V I~ N K H O A H Q C V I~ T N A M TSRQPONMLKJIHGFEDCBA N " TUYEN BAo cAo TAP • KHOA HOC yxwvutsrqponmlkjihgfedcbaZYXWV A I< ' ," HQI NGHl KHOA HQC TOAN ouoc ~ '1 VE BIEN , L A N T H l1 III (H a NQi J 28 - ZYXWVUTSRQPONMLKJIHGFEDCBA tlu in g 11 n a m 9 ) T~P II K H I T U Q 'N G T H U V V A N , D Q N G L l)'C , , ,., D !A L V - D !A C H A T , ,."' A' ow D !A V ~ T ", A L V , K Y T H lY ~ T ~ A N' C O N G T R IN H , K IN H T E - X A H Q I B IE N Ha NQi - 1991 37.NGlIlEN TRANG ZYXWVUTSRQPONMLKJIHGFEDCBA s ir DUNG ~ ." CUU MOT SO DIEU KIEN SINH THAI VA lIIEN " ' : • • DAT VUNG CAT VEN BIEN QUANG e T r iin N g o c l' SOME RESULTS OF ECOLOGICAL : - r '; ' DA NANG edcbaZYXWVUTSRQPONMLKJIHGFEDCBA NAM· N in h ENVIRONMENT v a TSRQPONMLKJIHGFEDCBA n h iin g n g u o i k lu ic STUDY FOR COASTAL 206yxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA SAND AREA OF QUANGNAM - DANANG PROVINCE T ran N goc / 38.S~ BIEN ~Ol D!A lIi~lI BAI T!IE~ I1UYJ;.:N DUYEN HAl THANH N in h TH~H GIAN T~I KIIU VVC Mfll PlIO lIO em e t a l CAN GIO, MINH 254 N guyen Van T {}e SOME FEATURES ON TIlE ROLE OF GEOLOGICAL STRUCTURES IN THE FORMATION AND DEVELOPMENT OF TIlE RELIEF OF VIETNAM CON- 213 TINENTAL SIlELF N guyen •• l' • • • 39.DQNG SAN LV0HOI no TRUONG ' ') •• •• A •• Van 'ru XOI La n o VA SV THAY DOl I1INH D~NG DAO 266 SA T r iin D u e 218 DEPOSITION - EROSION DYNAMICS OGY OF SPRATLY CORAL ISLAND AND CIIANGE OF TilE T h{}nh MORPHOL- T ran D ue 40.I1iNH ~ VEN THAI, CAU TRUC VA T1EN I10A CUA CAC HAl TRIEU no PIllA Tae •• Thanh LAY 273 B A c VI(~T NAM r-s« 224 D ue T h { } l1 h , N g ly e n H L ( u MORPIIOLOGY, STRUCTURE AND EVOLUTION IN TI IE COASTAL ZONE OF NORTII VIETNAM OFTIIE ca D in h V { 'in H u y TIDAL MARSIIES Tran Due Thanh, Nguyen Huu Cu, Dinh Van Huy 230 41 D~C DIEM QLJA TRiNH BOI XOI B O ' HII1N VUNG CHAU THO SONG t.e Xudn HONG 282 H ong TIlE CIIARACTERISTIC FEATURES OF TIlE ERODING AND DEPOSITING PROCESS ALONG TI IE SEA COAST OF RI,::D-RIVER DELTA 42.U~C DIEM Le Xuan KII~N T~O VA TAl NGUYEN KIIOANG H ong BIEN UONG 290 ce 23R D uy B aeh TECTONIC CIIARACTERISTICS AND MINERAL RESOURCES OF UIEN DONG (EASTERN SEA) Le D uy B acn 43.KIEN 244 TAO m SONG II()NG VA T11~M NANG DAU KIll t.e T r ( m g C a n , T r o " , H t iu T h a n , TECTONIC OF RED IUVEH BASIN AND IIYDROCARI30N Le 44.TRAM rtcu THEM T rang C an, T ran H uu Than, 302 Pham X u /I n tn o POTENTIAL Pham Xuan Tho 311 Ll)C U~A PHAN PHIA NAM VI~T NAM T r in h The nu« 515 tier A ~ " DONG Ll)'C BOI Tl} XOI La so VA str THAY DOl ", ••• HINH D~NG DAoSANHOTRUONGSA ZYXWVUTSRQPONMLKJIHGFEDCBA T h ( lllh t m « D t1 :c TSRQPONMLKJIHGFEDCBA Tn ch tri 0, I T r u n g ta m n g h ie n c tiu b ie n H d i P h o n g da I MODAU Hien tU'QTlgthay d6i hinh dang dao san ho duov Krempf A.P /1/ nghien ciru ran ctau a quan dao Truong Sa Trang dip khao sat dai 42 VaGcudi nam 1988, dfm 1989, chiing toi da tien hanh khao sat chi tiet dia chat - dia mao dao va quan trac dong hrcedcbaZYXWVUTSRQPONMLKJIHGFEDCBA b o d~ tim hi~u moi quan h ~ giiia bbi, xoi bai voi bo Sl;! thay d6i hinh , dang dao Bai viet 180 ket qua phan tich 110 mat cllt ve lap lai cua trac dien gl bo, cac dau hieu tram tich, dia mao, sinh v~t ket hop phan tlch cac ban ve trac dac.cac anh chup may bay tir truce va sau nam 1975 Ole tai lieu quan trac tuong hai van P trang thoi gian khao sat duoc cung cap tir tram hai van tren dao / II K.ET QtJA NGHIEN CUu tti : Nhfrng nhan to' co ban chi ph6i dt)og hrc boi xoi ba va Sl! thay d6i hlnh d a n g dao va N Dao Truong Sa nam don Ie, chu yeu cau tao tir cuoi ket, san k~t manh san ho 1& Dien tich dao 9,4 ha, cao 2,4- m Dai bai bi~n vien quanh bo dao cau t~'? bang cuoi ber cat rong - 10 m den 50 - 80 m, day trung binh 3,5 m Chan bai throng cao 0,5 - ph 0,8 m/O HD Them san ho quanh dao rong khoang 30 ha, cao trung binh 0,3 - 0,5 a phia gong va t6i 250 - 300 m a phia Bac, Dong Bac V~t 23 bai thuong co duong kinh hat trung binh (Md) 0,5 -30 mm Chung co d¢ 16 g6 m/OHD, rong 20 - 40 m lieu 410 h6ng 35 - 55 %, dO chon 19C tir rat tot den rat xau (So thuong co hlnh = 1,1 -6) Cac rnanh vun dang canh hoac dep voi dung thap '(1,27 - 1,46 g/crrr'), co ~ nhieu 16 h6ng nho cau tao cua san ho, nen d~ di chuyen dieu kien mroc bi~n co ty cao-(1,033) va ~bng song manh a dilOco hai mua gio r6 ret, voi toc dO trung blnh tn l« , ClJC dai 34m/s Mila gio Dong B~ctir.thang 10-4, miia gioTay Na~ va thang 5-9 Vao cac thang chuyen 266 m tiep 10 toc d¢ gio yeu, trung binh durri m/s va ve rnua gio NE, song N&co din suat 90 % Song cao cue dai toi 4,5 m, cao - 2,5 m co tan suat 20 - 25 % ve rnua gio NSW, song huang Tay Nam co tan suat 68 %, song cao nhat m, song cao 2,5m co tan suat - % /2/ Thuj trieu co bien d¢ ClJC dai 2,1 m, ki€u nhat trieu khong deu Thai gian trieu len dai hon hltn ( 15 h, 30') thai gian trieu rut ( 9h,20') Trieu manh VaG cac thang song, gio manh ( thang 6,7 chuyen tiep co song, gio yeu (thang 3,4 trj W va SW toc d¢ 0,4 - hai Iy/gia va ve 9,10) ve rnua va 12,1),yeu VaG cac thang He dong chay huang thong mua Dong huang chu dao Eva NE toc d¢ 0,3 - 0,8 hcii IY/gia Nhieu dau hieu cho thay mire mnrc bi~n hien khu vue d~lO dang dang cao dan D~c di~m d()ng hrc va SIf bien d(1i hlnh thai trdc di~n tfr Dac di~m q(mg luc boi tu, xoi la bo, bai va kern theo la Sl! chay d{Sihinh thai trac dien bo va hinh dang dao duoc thE hien qua xu the sau day: n 2.1 -ZYXWVUTSRQPONMLKJIHGFEDCBA X u TSRQPONMLKJIHGFEDCBA I llf r b ie ll d d i th e o g ia th u y tr ie u : h Xu the biEu hie n r6 cac trieu cuong, mat bai trtnrc kha dcm n gian va nghieng deu Khi tr ieu dang cao aan,a chan bfli hinh mot Ie - 30 ern va di chuyen dan ga cuOi cao ve phia dinh bai Khi trieu rut, go cuoi di chuyen xuong I n yxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA phia chan bai va bien mat 2 - B o i IL I, x o i fa v a S~( ky th a y d 'i h tn li th tii tr d c d ie n b o b d ith e o c a ll m a le tr ie u : ThO; gian quan trac bai narn giai doan sung gia J6n n hat cua mua Dong va keo dai ky rnnrc cuUng va ky nurrc kern (xem bang 1) Trir khu goc Tay Nam, gan nhu toan bO cac doan bai quanh dat deu boi tu ky trieu kern va xoi la thoi ky trieu cuUng (h inh 1) T6ng hop, bai bi xoi la bo Bac va xoi Ja rn a n h a a bir Tay, goc Tay Bac, goc Dong Bac Nguoc lai, bai boi tu manh {y ba Dong (rura phia Narn) va rat rnanh a goc Tay Narn Sau 42 quan trac, m~t bai sau bi xoi 1& liii m & bo Tay, m 23,5 m & brr goc Dong Bac Bai sau boi tu mo rong 17,5 m goc T a y Nam rn/ngay a a bo Bac va bo Dong Nam, 58 m goc Dong Bac, toc dO xoi \('1 trung birth 0,6 m/ngay, g6c Tay Narn toc dO boi trung blnh 1,3 rn/ngay, 6/1/19890 a a CI!C a cue dai 3,4 dai 4,2 rn/ngay Den bo Tay chi - m, g6c Dong Bac 9,5 m mra bai se xoi 10 den vi tri x6i cua mua gio Dong bac tnnrc a bo Tay toc dO xoi cham nhirng bai hep nen vach xoi 10 gan doc dung dfl tien sat gan ria tang cuoi san ket mat dao a bo Hac, xoi 10 dfl d~t den vi trf cua mira xoi truce 267 Vao ky mnrc trieu cuong, -trac di~n ngang bai thuong don gian, hoi 16m ( I1 U the ), vao cac ky trieu kern, trac dien ngang bai rat phirc tap, co hinh thai xoi 16edcbaZYXWVUTSRQPONMLKJIHGFEDCBA mi (do bOi tu uu the) v o i - tharn chi bac bai p h u tren suon cua b a i tnnrc V~t lieu mat b5i ky trieu cuong co dt:: TSRQPONMLKJIHGFEDCBA Cl' ' la cac doan voo cac yeu to dOng bai Truong Sa hrc gin, song va tri'eu vao mua gin DCmg-Bae Ngay \ 26/11- 2/12/88 3-6/12/88 Cuong Kcm2 0,9 - 1,7 0-0,8 NE NNE 10 - 28 NE Con nuoc Trieu Bien Gi6 (m) Hg thinh hanh Vmax SOng = m/s Hg thinh hanh Hmax = m clip ~- BaTay G6c Tay Bac ~- Cut'mg3 K cm d Cuong S Kem6 Cuong 0,9-1,9 0,1 - 0,8 0,9 - 2,0 0,6 - 0,9 - 1,1 NNE NE NNE 12 - 20 12 - 18 10 - 14 10 - 14 N.NE/NE NE NE • ,0 r.v 1,5 - 1,5 - IV- V IV - V Gi6DongBlk - Giiia goc Dong Bac - cau tau Sat Bac cau tau Sat Nam cau tau + + Nam 4-6/2/89 1-3 G6cTay 31-3/1/89 III - V BaBk Gan g6c Tay Nam 17-20/12/88 JII - VI Giiia cau tau - goc Tay Nam 7-16/12/88 1,0 - 3,5 - • ~- - ~-, - -, ~ -r c • ~ II ~ + + + + + '+ ++ ++ +++ _ ' _-:t::.- ~ ~ ~ + : Boi tu ; : X i f a ; 0: - -' I, !J -1 i -~ ' - - -r- ~~ -' , , + + ; -r- - I ,.- - y t - , " - , I 't,,~ '"-'- , C hi chu: b ZYXWVUTSRQPONMLKJIHGFEDCBA b~ B a n g 1: Quan h~ gifra bui tu-xoi ::~ 1,,.- 21-30/12/88 , , NE ; 1-2 ~ ':.:~ - ~ '- -_ - -.".- • ~ ,,-., ":.- 10 NE ~~ III-V + + + + : • "+ -' ~ " + , " + ++ ~ ++ +++ NE 10 - 16 NNE f - 1,5 - 1,5 - IV - V ~ < , ~~~,-~ :': ' :- - ,~ ,~ - - :" ,," ~ ~-~ I ; NE :: IV - V + + \0 :C-~4_ " : f t r - '!,' -, ' , J C't (, 'L ~' - -" , \ ' > 'i ~ ".=.' ,\, \! - ~l::~- ~-.•• ~-•• ~••.l.j I-,.j, ,},.~ •.• -,-.••.•• _ l- ' • + , - + ~ + + ; \ + ~, , ;-; ++ '\ +++ ~ T6ng hop 0 O n d in h I\) en