tieh ban nghiem trong md rdng hon vl phia Bac, dien tich ban nang cung tien vd phia Tay, hdu nhu khdng cdn dien tieh cd ban trung binh
(iii) Bu bao nam 2030
Theo kit qua tinh toan, chi sd khd ban vao nam
2030 so vdi nam 2020 tai cac tinh, thanh Da Ning, Quang Nam, Quang Ngai khdng co thay ddi nhieu Tinh Binh Dinh tuy giam khdng nhilu, nhung vao tiiang 3 chi s6 khd han da virgt qua nguong trung binh sang khd han nhilu Ttnh Phii Yin, Khanh Hda, Ninh TTiuan, Binh TTiuan din nam 2030, chi so khd ban van tilp tuc giam, nhung miic giam rat it so vdi 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
Tmh/Thanh
phd
Da Nang
Quang Nam
Quang Ngai
Binh Dinh
Phii Ydn
Khanh Hda
Ninh Thuan
Bmh Thuan
Tdng
Co can
Tdng didn
tich dit bi
kho ban
10.166
127.096
62.528
197.443
163.045
142.572
178.878
484.791
1.366.519
100,00
Dit san xu^t ndng nghiep
Tdng
3.944 21.175 28.513 38.048 27.491 33.365 49.215 209.156 410.907 30,07
Dit trdng ciy hang nam
Tdng
3.220 10.757 16.977 17.510 19.285 13.227 40.568 78.074 199.618 48,58
Dit trdng lua 2.426 6.531 11.663 7.195 8.280 2.904 7.793 9.502 56.294 28,20
Dit trdng ciyHN khac
794 4.226 5.314 10.315 11.005 10.323 32.775 68.572 143.324 71,80
Dat trdng ciyliu nam
724 10.418 11.536 20.538 8.206 20.138 8.647 131.082 211.289 51,42
Dit lim nghiep
4905 105.688 33.962 159.242 135.522 109.040 128.550 275.364 952.273 69,69
Dat lam mudi
2
19
14
7
63
738
115
958 0,07
Dat ndng nghiep khic
1.317
231
34
139
25
104
335
196 2.381 0,17
Ngudn: Ket qui nghien aiu
Trang 6Di?n tich dat ndng nghiep bi khd ban chu yeu
md rdng trdn cac nhdm dit bai cit, cdn cit vi dit cat,
dat min, dit xam biic mau, dit do vang, nhdm dit
xam bac mau Du bio den nim 2030, didn tich dit
ndng nghiep hi khd han cua toin viing la 1.366.519 ha,
tang 5.774 ha so vdi nam 2020, tang 206.213 ha so vdi
hidn nay Trong dd, du kidn didn tich dat ndng nghidp
hi khd han nhe la 899.336 ha (chidm 65,81%), kho han
trung binh 237.752 ha (chidm 17,40%), khd ban nang
229.431 ha (chidm 16,79%) Didn tich dat ndng nghiep
bi khd h?n tang vio nam 2030 chu yeu trdn dit trdng
ciy hing nam, dit trdng ciy liu nam va dit lam
nghiep So vm nim 2020, dien tich dit ndng nghiep bj
kho ban nam 2030 tang khdng nhidu, drr kidn didn
tich dit ndng nghidp bi kho han ting nhidu a tinh
Binh Dinh, Ninh Thuan (tang 1.253 ha va 2.029 ha), o
ckc Hnh cdn lai ting khoang t i 200 ddn 600 ha So voi
hien nay, di6n tich dit bi khd hgn tang tip hung chii
ydu a tinh Binh Thuin (tang 169.198 ha, chidm 82,05%
didn tich dat nong nghidp bi khd ban tang thdm cua ca
viing) Tidp den li cic tmh Phii Yen, Khanh Hda cd
didn tich dit ndng nghiep hi khd ban ting th^m
khoang 12,5 den 16 nghin ha; Binh Dinh, Ninh Thuan
cd dien tich ting thdm khoing U-dn 3 nghin ha; cic
xuit hidn thdm mdt sd didn tich dat ndng nghidp (125 ha) hi khd ban nang ^
(iii) Da bio nam 2050
Chi sd khd han t?i cac tinh trong vung vio nim
2050 so vdi nam 2030 nhin chung ddu giam nhung muc dd khac nhau Cac tinh/thanh Da Nang, Quang Nam, Quang Ngii cd chi sd khd hiin giam khdng nhidu (dao ddng trong khoang -0,1) Cic tinh Binh Dinh, Phii Ydn, Khanh Hda cd xu huong giam manh hon, die bidt vao cic thing 2,3,4 cd thing giam trdn -0,3 So vdi hidn nay, dvt bio den nam 2050, chi sd khd ban ciia cic tinh trdn dia ban duydn hai Nam trung bp cd sir thay ddi nhu sau: Tai cac tinh/thanh
Da Ning, Quang Nam, Quang Ngai chi sd khd hjii nhin chung giam, miic giam khdng nhidu ttr 0,01 ddn -0,2; tai cac tinh Binh Dinh, Phii Ydn, Khanh Hda chi
sd khd ban cd miic giam dang kd, giam tat ca cac thing trong nim; tai Ninh Thuin va Binh Thuan mjc dii hien nay chi sd khd han da d miic cao, die bidt vio cic thing 1, 2, 3, tuy nhi6n theo tinh toin thi vio nim 2050 chi sd niy cd miic thay ddi rat Idn theo chidu hudng giam ding ke, giam tdi trdn -10 Tai Binh Thuin xuit hien miic ban nhidu vao thing 12
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
Tdng dien
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
Dat san xuit ndng nghiep Tong
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 Tdng
617 5.209 3.670 8.416 6.024 100.938 132.076 256.950
28,32
Dit trdng Ilia
437
381 127.470 158.792 287.080
111,73
Dat trdng CiyHN khic 2.507 6.592 11.718 7.958 8.280 3.284 12.648 16.928 69.915
27,21
Dat trdng cay liu nam
909 4.297 5.618 10.872 11.351 10.671 39.615 84.176 167.509
18,47
Dat lam nghidp
807 10.507 11.638 21.067 8.317 20.218 8.708 150.614 231.876
15,57
Dat lim mudi
2
31
34
28
75
943
541 1.654
0,11
Dit nong nghidp khac 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 c i viing Ii 1.489.193 ha, chidm 43,91%
didn tich dit ndng nghidp Trong do di^n tich dit bi
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)
38
Trang 719,27%) 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, k i t 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 it tidu thu 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 d l 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
3.2.2 Bidnphip cay trdng
- Chuyin dich co cau cay tiong phii hop nham sii
dung tilt Idem, hidu qua nguon nude; sir dung cac
gidng ehm ban, sinh trudng nhanh, dac bidt la cac
gidng cay ban dia, eac cay hp dau phii hgp vdi hd
thdng ndng nghiep cua vimg va cac tinh trong vimg
- Nghien ciiu chgn tuyIn nhiing cay gidng khoe
chiu khd ban nhir dieu, ea cao, dliu ; cac cay ndng
nghiep ngdn ngay: hanh tim, khoai lang, mi ( s ^ ) ,
dau, mia ; cac cay an qua dan xen: thanh long, xoai
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 t l , 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 d l san xudt cae vimg chuyen canh, thSm eanh, viing san xuat ndng san hang boa quy md Ion viia dam bao tidu thu ndi dia vira dam bao yeu cau xuat khau Dau tu phat trien thuy lpi cua tinh phai phii hgp vdi quy hoach thuy Igi, cap nude va phong chdng ban ban, lu lut, lii quet, lii dng chung eua tinh, gdn chat vdi phat trien dan cu va giao thdng ndng thdn;
- Bd tri quy hoach cac vung ed kha nang bi anh hudng thien tai do BDKH, gdn liln vdi pbdt trien xa hdi, xay dung ha tdng, phiic Igi cdng edng de phue vu
39
Trang 8san 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
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
40
Trang 9Quan ly dat dai Danh gid tdng qudt tac ddng ciia Regions of Greece
biln ddi khi hau ddi vdi tdi nguydn ddt dai va cdc g g KaneUou, C Domenikiotis, A Blanta, E biln phap ling phd TuyIn tap bao cdo Hpi thao khoa Hondronikou and N R Dalezios, 2008, hidex-based hgc lan tiiii 10 Viln Khoa hpc Khi hipng Drought Assessment in Semi-Arid Areas of Greece Tlmy van va Mdi bnidng ^^^^^ ^„ Conventional Data European Water 23/24:
7 D Tigkas, H Vangelis and G Tsakiris The 87-98
RDI as a composite chmatie index Lab Of ^Q G Tsakiris, H Vangelis and D Tigkas
Reclamation Works and Water Resoureces Drought impacts on yield potential in rainfed Management National Techmcal University of agncultiire Centre for tiie Assessment of Nahu-al Atiiens, Greece Hazards & Proactive Planning National Technical
8 D Tigkas, Nationnal Technical University of University of Athens, Iroon Polytechniou 9, 15773, Athens Drought Characterisation anf Monitoring in Athens (Greece) e-mail: water@survey.ntua.gr
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 Climate change have manifested temperature increase causing mucli impact on the usage of agncultural
'•> land, in which, drought is one of the limiting fectors and becoming more severe The South Cential Coast
E 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
ji months from May to August, some areas Lke Nmh Thuan, Binh Thuan often feced with 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
\t was calculated based on the Reconnaissance Drought Index (RDI) and forecasting for drought agncultural
;j- land area due to the impact of climate change for the South Central Coast This is a really necessary IJ.- 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