KHOA HOC COI.
T R D LUpiMG VA KHA IMAIMG D A P IJIVG IMUOC IVfipT CHO CAY TROIXIG VIJIMG TAY SOIXIG HAU, TilXIH KiEIXI GIAIXIG, VIET IXIAIVI IXIAM e 0 1 5 - S 0 l G
Thm Minh Tin', Nguyln Thi 'Oiii U\
Dirong Be Th?nh', Duong Van Nha^
TOMTAT
Trong nhung nam gdn day, tinh trang thieu nuoc ngot phuc vu cho canh lac nong nghiep viing Ta\ s{ini;
Hau, tinh Kien Giang dang la van de dang quan lani. Nghien ciru dirpc tien hanh tai vung Tay soni: Hau, tinh Kien Giang nhkm danh gia: (i) tru tuong niroc ngot; (ii) nhu cau sii dung nuoc cho 3 loai cay trong chinh Oiia, khom va mia) va (lii) kha nang dap img nude ngot hang ihang cho cay trong lir 7/2015 den 6/2016. Nghien cuu da thu thap so lieu va chay mo hmh VKSAP de uoe tinh iru tirong niroc cho viing. (long thdi, ling dung GIS xay dimg cac ban do nhu cau sir dung va kha nflng dap ung niRTc ngpt cho eav trong tren co so cac dCr lieu, gdm: hien trang sii dung dat, nhiel do, phan loai dai va trir lupng nuoc ngol. Ket qua nghien ciiu cho thay, tOng trir luong nuoc ngpt ciia vimg cao nhAt 1.817 trieu m^ (9/2015) va thap nliM 223 trieu m^ (4/2016). Tdng nhu cau nirdc tudi ciia vung cao nhal vao thang 3/2016 (khoang 460 tneu m'^ va thap nhal vao thang 9-10/2015 (khoang 4 tneu m^. N'ungTay song Hau. tinh Kien Giang thira mroi." tuoi vao cac thang lu va thieu nuoc tudi nghiem trpng vao cac thang han gom 1, 3, 6/2016.
Tii khoa: Cay trong. nhu cdu tudi. tru lupng nuoc. limg Tay song Hau.
1. BAT VAN BE
Bien ddi klii hau (BDKH) la van de loan cau, thach thirc Idn ddi vdi nhan loai. BDKH da va dang gay ra nhimg hau qua khd ludng. Ddng bang sdng Cuu Long (DBSCL) la mgt trong nhiing viing bi anh hudng nang ne nhat do BDKH. dac bidt la he sinh thai tu ninen (Hanh va T u i i , 2014). BDKH tac ddng len nhieu hnh vuc, anh hudng nghiem hong den ndn ndng nghiep DBSCL (Hoang va ctv, 2015; Nha va ctv.
2019; Rasmussen va ctv, 2013). Mdt trong nhung tac ddng cua BDKH den san xuat ndng nghiep (SXNX) la hien tuong thidu nude ngot do xam nhap man (XNM) d- vung ven bien, cua sdng (Hoang va ctw 2015; Seal va Baten, 2012). sdng va tndu cuong dua nude man vao sau hon hong dat hen, lam gia tang tinh ti-ang ngap lut, lupng mua giam se lam tang tinh ti-ang XNM va khd khan cho viec cap nude (Dat va Thu, 2012).
Nuoc ngpt la nidi tai nguydn quan trong, dac biet ddi vol ngudi dan ^ n g ndng thdn sdng phu thude vao ndng nghiep (Castillo va ctv, 2007; Chartzoulakis va Bertaki, 2015). Ngudn nuoc phuc vu cho SXXX va sinh hoat cua ngudi dan DBSCL phu thuoc rat nhieu vao didu kien khi hrong thuy van ti-ong khu vuc
' Khoa Nong nghiep \a PTNT. Tnrdng Dai hoc Kien Giang
• Cdng IV Cd phan Tap doan Ldc Trdi
(Chinvanno, 2011; Tin va ctv. 2018). Su tliay ddi Iuong mua bat thudng, nhidt dd tang va cac hien lucmg thdi tiet cue doan nhu han han, lu lut se tac dpng true tiep den chat Iuong nuoc va suy giam trir luong nude, dan ddn khan hidm ngudn nuoc (FAO, 2013). Hidn tuong khd ban keo dai cung vdi viec khai thac nude ngdm cung la nguyen nhan d^ den hien tugng XNM hong miia khd, anh huimg den SXNN (\^eemian,2013).
Tieu vung Tay sdng Hau thude tinh Kien Giang (TSH-KG), nam d' ha ngudn sdng Me Cdng. chiu anh hudng nang nd ciia BDKH trong nhieu nam qua. Dac biet. hong nam 2015-2016, van de nay tid nen tiam trong hon do tac ddng cua khd han va XNM Vimg TSH-KG cd dia hinh cao a cudi ngudn nen viec dua nucrc nggt tir sdng Hau ddn vung gap nhifeu khd khan, miia khd nhieu khu vuc bi nhidm man (do man ti'dn 4%o), gay khd khan cho SXNN. De cd co so cho viec quan Iy, su dung hieu qua ngudn lai nguyen nude, bao ve canh quan va mdi Iruong smh thai dao ung yeu cau phat hien kinh te - xa hdi thi quy hoach ke hoach sir dung nuoc giir vai tro r^t quan trgng (Vien Ky tiiuat Bien, 2012). De tnen khai, can tinh toan nhu cau nude cho cay trong theo timg gjaj doa sinh truong, xem xet cac yeu td khi hau, thoi tiet ' phan tich yeu to dat (Nha va ctv, 2019) Vi - nghien ciru dugc thuc hien nham danh gia tonp h '
NONG NGHIEP VA PHAT ™CM MONG THON - KY 1 + 2 - THANG 2/2020
KHOA HOC CONG NGHE
ngudn lai nguyen nuoc mat ve trii lugng, nhu cau nuoc tudi cho 3 loai cay hong chinh Qua, khdm va mia) va xac dinh kha nang dap ung nude ngot voi buoc thdi gian 01 thang cho cay trdng giai doan tu 7/2015 den 6/2016. Ket qua nghien cuu se gop phan xay dung ca scr khoa hgc phuc vu cdng tac quan ly, hoach dinh khai thac, sir dung va bao vd hieu qua ngudn nude.
Z. PHUONG PHAP niGHBU CUU 2.1. Dac di^m vimg nghien cuu
Tong dien tich tu nhien ciia vung TSH-KG la 179.645 ha; dia hinh tuong ddi bang phang, co hudng doc tir Ddng Bac sang Tay Nam, la vimg cua md- tiep giap vdi vung Tu giac Long xuydn, thoat Iii ra sdng Hau va sdng Cai Ldn (Vidn Ky thual Bien, 2012).
Nghien cuu dupc thue hien tai bdn huyen Ihudc viing TSH-KG gdm: Tan Hiep, Chau Thanh, Gidng Ridngva Gd Quao.
Ddi tugng nghien cuu: tdng tnr lugng nude ngot (nude sdng, nuo'c iru va nude mua). nhu cau nude tucVi tren cac mo hinh SXNN chinh Oua 3 vu, lua 2 vu.
Ilia tdm, lua mau, khdm va mia) trong 12 thang lir 7/2015 ddn 6/2016 (Hinh 1).
Hinh 1. Iich thcri vu vitng TSH-KG n5m 2015-2016 2.2. Phuong phdp
2.2.1. Thu thap so heu
* Solieu thucap:
- Nghidn cuu thu thap cac du lieu ban dd gdm:
ban dd hanh chinh, ban dd hien trang su dung dat (HTSDD) nam 2015 tir Phdng Ndng nghiep va PTNT
cac huyen, ban dd dat nam 2015 (tir Bd mdn Tai nguyen Dat dai, Tnidng Dai hpc Can Tlio).
- Sd Ueu: cac sd lieu, bao cao dd tai nghien cuu khoa hpc da dupc cdng bo vdi ndi dung vd quy hoach nuoc va BDKH tir Sd' Tai nguydn - Mdi trumig tinh Kien Giang va Vien Ky thuat Bien. Cac sd lieu ti-ir lupng nuoc theo thang thu thap tir Vien Quy hoach Thuy Igi mien Nam va lupng niira tir Tmng lam Klii tupngThuy van tinh Kidn Giang.
* Sd lieu SO' cap: nghien cuu thu Ihap va phan tich cac mau dat ve cac chi tieu vd sa cau dat, dung trong dat, thuy dung ddng rudng, diem cay heo a tang dat (0-20 cm). Sd lieu duoe xu Iy bang phan mdm Microsoft Excel de tinh tiling binh va sai sd chuan dd so sanh cac nhdm dat.
2.22. Phuong phap tinh tiir lupng nude ngot (nude song vd nude tiir)
Trir lugng nude sdng va nude tru dugc tinh loan dira vao ket qua chay md hinh lir Vien Quy hoach Thuy loi midn Nam cu the nhu sau:
- Nuoe sdng: md hinh totin thuy luc md phdng ddng chay va XNM (VRSAP) de nid phdng tinh loan cho miia mua. VRSAP giai he phuong hinh Saint- Venanl bang sa dd sai phan an 4 diem, phuong trinh tai, khudch tan bang so dd sai phan an 6 diem. He phuong trinh Saint-Venant cho mdi doan sdng dugc sai phan an de nhan dupc cac phuong trinh sai phan cho mdi bude Ihdi gian. Cac phuong trinh nay duoe hen ket theo quy luat can bang khdi lupng d- cac niit de tao he phuong hinh cho ca ludi sdng; cimg vdi cac didu kien bien la muc nude cho truoc 6' mot sd mat cat, luu lupng dong ngudn a dau ciia cac nhanh sdng, mua lai chd hoac Iuong hao nude lay ra de dung b cac nut; tao thanh mdt he phuong trinh bac nhat nhidu an va giai he phuong trinh theo mdi budfc thdi gian. Lupng nude ngpt dugc tinh bang luu lupng cua cac song, kenh khdng bi nhiem man chay vao vung nghidn cmi nhan voi thdi gian.
- Nuoe trii: xac dinh bang the tich hinh hoc cua cac khu tru nhu sdng kenh, khu bao tdn, rung, d rupng ung vdi cac dd sau trir (chi tinh loan vdi nhimg khu vuc ranh man khdng vuol qua nguong cho phep).
2.2.3. Phuong phdp noi suy luong mua Nghidn cuu thu thap sd heu tdng lupng mua hang thang (7/2015 - 6/2016) tai 27 tram quan trac tu
AT Tniciti t.\r\\ NG THON - KY 1 + 2 - THANG 2/2020
Tmng tam Khi tuong Thuy van tinh Kien Giang. Su dung phan mem ArcGIS 10.1 chay ndi suy SpUne.
day la phuong phap npi suy tdng quat nham hieu chinh be mat duong cong. Phuong phap nay phii hgp de ndi suy cac yeu td khi hau theo khoang thdi gian theo thang hoac nam. Npi suy Spline sir dung mgt ham loan hpc nham giam thieu do cong tdng the cua be mat (EI^I. 2004). Ddng thoi. sir dung phan mem Mapinfo 15.0 xir !y, bien tap va thanh lap cac ban dd phan bd lupng mua tit 7/2015-6/2016.
2.24. Phuong phap xac dinh nhu cau nuoc cho cay trdng
Nghidn cuu da tinh tdng nhu can nude cho cay trdng vdi buoe thoi gian 1 thang bang tdng luong nude can tudi theo thdi gian smh trudng cua cay ti'dng.
2.2.4.1. Nhu cdu nude cho lira
Nhu cau nude cho liia duge tinh theo cdng thuc FAO (2001) nhu sau:
IN = ETc -H SAT + PERC + \M. - Pe (1) Trong dd:
IN la Iuong nudv can tuoi (mm/ngdy):
Etc Id nhu cau nude cua cay (mm):
ETc = ETo x Kc (2)
ETo: Bdc thoat hoi cay tham chieu theo phuong phap Blaney-Cmdle; Kc: He sd cay hdng phu thugc va tiing giai doan phat tnen cua cay (tra bang 1).
ETo = p X (0.48 X T + 8) (3) p: Tra bang ket hop GPS thuc dia: T M"^' ^^
tmng bmh ngay (C);
- SAT: Luong nude bao hoa cho dat (200 nini).
- PERC: Dp tham lau (mm/ngay), dinvxac dinh dua vao sa ciiu, cu thd: Dat set: PERC = 4; dat cat:
PERC = 8; dat set pha: PERC = 6.
- ^^T: Lupng nude can huih tiianh muc tJiuy cap (100 mm);
- Pe: Luong mua hieu qua, tuy tJieo cudng dp mua (mm): P: Luong mua (mm/thang);
+ Pe = 0 , 8 x P - 2 5 n e u P > 7 5 ; + Pe = 0 . 6 x P - 1 0 n e u P < 7 5 . 2.2.4.2. Nhu cdu nuoc cho khdm. nua Nhu cau nucrc cho khdm, mia diroc tinli theo cdng Ihiic Mladen Todorovic (2016) nhu sau:
CSWC = PSWC + Pe + IRR - LTc - DP (4) Trong dd; CSWC: Lupng nude hong dat hien tai (hom nay) (mm); PSWC: Lupng nude trong dit hien tai (hdm qua) (mm); Pe: Lugng mua hieu qua tir hdm qua (mm); IRR: Luong nude tuoi hr hdm qua (mm);
ETc: Nhu cdu nuoe cua cay (mni)(dirpc tinh theo cdng thirc 2 va 3); DP: Luong nude Ih^m lau, tang rd (mm).
Bang 1. Kc theo giai doan sinh tnidng cua ltia va khom (FAO, 2001) Cay trong
Lua
Khom
Mia
Thong so Kc Thai gian (ngay)
Kc Thoi gian (thang)
Kc Thcri gian (thang)
Giai doan diiu (gieo hat)
1.125 15 Trdng va phat trien
0.5 13 0,4 3
Giai doan phat trien
1,3 30
Giai doan ra hoa, ke-t trai
1.2 15 Rahoa
0,5 5 1,25
5
Giai doan thu hoach 1,0 30 L__Chiii_^
0,5 chin 0,75 2 22.J. Phmmgphap ung dung cong nghe GIS
Trong bai viet nay, lupng nude sdng va nude trir tit ket qua chay md hmh X'RSAP (muc 2.2.2) va kdt qua ndi suy lupng mua (muc 2.2.3). Tien hanh chdng lap ban dd nude sdng, nude trii va nude mua. Thanh lap ban dd tdng trir Iuong nude ngot hang thang tu 7/2015^5/2016.
Sir dung phan mem Mapinfo 15.0 chinh ly, cap nhat hch thdi vu tir ban dd HTSDD phuc vu cho nb"
tich khdng gian, thoi gian, hien tiang canh tac ndng nghiep (lich tiioi vu). Ket hgp vdi phirong phap xa dinh nhu cau nude cho cay trdng (muc 2 241 • chdng lap ban do phan loai dat. Tu kel qua tinh - sau khi chdng lap ban do lich thoi vu va han d' rt-' thanh lap ban dd nhu cau nuoc cho 3 Inai ,.s
chinh (lua, khdm va mia). ^ 12 N O N G NGHIEP VA PHAT ^=^^^ ^O^^ THOW - KY 1 + o . TH.A.NiS
3/2020
KHOA HOC CONG NGHE
Tidn hanh can bang nuoc bang ky thuat chdng lap ban do tdng trii luong nucrc ngot trir nhu cau nude tudi theo tiing thang hong giai doan 7/2015- 6/2016 (trir cac nhu cau nude cho hoat dgng khac nhu thuy san nggt, chan nudi, cay trdng khac. sinh hoat, dich vu, thuong mai va cong nghiep dugc tinh loan tir Vien Ky thuat Bien, 2012). Tiep theo, thanh lap ban dd mite dd dap ung nude nggt cho 3 loai cay trdng chinh lua, khdm va mia.
3. KET QUA hIGHfiV CUU VA THAO LUAN 3.1. D ^ h gid trQ lugng nu6c nggt
Vung TSH-KG cd 3 ngudn nude mat chinh gdm nude sdng, nude trii va nuoc mua. Dua vao kel qua md hinh VRSAP ude tinh lupng nude sdng, nude tni va ket qua ndi suy Spline lupng mua cua vimg. Ket qua cho thay, tdng trir lugng nude nggt cua vung cd su khac biet Idn giua miia khd va mua mua. Nhimg (hang miia mua tdng luong nuoc tiem nang cao nhd' vao lupng nude sdng (do lu) va nude mua.
iliyLtJj
Hinh 2. T6ng trii lugng nu6c theo t h ^ cua vimg TSH-KG
Tong luong nude ciia vung TSH-KG cd xu hudng tang nhanh tir thang 7/2015 (937 tridu m') den dinh vao thang 9/2015 va giam manh den thang 1/2016.
Trong giai doan 4 thang mua khd (14/2016), long lupng nude cd xu hudng giam tii 367 trieu m' xudng cdn 223 trieu ni-\ day la giai doan hdu nhu khdng [nua, ndn long lugng nude vimg cung cap cho cay trdng chii yeu la nude sdng va nude tni. Sau giai doan miia klid, trir lugng nude cua vung lang manh vao thang 5/2016 (798 trieu m^ va giam nhe vao thang 6/2016 cdn 625 hidu m''. Didu nay cd the giai thich do thang 5, 6/2016 lugng mua tang cao. Dac biet, tai cac ham do duoe Iuong mua thang rat cao, dien hinh la tram Gd Quao vdi tdng lupng mua do dupe khoang 392 mm (5/2016) va 227 mm (6/2016).
Nhin chung, phan bd lupng nuoc ngot cua \Tjng khdng gidng nhau do dac didm dia hinh, cac nhanh sdng nhu sdng Hau, sdng Cai Ldn va dac bidt la Iuong mua. Tdng tiii luong nuoc ngot cua vimg TSH- KG cd su khac nhau ro rdt giua cac mua. Cu the.
mua lu vao khoang thang 9-10/2015, lupng nude ngpt tiem nang trong vung dat den Ian lugt 1.817 hieu ni' va 1.691 trieu m l Trong khi do, miia khd vao khoang thang 34/2016 tdng luong nuac nggt ude tinh lan lupt khoang 291 hidu m'' va 223 tiieu m'.
3.2. Nhu cdu sir dung nuoc cho cSy trong Oua, khdm va. mia)
Vung TSH-KG cd 6 md hinh SXNN chinh gom lua 2 vu. Ilia 3 vu, Iiia tdm, Iiia mau, khdm va mia.
Neu xet vd Iich thdi vu cd the chia thanh 9 md hinh (Hinh 1). Trong dd md hinh Iiia 2 vu (xudng gidng vao thang 12 va 06) chiem dien tich ldn nhat vdi hon 51.963 ha (chiem 28,93%) va md hinh lua mau chiem didn tich thap nhat vdi 337 ha (chidm 0,19%).
Tong dien tich hdng lua la 133.438 ha (chiem 74,28%) va phan bd b bdn huyen. Trong khi dd, md hinh khdm va mia cd dien tich lan lupt la 4.594 ha va 891 ha, phan bd chii yeu a buydn Gd Quao (tiep giap tinh Hau Giang) va mdt phan Tdc Cau (huydn Chau Thanh). Md hinh lua tdm tap hung 6 Gd Quao (dpc theo sdng Cat Ldn). Dien tich cdn Iai gdm phi ndng nghiep va mdt sd loai cay trdng khac khoang 40.720 ha (chiem 22,67%).
Nghidn cuu dua vao luong bdc thoat hoi nuoc va loai dat (viing cd 7 loai dat chinh, gdm: dat man it;
phen hoat ddng ndng; phen hoat ddng ndng man;
phdn tidm tang ndng man; dat phii sa; phen hoat ddng sau va phen hoat dpng sau man) de ude luong nhu cdu nud'c hang thang cho 3 loai cay hdng chinh Qua. khdm va mia) hong 12 thang tu 7/2015-6/2016 (Bang 2).
Nhu cdu nude tudi cua vung cao nhat vao thang 3/2016 (459,84 hieu m^ va thap nhat vao thang 9- 10/2015. Do vao thang 3/2016 cd dien tich canh tac lua khang 46.248 ha vd dang trong giai doan thang dau (nhu cdu hen 280mm/thang). Trong khi dd,giai doan thang 9-10/2015 (miia lu) hdu nhu khdng canh tac lua, mia (da thu hoach) va con khoang 4.199 ha trdng khdm, do do trong giai doan nay nhu cau nuoc tudi kha thap.
Nhin chung, khdm va mia chiem dien tich nho, phan ldn la dien tich hdng Ilia, do dd, tdng nhu cau
"NG THON - KY 1 + 2 - THANG 2/2020 73
KHOA HOC CdN<» nvtis
nude tudi cua vimg chu yeu phu thude vao dien tich tudi cho liia rat cao nhu thang 12/2013 v'a !•
canh tac lua va giai doan smh trudng ciia lua. Dac 6/ 2016.
biet, vao nhung thang vua xudng gidng nhu can nucrc
Bang 2. Nhu ciu sii dung nuoc (hi^u m^ cho cSy tr6ng theo 12 t h ^ g vimg TSH-KG Cay trong
Khom Ltia Mia Tong nhu cau
Cay trong Khom
Liia Mia Tong nhu chu
07/2015 3,06 243,54
0,54 247,14 01/2016
3,53 368,39
0,66 372,58
08/2015 3,06 181,01
0,55 184,62 02/2016
3,53 299,77
0,63 303.93
09/2015 3,06 0,00 0,00 3.06 03/2016
3,67 455.51
0.66 459,84
10/2015 3.50 0.00 0,64 4.14 04/2016
4.14 167.19
0.75 172,08
11/2015 3,16 114,19
0,56 117,91 05/2016 5,78 280.25
0,66 286,69
12/2015__
3J6 _28938_—
i _ _ a M _ _ _ 293,88 06/2016 4,18 370,42
0,75 37.';,35 3.3. Danh gia miic dO d ^ ling nu6c cho cay
h6ng
Tir ket qua tinh toan xay dung ban dd IITJ lupng nude ngpt va nhu cau nude tudi cho cay hdng vung TSH-KG hong giai doan 12 tiiang lir 7/2015^/2016 (cd xem xdt den nhu cau nude cho cac hoat ddng khac) khoang 447 hieu mVthang cho loan vimg. Kel qua nghien cuu cho thdy, lupng nude ngpt cung cap cho cay trdng cua vung vao miia mua (7/2015- 12/2015) rdt Idn, kha nang dap ung cho cac hoat dpng hong toan vimg thira nude tuoi tren 160 mm (tuong duong 1.600 m^/ha). Su phan bd lupng nuoc tidm nang cung nhu nhu cau nuoc tudi cua mpt sd hoat ddng cd tinh chat mua vu khdng ddu nhau theo cac thang va giai doan sinh tiordng ciia cay, didu nay
se ddn den tliira nude hong miia mua va Ihi^u nirde hong mua khd (Nha va cW, 2019). Vi vay, nghien cthi chi tap ti-ung danh gia kha nang thira/thieu nirdc cho cay hong theo khdng gian tai vung TSH-KG hong miia khd, tii thang 1-6/2016 (Hinh 3).
Giai doan thang 1-2/2016, phdn ldn dien tich vung TSH-KG thieu tir 100 mm den du nuoc ludi.
Thang 1/2016, khoang 12.555 ha (chidm 7%) bi tliieu nude nghiem hgng (300-400 mm) va khoang 3.697 ha thieu nude ludi hr 200 ddn 300 mm, phan bd chu ydu d' huyen Gd Quao. Trong thang 2/2016, khoang 68.830 ha (38,2%) bi thieu nuoc khoang 100 mm va phan bd deu d' cac huydn Go Quao, Gidng Rieng va Tan Hiep.
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NONG NGHIEP VA PHAT • ru^K, irv, ...0. THAMrj , 72020
KHOA HOC CONG NGHE
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Hinh 3. Miic dg dap ling nudt ngpt cho (a-1/2016; b-2/2016; c-3/2016; d-4/2016; e-5/2016;
Trong thang 3/2016, dien tich lua tap trung d' cac huyen Gidng Ridng, Gd Quao va Chau Thanh, ben canh cay khdm va mia (huyen Gd Quao), kho khan dua nude ddn cac Iihu vuc cd dia huih cao. Vi vay, cd khac bidt giiia cac khu vuc vd kha nang dap ung nude ngpt cho cay hdng, cu the:
- Khu vuc hdng lua tai huyen Go Quao thieu nude tudi khoang 100 mm, cay lua dang Q-ong giai doan chuan hi thu hoach (nhu cdu nude tudi khoang 15 mm) va nhan dugc Iuong nude ngpt tir sdng Cai Lon.
- Khu vuc trong lua tai huyen Gidng Rieng va Chau Thanh bi thieu nude nghiem hgng hen 300 mm. Do tinh trang XNM va viec quan Iy nude tudi khdng tdt da ddn den thieu nuoc ngot lam anh huong ddn nang sudt cay ti'dng, kdt qua nay phu hgp vdi
cay hong cac thang han vung TSH-KG f-6/2016)
nghien ciiu cua Nha va ctv (2019) vd quan Iy nude ngpt vung Tir giac Long Xuyen (Kien Giang).
- Ben canh dd, phdn dien tich khdng canh tac cung cd the gap tinh trang thieu hoac vira du nude (nhu cau nude cho cac hoat dgng khac nhu thiiy san nggt, chan nudi, cay trong khac, sinh hoat, dich vu, thuong mai va cdng nghiep cdng rdt cao khoang khoang 2.480 mVha). Tuy nhien, gicri han nghien cuu the hien hen ban dd nhdng vimg canh tac lua, khdm va mia.
Giai doan thang 4-6/2016, muc dd thira/thieu nude nggt kha phuc tap. Mdi sd khu vuc gap tinh trang thieu nud'c nghiem trgng khoang 200 mm va thira nude len ddn 400 mm. Trong dd, phan ldn dien tich trong lua thieu nude nghiem trong khoang 200
tinhiez W(=HIFP VA PHAT TRIEN N O N G THON - KY 1 + 2 - THANG 2/2020 75
mm (6/2016), day la thoi diem xudng gidng lai 3 huyen Gidng Ridng, Tan Hiep va Chau Thanh.
Nhm chung, vimg TSH-KG gap tinh Q^ang thieu nude tudi cho cay trdng vao cac thang han (it mua).
Dac biet, cac thang 1, 3 va 6 thieu nude nghiem trpng; cac thang 2, 4 va 5 thidu nuoc tudi cr miic dd trung binh.
4 . KET LUAN VA KIB\I N ^ l
Ung dung ket hgp md hinh VRSAP udc tinh luong nude sdng, nude trir; ket hpp ndi suy Sphne xay dung ban dd phan bd lupng mua cd the thanh lap ban do tong trir lugng nude ngot (nude sdng, trir va mua). Cu the, tdng tru lugng nuoc ngot cua vimg TSH-KG cao nhat vao tiiang 9-10/2015 (mua lu) va thap nhat 4/2016 (dinh mua han va hidn tirong XNM).
Dua vao cac yeu td ddt, nhiet dd va dac biet yeu to Ijch thdi vu anh hudng rat ldn ddn nhu cdu nuoe tudi cho mdi md hinh SXNN. Tong nhu cau nude tuoi ciia vung TSH-KG cao nhat vao thang 3/2016 va thap nhat vao tiiang 9-10/2015.
Kha nang dap ung nude nggt cho cay hdng phu thupc chii yeu vao tong trir Iuong nude ngot, nhu cdu nude tudi cho mdi Ihdi dieni sinh trudng cua cay trdng va cac nhu cdu sir dting nude khac. Giai doan cac thang han (1, 3, 6/2016) tiiieu nude ngpl nghiem trpng cho cay ti'dng.
Ket qua nghien ciiu nay se la co so khoa hpc giup cac nha quan Iy didu chinh hgp Iy va kip thdi ve Iich thdi vu, van hanh cdng trinh thuy loi, gdp phan the dn dinh SXNN thich ung vdi BDKH. day cung la CO- sd' cho cac nghidn ciiu tiep theo vd quan ly nude trong SXNN. Cdn Uep tuc nghien ciiu danh gia miic dp dap ung nuoc ngot mdt each todn dien, bao gdm nudi hdng thiiy san, cac loai cay hdng khac va cac boat ddng su dung nude khac; cung nhu trien khai lighten ciiu chi tiet che dd thuy ddng luc hpc ddng chay, hao ddi nude sdng, d tni, XNM Iheo cac kich ban phat trien de du bao tidm nang tru lupng nuoc va nguy CO tiiidu nude cho loan vung trong tuong lai.
TAI UEU THAM KHAO
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9. Le Anh Tuan, 2016. Nhu cau nude va nhu cdu tudi cho cay hdng. He thdng tudi lidu, 17-40.
10. Le Thi Hong Hanh vd Tnrong Van Tuan, 2014. Anh hudng cua bien doi khi hau den he sinh thai tu nhien d' ddng bang sdng Cuu Long. Tap chf Khoa hoc - Trudng Dai hoc Su pham TP. Ho Chf Mmh, 155.
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NONG NGHIEP VA PHAT TDIFN NONG THON - KY 1 + 2 - THANG 2/2020
KHOA HOC COHG NGHE
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Nong nghiep, 202-210. j7 y^^^ j^^ ^^^^ B-^^^ 2012. Quy hoach tat 15. Tran Tho Dat va Vu Thi Hoai Thu, 2012. Bien nguyen nude mat phuc vu phat trien kinh te-xa hoi ddi khi hau va sinh ke ven bien. Bai viet ti-ong dien giai doan 2010- 2020 va dinh hudng ddn nam 2030 dan phdt tiien Viet Nam. Nha xuat ban Giao thong cua tinh Kien Giang, cd tinh ddn tac dgng ciia bidn Van tdi. Ha Noi. doi khi hau. Bao cdo guy hoach tong the.
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FRESHWATER STORAGE AND ALLOCATION FOR CROPS IN WEST-BASSAC RIVER REGION, KIEN GIANG PROVINCE, VIETNAM IN 2015-2016
Thai Minh Tm, Nguyen Thi Thu Le, Duong Be Hianh, Duong Van Nha Summary
In recent years, freshwater shortage for agncultural production in West-Bassac river region in Kien Giang province has become a noUceable issue. This study was conducted to assess: 0) the freshwater amount; (li) the irrigation demand for 3 main crops (nee, pineapple and sugarcane); and (iii) the monthly freshwater allocation levels for cultivation. The sludy collected data and utilized model of VRSAP to estimate the freshwater amount. Besides, the application of GIS techniques was used to establish the maps of the irrigation demand and the water allocation levels for culUvaUon based on the freshwater amount, present land use, temperature, and soil data. The results of the study showed that the highest freshwater amount was about 1,817 million m' in September 2015 and the lowest freshwater amount was 223 million m^ in april 2016. Tlie total amount of imgation demand for cultivaUon was variable and fluctuating, including the highest value was about 460 million m' in march 2016 and the lowest value was approximately 4 million m^
in 2 months duration from September lo October 2015. A further result indicated that the region had enough water for culUvalion in flooding season. Meanwhile, the serious water shortages occurred in dry season including januaiy, march andjune 2016.
Keywords,' Crops, Eeshwater storage, imgation demand, Wesi-Bassac nver region.
Ngudi phan bien: GS.TS. Nguyen Van Tmh Ngay n h ^ bai: 11/10/2019
Ngdy tiidng qua phan Men: 12/11/2019 Ngdy duyet dang: 19/11/2019
""GTHON -KY 1 + 2 - THANG 2/2020
