Dinh gia six anh huong cua he so ma sat day toi mirc ntroc Bang do bap Wang mo hinh ADCIRC khu vkic Vinh BAc Bo

Transcription

1 Tap chi Khoa hoc DHQGHN: Cac Khoa hoc Trai dat va Moi tnremg, Tap 32, SS 3S (2016) Dinh gia six anh huong cua he so ma sat day toi mirc ntroc Bang do bap Wang mo hinh ADCIRC khu vkic Vinh BAc Bo Tran Thi Thao, Ha Thanh Huang* Khoa Khi twang They van va Hai &rang hoc, Truing DO hoc Khoa hoc Ty' nhien, DHQGHN, 334 Nguyjn Trai, Ha Ne)i, Viet Nam Nhan ngay 08 thing 8 nam 2016 Chinh sfra ngay 26 thing 8 nam 2016; Chap nhan clang ngay 16 thing 12 nam 2016 Tom tat: Cac tinh toan nubs dang do bao cho thay anh huang dm ma sat day la vo ding quan tong trong viec hieu chinh they trieu va la met trong nhimg yeu t6 quyet dinh sir chinh xac cua m8 phong nubs dang do bao cua mo hinh. Bai bao nay sir dung modun ADCIRC thuoc he thong mo hinh SMS de mo phong nuotc ding do bao, trong do khao sat den anh huemg dm he so ma sat day den ket qua tinh toan nu& dang thong qua viec Neu dien he so ma sat day ling vai cac trdmg hop cho la hang s8 tai cac nut va truong hop he s6 ma sat thay doi tai cac nut.tir do dui ra viec xac dinh he so ma sat thi uu ap dung cho khu vuc Vinh Bac BO de ket qua tinh toan nuoc dang do bao hieu qua va nhanh nhat. Tu kh6a: Nu& clang do bap, ma sat day, ADCIRC. 1. Dat yin de nu& vori thuc do tit d6 dim ra he so ma sat phu hop cho khu vuc tinh toan. He so ma sat sir dung trong mo hinh ADCIRC thuong la hang so khong doi ten toan mien tinh. Viec sir dung he so ma sat se dat dugc ket qua muc nuorc co do chinh xac cao khi tinh toan cho mot khu vuc nhe co ding che do thily trieu. De tinh toan cho ket qua tot nhat ngtroi thuong tim cac he so ma sat tucmg ling tai cac nut luoi. Tuy nhien viec xay dung mot file he so ma sat tai cac nut dm mien tinh lem la rat kh6 khan va ton nhieu then gian. Trong bai bao nay tic gia da tien hanh xac dinh do nhay cim he so ma sat yeti cac truing hop tinh toan khac nhau va so sanh ket qua tinh toan muc Tic gia lien he. DT.: huonghat@vnu.edu.vn MO hinh ADCIRC MO hinh ADCIRC dugc xay dung va phat trien bori cac trirong dai hgc bang Carolina bao g6m dai hoc Notre Dame, dai hoc Oklahoma va dai hoc Texas nuac My. M8 hinh ADCIRC (Advanced Circulation Model for Oceanic) la mot he thong nhirng mo hinh giai cac phuang trinh thily dong l rc mo phong hoan lint tang mat va bai toan thily dong hic hai hoac ba chieu [1]. Nhitng chucmg trinh nay ding phuang phap phan tir tau han cho phep sir dung cac luai phi cau triic co, tinh linh hoat cao, dac bit co the ling dung rat tot cho cac khu vuc cira song yen bien co dia hinh va duemg bo phirc tap. MO

2 T.T. Thao, H.T. Throng / Tap chi Khoa hoc DHQGHN: Cac Klzoa hoc Trai clot va Mai trtrang, Tap 32 So 3S (2016) hinh dtrac xay dung dua teen cac phucmg trinh co ban, bao gem: Phuang trinh lien tic: a4- _F auh avh at ax ay Cac phuong trinh bao toan dong luting: a ac Ts, 'rt. ±g4--g(1± PoH Poll Bx a +L +V-17-+JU=- 12+g Y ±Dy By a 4' 4, Poll 1W trong do: C la dao &Ong moc nu& U, V la cac van tec dugc lay tich phan theo de sau theo huang x va y P la ap suit, H la do sau moc nu& Dx, Dy la cac thanh phin khuech tan theo cac phuang Bx, By la cac thanh phan gradient ap suit theo cac phuang, (ri+y): the thug trieu Newton, thus, trieu trai dat va cac loc mang ban chat loc thus, trieu va y bx by la frng suit day theo cac hu&ng x SX, r SY la irng suit mat theo cac huang x va y Po la mat do tham chieu caa mrac 2.1. He so ma sat trong ADCIRC Ung suit day trong phial ban 2DDI cua ADCIRC duoc bieu dien nhir sau: vbx =Ur* v a V, =VT. Thy thuec vao cach sir dung, ket qua c6 the la ham tuyen tinh, toan phucmg hay to hop dm van toc trung binh theo do sau. Doi v6i hau het nhimg irng dung cho stung yen ba, ham ma sat toan phuang nen duac sir dung vai he so ma sat C J Trong stung nuac rat nong, ma sat to hop c6 hieu qua han, vai Cfinin , dac biet khi cac tham so kho va uat dirge tinh den, khi do bieu thirc nay giam nhanh khi de sau mrac trer nen nh6. Ma sat tuyen tinh chir yeu sir dung cho thin nghiem mo hinh hoac khi mo hinh tuyen tinh duoc chay theo yeu cau. Trong truing hop nay, de lon dm V. phai phi hop (it nhat la ve do 16n) voi gia tri duoc sir dung tinh toan bieu thirc ma sat town phuang va khong phai vbi gia tri cua Cf thong thuemg &roc sir dung trong Neu thirc toan phuang [1]. Trong truemg hop sir dung ham tuyen tinh: =C1 trong do C f = khong cf6i theo thai gian (co the thay dei theo khong gian), don vi la s 1 Trong twang hop sir dung ham toan 0 f (U2 +V2)1/2 phuang: r. trong do Cf = khong dei theo thai gian (co the thay dei theo khong gian), khong thir nguyen. z. = Ham to hop: C f (U2 +y-2)112 trong do C f =Cfmin (1+ ( Hb eak ) 0 ) 710 va Cf min 9 Hbreak 7 (?): khong den theo thai (?)' 9 gian. Trong quan N ma sat to hap, tiem can trong stung nu& sau (H > Hbreak) va tiem can vii break C f min( H H )Y trong yang nuac nong (H < Hbreak). S6 mu 0 xac dinh mac do Cf tien den gioi han tiem can va y xac dinh mire tang he so ma sat khi do sau giam. Neu Cfmin = gn2 I Hr,mak va =1/3, trong do g la gia tec tong truing va n la he se Meaning, ma sat to hop se c6 met phuang trinh Meaning xir 1s, ma sat cho truing hop H <Hbreak. Vi (111 ve mei quan he gifia Cfmin va n khi y = 1/3 ducyc dua ra duch day.

3 204 T.T. Thao, H.T. Hurmg /Tap chi Khoa hoc DHQGHN: Cac Khoa hoc Trai di ft vg MOi mtang, nip 32, So- 3S (2016) Bang 1. So sanh gifra f nun van thi c fm = 2 / r ' Hbreak Cf min n n n N Hbreak =1m Hbreak =5m Hbreak =1com H break =20m Dieu kien ban d"du va va dieu kien bien Op dung trong mo hinh Dieu kien hien muc nuac Dieu kien bien muc nuerc co the dugc xac dinh th8ng qua 2 cach: - Thu that: mo hinh to noi suy cac hang so dieu hem tai moi nut bien tit b0 hang so dieu hea toan cau va tinh toan chuoi muc nuot tai moi nut bien. - Thu hai: tir cac chub'i muc nuac theo theri gian tai moi nut bien. Dieu kien thong lugng ADCIRC cho phap xac dinh cac dieu kien bien bao gom thong lugng phap tuyen ten dun vi rong (nghia la thong lugng vuong goc bang khong tai cac door' bien dat va khac khong tai cac doan bien song). Quy tic dugc dung trong ADCIRC la thong lugng phap tuyen dua vao la thong lugng di vao mien tinh la ducmg va thong lugng di ra la am. Neu thong lugng phap tuyen dugc ap dung nhu mot dieu kien bien to nhien, se khong lam thay doi cac 'mong trinh dong lugng. Con neu dieu kien nay, dugc ap dung nhu mot dieu kien bien can thiet, van toe phap tuyen trung binh do sau U N, la luc de can bang vii th8ng lugng phap tuyen chia cho do sau va nhan veri -1 (?) (quy Ink U N. throng theo huang vuong goc ra xa mien tinh). Dieu kien gradient van t0c phap tuyen bang khong tai hien. au_ o ON tai cac nut tren bien. a v o an Dieu hen bien van toc phat xa - ADCIRC 2DDI Dieu kien bien phat xa yeti muc nuerc dugc thgc hien bang viec xac dinh moi lien he gifra van toc phap tuyen va truerng muc nuoc dgc bien. Dieu kien gradient muc nuerc phap tuyen bang khong tai bien = 0 a n Dieu kien bien phat xa tren mat - ADCIRC 2DDI Dieu kien bien phat xa vbi muc nu& có the dugc thgc hien bang viec xac dinh moi lien he gifra thong lugng phap tuyen va tnremg muc nu& doc bien Cac dieu kien trien khai cho mo hinh De trien khai mo hinh ADCIRC tinh toan muc nuerc clang do bao vui luo i tinh toan Bien Dong tai bien cling, sir dung dieu kien dinh khong tham, cac thanh phan van toe lay bang 0, Sir dung dieu kien bien dao &A% muc nuoc tai cac bien long. Dao d0ng muc nuac thily trieu tai cac bien long dugc dugc tao bang mo dun TIDE tir hang so dieu hea ciia 4 song Kl, 01, M2, S2. He so ma sat sir dung trong mo hinh dugc lay theo cac truing hgp tinh toan la:

4 T.T. Thcio, H.T. Throng / T9p cht'khoa h9c DHQGHN: Cac Khoa hoc Trai clot va Aloi twang, Tap 32, Si; 3S (2016) Hang so kh6ng de)i cho toan mien tinh dugc lay cho cac throng hop lan lugt la 0.003, 0.004, He s6 thay doi theo cac nut tren toan mien tinh dugc xay dung va ghi dinh da.ng theo file fort.21. Trong do file fort.21 dugc xay dung theo ding thirc tinh he so ma sat day sir dung trong mo hinh Porn [2]. He so ma sat dugc gioi han cho Bien Dong trong khoang [0.0025; 0.75]. Dua vao do sau dugc noi suy tir file luai tinh thuc hien tinh ma sat tai timg nut luai theo ding thirc duai day: k 2 cbc = log[ zsh + (1.e0 + zz)d ] 2 zob trong do: k la hang so Von Karman's bang 0.4 zob la do nham day (m) bang 0.7 zsh la do trugt lop Wien day theo ham Logarit (m) bang 0.01 D la do sau tai nut hkri 3.Ket qua tinh town 'dem tra do, nhay ciia he so ma sat den noon ding do bio Ltrai tinh sir dung a khdo sat la lueri phi eau true cho toan vimg Bien Bong gigi han tir 99 E E va 1 N - 25 N va khoang each luai thua u cac bien phia Bong, phia Nam va min dan ve phia b6,bien Viet Nam. Khoing each luai tinh nho nhat a yen b6 phia vinh Bac BO va Bac Trung BO la 5 km. Cac ket qua tinh toan dugc trich xuat va so sanh vii muc nuac thuc do tai cac tram Hon Dau va Hon Ngu trong ba'o Wukong (2000). Hinh 1. Ltr6ri tinh toan bi6n Dong. Hinh 2. QuSr dao Fab Wukong (2000). PTDH , TT TT Fon )-- TT 0 00S It III It 1 ti illiiiii it - Z -0.5 I I.: L I- I. 1 I 111 I.1 4 '1 ;. ) 1 pilliii :. if -- it, - 1, so.,. 1. I I. i!-' 11,111 3 illi 1 M :00 4'6,140: Thai gian (11) '1:' 140:00 Hinh 3. Ket qua nghikt trik tai Hon Dau (phan tich dik hem va tinh toan).

5 206 T.T. Thew, H.T. Huang / Top chi Khoa hoc DHQGHN: Cac Khoa hqc Trai cat va Men tnrang, Tdp 32, So 3S (2016) l: PTDH TT TT TT Fort.21. i is Ill I, t i. iti illifiliet, 1 i'lliiiiiiiit i i L ;'.,, HA TITFII ` ' 11!,, Ell 1,. 0: Z Thai gian thl 1 Hinh 4. K'C't qua nghim trieu tai Hon Ngu. Bang 2. Sai s6 tuyet doi caa cac trucmg harp tinh toan thily trieu Sai s6 tuyet doi so sanh v6i phan tich Tram dieu hoa they tri&j. [?] TT TT TT TT Fort.21 H6n Dau Hon Ngu Hieu chinh va kiem cluing they trieu De khao sat do chinh xac cua moc nuac they trieu, thoc hien hieu chinh thily trieu tai 2 tram Hon Dau, Hon Ngu, sae dohieu chinh vai so lieu trick to bang they trieu Trung tam Hai van (Tong coc Bien va Hai dao). Hieu chinh dao dung moc nuac thuy trieu tinh toan bang cach thay doi gia tri he s8 ma sat day. Chu& moc nu& thily trieu ducc tinh tir 14h ngay 01/04/2014 den 23h ngay 29/04/2014. Chu& dao dong moc nuac tai cac bien king lam dieu kien bien cua mo hinh da ducic hieu chinh ter gi6 UTC ve miti gia Ha NOi. Vii tat ca cac truemg hop cila he so ma sat dayducfc dua ra a ten ket qua hieu chinh trieu au cho ket qua kha tot ve pha va bien do dao dong they trieu (Hinh 3, 4). Tir bang tinh toan sai se tuyet doi cua they trieu tai tram Hon Dau va Hon Ngu trong cac trutmg hop he s8 ma sat khic nhau so,sanh viii phan tich diet]. hoa they trieu cho thay sai, so tuyet doi trong trtremg hop he s8 ma sat la hang s8 va bang cho gia tri nho nhat cho ca 2 tram va co gia tri xap xi sai so tuyet doi trong tnremg hop he se ma sat thay doi gia cac nut (fort.21). Dieu nay chimg to cac thong so dm mo hinh da dugc hieu chinh phu hop vai khu voc tinh toan va co the tien hanh tinh town nuac Bang do bao K'et qua tinh tam kiem tra do nhay dux he so ma sat den mak &Mg do bao De tien hanh kiem tra do nhay oh he se ma sat den moc nuac dang do bao tac gia thoc hien tinh toan nuac dang do bao Wukong (2000) theo 3 tnremg hop viii he s6 ma sat day kh8ng doi va truemg hop ma sat day thay doi tai cac nut cila mien tinh vai s6 lieu thoc do. Chu& so lieu khi Wong keo dai 7 ngay to 13h ngay 04/09/2000 den 18h ngay 10/09/2000 [3]. Bao Wukong bit dau anh huemg den dai ven b6 Viet Nam vao Oh ngay 8/9/2000.Bao bat dau anh huang den khu voc ven be' vai sire gio 10m/s. Luc nay, nuac dang tai khu virc Bac vinh Bac BO va dai ven be, Bac Trung BO cao khoang 1.5m do ket hop vai pha thily trieu len. [Nen CO hinh ye minh hoa].

6 T.T. Thao, H.T. Huang/Tap chi Khoa hoc DHQGHN: Cac Khoa hoc Trai clot vet Mai truong, Tap 32, sa 3S (2016) Hinh 5. Thai diem nuac dang cao nhat tai dai yen bar hoc 22h ngay 09/09/2000. Thin diem bao bit &Au do be vao tinh Ha Tinh lac 22h ngay 9/9/2000. Mvc nuac dang tai toan b0 dai yen b6 to BAc Ha Tinh den Quang Ninh cao khoang 1.5m (Hinh 5). Khu Arc yen bien tir Da Nang den phia Nam Ha Tinh invc nuac clang cao khoang 1.3m. Th&i diem bao bat dau do b0 rai vao thai diem pha trieu xuong nen nivc nuac clang toan yang thap han thai di6rn bao bat dau anh huang den dai yen bo CO the thay rang thay doi he s6 ma sat cho taw tnremg hop tinh toan cho ket qua tinh toan muc nuac chenh lech nhau kha lan. Doi voi truong hop tinh toan he so ma sat bang khi so sanh v6i mvc mrac they trieu cho chenh Lech lem (0.31m) nhung ket qua tinh toan mvc nuac clang bao c6 sai so tuyet doi kha nho (0.18m) va chi lan han cac truong hap tinh toan khac 2-3 cm tai Hon Dau. Tai tram Hon Nor do bao Wukong do be vao thai ks, trieu cu6ng nen anh hue:mg cua thily trieu den mvc nuac clang do bao lan. Viec thay doi he so ma sat trong cac truong hap tinh toan cho ket qua chenh lech nhau kha lon ca ye hieu chinh thiiy trieu va nuac clang do bao do che do they trieu khu vac nay la trieu hon hop do lan lm. Tuy nhien cac ket qua tinh toan nu& clang lai bat rat tot pha va theri gian nixac clang do bao. Sai so tuyet doi cua nuac dang dao dong tir 0.35m den 0.28m cao han rat nhieu so vori tram Hon Dau.,Tir bang 2 co the thay rang viec lva chon he so ma sat dac tang cho ca yang Vinh Ric BO la (TT 0.004) cho sai so nho va gan vori truong hop Iva chon he so ma sat tinh toan tai cac nut, luoi (TT Fort.21). Vi vay trong truong hop can du bao nhanh nuac clang do bao to có the ap dung he so ma sat la hang so cho toan vinh. do TT ITfort TT 0.604! - - TT TT :I.N TrA.004 %1111 lo A AI * 0111 * A 40 'Y./ tv, '441 *e ' ns10 ern; Hinh 6. Bik trinh nuerc dang do bao cac truong hop Hinh 7. Biecn trinh nuorc clang do bao cac truemg hop tinh toan va tiurc do tai tram Hem Dau. tinh toan va thirc do tai tram Hon Ngtr.

7 208 T.T. Thito, H.T. Huang /Tap chi Khoa hoc DHQGHN: Cac Khoa hqc Trai cat va Moi triton, TOp 32, SCI 3S (2016) Bang 3. Sai se tuyet doi cua cac truang hop tinh toan nu& dang Tram Sai se tuyet d6i so sanh veri mirc mac thuc do TT TT TT TT Fort.21 Hon Dau Hon Ngu r '2000 0:00 TT TT TT TT Fort2 1,J\ : :00 Thai On Hinh 8. Bien trinh nuerc dang do gio bao trong cac truemg hcfp tinh toan tai tram Hon Nir (kong xet den anh huemg cua thily trieu). Bao Wukong 6 bo vao than ky trieu cuang nen anh huamg cua thily trieu den moc nu& dang do bao lam. Moc nu& clang tong cong Len den han 1.5m nhung khi khong tinh den anh huong cua thily trieu, mgc nuac dang do bao vao thai diem cao nhat chi cao khoang 0.5m. Tai than diem bao clura anh huong tan khu voc yen bar, tat ca cac truang hop tinh,toan khic nhau so ma sat deu cho mot ket qua moc nuac (cac &rang tang khit nhau), chi kin bao anh huang toi khu virc ven bac (ter 15h ngay 08/9/2000) mai co so thay doi \ft moc mac gifra cac twang hop tinh toan (hinh 8) chenh lech moc nuac dang cao nhat gifra cac twang hop tinh toan lchoang 10 cm. 4. Ket 1u4n Ter cac k6't qua tinh town cho thay so thay doi dm he so ma sat anh huong lam den ket qua tinh toan nuac clang do bao khu voc Vinh Bac BO. Tac gia da,lciem nghiom va loa chon &roc he so ma sat bang ap dung cho toan khu voc Vinh Bac Bo thay vi phai xac dinh he so ma sat tai cac nut luai tinh va cho ra ket qua có sai so tuyot doi gifra hai truang hop nay la gan tucmg ducmg. Tai lieu tham khao [1] A (parallel) advanced circulation model for oceanic, coastal and estuarine waters. [2] Pom081 - Center for Coastal Physical Oceanography. [3] Typhoon (Wukong)-General Information (Pressure and Track Charts).

8 T.T. Thao, H.T. Huang / Tap chi Khoo hoc DHQGHN. Cac Khoa hoc Trai clot va MCA trufmg, TO 32, So 3S (2016) Assessment the Effects of Bottom Friction Coefficient to Storm Surge Water Levels by Model ADCIRC in the Gulf of Tonkin Region Tran Thi Thao, Ha Thanh Huong Faculty of Hydro-Meteorology and Oceanography, College of Science, VNU University of Science, 334 Nguyen Trai, Hanoi, Vietnam Abstract: The storm surge calculations show that the effect of bottom friction is extremely important to calibrate the tide and is one of the determinants of the accuracy of the storm surge simulation bymodels. In this paper modules ADCIRC of SMS model system is used to simulate the storm surge for assessment the effect of bottom friction coefficient to storm surges calculation results through cases with constant bottom friction coefficient and that coefficient to be calculated at every nodes of the grid.the optimum friction coefficients has selected and applied to the Tonkin Gulf region, that makes the calculated results storm surges to be more effective Keywords: Storm surge water, Bottom Friction, ADCIRC.