KHOA HQC C 6 N 0 N 0 H |
IVGHl£l\l CLTU Q U A TRilXIH LAIV TRUY^IVI SOIVG T A I K H U VVrC CLTA B A L A T V A CLTA L A C H GIAIVG T H E O CAC K | C H BAIM B A I S d l V A COIVG TRilXIH C H I I V H T R !
Dodn Tiln Hd\ Nguyin l^ilnAnh^
T6MTAT
Ddi bd biln bi cita Ba Lat din cua Lach Giang thuOc tinh Nam Dinh trong nhllu nSm qua luon diln ra cdc qud trinh diln biln dudng hb, bai biln, chu ylu la hi^n tupng x6i vd xdm thuc b3i din din qua trinh sat Id bd, dfi biln t^i ddy. M^t trong nhiing nguyfin nhdn chinh tac dpng din qud trinh xdi Id, phd ho?! d6 biln trong khu vpc ndy Id sdng biln. Do dd, v i ^ nghifin ciiu qua trinh lan truyin sdng ddi voi khu vi^ nay dudi su dnh hirdng ciia dja binh khu vyc va cdc c6ng trinh chinh tri bd tn trfin bai Id dilu cd y nghia thi^ tiln. Bdi vilt trinh bdy kit qud iing dung m6 hinh todn dl mo phong qud trinh lan truyin sdng nhdm ddnh gid co chl Ian truydn s6ng trong dilu ki^n dia hinh bai tir nhifin vd hifiu qua cdc phuong an c6ng trinh chinh til, ddy Id mdt sdn phim ciia dl tdi: "Nghidn aiu coso khoa hoc v^dS xuit giai phip tdng thi didnd/nh vungb&biSn Nam Dinh tit cua Ba Lat din cua DAy". Mo hinh da dupc kilm djnh vdi cac s l lifiu sdng do dpc tai hifin trudng. Cdc kit qua kilm dinh cho thiy mo hinh hoan toan cd thi dupc ting dpng vao tinh todn thuc tl cd do tin cdy dam bao.
Tii Khda: Lan truyin song, suy giam song, cOa Ba Lat, cua Lach Giang.
I . G N t H H ^ CHUNG
Dai bd biln Nam Dinh tir cua Ba L^t din eiia L ^ h Giang cd ehilu ddi dirdng bd biln khodng 65 km. Ddy Id mdt vimg cd tim quan trpng d$e bi|t trong str phdt triln bin vtrng ciia ddng bing bic bp ^ B B B ) vd ciing l l trpng dilm sat Id bdi, dfi biln cin cd cdc giai phdp khoa hpc cdng n g h | d l I n dinh bdf biln. Khi nghifin Cliu clc gidi phdp cdng trinh thi r i t cin thilt phli bilt hi|u qud cua gidi p h ^ cdng trinh nhu ttil nio?. Kinh nghi|m phdng chdng xdi Id bdi tu bd biln ciia sdng cua ede nudc trfin till gidi vd nudc ta dd chi ra ring: Cin phai tiln hdnh ddng bd vd todn di|n cac gili phip tir tim vi md din vi md, ca tryc tilp vd gidn tilp, ca giai phdp cdng trinh va phi edng trinh phd hpp vdi timg d o ^ bd, tung ciia sdng cu tfai. Cde giai phdp cdng trinh cin phli phu hpp qui ludt ttr nhifin trfin co sir xdc dinh edc tdc nhdn gdy xdi Id bdi tu va co chl ciia chiing, ddng thdi phli cd hi|u qua vd tde dung lau ddi, phli hpp vdi dilu ki|n kinh ^ x d hdi ciia dia phirong, khdng gdy tde ddng tifiu cue din mdi trudng vd tai biln cho clc khu vpc ldn c$n. Mdt sd cdng trinh gdy bdi bdo v | bdi dd dupc xdy dyng thii nghi|m ti^n mdt sd khu vyc thudc Nam Djnh. Vi|c iing dpng md
* Trung tfim Nghifin ciiru Ddng l^c CSVB&HD - Phdng TNTDQG vi DLHSB - Vi^ KHTLVN
' Vv Khoa hpc, Cdng n ^ $ vd Mdi trudng, Bd Ndng n g h i ^ vdPTNT
hinh todn nhim tao ca sd khoa hpc cho vi|c lya chpn qui md vd qui hoach cho hd thdng cdng trinh bao v | bd, dfi biln d ddy la rit quan trpng.
Nhim myc dich tim hilu rO eo c h l lan truyin sdng tai khu vue nghifin ciiu tir cira Ba Lgt din ciia Lgch Giang, d l cd eo sd khoa hpc trong vi|c d l ra clc giai phap cin thilt vd Idu dli trong vi|e dn dinh, khai thic viing eiia sdng-ven biln nly, dudi ddy Id nhung k i t q u i nghifin ciiu v l tinh todn qud trinh lan truyin sdng vd su suy gilm sdng dudi dnh hudng ciia dilu ki|n dia hinh bdi, cdng trinh chinh tri dupc bd tri nhdm gilm sdng, gdy bdi tgi ddy. Md hinh dupc kilm chiing qua sd li|u do dgc khao sdt vl sdng, myc nudc v l ede sd li|u Ihu thdp v l dia hinh bd, bdi. Md hinh cd t h i sii dung d l nghifin ciiu vdi edc kich bin khde nhau d l giiip cho vi|c hoach dinh k l hoach khai thdc lau ddi vung ven bd tii ciia Ba Lgt din ciia Lgch Giang. Cdc k i t qua dd dgt dupc tir nghifin ciiu tinh i»dn kilm chiing vd cdc nghifin eiiu tinh todn v l sdng, tirong tic sdng edng trinh tai khu vyc quan tdm bang md hinh Mike 21 SW.
Z. CAC K^ QUA TfeW TOAN 2.1. Thilt l|p md hinh Mike21 SW
Trong nghifin cmi tinh todn md hinh sdng ndi chung, vi|c tiiilt l$p md hinh, lya chpn miln tinh todn, ludi tinh todn Id budc quan trpng quylt dinh din todn bd c l c vln d l c i n quan tdm nghifin eiiu vd
N 6 N G NGHlfP VA PHAT TRI^N N O N G THON - K t 1 - T H A N G 9/2013 51
KHOA HQC C 6 M 0 NOHg kha ndng eiing nhu chat lupng ciia md hinh. Vifie Iua
chpn vd thilt l^p miln tinh, ludi tinh cho khu vyc ven bd tu oia Ba Lgt din ciia Lach Giang dupc trinh bdy ti-fin hinh 1.
Hinh 1: Miln tinh, d|a hinh vl ludi tinh khu vuc nghifin ciiu tu ciia Ba Lgt din cua Lgdi Giang
Miln tinh todn bao gdm bifin ngoai khoi tai dd sdu 20 m (cd dilm do sdng ttiyc tl), bifin phia Bic vd bifin phia Nam bao todn bd khu vuc cua Ba Lgt vl ciia Lgch Giang, trong miln tinh nay ed 2 m$t cit ed sd li^u dung dl tinh toan sdng thilt kl dfi biln (Giao Xudn vl Hai Hda) ttieo tifiu chuan tiiilt kl dfi biln CTCTKDB) ndm 2012. Ludi tinh ti)an gdm ed 23039 mit vd 64431 phin hi. Cd ttil ttily cdch lya chpn miln tinh vd ludi tinh dl nghifin ciiu khu vuc 11 kha ^i uu va hpp ly, dap iing dupc yfiu clu nghifin eiiu tdng thi cho khu vuc ven bd ttr cua Ba Lat din ciia Lach Giang va khu vuc cdng Tlianh Nifin.2.2. Kit qua kilm dinh md hinh vl muc nudc
Trong tinh todn kilm dinh md hinh vdi muc nudc da linh toin kilm chiing vdi 2 chuoi myc nudc do dge thye tl tai khu vyc ciia Ba Lat vl ciia Lach Giang [7], ttidi gian tir 5/11/2009 din 13/11/2009.
Kit qua kilm dinh muc nudc dupc thi hifin trong hinh 2 vd hinh 3 dudi ddy.
Hinh 2. So sinh gitra myc nudc thuc do vd tinh toin tgi ctia Ba Lgt
Hinh 3. So sdnh gifia myc nudc thyc do vl tinh todn tgi ciia sdng Lgch Giang
Kilm dinh sai sd ciia md hinh ta dung ehi tifiu Nash (Nash and Sutcliffe 1970) dl xdc dinh. Hfi sd Nash-Sutcliffe cd ttil tii - oo din 1. H^ sd 11 1 tirong ling vdi mdt kit hpp hodn hao oia md hinh vl clc dii lifiu quan trie. Cde kit qua ddnh gil sai sd vl muc nudc tai Lgch Giang vl Ba Lat lln Itrpt cho clc tri sd nhu bang dudi ddy:
Cdc tham sd Nash
Cua Lach Giang 0,84
Cua Ba Lat 0,91 K^t qud tinh t o ^ ki^m chihig mfi hinh v6i myc nuoc thiic do tai khu vtrc nghign ciiu cho k^t quJ tdl, c6 th^ dp dyng d^ tinh todn thuc t^.
2.3. K^t qud hi^u chinh vd ki^m djnh md hinh vbi chudi s6 li^u s6ng
K^t qud Id^m djnh v6i chuoi s6 lifeu thl;tc do tir 15 gift ngdy 6/8/2006 d& 21 gift ngdy 13/8/2006 vfti OBS do 3 gift/1 lan do tai hai trsrai ft vimg bifa HSi Hdu-Nam Djnh (Dif dn hijp tdc quoc t^ Vi^t Nam- Thuy Difa (SIDA)):
- Tr?m tl cd tpa dO 20°02.0'N-106<'21.15'E t?i d?
sdu 20,0 m.
- Tram t2 c6 tpa dg 2O°O5.548'N-1O0^O.794'E t?i do sdu 10,0 m.
Tr?m tl dui?c ISy ldm s6 Iifa bita ddu vdo cho mft hinh. Kft qua tinh todn higu chinh diKjc trich t?i vi tri tram t2 d* so sdnh vfti s6 Ufa thvrc do (Xem hinh 4).
Sau khi da tinh todn hifa chinh vfti nhiimg hf s6 cia thi^t, da tifa hdnh tinh Hbn djnh md hinh vdi s6 Iifa thyc do tai khu vyc. Kft qud tinh Hira djnh m6 hinh nhy sau:
52 N 6 N G NGHllP VA PHAT TRI^N N 6 N G T H 6 N - KV 1 - THANG 9/2013
KHOA HQC C O N G N O H I
Hinh 4. Vi tri cdc trgm do sdng (tl vd t2) tai thyc dja khu vyc nghifin ciiu
Hinh 5. Kit q u i tinh toin kilm djnh chilu cao sdng TCr k i t q u i tinh todn kilm dinh trfin hinh 5 cho thiy giira k i t q u i tinh todn vd ttiyc do Id khd tdt, ngogi trir mdt sd thdi dilm sy l|ch nhau v l hirdng ed till do sy chi tilt eua dia hinh chua thdt dii chi tilt d l t h i hifin dilu ki|n thay ddi tgi ldn e|ui dilm do. Tuy nhifin cd thi thiy md hinh hoin toin cd khd ndng phdn dnh khd tdt biic tranh dOng lyc v l sdng. Do dd hodn todn cd co sd d l svr dyng md hinh d l nghifin Cliu v l tinh todn c l c q u i trinh sdng tai khu vyc ven bd vdi clc dilu ki|n khic nhau.
2.4. C l c k|ch bin tinh todn v l dilu ki|n bifin phye vy tinh toin
2.4.1. Cic kich bin tinh toin:
2.4.1.1. Tinb toin d6l vdi khu vt^ cua Ba L^t TYong tinh todn sdng ddi vdi khu vyc cua Ba Lat, cde kich bin dupc tinh todn bao gdm:
- Tinh todn vdi hi|n trgng bdi bdi phdt b i l n ndm 2010;
• Tinh todn vdi h i | a trgng bdi bdi phit triln ndm 1990;
- Tinh toin vdi d u bdo bdi bdi phdt triln ndm 2025.
2.4.1.2. Tinb toin ddi vdi kbu vuc cua L^ch Giang
Trong tinh todn sdng ddi vdi khu vuc cua Lgch Giang, cde kich bdn dupc tinh todn bao gdm:
- Tinh todn vdi phuong dn bdi hifin trang ndm 2010;
- Tinh vdi phuong dn edng trinh 1: Phuong dn edng trinh 1 (PAI) chinh tq khu vyc ciia Lach Giang bao gdm hai dfi phia Bic va phia Nam. Dfi phia bic Id mdt dudng gip khiic cd tdng chilu ddi 1240 m vd dfi phia nam cd chilu dli 700 m, cao trinh dinh dfi la +3,5 m, b l rdng eua eang 700 m.
- Tinh todn vdi phuong In cdng trinh 2: Tuong tu nhu PAI, phirong In cdng trinh 2 (PA2) chinh tii khu vyc Clia Lgch Giang bao gdm hai dfi phia bic vd phia nam. Dfi phia Bic cd chilu ddi 1300 m vd dfi phia Nam cd chilu ddi 530 m, cao trinh dinh dfi la +3,5 m, chilu rdng ciia eang Id 820 m.
Ddy Id hai phirong dn cdng trinh da ndng dd dupc d^ tdi d l xult, trong nghifin ciiu ndy chi x l t din tinb hi|u qua trong giam sdng eiia timg phuong dn cdng trinh.
2.4.1.3. Tinh toin dSi vdi kbu vi^ ximg quanh cdng Thanh Nidi
Trong tinh todn sdng ddi vdi khu vyc xung quanh edng Thanh Nifin, clc kieh bdn dupc tinh toin bao gdm:
- Tinh todn vdi phuong dn bd tri 5 md hdn chu T d^t vudng gdc vdi bd: Bd tii h | thdng bao gdm 5 md ban cha T cd chilu ddi thdn l l 350 m, chilu ddi cinh md hin 300 m, chilu rpng md hdn Id 5 m, cao trinh dinh md hin +3,5 m, mdi md hdn cdch nhau mdt khoang 150 m;
- Tinh toin vdi phuong In bd tri 5 dfi p h i sdng song song vdi bd: Bd tii 5 dfi p h i sdng ddt song song vdi bd, cleh bd khoing 350 m, dkt tgi dudng ddng miic khoing -2 m. Clc dfi p h i sdng ndy cd chilu dli 300 m, rdng 5 m, cao trinh dinh dfi Id +3,5 m, mdi dfi phd sdng d$t cleh nhau mdt khoing Id 150 m.
2.4.2. Biiu kiin biSnpbi^c vi^ tinh toin Dilu kiln bifin v l myc nudc vd sdng phye vu cho c l q u i tiinh tinh todn dupc hich xult tir sd li|u tiong Tifiu chuln TK DB mdi ban hdnh ndm 2012
N 6 N G NGHlfP VA PHAT TRI^N N O N G T H 6 N - KY 1 - T H A N G 9/2013
KHOA HpC C 6 N C NOHt
cua Bft Nong nghifa vd FTNT, cy th^ ta co bang sft Ufa ddu vdo phuc vy tinh todn nhu sau (Bang 1):
Bdng 1. S i Ufa ddu vdo phye vu tinh todn sftng khu vyc nghito cuu
Cdp tdn sudt
P.1%
P=a6
Song
H.WI 4,63 3,50
T(s) 11,75 1039
Huftng
45; 90; 135 Mycnux tong oong H,(m)
3,482 2,214
giai doan khde nhau cua nhung nghita ciiu truftc day md d i tdi da thu thdp du^ic, tir dft Hta hdnh phdn Hch d^ CO c a sft dy bdo cho nam 2025.
- Vfti cdc mo hdn phdt trifa ft cua Ba Lat nhu cdc phuong dn t r t a , Idii tinh todn sftng lan truyfa theo cdc hudng khde nhau cho thdy dfti vfti sftng lan truyta theo huftng NE da bi suy giam rdt nhifa so vfti ede huftng E vd SE:
M6i cdp sftng vd muc nuftc tinh todn cho khu vuc dugc tinh theo 03 huftng lan truyta khde nhau dft Id huftng Dong BSc (NE), huftng Dong (E) vd huftng Dftng Nam (SE).
2.5. K^t qud tinh todn sy lan truyta sftng vdo khu vyc nghita Cliu
2.5.1. Kit qui tinh to^ ddi vdi khu vuc ciia Ba Lat
- Trong truftng hop tinh toan vfti cdc phuong dn bai hifa trang va bai boi tai khu vyc cua Ba L^t theo cdc cdp tan sudt vd huftng khde nhau eho thdy song eft sy suy gidm khi tifa vdo viing nuftc nftng do dnh huftng cua dia hinh ddy.
Hiiih 6. Bai b6i khu vyc ciJra Ba L^t vfti dia hinh hi^n tr^oig ndm 2010 - Tir cde kft qud tinh todn doi vfti khu vyc ciia Ba L^t cho thay, khi bai boi phdt trifa ft cua Ba L^t nhu mOt mft han tu nhifa tuong irng vfti chifa ddi: 11,5 km nam 1990; 12,5 km ndm 2010 (xem hinh 6) vd dy bdo cho ndm 2025 ld:13,5 - 1 4 km che chdn cho khu vyc ldn cdn, difa ndy eft tdc dyng ldm gidm_sftng dfti vfti khu vuc xung quanh, nhdt Id d6i vfti khu vuc cftng Thanh Nifa. Cde phuang dn phdt trifa bdi boi khu vyc ciia Ba Lat dya trfa edn eii chdp ede dnh vifa thdm, cdc kft qud quan trdc duftng bft trong nhifa
Hinh 7. T^ '* suy gidm ehifa cao sftng theo huftng NE so vfti huftng E khi lan truyfa vdo khu vyc cftng l l i a n h Nifa vfti cdc k)ch bdn phdt trifa bai b6i
(truftng h(>p tinh P-ISO
+ Truftng hop vfti bai boi nam 1990, chifa eao sftng lan truyfa vdo khu vyc cftng Thanh Nifa theo huftng NE bi suy giam 30-35% so vfti ede huftng E va SE;
+ Truong hgp voi bdi boi ndm 2010, chifa cao sftng lan truyta vdo khu vyc e6ng Thanh Nifa theo huftng NE bj suy giam 4045% so vfti ede huftng E vd SE;
+ Truftng h a p vfti bai boi nam 2025, chifa cao song lan truyta vdo khu vyc edng Thanh Nita dieo huftng NE bj suy gidm 50-55% so vfti ede huftng E vd SE.
2.5.2. KSt qua tinh toin ddi vdi khu vuc ciia L ^ Giang
- Tinh todn vfti phuong dn bdi hifa t r ^ g nam 2010 eiia khu vye eua Lach Giang d i bift d u ^ qud trinh lan tiuyfa vd tdc d^ng ciia sftng ddi vfti khu vyc ndy nhu t h i ndo trong difa kifa ty nhifa. K i t q u i tinh todn cdc thftng sd sftng vfti cdp t i n sudt P=l% vd P=5% cho I h ^ huftng sftng bdt lgi nhdt khi truyin vdo khu vyc cua L?ch Giang Id huftng SE. Tuy nhiin, trong truftng hop vfti myc nuftc cao thi ciing khftng eft sy chinh lieh ddng k i v i chifa cao sftng khi truyin vdo khu vyc trong ciia theo cdc huftng khde
54
N 6 N G NGHllP VA PHAT TRIEN N 6 N G T H 6 N - KV I - THANG 9/2013KHOA HQC C 6 N 0 MOHfe nhau, khi vdi myc nudc t h ^ hon sdng truyin vdo
khu vuc cua Laeh Giang cd su suy giam ding kl.
Hinh 9. Bd tri phuang dn cdng tiinh chinh tr} tgi ciia Lgch Giang (PAI)
Hinh 10. Bd tii ihuong In cdng trinh chinh tri t Uch Giang (PA2)
Hinh 8. TVudng sdng khu vyc eiia Lach Giang hudng NE, tin suit P-1% ff)ia hinh ndm 2010) - Khu vyc cua Lach Giang trong nhiing ndm gan ddy da cd nhung biln ddi rat nhilu, bdi b khu vyc hai bfin cua bi xdi manh, ludng lach biln ddi, mpt trong nhimg nguyfin nhdn chinh gdy ra hi|n tirpng trfin ehinh Id tdc dpng cua sdng. Bi giam thilu, ngdn ch$n tinh trgng trfin vd cd phuong an chinh \r\ hpp \f, nhdm nghifin ciiu dd dua ra 02 phuong dn bd tri edng trinh ehinh h\ (hinh 9 vd hinh 10).
Hinh 11. Tmdng sdng khu vyc ciia Lgch Giang hudng NE, tin suit P=l% (PAI)
Hinh 12. IWdng sdng khu vyc cua Lgch Giang hudng NE, tin suit P-1% (PA2) - Kit qua ciia su suy giam chilu eao sdng khi cd edng trinh chinh tii ddi vdi khu vuc cua Laeh Giang dupc thi hi|n trong edc bing 2 vd bang 3.
Bdng 2. Suy gilm chilu cao sdng khi truyin vio khu vyc cua Lgch Giang theo cdc hudng khic nhau
(tinh todn vdi cdng binh PAI, tin suit P-1%) TT
1 2 3
Cdc huftng truyin sftng
NE E SE Bdng 3. Suy gidm chl
vye ciia L^ch Gian (tinh todn vfti cdn TT
1 2 3
Cdc huftng truyin sftng
NE E SE
Su suy gidm chiiu cao sftng tai eiia sftng sau khi eft cftng trinh bft tri theo PAS (%)
86,2 86,1 79,0
iu eao sftng khi truyin vdo khu g dieo edc huftng khde nhau lg hinh PA2, tdn sudt ?-!%) Su suy gidm chiiu cao sftng tai cua sftng sau khi eft cftng
trinh bft tri Iheo PA4(%) 90,0 87,8 91,6
NdNG NGHllP VA PHAT TRI^N N 6 N G T H 6 N - KY 1 - THANG 9/2013
KHOA Hpc C 6 M 0 NOHfe Ca hai phuong In chinh trj ddi vdi khu vuc ciia
Lgch Giang diu eho hifiu qua suy gilm ehilu eao sdng khi tdt vd khdng cd sy chfinh Ifich ding kl vl gid tri suy gilm. Tuy nhifin, ddi vdi PAI sfi eho dupc khdng gian luu thdng tdt b khu vuc cira, tgo kha ndng thoit lu, hogt ddng giao tiidng thuy. Bfin canh dd, vdi khoang khdng phia trong rdng sfi 11 dilu kifin rit tdt dl ed till neo d^u, tni ngu eiia tau thuyin.
2.5.3. Kit gui tuih toin ddl vol khu vuc cdng Thanh Niin
- Bdi biln khu vyc cdng Thanh Nifin trong nhiing ndm gin ddy bi xdi Id rat nghifim trpng, biln da tiln sdt vdo chdn dfi, sdng v6 tryc difin vdi dfi biln nfin mdi khi cd sdng to, gid ldn va nudc ddng cao sfi rit nguy hilm ddi vdi hfi thdng dfi biln tgi day. Do dd, vific phai cd clc phuong In cdng trinh trfin bai nhim lam suy giam sdng d bfin ngoai trudc khi tiln vao khu vyc dfi biln Id dilu rit cin thilt Trong nghifin cuu ndy, nhdm nghifin ciiu da dua ra 02 phuong In bd tri cdng trinh chinh tri tai khu vtrc cdng Thanh Nifin (h| thdng rad han chii T va dfi phd sdng song song vdi bd).
- Tnrdng sdng tinh todn dai difin cho hudng NE, tin suit P=l% tgi khu vyc nghifin ciiu ddi vdi el hai phuong In dupc thi hifin trong cac hinh 13 vd 14 dudi ddy.
Hinh 13. Trirdng sdng khu vuc cdng Thanh Nifin theo hudng NE, tin suit P=l% (Phuong dn md hdn chGl)
Hinh 14. Tnrdng sdng khu vyc cdng Thanh Nifin theo hudng NE, tin suit P-1% (Phuong In dfi phi
sdng song song vdi bd)
- Kit qui tinh toin dd suy gilm ehilu cao sdng ddi vdi hai phucng dn cdng trinh dupc thi hi|n trong clc bing 4 vl bing 5 dudi ddy. Cdc dilm trich xult tgi 3 dilm d phia trudc vd phia sau ciia 3 edng trinh nlm d giua.
Bing 4. Kit qui suy gilm chilu cao sdng khi di qua hfi tfadng md hdn eh&T, vdi P-1%
Cdc huftng tdc dftng Huftng Dftng Bde (NQ Huftng Dftng (E) Huftng Dong Nam (SE)
Tyli suy gidm (%) Tl
82,95 71,10 81,57
T2 83,22 71,47 81,73
T3 83,48 71,29 81,45 Bing 5. Kit qui suy gilm chilu cao sdng khi di qua
h^ thdng dfi phi sdng, vdi P=l%
Cdc huftng tdc dftng Huong Dftng Bdc (NE) Huftng Dong (E) Huftng Dftng Nam (SE)
Tyli suy giam (X) Tl
35,26 53,48 64,05
T2 35,16 50.20 60,67
T3 36,96 50,79 61,15 LKfrUMN
Mo hinh tinh todn qud trinh lan truyin sftng ddi vfti khu vye eua sftng ven biin tai trgng diim tir ciia Ba Lat din ciia Lach Giang dugc kiim chiing qua cdc sd liiu do dac khdo sdt vi muc nuftc, sftng cho kit qud tin edy, ldm ca sft di nghiin ciiu tinh todn anh huong cua sftng din cftng trinh bft biin. Cdc kft qua tinh todn ddi vfti cde kich ban bai bdi vd cdc phuong dn cftng trinh chinh hi ft khu vuc hai cua Ba lat, Lach Giang vd cde viing Idn cfa thu dugc si Id ca so khoa hgc di lua chgn nhQng phdi phdp, phuong dn bd tri edng trinh ehinh tri hpp ly nhdm gidm thiiu tdc dftng eua sftng, dn dinh bft, di bai vd cdc tuyin ludng lach dam bao giao thdng thiiy vd thodt IQ cho vimg dia song.
mv$immmlia
1. Nguyin Khde Nghla vd nnk. Viin KHTLVN.
"DTCB biin dgng hinh thdi dai ven biin Bdc bd din Trung bg". Kit qui difin DTCB giai doful 1999-2004.
2. Tniong Van Bdn, 2006. Dy tinh muc nuftc thuy triiu ven bft vinh Bdc bft bSng phfa mim Mike 21 HD. T^p chl Khoa hipc Cdng ngh$ Thuy Lpi sd 3/10, 2006.
3. Huftng ddn sit dung Mike FM, 2007.
4. Nguyin Khde Nghia vd nnk. Viin KHTLVN.
"Xdc djnh chiiu eao sftng trong tinh todn thift ki di biin til Qudng Ninh din Quang Nam". Kit qui di Hi trpng diim cip B0 NN&PTNT 2007-2008.
56 N 6 N G NGHlfP VA PHAT TRI^N N 6 N G T H 6 N - KY 1 - THANG 9/2013
KHOA HQC C 6 N 0 MOHt
5. Nguyfa Khde Nghia vd nnk. Tiin KHTLVN. 7. Nguyin Vdn Himg vd nnk. Viin KHTLVN.
"Nghiin Cliu gidi phdp KHCN xdy dung d i bifa "Diiu tra hiin tr?ng cdc cua sftng fliupc h i thdng chdng dygc bao cdp 12, triiu cuftng (td Qufag Ninh sftng Hdng (Ba Lat, Trd L]^, Ddy, Ninh Ca), kiin din Ninh Binh)". Kit qua di tii c^ Bf NN&PINT nghi edc gidi phdp khai thde mftt cdch hodn thiin 2006-2008. phuc vu phdt triin kinh t i " . A i * 9 u i ( / ( r i n i J T T S
6. Nguyfa Khde N i ^ vd nnk. Viin KHTLVN. nam 2009.
"Iheo doi difa biin sat Ift vimg cua sftng, ven biin 8. Ti6u chudn ky thudt thiit k i d i biin. B^
Nam Dinh". KSt qui duin BTCB gial doan 2005-^11 NN&PINTnSm 2012.
STUDY WAVE PROPAGATION IN THE AREA BA LAT ESTUARY AND LACH GIANG ESTUARY BY THE BAR SCENARIO AND REGULATION STRUCTURES
Doan Tien Ha, Nguyen Tiian Anh Summaiy
Coastline from Ba Lat estiiaiy to Lach Giang estuaiy. Nam Dinli province for many years always place the course of the shoreline, beach, mainly erosion phenomenon and beach erosion led to bank erosion process, sea dykes here. One of the main causes affecting the process of erosion, destructive sea wave in this region.
Therefore, the study of wave propagation process for the area under the influence of regional topography and regulation structures on the beach layout is extremely practical significance. The paper presents the results of application of mathematical models to simulate the process of wave propagation, wave-interaction structures in order to assess the mechanism of wave propagation in natural teirain conditions yards and efficiency plans political process, this is a product of the project "Science-based research and proposing solutions to stabilize the overall coastal Nam Dinh Irom Ba Lat estuary to Day estuaiy*. The model has been tested by real data wave measurement The test results show that the model can be fully applied in practical calculations to ensure reliability.
Keywords: Propagation wave, decay wave, Ba Lat, Lach Giaag.
Ngufti phdn biin: PGS.TS. Thifa Quang T^idn Ngdy nhdn bdi: 7/6/2013
Ngdy thftng qua phdn biin: 3/7/2013 Ngdy duyft dang: 5/8/2013
