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.
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 da, dang vk se gSy nhi^u tac dong d^n vi§c sir dung dat ndng nghiep, han han la m^t nhung y^u td gioi hgn quan trpng nhat va cang trd nen nghiem trpng Viing duy6n hai Nam Trung bfl co di&n tich tir nhien 4.437.653 ha, d6 di§n tich dat nong nghiep chi^m tr^n 76% Dac di^m h^u cua vung vdi 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^ cac thing mua kh6 Hien diSn tich dj(t hi kh6 h ^ cua viing chiem mpt ty 1$ d^g k^ 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 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 (tang 62.689 so voi nam 2030 va 191.551 so vol hien nay) Dat san xu^t nong nghiep (g6m dat cay h ^ g nam vk dat c^y lau nam) du bio co di^n tich kho han vao nam 2050 U 469.300 (tang 58.393 so vol nam 2030 va 135.250 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 tuong theo ckc kich ban bi^n ddi h^u khdc (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 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 gom tinh, ph6 t n ^ thudc Trung uong ^ a Ning, Quang Nam Quang Ngai, Binh Dinh, Phii Yen, Khanh H6a, Ninh Thuan va Binh Thuan), dien tich dlit ndng nghiep chi^m tren 76% difin tich tu nhiSn Voi d#c di&n hau co mua ro r^t nSm, miia mua va miia kh6, 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 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 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 tac ddng ciia bien ddi hau cho vimg duydn hai Nam Trung bd 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 tuong theo thang nhidu nam (1960 - 2013) ciia 12 tram 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 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 - 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 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 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 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 c h o t h a n g dau tidn ciia tiieo FAO till a = ^ R^: Biic x a m a t trdi (MJ/m^-ngay) R, n a m tugng B6i vdi k h u vuc Dia T r u n g hai k = (0.25+0,5n/N)R, vao t h a n g 10 vi cac n a m 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 n va H e so ajj cd 1h^ dugc tinh cho giai doan b a t ky ciia n a m , d i l u c6 nghia la h e sd 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 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 âs =arccos(-tanƠtan5) 3, 6, , 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 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 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) AT Hr! D d im t u o n g ddi t r u n g binh ciia k h d n g 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 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 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 N - KY - 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 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 m, dd eao khac m thi phai hieu chinh Do dd, 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 - Ban Ah ii^nh chfnh - Bin dd tufn Inmg kho ban - BSn Ah luen tr?ng sii dung dat n6ng nghi$p Kjch ban bien d^i hSu (nhi^ do, \wfn% mua nam 2026,2030,2050) Luong boc hoi dem nang Chi so kho han B i n d6 d ? bao ikt NN bj kho han v^o nam 2020, 2030,2050 Sad6 Cacbu6c1haiihl^band6 di|bao d^ndng nghi^bikhdhfin +Tdng hgp dii li^u ddu vao + cac dii lieu thoi gian kho han cua cac thang nam cho tung tram dupe xac dinh dl tinh toan lupng hoc hoi mat rudng (ET) + Tinh chi sd khd han KDI (RDI^ va RDI_^^ sau dd ndi suy vimg anh huong cd tinh din tac ddng ctia ylu t l mat dim va t6ng hgp dU lieu didn tich Ait bi khd ban theo sd thang khd hEui nam cho toan khu vuc + Ndi suy bang phuong phap Moving average {trung binh trupt), su dung sd lidu cua cac trgm va sd li$u dugc noi suy theo khoang each va gia tri ciia eac tram + Tinh toan dii lidu hien trang d^t ndng nghiep hi anh hudng biln ddi 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 nude bien dang theo cac kich ban K ^ QUA VA THAO LUAN 3.1 Th^c trang va du bao d^t bi khd h^n tac dOng cua biln d6i 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, ning ndng keo dai, nhilu noi 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, Da NSng, Quang Nam, Quang Ngai co chi s6 khd h ^ b miic ban nh? vao khoang thdi gian tir thang din thang 7, chi s i khd han vao cac thang 2, 3, thudng thtip hon (chi s6 RDI_st dao ddng tir 0,21 den -1,05) thang 5, 6, (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 - THANG 9/2015 35 KHOA HOC CdNG NGHt (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 (chiem 14,23% di6n tich dSt ndng (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 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: Dat san xuat nong nghiep Dat 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 17 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 tic ddng ciia bien ddiktiihau (i)Brib^onSm2020 Kit qua tinh toan chi sd khd ban (RDI_st) cho thay tinh Quang Nam (tram Tam Ky, Tra My) co ban khdng giam; cac tinh, Da NIng (tram Da Nang), Quang Ngai (h^im Quang Ngai) giam khdng nhilu; tai Binh Dinh (tram Quy Nhon, Hoai Nhon) nhin chung giam, tram Hoai Nhon giam nhieu hon d tram Quy Nhon giam khoang -0,3 din -0,5 (dac bidt vao cac thang 1,2,3,4), vao cac thang 3, chi sd kho han giam tir miic han nhe sang han tiling binh Cac tinh Phii Yen (tram Tuy Hoa), Khanh Hda (ti^im Nha Tran^, Ninh Thuan (tram Phan Ran^, Binh Thuan (hmn Phan Thilt, Ham Tan) giam xudng rat manh, dae biet vao cac thang 1,2, 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 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 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 civ hang nam Dit Dat Tmh/Thinh Dat lim ndng tich dat lam Dat Dit trdng 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 10.315 105.669 216 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 - 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 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 so vdi hiln 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 nghin ha, ban nang tang Idn hon 62 Ddng Pban Thilt va phan Ion dien tich phia nghin 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 cay hang dien tieh ban nghiem 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 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, Da Ning, cat va dat cat, djit man, dat xam bac mau, dat Quang Nam, Quang Ngai khdng co thay ddi nhieu vang Tinh Binh Dinh giam khdng nhilu, nhung vao Dien tich khd han cua viing tang thdm vao nam tiiang chi s6 khd han da virgt qua nguong trung 2020 chu yeu la tang tinh Binh Thugn (tang 168.710 binh sang khd han nhilu Ttnh Phii Yin, Khanh Hda, 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 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: 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 - THANG 9/2015 19 14 63 738 115 958 0,07 1.317 231 34 139 25 104 335 196 2.381 0,17 KHOA HOC C 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 vang, nhdm dit xam bac mau Du bio den nim 2030, didn tich dit Chi sd khd han t?i cac tinh 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 so vdi nam 2020, tang 206.213 so vdi muc dd khac Cac tinh/thanh Da Nang, Quang hidn 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 (chidm 65,81%), kho han nhidu (dao ddng khoang -0,1) Cic tinh Binh trung binh 237.752 (chidm 17,40%), khd ban nang Dinh, Phii Ydn, Khanh Hda cd xu huong giam manh 229.431 (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 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 So voi sd khd ban cd miic giam dang kd, giam tat ca cac hien nay, di6n tich dit bi khd hgn tang tip chii thing nim; tai Ninh Thuin va Binh Thuan mjc ydu a tinh Binh Thuin (tang 169.198 ha, chidm 82,05% dii hien 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, 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 nghin ha; cic tinh cdn lai chi ting 260 - 700 ha, riSng tinh Binh Djnh Bing 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 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 di^n tich dit bi 38 han nhe li 907.163 (chiem 60,92% didn tich dat ndng nghidp bi khd han), ban trung bmh la 294.950 (chidm 19,81%), han nang li 287.080 (chidn) NONG NGHIEP VA PHAT TRIEN N N G THON - KY - 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 tinh/thanh Da Nang, Quang Ngai ed di$n tich dat ndng nghi?p bi khd hgn thap, diln tieh d^t hi khd han tirong ling la 10.865 va 63.165 ha; cac tinh lai cd diln tich dat ndng nghiep hi khd han tir 130 nghm den 200 nghm 3.2 Giai p h ^ ling phd tdc ddng djia biln d6i hau quan ]y, su dung d^t ndng nghidp hi khd han 3.2.1 Bidn phip cdng trinh - Ddu tu xay dimg he thdng h6 dap du tru nude, kinh muong din nude tuoi va sii dung hgp ly cac nguon nirde He thong tiiuy loi duge dau tu, kit nii vdi mang thuy Igi lien thdng, se bd sung kip thdi cho nhirng noi tiiieu nude cue bp- Sir dung cac bien phap thu trir nude nhu ddp dap, xay b l tru nude, tao ho tru nuoc trdn cat, trdn sirdn ddc Song song vdi vide thu trii nude, viee bao ve nguon nude va dat chdng hoang mac hda bude dau cung da dugc quan tam nhuiam dat tdi thieu dviing dat doe, tang dd nham be mat dat b^ng each tao tham phu thuc vat, che phu goc cay, mat dat bang xac thue vat, bdn phan hiiu co sinh hoc, phan xanh, chpn va bd tii cay hop ly miia khd ittiduthu nude - cac bien phap chdng ban, nhu td chiie nao vet khoi thdng ddng chay hd thong kdnh muong thuy lpi, hudng dan ndng dan ap dung nhiing phuong phap tudi phun mua, nhd gigt san xuat dl tilt kilm nguon nirdc, gieo tr6ng cae cay chiu han; to chiie dao gieng, ao ho du tru nude sinh boat eho ngtrdi dan va nude uong cho dan gia siic mang cau xidm (na); mdt vm loai rau, dt diu duge tuyen chpn da chiu dugc ban Dli vdi tinh chiu han nang la Ninh Thuan va Binh Thuan, cdn thay liia bang nhimg loai cay chiu ban, ed hilu qua kinh te cao hon - Phat triln Idp phii tiiuc vat tren dat thdng qua vile trdng rung va bao vd rimg, khai thac sii dung dat hgp ly, dae bidt la vimg dat ddc, rimg dau nguon 3.2.3 Bi$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, ) 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 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 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 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 BDKH, gdn liln vdi pbdt trien xa nghiep ngdn ngay: hanh tim, khoai lang, mi ( s ^ ) , hdi, xay dung tdng, phiic Igi cdng edng de phue vu dau, mia ; cac cay an qua dan xen: long, xoai NONG NGHIEP VA PHAT TRIEN N N G THON - KY - THANG 9/2015 39 KHOA HOC C6M0 NOHfe san xuat, dan sinh, h^in ehl, giam tiiilu tdc ddng 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 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 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 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 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 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, 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 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 la 1.160.306 (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 Mac dii cd su tang khdc 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 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 (tang 62.689 so vdi nam 2030 va 191.551 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 (tang 58.393 so voi nam 2030 va 135.250 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 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 hau 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 Bd Tdi Nguyin vd Mdi hiidng, 2012 Dilu tra, danh a thoai hda ddt vimg duyen hai Nam Trung bg phuc vu quan ly su dung dat bin viing Ngan hang T h i gidi, 2008 Tai Ueu tham khao quan l;y bin virng dat dai 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 Mai Hanh Nguydn, 2012 Viln Nghiln ciiu NONG NGHIEP VA PHAT TRIEN N N G THON - KY - THANG 9/2015 KHOAHQC C N G NGHfe Quan ly dat dai Danh gid tdng qudt tac ddng ciia biln ddi 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 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 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: 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 '•> 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 Of which, drought forest land area is increased the most and forecasted is 1,014,962 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 - THANG 9/2015 ... 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... 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 hau Bd Tai nguydn vd Mdi tiirdng, 2006 Bdo cdo thuylt minh tdng... dyng ddt din nam 2010 va dinh huong quy hoach sir dung ddt din nam 2020 vimg Duydn hai Nam Tnmg bO Bd Tdi Nguyin vd Mdi hiidng, 2012 Dilu tra, danh a thoai hda ddt vimg duyen hai Nam Trung bg phuc