PETROVIETNAM DANH GlA QUA TRlNH VAT LY D A U TRAN TRONG MOI TRUONG BIEN ThS Nguyen Quoc Trinh', TS NguySn M i n h H u a n ' TS Phiing D a n g H i e u ^ ThS Nguyen Quang Vmh* ' Tmng tdm Du bdo Khi tifang ThOy van Trung i/ang, Bd Tai nguyen vd Moi tradng 'Tn/ifng Dgi hoc Khoa hoc Ti/nhi€n, Bgi hgc Quoc gia Ha N6i Wien Nghien cCtu Bien vd Hai ddo Viet Nam, 86 Tai nguyen vd Mdi trUcjng *Bai Khi tugng Cao khong Bo Tdi nguyen vd Moi trUdng Email: maitrinhvinh@gmail.com T6mtSt Bdi bdo gidi thieu mdt sd ddnh gid qud trinh vdt ly ddu tran mdi trudng biin theo phUdng phdp md hinh hda red rac trin ctfsdxem xet cdc qud trinh vdt ly (nhu binh luu, khuich tdn, xdo trgn thdng ddng vd lan truyin ngdu nhien) DUa trin cdc cdng thirc dUdc dp dung bien tren thigicd, so sdnh kit qud vd sdlieu phdn tich, nhdm tdc gid dd xdy dtfng cdc phucfng trinh thich hop de md phdng cdc qud trinh vdt ly, tinh todn cdc he so, tham so hda cdc qud trinh vdt ly mdi trudng tdc ddng lin ddu trdn vd qud trinh tucmg tdc ngdu nhien cda ddu trdn TCr khda: Trdn ddu, cdc qud trinh vdt 1% mo phdng todn hoc Trong do: 1, Gidi thieu Su ed tran dau gay t i c dpng nghiem trpng den mdi trudng, cac h& sinh thai va kinh te - xa hpi khu vUc ven bien Dlu t r i n mPi trudng t u nhi&n dudi t i e dpng ctia d e q u i trlnh se di ehuyen tir ndi n i y den nOi khic Cie qua trlnh vat ly bao gdm eic q u i trinh ndi lUc (tu khuech tan loang ngau nhien) v i ngoai lUc (thuy dong lUc moi trUdng nhU blnh luu, khudch tan va x l o trdn thang ddng cua gid, ddng ehay va sdng) V^(u^, v^, w j : Van tdc trdi dat eiia dau (m/s); V J u ^ vJ: Van tdc gio tai dd cao 10m tren mat nUdc (m/s);" VJu^, v^ w^y v i n tdc dong chiy trung blnh tang mat (m/s); V^(Uj, v,, w^): Van tde dong ehay sdng trdi Stokes (m/s); a^: H& sd ma sat ciia gid, thudng dUdc chpn bang 3% Khi x i y sped t r i n dau, dau chju t i e dpng eiia ItJe loang xung quanh, sau dd chiu tac dpng true tiep v i chii yeu cua cic qua trlnh thiiy dpng iUe bien, tr&n n]vi2,5-4,5%[2-4]; a^: He sd trdi cCia ddng chay, thudng dUpc chpn bing 1,1 [5]; mat bien {nhu gid, dong ehiy mat, xao trpn thang ddng Idp m i t , sdng ) khien dau lan truyen, phan t i n xung a : He sd troi eua sdng, thudng dUOe chon bang 0,010,10 [61; quanh va di v i o Idp nude mat Tr&n eo sd ket q u i nghi&n edu tren the gidi, nhdm tie D: Ma tran chuyen ddi cCia gid K[(i.' ^^.wj=vjx,y, z,t] g i l da tdng hpp v i xay dUng eae cong thdc tfnh toan qua trinh binh iuu, qua trinh khuech tan, xao trpn t h i n g ddng v i lan truyen ngau nhien phu thupc vao tfnh chat d l u v i t i c dpng cCia moi trudng (la) De thUc hien ehi tiet theo tdng phin trUPng tdc van chuyen ciia lan truyen u^, v^ va w^ dUpc xae dinh theo edng thdc: Mot sd q u ^ trinh vat ly dau trdn u^ = aj)u^ + a^u^ + a^u, 2.1 Qud trinh binh lUu Vfl = ct^Dv.^ + or^Vj + fljVj (1 b) w„ = a^w^ + ttjiVj + Wp Q u i trlnh blnh lUu la q u i trlnh cO hpc x i y tong hpp cic I n h hudng ciia dong ch3y bi mat, lue keo cua Trong do: gio va t i c dpng sdng Van tde trdi cua d l u tai be mat dMc u ^ VJ Thinh phin tdc dp gio 10m (m/s); xem la tdng cua van tde gid, sdng va ddng ehiy trung binh u^ v^ v i w^:Thanh phan van tdc dong ehay (m/s); Idp mat nhusau: vJu„v,.wJ=a„DV„+aX u^ v^ v i w,:Thanh phan tdc dd trdi song (m/s); *".K (D w :Thlnh phan luc not ^0 •ABKri-so 12/2015 51 \ AN TOAN - MOI TRUONG D A U KHI D l i ma tran ehuyen ddi cda gid dupc xlc dinh theo [7,8], nhusau: pi Uo-BijuJ +vj sinp cosp\' IQ 'juj+vj< {2a} ^uj +vj > 25 Dua tr&n cd sd ly thuyet eua ddng ehiy Ekman [9] v l danh gia tuong quan gdc lech (., m i X l i bUde sdng hay chieu dai sdng {m)); z: Dp sau cua vi tri hat tfnh t d m i t xudng day {m); t:Thdi gian {s) 2.3 Qud trinh xdo trdn ddu vd di chuyin thdng d&ng Sdng cd vat trd quan trpng tie dpng l i m vd Idp dau tr&n m i t v l ehia d l u cic gipt d l u nhP va di vao nUdc Ldp xao trpn sdng ed the dupe xem eo bae vdi dp eao sdng tren mat Song dd cd t h ^ truyen mpt ning lUdng Idn v i o ldp nUPc mat bien theo Tkalich v i Chan [17] Cae lue t i e dpng l&n eae gipt dau nhd bao gdm: vdi ; / : (11) La phd kfch thUdc gipt dau phu thupc vao the tich d l u , dudng kfnh gipt dau v i dUdng kinh gidi han dau: N(d) = (3-s)V, 4^(d'^,^,-dl-;jd' V, = 47rd^/3; (d^,„, d„J ^ (U 000)fan; (12) s = 2.3± 0.06 Khdi lupng phan t i n gipt d l u phu thupc dac tinh, dudng kinh gipt dau va dp eao sdng: Mj =C(0)D^fAd''-'Ad DB^ = 0.0034 (13) p^gH^ Cong thufc eiia Raj [241 la tdc dp t h i n g dOfng cua gipt dau se phu thupc vao trang t h i i khdi nude v i d c die trung dau: \9d'il-p/pJ/(18y) lyll9d(l-p/pj R^50 (14) D