Top chi Khoa hgc Tnt&ng Dai hgc Cdn Tha Pbdn B Ndng nghiip Thuy san va Cdng nghi Sinh bgc 26 i20l3) 22 236 Tap chf Khoa hpc Tru''''dng Oai hoc Can Thd website sj ctu edu vn PHAN VUNG SINH THAI NONG NGHIE[.]
Top chi Khoa hgc Tnt&ng Dai hgc Cdn Tha Pbdn B: Ndng nghiip Thuy san va Cdng nghi Sinh bgc: 26 i20l3) Tap chf Khoa hpc Tru'dng Oai hoc Can Thd website: sj.ctu.edu.vn PHAN VUNG SINH THAI NONG NGHIEP THEO THUY VAN, T H NHlTOfNG VA HI?N TRANG CANH TAC CHO CAC HUYEN VEN BIEN TINH BEN TRE Le Van Khoa', Nguyen Thi Cam Su^, Vd Quang Minh" va Pham Thanh Vu' ' Phdng Qudn Ly Khoa hgc, Trudng Dgi hgc Cdn Tlia Khoa Mdi Trudng vd Tdi nguyen Tliiin nhiin, Trudng Dgi hgc Cdn Tha Thong tin chung: Ngdy nhdn 27/02/2013 Ngdy chdp nhdn: 20/06/2013 Title: Agro-ecological zoning according to hydrology, pedology and present land use for coastal districts in Ben Tre province Tu khda: Kich bdn bien ddi hdu muc nudc biin ddng, phdn vitng sinh thdi ndng nghiep, hiin trgng sir dung ddt Keywords: Climate change scenario, sea level rise, agri- ecological zoning, present land use ABSTRACT Ihis research was implemented at the coastal districts in Ben Tre province (Ba Tri Binh Dai and Thanh Phu) based on the evolution of hydrology (salinity and saline intrusion) according to climate change scenario ofBl and AlFl, pedology and present land use are selected as main factors for zoning at current condition, in 2020 and 2050 Soil survey has also been done at 25 sites by augeringfor testing and 25 households concurrently investigated in the study area Tlie results showed that having agro-ecological zones were determined: (I) Fresh water ecological zone: (2) Brackish water ecological zone; and (3) Saline water ecological zone Due to the negligible change of hydrology in 2020, the agro-ecological zones at current time and in 2020 will be the same In 2050, sea level rises to 33 cm driving the strongly saline intrusion to the land, consequently reducing 30% area of freshwater ecology and increasing 30% area of brackish water ecology and saline M'ater ecology is almost stable To enhance the effects of response and adaptation lo the climate change, the detailed researches of changing on soil quality, the selection of land use planning and suitable fanning systems need to be done in the impacted area TOM TAT Nghien cuu duac thuc hiin tgi cdc huyin ven bien thudc tinh Bin Tre (Ba Tn, Binh Dgi vd Thanh Phd) tren ca sd su thay ddi cda thuy vdn (dg man vd xdm nhdp man) iheo kich bdn biin ddi klii hgu BI vd AlFI thd nhudng vd hiin frgng canh tdc cua vitng nghiin cuu dugc chgn ldm tiiu chi phdn vimg sinh thdi ndng nghiep diiu hi$n hien tgi, d ndm 2020 vd 2050 Nghien cuu da khdo sdt ddt kiim chung vdi 25 mdi khoan vd dieu tra 25 ndng hg vitng Kit qud nghien cdu cho thdy cd vitng sinh thdi ndng nghiip dugc xdc lap: (1) Vitng sinh thdi nuac nggt; (2) Vimg sinh thdi nudc lg; vd (3) Vitng sinh thai nudc man Do sir thay ddi thuy van khdng ddng ki a ndm 2020 nen phdn vitng sinh thdi ndng nghiip a hiin tgi vd ndm 2020 gidng Den ndm 2050, nudc biin ddng 33 cm, man xdm nhdp sdu vdo ddt lien nen ldm gidm 30% diin tich vitng sinh thdi nudc nggt vd tdng 30% diin rich vimg sinh thdi nudc lg Vitng sinh thdi nudc man thay ddi klidng ddng ki Bi ndng cao hiiu qud ciia cdng tdc ung phd vd thich nght vdi BDKH, cdn nghien cuu sdu ve sir thay ddi linh chdt ddt, cmg nhu tiin hdnh quy hogch vd xdc dinh eac md hinh canh tdc thich nghi vitng bi dnh hudng Ti^ chi Khoa hoc Tru&ng Dgi hgc Cdn Tha Phdn B Ndng nghiep Thuy san vd Cong ngh? Sinh hgc 26 (2013): 22''-236 MODAU Nhftng thap ky ddu ciia The ky 21 vdi ddc trung ndi bat: i) Phat frien ben vimg da trd thdnh chien luge phat trien cua loan the gidi; ii) Hdi nhdp va loan cdu hda va iii) Bien ddi hdu (BDKH), nhftng dac trung da frd thach thuc Idn nhdl cho loan nhan loai thi ky 21 (Truong Quang Hgc, 2009) Bien ddi hau dugc cdng nhan nhu Id mdt mdi de dga Idn ddi vdi su sdng cdn cua cdc loai va linh todn ven cua h? sinh thdi thdng qua tdc ddng Ien che dp thuy van, nhiet do, lugng mua va ban hdn (Hulme, 2005) Viel Nam la mgt frong cdc nudc dugc du dodn se bi lac dgng nang ne nhdt cua bien ddi hdu, nudc bien ddng cao la nguyen nhdn chinh gdy ngap lut, nhiem man ngudn nudc, anh hudng man den ndng nghiep, gay nii ro ldn den cdng nghiep va cac hoat ddng kinh te khac cua ngudi (Le Anh Tudn, 2009: Van phdng chuong frinh muc tieu qudc gia ung phd vdi BDKH tinh Bin Tre, 2011) Bin Tre Id linh ndm d cuoi ngudn sdng Cuu Long va tiep giap biln Ddng, dia hinh thdp va bi chia edt bdi sdng Idn la sdng My Tho, sdng Ba Lai, song Ham Ludng va sdng Cd Chien Vdi dieu kien dia ly nhu tren Bin Tre la mdt nhung viing chiu dnh hudng nang nl nhat bdi tac ddng cua bien ddi hau (Bd Tai nguyen & Mdi tnrdng, 2009; Le Huy Ba, 2010) Trong dd, che thuy van (xam nhap mdn nudc bien ddng va man) cd anh hudng quyet dinh Hon nua, cac yeu id ciia dieu kien thu nhienfrongvung thay doi khdng Idn so vdi cdc kich bdn bien ddi hdu cho tinh Ben Tre Do dd, dl tai nghien cmi da chon yeu to che thiiy van ket hop vai dieu kien tho nhirong va hien trang canh tac lam tieu chi de phan viing sinh thai nong nghiep cho ba huyen ven bien tinh Ben Tre nham gop phdn cho cdng tdc quy hoach su dung ddi hieu qua PHU'ONG PHAP NGHIEN Ciru Nghien cuu dugc lien hanh tren pham vi loan huyen cua huyen Binh Dai, Ba Tri va Thanh Phii cua tinh Ben Tre Tham khdo, bien hdi cdc thdng tin vd sd lieu tu cac ban don tinh lien quan den dat dai ddng thdi khao sal kilm chimg 25 mui khoan vd 25 phieu dieu tra ndng hd -+• Hinh 1: Viing nghien cuu va vj tri cac diem khao, lay mau Ngoai nghien cuu da su dung cdc ket qua tir nghien cuu biln d6i hdu xdy dung cho tinh Bin Tre nam 2011 d hai kich ban, phat thai thdp (BI) vd phat thai cao nhdt (AIFI) cua Van phdng chuong frinh muc tieu quoc gia img phd vdi BDKH tinh Ben Tre, 2011 Theo hai kich ban nay, muc nudc bien dang vd su xam nhap man cung nhu muc man frong vung nghien cuu dugc dien bien nhu uinh bay Bang 1, Hinh va Hinh Tap chi Khoa hoc Tntang Dgi hoc Cdn Tha Phin B: VoHg nghiip Thin- san va Cong nghi Sinh lioc 26 (2013) 227.236 Bangl: Bien ddng cua mirc nu^c bien dang (cm) theo Dam ciia cac kich ban Kjch ban Thap(Bl) Cao (AlFl) 2020 11 12 17 17 23 24 28 33 25 44 42 57 ^ 2080 50 71 2090 57 86 (Nguon: Van phong muc tieu quoc gia iwg v&i BDKH, 2011} + Hinh 2: Dien bien xam nfaap man huy|n ven bien tinfa Ben Tre den nam 2020 CbAu Thunti » - ^ R Ranh ludj n u n ^ KaDh g»ta nuui 10 ppl Kunh iptii n u n 26 ppl Tn Ranh pioi m f n V ppl Hinh 3: Dien bien xam nfa^p man huy|• ven bien tinfa Bin Tre den nam 2050 2100 65 100 Tap chi Khoa hgc Tnt&ng Dgt hoc Cdn Tha Phdn B .\'6 •.nghiip Thuy san vd Cdng ngbe Smh bgc: 26 12(1} 3l 227-236 Viec xdy dung ban cac vung, tieu vung sinh thai uong dieu kien hien tai va theo kich ban biln ddi hau dugc thuc hien dua fren cdc tieu chi lua chgn: Thd nhudng, thuy van (do man va xam nhap man nudc biln dang) va hien trang canh tac Nghien cuu khdng dl cap den nhung tac dgng ciia cac he thdng cdng trinh hien cd anh hudng den che thuy van cdc kich ban bien ddi hdu gay Day cung la pham vi nghien cuu cua de tai Bang 2: P h a n viing thiiy van t u o n g iing vdi cSc dQ m a n STT , , D a c tinfa tfauy v a n Viing nudc ngpt - lg Vungnudclg Vung nudc Do m a a Tfadi gian mjin i';^>L Cha giai ' ,1 1' 1* 1^ Ranh giaj huvfn, x i Biin DOOR Vung ST nuor DBOl Ire VuiiR ST nudc npH Ira djilphin IJ Vimg ST iiin>c hr [ '' Viing ST luldc man Tra Vinh Hinfa 4: Phan vung sinfa tfaai ndng ngfaiep viing ngfaien cuu dieu kien hi|n t^i vd su tfaay doi cfae thiiy van tfaeo k|cfa ban BDKH den nam 2020 Tieu vimg bao gdm cac don vi hanh chi'nh vdi cac dac diem nhu sau: Huyen Ba Tri Hien tai fren dia ban huyen cd cdc md hinh canh tdc bien khdc nhu: Co cdu liia vu, vu Ilia - I vu mau, chuyen mau, cdy hang nam (cdy mia) cay cdng nghiep (cay dua), thuy sdn nudc nggt, cay an frdi, chan nudi gia sue va gia cam Viing cd dien tich khoang 17.846 ha, chiem 56.56% dien tich loan huyen, bao gdm lodn bg viing nggt tu ranh gidi huyen Gidng Trdm den Id An Due, cdc xa Phii Ll, Phudc Tuy, An Due, Tan Xudn Dac diim viing gan nhu nggt quanh nam (thdi gian man < thang) dia hinh tuong dii trung thap, khoang 2.625 dien tich ddt frong vung bi nhiem phen Huyen Thanh Phu Cac kieu su dung ddt chinh frong huyen gim co: Liia I vu, Iiia vu (HT - TD), I vu Ilia - vu mau, chuyen man, cay mia, cay diia, cdy dn trai Td ranh gidi huyen Md Cay den thi fran Thanh Phu, xa Bao Thanh, vung cd dien tich khoang 11.187 ha, chilm 31,43 % dien tich todn huyen Trong dd, cd khoang 1.971 dien tich dat frong vimg bi nhilm phen, ddy la vimg gan nhu nggt quanh nam (Uidi gian man < thang) Hien frang san xuat cua viing la frdng dua va mia d khu vuc xa Phii Khanh va Dai Dien, md liia vu d cac My Hung, Hda Lgi, Binh Thanh Ngoai cdn phat Uien rau mau fr^n ddt gidng d xa Binh Thanh Tieu viing sinh thai nu&c nggt tren ddt phen Tieu vung chi xuat hien d huyen Binh Dai, chiem dien tich khoang 12.682 ha, (37.1%) dien tich loan huyen, lu ranh huyen Chdu Thanh den ranh gidi cac xa Thanh Tri, Djnh Trung ciia huyen Binh Dai Trong dd dien lich dat bi nhiem phen kha Idn, dac biet la phen boat ddng Dieu kien thiiy van viing la nggt - Ig uong nam nudc bi nhiem man Tap chi Khoa hgc Tru&ng Dai hgc Cdn Tha Phdn B Nong nghiep Thuy san i a Cdng ngbe Sinh hgc khodng thdng den thang (duong lich), man cao nhat vao mua khd khodng - 7%o Khu vuc cac xa Long Dinh den Chau Hung, Vang Qudi Tdy, dat gd it bi nhiem man Hien tai fren dia ban huyen cd cac md hinh canh tdc phd bien khac nhu: Lua vu (HT - M), lua vu (DX - HT - TD), chuyen mau, cdy mia, cdy dua - ca cao va mdt sd loai cdy an frai cd the chju dugc man ngdn han, phat trien rau mau fren ddt gidng cat b Vung sinh thdi mr&c Iff Chilm di?n tich 30.257 (29,6%), hien Uang san xudt cua vimg phd biln Id nudi Uong thiiy sdn vdi md hinh tdm - Ida, liia - tdm cang xanh d nhirng noi cd man thap, dong thdi phat frien rau mau Uen ddt gidng cat cd dia hinh cao Vung cd man thay ddi lu 10%o va keo dai lu - thang Dat frong vung sinh thai la cac loai dat phii sa va ddt cat Viing phdn bd fren ca dan vi hanh chinh, gdm huyen Ba Tri, huyen Binh Dai va huyen Thanh Phu vdi cac dac diem rieng nhu sau: Huyen Ba Tri Bdt ddu li!r ranh Tieu vitng sinh thdi nu&c nggt den cac xa Bdo Thanh, Bao Thuan, Tan Thuy, An Hda Tay co dien tich khodng 6.273 ha, chilm 19.94% dien tich loan huyen Trong dd khodng 666 dien tich ddt vung bi nhiem phen Day la vimg cd thdi gian man lu - thdng, rieng ddi vdi khu \'uc gdn cua song (xa An Due, An Hda Tay) thdi gian man lu - thang man dao ddng tu - 10%o nen khu vuc cd cac md hinh canh ldc nhu Ida thuy san Ig, tdm - Iiia va lua (HT muon - DX sdm) Ngudi dan nuoi trdng thiiy sdn vung gdn cua sdng vdi mo hinh tdm - liia, trdng mau fren cdc khu vuc ddt gidng cat va tham canh liia d nhung noi cd dilu kien cung cdp du nudc Trong viing co man nhe ngudi dan dia phuong da phat triln nhimg md hinh nudi cd nudc nggt md hinh lua - tdm cang xanh Rieng khu vuc phia Tdy Bdc cua lilu vung cd he thong de kha kien co nen dugc nggt hda kha CO ban Hien trang sdn xudt cua khu vuc ndy la nudi Udng thtiy san nudc nggt Ida vu vd frdng mau fren ddt gidng cat Huyen Binh Dai Tu ranh Hew vitng sinh thdi nuac nggt tren ddt phen den ranh cdc xa Thanh Phudc, Thira Due, rach Vung Ludng den sdng Ba Lai, vung cd dien lich khoang 10.010 ha, chilm 29,28% dien lich toan huyen Dac diem thuy van vung Id cd thdi gian man tir - thang, dp man dao ddng tu - 10%o dia hinh luong ddi thdp Md hinh liia vu - thuy sdn va nudi torn cdng nghiep dugc phdt trien lai xa Binh Thang gdn khu vuc cua Dai Viing tiep can khu vuc nggt hoa ngudi dan ap dung mo hinh tdm - lua d nhirng noi cd dieu kien thich hgp - Huyen Thanh Phu Tir ranh Tieu viing sinh thdi nu&c nggt tren ddt phil sa den het cac xa An Nhon An Dien, vung co dien tich khoang 13.974 ha, chiem 39,26% dien lich todn huyen Trong cd khodng 1.379 dien tich ddt uong vung bi nhilm phen Viing ndy cd thdi gian man tu thang, man dao ddng tu - 10%o Md hinh ldm lua nudi trdng thiiy sdn nudc man tren ddt rupng va phat frien rau mau fren dat gidng cat tai cdc xa An Dien, An Thudn va An Thanh c Viing sinh thdi nu&c man Vung ddt man chiem dien tich 29.390 (28.2%), phdn bl fren ca huyen Ba Tri Binh Dai va Thanh Phii Viing cd man lu Idn hon 10%o din 30%o Md hinh sdn xudt chinh cua viing bao gdm: San xudt mudi, nudi frdng thiiy san nudc man (tom - rung, chuyen tdm, tdm sd) Tuy vdy, mdi dia phuang cung cd nhung ddc diem rieng biet sau ddy: Huyen Ba Tri Vung cd dien tich khodng 7.455 ha, chiem 23.50% dien lich loan huyen Bdt ddu tu ranh gidi Vitng sinh thai nu&c lg den bien Ddng thugc dja ban cac xa An Thuy Bao Thanh, Bao Thuan dac diem viing na\ la nhiem man gdn nhu quanh nam, man dao ddng 10 - 30%o Ngudi dan san xudt muoi nudi trdng thiiy san nudc man nhu: tdm - Tgp cbi Khoa hgc Tfu&ng Dgi hgc Cdn Tha Phdn B'Nong nghidp Thuy san vd Cdng nghe Sinh hgc 26(2013) _- -'6 ChanlliAnh / ^'^^ ^ TitnGia^ 7"" Gii'ing Trom ~- *~^T^^ 35 ^ kilometres ! " - ^ ' ^l^^j M6CS.V # Chil gMi Ranh itiin huvrn \ i I Bisn l)onB ' , ' " m - • • : , • • • • ' " ' ' " L 1'^ _ Vimg ST nudc ngot trendalphiisa JB Vimg ST nirdc ngM tnn d*f phin [ " i j " Vimg ST nudc to *i Tni Vmh Vung ST n i r * man ^ ]j^mtl^ Hmfa 4: Pfaan viing sinfa tfaai nong ngfaiep viing ngfailn ciru dieu Iden hien tai vd sg tfaay ddi cfae tfauy vdn theo kicfa ban BDKH din ndm 2020 Tieu viing bao gdm cdc don vi hanh chinh vdi cdc dac diem nhu sau; - Huyen Ba Tri Hien lai fren dja ban huyen cd cac md hinh canh tac phd bien khdc nhu: Co cdu liia vu, vu lua - vu mau, chuyen mau, cay hang nam (cay mia), cdy cdng nghiep (cay dira), thuy sdn nudc nggt, cay an frdi, chan nudi gia siic va gia cam Vung cd dien lich khoang 17.846 ha, chiem 56.56% dien ti'ch loan huyen, bao gdm todn bg vung ngpt lu ranh gidi huyen Gidng Trom den Id An Due, cdc xa Phu Ll, Phudc Tuy, An Due, Tan Xudn Dac diim vung gdn nhu nggt quanh nam (thdi gian man < thang) dja hinh tuong ddi trung tiidp, khoang 2.625 dien n'ch ddt viing bj nhilm phen Huyen Thanh Phu Cac kieu su dung ddt chinh frong huyen gom co: Lua I vu lua vu (HT - TD), I vu Ilia - I vu mau, chuyen mau, cdy mia, cdy dda, cay an trai Tir ranh gidi huyen Md Cay den thi Iran Thanh Phii, xa Bao Thanh, viing cd dien tfch khoang 11.187 ha, chilm 31,43 % dien lich toan huyen Trong do, cd khoang 1.971 dien lich dat vimg bi nhiem phen, day la vimg gan nhu ngpt quanh nam (thdi gian man < thang) Hien trang san xudt ciia vimg la frdng dira va mia d khu vuc xa Phu Khanh va Dai Dien, md liia vu d cac My Hung, Hda Lgi, Binh Thanh Ngoai cdn phat triln rau mau Iren ddt giong d xa Binh Thanh Tieu vung sinh thdi nu&c nggt tren ddt phen Tiiu vimg chi xudt hien d huyen Binh Dai, chiem dien tich khoang 12.682 ha, (37.1%) dien tich loan huyen, tir ranh huyen Chau Thanh den ranh gidi cdc xd Thanh Tri, Dinh Trung cua huyen Binh Dai Trong dien lich ddt bj nhiem phen kha Idn, dac biet la phen boat ddng Dieu kien thuy van viing la ngpt - Ig uong nam nudc bi nhilm man Tap chi Khoa hoc Tnr&ng Dai hoc Cdn Tba PhSn B: Ndng nghiep Thuy san vd Cdng ngh? Smb bgc 26 (2013) 227-236 khoang thanp den thang (duong lich), man cao nhdt vao miia khd khoang - 7%o Khu vuc cac xa Long Dinh den Chdu Hung, Vang Qudi Tdy, dat gd it bi nhiem man Hien tai fren dia ban huyen cd cac md hinh canh tac phd bien khac nhu: Liia vu (HT - M), Iua vu (DX - HT - TD), chuyen mau, cay mia, cay dua - ca cao va mgt sd loai cdy an trai cd the chiu dugc man ngdn ban, phat trien rau mdu fren dat gidng edt b Vung sinh thdi ntr&c lot Chilm difn tich 30.257 (29,6%), hien frang san xudt ciia vimg phd bien la nudi frdng thuy san vdi md hinh torn - lua, Ida - tdm cang xanh d nhimg noi cd dp man thdp, dong thiri phat frien rau mau fren dat gidng edt co dia hinh cao Vung cd dp man thay ddi tu IO%o vd keo ddi tu - thang Dat frong viing sinh thai la cac loai dat phu sa vd dat cat Vimg phan bd fren ca don vi hanh chi'nh, gdm huyen Ba Tri, huyen Binh Dai va huyen Thanh Phu vdi cac dac diem rieng nhu sau: Huyen Ba Tri Bat ddu tu ranh Tieu viing sinh thdi nu&c ngot din cac xa Bdo Thanh, Bao Thuan, Tdn Thuy An Hda Tdy cd dien tich khoang 6.273 ha, chilm 19.94% dien tich loan huyen Trong khoang 666 dien lich dat viing bi nhiem phen Ddy Id viing cd thdi gian man tu - thang, rieng ddi vdi khu vuc gdn cua song (xa An Due, An Hoa Tay) thdi gian man lu - thdng man dao ddng td - 10%