Tgp ehi Khoa hgc va Cdng nghe Bien; Tap 14, Sd 1; 2014 18 24 ISSN 1859 3097 http //www vjs ac vn/mdex php/jmst KET QUA BJJdC DAU DANH GlA TAC D O N G CUA BIEN DOI KHI HAU DOI V(3l NGHE CA BIEN VIET NA[.]
Tgp ehi Khoa hgc va Cdng nghe Bien; Tap 14, Sd 1; 2014: 18-24 ISSN: 1859-3097 http://www.vjs.ac.vn/mdex.php/jmst KET QUA BJJdC DAU DANH GlA TAC D O N G CUA BIEN DOI KHI HAU DOI V(3l NGHE CA BIEN VIET NAM B A N G PHU'ONG P H A P HAM SAN XUAT Nguyen Ngoc Thanh^ Nguyen Viet Thanh^', Dir Van Toan', Ngo Tho Hiing^ Dai hgc Tai Nguyen va Mdi trudng Ha Ngi, Viet Nam t r u d n g Dai hgc Kinh tg-Dai hgc Qude gia Ha Ngi, Vigt Nam Tdng eye Bien va Hai Dao Vigt Nam, Vigt Nam "Cdng Ty Cd PhSn DSu Tu Va Phat Trign Hda Phong E&C, Viet Nam E-mail; thanhmpa@gmail.eom Ngay nhan bai: 16-12-2013 T6M TAT: Nghien cihi ddnh gid tdc ddng cua biin ddi hau ddi v&i khai thac thuy sdn Viet Nam Hdm sdn xudt dugc su dung nghien euu di mo hinh hda tdc dgng cia biin ddi hgu doi v&i sdn lugng khai nhdm ddnh gid tdc dgng cua biin ddi hau ddi v&i nghi cd biinVi^t Nam DH lieu theo ehudi th&i gian tir 1976 din 2010 cua sdn lu(mg khai thac, cu&ng luc khai thac lao dgng nghe cd lugng mua trung binh nhiet trung binh s6 lugng bao hang ndm dd du^c thu thgp va phan tich Kit qud nghien euu ban ddu cho thdy lugng mua trung binh hdng nam khu vuc ven biin co tdc ddng tieu cue din sdn lugng khai thac hdi sdn cua Viet Nam Tuy vgy anh hu&ng ctia vi4c tdng lugng mua ddi v&i sdn lugng khai thac hdi sdn Id tuang ddi nhd so v&i cdc yiu td khac dugc nghien citu nhu cu&ng luc khai thac vd lao dgng nghi cd Tu khda: Biin ddi hdu, nghi cd biin Viet Nam, hdm sdn xudt GIOI THIEU Cae nghien euu khoa hoc da chi rang bien doi hau la mdt mdi de dga nghiem tigng tren pham vi toan eau va ddi hdi tat ea cac nudc phai cung hanh dgng dg phdng ngira va ngan chan cac tac dgng tieu cue bien doi hau gay Theo ket qua nghign ctiu ciia Stern [12], ngu eae nudc khdng cd hanh dgng de ddi phd vdi bien ddi hau thi thigt hgi bien ddi hau gay ude tinh vao khoang 5-20% GDP toan cau mdi nam, dd chi phi dg giam thai gay higu ting nha kinh nham ngan ehgn tae dgng tieu cue cua bien ddikhi hgu ehi vao khoang 1% GDP toan cau mdi nam Kgt qua nghien euu ciia Yusuf va Francisco [15] cho thay^ Viet Nam la mgt nhirng nudc rSt dl bi tdn thuong bdi tac dgng eua bien ddi hau tiong khu vi;c Ddng Nam A Vigt Nam dting thu bang xep hgng toan eSu ehi sd nii ro bign ddi hau (CRI) giai doan 1991-2010 [9] Viet Nam eung dung thu 23 bang xdp hang toan cau ehi sd tdn thuong bign ddi hgu gay 30 nam tdi [11], Theo eae kich ban ve bign doi hau eho Vigt Nam [4], dgn cudi thg ky 21, hgu tren tat ea cac vung cua Vi^t Nam se ed nhieu thay ddi, tdng lugng mua nam va lugng mua mua mua tang lugng mua mua khd Igi giam Ngoai ra, mue nudc bign se dang len khoang 75 cm so vdi trung binh thdi ky 1980 - 1999 Tuy chua cd danh gia thiet hgi bien ddi hgu gay ra, nhung thift hgi cac hi?n tugng thdi tiet bat thuong nhu bao, lu va trieu cudng gay la dang ke ddi vdl Vi?t Nam hang nam Theo kdt qua nghien ctiu ciia Le Trudng Giang [8], ti-ong khoang thdi gian tii 1994 den 2003, thigt hai tiimg binh Kgt qua budc dau danh gia tac dgng thien tai gay ddi vdi_ Vigt Nam yao khoang gan 250 trigu ddla mdi nam, chigm khoang 0,8% GDP trung bmh tiong cung khoang thdi gian Thuy san la nganh kinh te quan trgng ngn kinh tg Vigt Nam, theo thdng kg [14], gia tii xuat khau thiiy san da tang gap ba lan 10 nam qua va da dat hon 6,1 tiddia nam 2011 Tuy nhien, thuy san lai la nganh chiu nhieu anh hudng tu cac hign tugng thdi tigt bat thudng Chi tinh rieng bao Linda nam 1997 da lam chim va hu hgi gkn 2.000 tau thuygn khai thac thuy san, gay thigt hai khoang 136.000 heeta dign tieh nuoi thuy san va han 34.000 tan thuy hai san [3] Ngoai ra, vdi hang trieu lao dgng tryc tigp va gian tiep tham gia hogt dgng san xult thuy san, chu ygu sdng d khu vue ven bien, nganh thuy san Vigt Nam rit dg bi tdn thuong bdi cac tai bign thidn nhien va nude biin dang bign ddi hgu gay Do vay, vigc nghien euu tac dgng ciia bign doi hgu ddi vol thuy san la het sue can thigt nham xac djnh cae yeu to va mue dg tac ddng eiia bien ddi hgu vdi thuy san dg lam eo sd xay dung cac bien phap ting phd phu hgp Nghign etiu danh gia tac dgng eua bign ddi hau ddi vdi khai thac thiiy san Vigt Nam Ham san xult duoc sii dung nghign cihi dg md hinh hda tac dgng ciia bign ddi hau ddi vdi san lugng khai thac thuy san nham danh gia tac dgng eua bien doi hau ddi vdi khai thac thuy san eua Viet Nam Cau true nghien ctiu dugc trinh bay nhu sau: phan tiep theo md ta phuong phap sii dung ham san xuat nghien ctiu tae dgng ciia bign ddi hgu Phan ke tigp md ta dfl lieu va cuoi cung la phan ket qua va thao luSn PHU'ONG PHAP NGHIEN CUtJ kinh te [5] Gia djnh eo ban ia, mgt thugc tmh mdi trudng dugc dua vao ham san xuat cua mgt doanh nghiep, tae ddng kinh te thay ddi mdi trudng cd the dugc bang each xem xet higu qua san xuat va xae dinh gia tri eua tae ddng theo gia thi trudng dau cua san phim Day la phuang phap lugng gia gian tiep, khdng dya vao dudng cau (nhu phuong phap chi phi du lieh hay gia hudng thu), vi vgy sd tign ude tinh nen dugc hieu ia mgt chi thi (khdng phai gia trj thyc su) tae ddng ciia thay ddi mdi trudng tdi phuc Igi cudi eiing Phuang phap tiep can ham san xuat da duge su dung rgng rai, dae bigt la de danh gia nhung tae dgng cua su thay ddi chat lugng mdi trudng (vi du nhu mua axit, d nhiem nude) vao ndng nghiep [I] va thuy san [10] Vi dy khac ve ung dung bao gdm phan tich tae ddng eua ddng chay [2] va xae dinh gia tri Igi ich bao ve cua vung dat ngap nudc ven bign ehdng Igi thigt hgi bao gay [7], Theo Barbier, phuong phap ham san xuat phii hgp dg ap dung eho cac nudc dang phat tiien bdi vi suj)hu thudc true tigp cua nhigu he thongs san xuat d cae nudc ddi vdi tai nguyen thign nhien va eae chtie nang sinh thai Mdt each khai quat, phuong phap tiep can ham san xuat bao gdm mgt quy trlnh hai budc Budc diu tien la xac djnh cac tae dgng vgt ly eua su thay ddi mdi trudng Ign boat ddng san xuat Budc thu hai la lugng gia nhung tac ddng dua tren diu ciia boat ddng san xuat Ro rang, d giai doan dau tien, hgp tac la can thigt giira eae nha khoa hgc tir nhien, kinh te va cac nha nghien euu khac, dg xac dinh ban ehat eiia cac mdi lign hg giua cac ygu td mdi trudng va hoat dgng san xuat [7, 10] Ggi Y la dau ciia hoat ddng san xuat, ENV la bien mdi trudng quan tam, X, X^ ta cac bien diu vao khac ciia hogt dgng san xuat, ham san xuat eua mgt doanh nghiep hay mdt nganh san xuat ed the duac md ta blng edng thuc (I): Md hinh ham san suat Phuang phap tigp can thay ddi nang suat (change-in-productivity approach - CP^ edn dugc ggi la phuong phap ham san xuat (the production-function method), tiep can tac dgng len san xult (effect on production approach), hay dinh gia mdi trudng nhu la mgt diu vao (valuating environment as an input) tim each khai thac moi quan hg gi&a eae thugc tinh mdi trudng va mtic san lugng cua mgt boat ddng Y = f(X, Xk,ENV) (1) Neu 5Y/5ENV khae khdng, bign mdi trudng thg hign qua ENV (vi dy nhu tang hoac giam nhigt do, lugng mua) vdi dieu kien cac yeu td khae khdng ddi,se lam giam/tang mue san lugng Nhin chung, san lugng dau Y la mdt hang hda thi trudng, va gia ca cd the quan sat duge va khdng bi anh hudng bdi cac Nguyen Ngoc Thanh, Nguyen Vigt Thanh, yeu to lign quan ngoai thi trudng, mue gia cd the dugc su dung dg ude tinh gia tri cCia mgt Sir thay doi tac dgng cua eae yeu to mdi trudng (qua bien ENV) Ngoai ra, gia trj cung ed the duge ude tinh blng each xem xet nhiing thay ddi cua thi trudng cae yeu to dau fn(lO =J?o vao (X, Xk) cln thiet de tri san lugng dau d mgt mue dg nhat dinh Trong nghien ciiu md hinh ham san xuSt vdi cac bien dau vao tiuyen thong dugc sit dyng nghe ca [6, 11] dual dang logarit dugc md ta phuong timh (2): +T,%Mn(xd+-L%ui-i^jCq Trong dd CCj - la cac bign lign quan dgn bien ddi hgu (2) Md hinh ham san xuat cd dang (3) sau: ln(catcht) = jSo + A 7* + fizln(capacitryc) + fistnilabaurt) + p^RaiUt, -H ^^Temp^ + P^typhoouc 4- Sc Catcht = san lugng khai thac (tan) nam t Capacityi - cudng lye khai thac cua dgi tau (1.000 CV) nam theo thdi gian nam t Labour, = sd lugng ngudi tham gia khai thac hai san nam theo thdi gian nam t Rain, = lugng mua tmng binh nam t (mm) Temp,= nhigt dg mat bign tnmg binh nam t (°C) Hurricane, = so lugng bao bien nam t (sue gid mgnh hon 100 km/h) T = xu hudng thdi gian (3) P,,j = cac hg so thue nghigm Du li^u Dfl ligu su; dung cho md hinh duge thu thgp tii eae n ^ o n thong kg cua Bg Ndng nghigp va Phat tiien Ndng thdn, Bg Tai nguygn va Mdi tmdng va Tong cue Thong ke [4, 12, 13] Du lieu theo ehudi thdi gian tu 1976 den 2010 cua san lugng khai thae, cudng lye khai thae, lao dgng nghe ea, lugng mua tmng binh, nhigt dg tmng binh, sd lugng bao hang nam da dugc thu thap va phan tfch Cac du lieu dugc md ta tiong bang Bang Md ta dii ligu su dyng nghien euu (1976-2010) GiA trj trung binh B$ l$ch chu^n Gid tri nh6 nhit Gid trj 16^ nh4t 1.073 771 626.058 377.192 2.420.800 665.872 566031 190 399 1.767,000 2,082.611 883 244 453.871 6.123.000 1.793,79 246 1.311.33 288,60 Nhiet (50("C) 25,72 0,34 25,23 26,67 Bao (ccn bao) 1.41 1,37 U&u thu thSp Sdn lif^ng (tSn) Lao Qtfng (ngudi) Cuitmg l^c (CV) Lu^ng mua (mm) KET QUA VA THAO L U ^ Bang md ta ket qua tinh toan ban diu md hinh him san xuat ddi vdi nghe ca cua Vi$t Nam vdi du lieu theo ehudi thdi gian tir 1976 den 2010 Ket qua budc dau danh gia tac dgng Bang iTdc lugng ham san xult cho nghe ea Vigt Nam vdi dii ligu tu 1976-2010 Ky hi^u Cdc bi^n [f&c luyng (d6 l^ch chuJIn) H$s6 9,39" (1,58) Xu hirdng th&i gian (T) 0,009 (0,005) Cu&ng li/c (capacity) 0.23 (0,14) Lao dOng (labour) 0,31-(0,13) Lirgrng mi/a (rain) -0,00022* (0,0000698) Nhi$l dO (temperature) -0,1056(0,064) S6 li/grng bSo (hurricane) -0,0016(0,0011) R^ 0,97 F Statistic 216 DW statistic 1.31 Bienph^ thuQC Id ln(Catch), n=34 *p