Tác động của con người tới môi trường địa chất hệ đầm phá tam giang cầu hai (thừa thiên huế) tuyển tập tài nguyên và môi trường biển, tập 9

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TRUNG TAM KHOA HOC
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VA MOl TRUONG BIEN
T~P IX

BAN BIEN T~P:
Tntdng ban:
Thu' ky:
Cac th anh v ie n:

PGS., TS. Nguyen Van Tien
TS. Nguyen Huy Yet

TS N guy~n Due Cu
T~ N guyen H iruedcbaZYXWVUTSRQPONMLK
C ii
TS. Luu Van Dieu
TS. Tran Due Thanh
/rs D6 Cong Thu~g

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NHA XUAT BAN KHOA HOC V A KY THUA-T
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Trang
1. Di[lctrung hinh thai - de)ng luc va bien dang bo dao Cat Hai, Hai Phong

5kjihgfedcbaZYXWV

D inh. W in H uy, Trtin. D ue Th(;m h,
D 6 D inh. C hien, Bui Van VlifJng

2.ponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
A p dung mo hinh Sbeach tinh toan bien dang dia hinh day khu vue phia
nam dao Cat Hai
Trdn Anh

t», D 6

D inh C hien, N guy€nThQ

23

Stio

3. Ung dung mo hinh MIKE21 d~ danh gia va.du bao thuy dong lire va chat
IUQngnude vinh Ha long

33

D 6 Trong Binh

4. ¥9t so ket qua ung dung vi~n tharn va h~ thong tin dia ly nghien cuu tai
bien moi truong vung bo tay vinh Blle Be)

52

Trdn D inh. Ltin, Trtin. Van D ien,
N guy€n

Van Thao, D 6 Th? Thu edcbaZYXWVUTSRQPONMLKJIH

Huang

5. T6ng quan tinh trang x6i sat ld bo bien Blle Vi~t Nam, ket qua phan tich
tir tai lieu vi~n tharn

64

Trdn Van D ien, N g u y e n . Van Thao

6. Xac dinh gia tri cua tai lieu mau nude dai duong xv. ly tU anh' v~ tinh
seawifs va sv. dung nghien cuu phan bo chlorophyll-a d vung bi~n Vi~t
Nam
Trtiti Van D ien, D anLing

75

Tang, H iroshi K aw am ura

7. Me)t so dac di~m chat IUQng nude vung bi~n yen bo Tien Lang
Phong

Hai

88

C ao Thu Trang, Luu. van o u « Ph< ;t:nVan L u o n g ,
Vii Th? Llju, N guy€n M ai Anh,
D u o n g Thanh

N gh?, N guy€n x c a «

Tuyeti

8. Tac dong cua con ngiroi tdi moi truong dia chat h~ darn pha Tam Giang Cllu Hai (Thua Thien - Hue)
N guy€n
N guy€n

nau

ce. Trtin. D ue

Vii Turin, N guy€n

103

Th(;m h,

Th? K im Anh

9. Anh hirong cua cac dap chua tren luu vue den moi truongsinh

thai yen

121

bd
Trdn. D ue Thanh, D 6 D inh. C hien

10. 6 nhiern trllm tich day d cac khu vue cang bien Viet Nam
N guy€n

137

Th? P h u a n g H oa

308

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T uyln

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t~p T ai nguyen. ,va M 6i truang bien. T ~p IX

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•••.

TAC DQNG CUA CON NGUOI Tal MOl TRUONG
DIA

. CHAT HE. DAM PHA TAM GIANG ~ CAU HAl
.

(THUA THIEN - HUE)zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQP

. N guy~n H itu edcbaZYXWVUTSRQPONMLKJIH
C a , T rtin B ite T hanh,
N guy€n V u T ufin, N guy~n T hj K im A nh ponmlkjihgf

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1. M dDAU
H~ dftm pha Tam Giang
mot lagun

ven bo nude 1<;1 IOn nhat

Trung Viet Nam trong khoang
vao khoang

trong

vy

tieu

- Hue la

bi~u d ven bd rnien

216 km2 va cung thuoc loai IOn cua the gidi [3 - 6]. Tai nguyen

vung

do co lagun.

sinh v~t,t~p

trung

chu yeu d cac loai hinh thuy

That vay, h~ dftm pha TG - CH chua

dung ngudn

da dang va giau ti~m nang phat tri~n, co lich si'i khai thac lau d~i va

gift vi tri quan trong

trong

quan true tiep tdi 5 huyen

t6 chuc lanh th6 kinh te tinh Thua
(Phong

Phu LQC)trong t6ng s6 8 huyen

Dien, Quang

Dien, Huong

Thien

cua tinh.
ung vdi mot ki~u

dia chat ddi bo, nhay earn bien dQng v~ tai nguyen

gay hau qua kinh
cua cac qua trinh

va moi truong

te - xii hoi nang n~ nhu dii tung xay ra nhieu
tv nhien

- Hue, lien

'I'ra, Phu Vang va

H~ dftm pha TG - CH Ia mot th~ dia chat hien dai tuong
moi truong

Thien

binh

vue ven bd trong

11° - 16°

s6 12 lagun

Thua

bac, vdi dien tich mat nude trung

bd bien, d~c biet la tai nguyen
tai nguyen

- Cau Hai (TG - CH)' d tinh

va

Iftn do tac dQng

cfmg nhu tac dong cua con nguoi dudi nhieu hinh thuc

khac nhau va quy mo khac nhau.

Tren cd songhien

cuu cac d~c trung

moi truong

dia chat h~ dftm pha TG - CH, bai viet nay nharn danh gia tac dQng cua con ngiroi
tdi h~ dftm pha thong
duoc hoan thanh

2. co

qua cac hanh

dQng ph at tri~n kinh

te - xii hQi khu vue va

vdi su h6 tro cua HQi d6ng Khoa h9C tv nhien

nam 2002.

Sd TAl LltU vA PHudNG PHAp

Co sd tai lieu chu yeu xay dung bai viet nay la ket qua nghien
tai khac nhau

do Phan

cuu cua cac d~

vien Hai duong h9C tai Hal Phong C;hu tri thuc hien trong

nhfmg narn 90 cua the ky truce ma tac giatruc

tiep tham gia [5, 13, 14, 16].

103


tifp edcbaZYXWVUTSRQPONMLKJIHGFEDCBA
T a i nguyen v a M 6 i t.ruim g b ie n . T ifp IX zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPO

T uyin

Bai viet nay duoc thuc hien tren co sd phuong
dong luc rnoi truong

dia chat,

trong

phap

luan

d6 c6 dong luc nhan

tiep can h~ thong

sinh,

va phuong

phan tich logic tac dong' cua 'con nguoi tdi cac yeu to ~oi truong

phap

dia chat va d§.n

suat hai: qua cua n6 [7, 10].

•.••

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3. DAC DIEM MOl TRUONG DIA CHAT HE DAM PHATAM
CAUHAI
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3.1. Cau true moi tnidngponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
dja chat khu vu'c
8 .1 .1 . C ii'u

true th& ng ditng .

Cac thanh

t9-0 m6ng cung cua moi truong

CH trong

a

dong bao

g6m

da phien

luc va porfiroid

toa dQ van khoang

16°14' - 16°42' vy b~c va 107°22' - 107°57' kinh

cac da filit, quaczit,

tay nam; cac thanh

dia chat khu vue d
cuoi ket, da hoa, da phien mica, da phien

set,

thuoc h~ t

t9-0 vu n luc nguyen,

phun trao thuoc h~ tang Long Dai (0 - S

ld), lQ ra chu yeu d phia tay; da phien set, da voi, bot ket va cat ket thuoc he t~ng
Tan Lam (D 1

~'2

tl), lQ ra d phia tay va phia narn ; da voi thuoc h~ t
cb), lQ han che' d phia tay; cac d~ granit

dang gnai, gr anodiorit

LQc (y23 dl), lQ ra d phia tay; gabro - olivin va gabronorit
(v 4nc), lQ ra d phia tay d3

thuoc phuc h~ D9-i

thuoc phuc h~ Nui Chua .

biotit va granit

hai mica thuoc phuc

h~ Hai Van (y34 hv), lQ ra d phia nam dva

l
- y14 bq),
lQ ra d phia tay; cac da
granit thuoc phuc h~ Ban Giang - Que Sdn(8 'l
granosienit,
Phan

sienit

va granit,

thuoc phuc h~ Ban Chieng

(yc

3

"

be), lQ ra d phia tay.

m6ng g~n ket yeu gom cac da set ket, cat ket va cuoi - S9-n ket thui)c h~

t
tich song, song - bi~n

tu6i Plioxen sdm.

Cac thanh

t9 -0

bb rdi cua moi truong

tr
dia chat h~ dgiira - muon (a, am QIl. Ill), 19 han che

d ria phia tay dong bang; tram tich song - bi~n, bien tu6i Pleixtoxen

muon (am. m

QIll); tr arn tich bien, song - bi~n tu6i Ho1oxen sc.n - gifia (m , am QI/·
tich song - bien, bi~n - gi6 va bi~n tu6i Holoxene
Cac thanh

t9-0 dia chat

va bd sau.

]04

1 [5]

)

va tram

mudn (am, mv, m Q[/).

g~n ket va bd roi n6i tren

TG - CH voi bon don vi cau true nhu hinh

2

I!o m :

aa

t9-0 nen h~ d
vue nude, de cat chan,

cua


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Tai nguyen. va M 6i truang

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lra m fic n
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xci,;""(m Q N 3),4 _ Derua triw xuonq, gem c a t truno.Ln»,
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3.1.2. C au true

1. So d6 eau true h~ d:im ph a Tam Giang - c:iu Hai

ng ang

Cau true ngang rnoi truong dia chat khu vue d~m pha TG - CH phan ddi doc
theo bo bi~n dinh huang tay bac . dong nam, phan biet thanh 3 he: h~ moi trucng
dia chat (MTDC) bi~n, he MTDC bo bi~n va h~ MTDC luc dia (hinh 2).
. H~ MTDC bo bien g6m hai kieu: ki~u MTDC c6n - dun va bai bi~n va ki~u
MTDC lagun ven bo. Kj~u MTDC c6n - dun va bai bi~n tuong ling vdi de cat chan
lagun ven bo (hinh I). Ki~u MTDC lagun ven bo g6m bon phu ki~u: phu ki~u cua
lagun, phu ki~u bai b6i lagun, phu ki~u long chao lagun va phu kiJu cua song
chau th6 lagun. Phu kiJu MTDC cua lagun di[tctrung bci dong luc dong chay, c6
anh huong cua song va thuy trieu. bqi su phat tri~n delta tr ieu len d cira Tu Hien
(Vinh Hien) va delta tr ieu

xuong

d cua Thuan An vdi vat lieu cat trung va tho.

Phu kiJu MTDC bai b6i lagun g6m hai dang: bai b6i cao dang them lagun, dac

105

Tuyin

tiJp Tai nguyen. va M 6i t edcbaZYXWVUTSRQPONMLKJIHGFEDCBA
r u a n g bie'n. Tiip IX zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM

trung bci che' dQ tich tu dinh ky ve mua mua voi vat lieu chuponmlkjihgfedcbaZYXWVUTSRQP
yeu Ia bot va cat
nho, bai boi thap dang bai trieu vdi che' dQ tich tu tr~m tich nho heat dQng cua
thuy trieu va bien d6i muc nude trong ngay. Phu ki~u MTDC long chao lagun c6
quy mo ldn nhat, chiern phan ldn khong gian MTDC pha Tam Giang, d~m Sam An Truyen, Thuy Tu va darn C~u Hai. Dac trung cho phu ki~u nay la qua trinh
lang dong tr arn tich hat min dQ uct cao tuong lagun thuc thu va min dan theo dQ
sau. Tram tich hat min d day c6 dQ udt rat cao, dat tdi 81,8% d pha Tam Giang,
47,1% d d~m Sam, 55,5% d d~m Thuy Tu va 63,9% d d~m Cau Hai. Phu ki~u
MTDC cua song chau tho lagun chiern phan khong gian han che'd cua 6 Lau, cua
song Huong va cua song Truoi - D9-i Giang, dac trung bdi uu fhe' dong' luc song,
tich tu bai boi thap, bai bOl cao vdi chu

tr~m tich hat min, dQ udt cao va phat

yeu

tri6n qua trinh Jliy h6a vdi vai tro dang k~ cua thuc vat thuy sinh.

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1 He moi 1"1<:>n9dia chat (Ml DC\ b;~n
2 . 6 He MTOC
Iacun

yen

~ - ~hu

t-O.

00 bi~n: 2 - Ki~u MTOC

J -

Phy

kiell

cita

J

iagun.

"

lonq c:dlo laqun
6 - 0hu kleu ora song
cr.o1,J tho bgu;!
-; - 8 Hiluc dta:

I.

r-noc

7 - }\lcu

f\\TPC

06ng

h~ng

'lien

I'

ri . :

kle:J b5, b6. iJ'-:lun, 5 - Phu kieu

1'1

I

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t---:"""r-;-~

bien,

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I

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S - Kieu MTDC dc":: va nut "tr'lap.

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2. So db mo i trtiong d ia chat khu v1.f.c dl1m ph a Tam Giang·

_

Cau Hai


T uyin

Lagun

tijp T ai nguyen. va M 6i t ruirng bii'n. T ijp IX zyxwvutsrq

venponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
bo, mot ki@u moi trucng larig dong tram tich hien dai (Evans

al, 1973, Reineck

and

Singh,

1975[5]), phat

tri@n phan

di thanh

et

cac phu ki~u

tuong ling vdi cac phu ki@u MTDC (bang 1).
Bdng 1. Phan chia m6i truong

Phan kic~um6i twang

PM.n vung
Cua s6ng

tram tich he dam pha Tam Giang - Cau Hai
Dac tnrng

tram tich

6 Lau

Lang dong tram tich chu yeu hat nho. giau

Cira s6ng Huong

vat chat hiru ca. d¢ Hat cao (>60%). rnoi

Phu kieu chau th6 lagun

twang tram tich khir yell

Cira s6ng Trudi - Dai Giang
Cira TII Hien

Lang dong tram tlch hat tho Ian manh V~lI1
vo sinh vat d¢ uot rhap, m6i twang tram rich

Phu kieu cira lagun

oxy h6a, phat trien delta trieu len 0 cira TII

Cira Thuan An

Hien. delta trieu xuong 6 cira Thuan An
Lang dong tram tich hat vira (cat nho, bot),
d¢ 1I0t thap, tao thanh biii boi cao dang them

Phil kieu bai boi lagun

H¢ thong bai boi yen bo

ngap IG ve mua mira, bai boi thap dang bai
trieu, m6i tnrong tram tich khir trung blnh
Lang dong tram tfch hat nho, d¢ trot cao

Pha Tam Giang
Dam Thuy

'ru

(>60%), phan di co h9C min dan theo do sau,

Phil kieu long chao lagun

m6i twang tram tich khir trung binhedcbaZYXWVUTSR

Dam Oiu Hai
N guon:

Nguyen Hii'u

H~ MTDC
tich aluvi

muon, trong

1996 [5]. c6 b6 sung.

luc dia g6m hai ki@u: ki@u MTDC

MTDC d6i va mii thap.

tram

ce.

d6 c6 h~ thong

dia hinh

cac lagun

d6ng bang ven bien cua Strickland
VaG dam pha.
thanh

trung

c6, trong

thap

bdi Illng dong

t6n tai tU truce

pha ~ theo nguyen

Holoxen

ly phat

tri@n

(1926) [5] d noi giau b6i tich cat va cac dang

nay vAn con tiep tuc boi heat dong dia chat cua cac song d6

Ki~u MTDC

d6i va nui thap

thuc b6c men va r-lia troi be mat cac thanh
hinh

ven bi@n va ki@u

Ki@u MTDC dong bang ven bi@n dac trung

lap d~y cac dang

tich tu cat. Qua trinh

d6ng bang

ph6 bien cac th@ tich tu deluvi,

phat

tri~n

dac trung

tao dia chat
proluvi,

truce

qua trinh

xarn

D~ tu, mot mat

bib b6i ven song nhirng mat

khac cung cap mot lucng IOn b6i tich cho d~m pha va bi@n.
3.2. Dc}ngIuc va tien hoa moi trdong dja chat khu vl.jc d~m pha
3 .2 .1 . D ( m g

iu c

Moi truong
ke" thua

va nang

n9i sinh

dia chat he d~m pha TG - CH chiu a nh huong
phan

cua che' d9 nang

di phuc tap. Ki@u MTDC c6n - dun va bai bi@n, lagun ven

107


tij,p Teii nguyen. vei M 6i t ruirng bien. Tij,p IX zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM

Tuyln

bd va d6ng bang yen bi~n phat
d9 nang trung

tri~n tren ddi sut ha tuong

binh 0,12 - 0,15mm/nam

doi trong

D~ tU vdi toe

(Le Due An va Ma Kong CQ, 1979 [5]) ben

canh khoi nang tay Hue' (toe d9 van dorig 0,3mm/nam)

va khoi nang

Bach Ma (toe

d9 van d9ng 0,5mm/nam).ponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
d phia nam. H~ MTDC bi~n phia ngoai phat tri~n tren
ddi cang gian (Le Nhu Lai, 1995 [5]) chuyen
cac thanh

tiep vdi ddi rift song H6ng.

Toan b9

tao dia chat khu vue bi pha huy manh

bdi cac h~ dirt gay hien dai ph at

sinh tU h~ dirt gay sau A Ludi, cac dut gay phat

sinh cue b9 va cac dirt gay thuoc

h~ dut gay Hili Vap - Son Tr a [12]. Phat
dut gay Pho Trach,

sinh tU h~ dirt gay sau A Ludi, e6 cac h~

h~ dirt gay Hue', h~ dirt gay Rao Trang,

truot phai, dinh huang

a

vy

tuyen (hinh

Day la cac h~ dut gay

3),

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Tam Giang - Cllu Hai

Trong cac dirt gay phat
truot

phai va dinh huang

a

sinh cue b9, di~n hinh
kinh

Thuy Tu. Thuoc

la h~ dirt gay song Ta Trach,

tuyen (BTB - NDN) e~t qua pha

dut. gay song Hiru Tr ach bieu hien

108

I C1Y'S7

-4 1 ;-

truot

trai,

dinh huang

Tam Giang,

h~

DB - TN e~t qua d~m

he dut gay Hili Van - Son 'I'ra, cac dirt gay chinh

e6 bi~u hien


T uyln

tgp T ai nguyen va M 6i tr edcbaZYXWVUTSRQPONM
u a n g biin. T gp IX zyxwvutsrq

truot phai, dinh huang TB - DN chia cat khci Bach Mil va d§.m Cau Hai. Van
dong nang va heat dong cua cac h~ dut gay pha huy hien dai dil lam xuat hien
cac vorn nang C\lC bo, gay bien dang cau true mang ludi dong chay mat d6 van
d§.m pha, nhu vorn nang Phu Yang, vorn nang Thuy Thanh.
3.2.2. D i}ng 11/cngoai sinh

H~ darn pha TG - CH la b6n hQi luu cua h§.u het cac h~ thong song 'I'hira
Thien .: Hue (tru h~ thong song Xe Xap d mien tay), hang narn tiep nhan t6ng
thuy luong 5,171 x 109m 3, va tai luong phu sa 620 000 ta'n, chua tinhden
luong
trao ' d6i voi bien. Qua trmh san bang dia hinh dong b~ng ven bi~n va lip d§.y
lagun ven bo di~n ra lien tuc thong qua cac co che: tich tu bai b6i chau th6 lagun
Ian tien va thu hep dien tich d§.m pha, tich tu la'p d§.y va nong h6a vue nude d§.m
pha vdi t6c dQ van khoang 2, 17 n~m/nam [14] nho hoan luu noi tai va trao d6i
nude giira bi~n va d§.m pha, va co che' san bang bo cua bien vdi luong xuat chuyen
b6i tich doc bo do s6ng van khoang 3,5 trieu ta'n/nam, trong d6 uu the ve phia
nam 0,5 tr'ieu ta'n/nam, d~n den trang thai va vi tri cua d§.m pha khong 6n dinh
[5, 14, 15, 17].
3.2.3. 81/ ph.at triln

va

tien h6a m tii tr uang dia chat hh/u uuc dam phii

Trai qua lich s~ phat trien dia chat khu vue lau dai trudc Holoxen (giai
dean tien lagun) va Holoxen (giai dean thanh tao lagun) tren ddi sut ha tuong d6i
'tan kien tao va kien tao hien dai, h~ d§.m pha TG - CH ra doi trong Holoxen
mUQ~

sau khi Dai Truong Sa (he thong c6n - dun va bai bi~n d6 sQ keo dai tU cua

Vi~t tdi nui Linh Thai) hinh thanh. Sau khi hinh thanh, h~ darn pha TG - CH
phat tri~n c6 tinh giai dean ro rang.' K~t thucgiai

dean tre duoc danh diu bang'

su kien md cua thu hai tai lang Hoa Duan van nam 1404, va h~d§.m pha TG CH dang phat tri~n d giai doan trucng' thanh [5]. Tu khi mo cua Hoa Duan, cua

Tu

Hien t6n tai trudc d6 trd thanh cua phu va trang thai t6n tai cu~ ca hai cua

trd nen khong 6n dinh, moi truong lang dong tram tich lagun ph an di manh giira
cac phu ki~u, dac biet la gifia cac ti~u vung cua phu ki~u chau th6 lagun.
Luc mdi hinh thanh, h~ d§.m pha TG - CH rong hon Qay gid nhieu (Le Quy
Don, 1976 [5]) va trong su6t giai doan phat tri~n tre, chi t.6n tai mot.cua Tu Hien
(xua c6 mot thoi goi la cua "I'u Dung). B6i tich tU cua song 6 Lau va song Huong
cung tham gia tao h~ thongbai b6i ven bd lagun theo suot chieu dai tU cua 6 Lau
tdi Ha Trung. Ngoai bai b6i dang them, can xuat hien hili b6i dang dao d cu6i

darn Thuy 'I'u c6 ca'u true hinh thai delta rfft di~n hinh (khu Ba C6n). Phat tri~n
sang giai doan truong thanh, h~ d§.m pha TG - CH t6n tai hai cua, trong d6 cua
Tu Hien chiu anh huong cua thuy trieu c6 bien dQ cao hdn' thiiy trieu d cira
Thuan An. nguon nuoi b6i tich cho bai b6i ven bd d§.m Thuy Tu va bai b6idljlng

109


t~ p T ai nguyen. va M 6i tr edcbaZYXWVUTSRQPONMLKJIHGFEDCBA
u a n g biin. T ~ p IX ponmlkjihgfedcbaZYXWVUTSRQPONMLKJIH

T uyin

(

•zyxwvutsrqponmlk
dao

d phia cuoi khong con dang k~. Thay VaG d6 la su IOn nhanh

th6 song Huong

Iffn tien vg phia

d~m pha cang giarn nhanh
th6 lagun,

cua Thuan

An. Cac dac trirng

tinh chat d6ng nhat

gifia cac cua va th~m

cua bai b6i chau
ly h6a khoi nude

gifta cac ti~u vung cua song chau

chi giira cac bQ phan

khac

nhau

(Tam

Giang,

Tu, C~u Hai) cua long chao lagun.

Thuy

Lagun

ven bo, mot b6n tich tu hien dai, tfft yeu trai

tre, trucng

tri~n

thanh

va suy tan

d~ hoan thien

qua cac giai dean phat

cau true hinh

thai

d6ng bang

ven bi~n nhu da tung xay ra trong lich stt phat tri~n dia chat d6ng bang ven bi~n
mien Trung

Vi~t Nam

bd hien nay n6i chung

[3]. Ngoai cac qua trinh

dQng luc tu nhien,

Vi vay, khorig

toc dQ bing dong tram

h~ d~m pha TG - CH tiep tuc phat

sinh) dudi nhieu

hinh

thuc khac

thoi gian suy tan cua h~ d~m pha TG -

th~ du bao khoang

CH khi chi udc dinh

ven

va h~ d~m pha TG - CH n6i rieng con chiu tac dQng manh

cua con nguoi ngay cang gia tang (dQng luc nhan
nhau.

cac lagun

tri~n

tich nhu hien nay ngoai viec cho rang
phan

di manh

trong

thoi gian

du dai

trong digu kien dang cao muc nude dai duong the gioi.

3.3. 'I'ai nguyen va tai bien moi trtidng dja chat khu v1:jc diim pha
Tam Giang - ciiu Hai
3.3.1. T iL i ngtiyen.

Tai nguyen

MTDC khuvuc

d~m pha TG - CH duoc dg cap tdi trong

ki~u MTDC c6n - dun va bai bien, ki~u MTDC lagun
bang' ven bien.

Theo

quy luat

chung,

tiern

nang

nang tai nguyen
kien tu nhien

nghiet

va tai nguyen

thien

vung

d6 c6 lagun,

sinh vat. Doi vdi vung bo bi~n mien trung

khac

vi

ven bo va ki~u MTDC d6ng

tai nguyen

chu yeu d cac loai hinh thuy vue ven bo, trong

trung

pham

nhien

be bi~n

va uu the tiem

Viet Nam,

ngheo

tap

kiet,

noi c6 dieu

tiern riang

nguyen

va gia tri stt dung cua cac thuy vue ven bo, trong

cang c6

y nghia va c6 vai tro quan trong trong quy hoach phat tri~n kinh te - xa

hQi khu vue [6]. C6 th~ khai

quat

cac dang tai nguyen

d6 c6 h~ thong

tai

thien

nhien

d:1m pha,

lien quan

cac don vi cau true MTDC khu vue d:1m pha tren bang 2 vdi gia trj tai nguyen
nhat,

ca tai nguyen

sinh vat va phi sinh vat, thuoc vg ki~u MTDC

Mac du gia tri stt dung ldn nhung
su 6n dinh co cau tai nguyen

lagun

tdi
ldn

ven bo.

tiern nang khai thac chi c6 han dinh d~ duy tri

va phat

tri~n cac gia trj tai nguyen,

d~ han che' nay

sinh cac van dg dia chat moi truong.
3.3.2. T ai bitn

Tai bien MTDC
anh hudng
MTDC

vung

ngoai sinh,

110

toan

dien

vung

toi su phat

bo bi~n Thua
duoc trinh

bo bi~n luon la van dg dia chat
Thien

bay khai

tri~n

kinh

- Hue
quat

tren

moi truong'

birc xuc,

te - xa hoi vung

bo bien.

Tai bien

chu yeu la cac dang

tai bien

dia chat

bang

3 theo each phan

tich logic d~n


Tuye"n tij,p Tai nguyen va M 6i edcbaZYXWVUTSRQPONMLKJIHGF
t.r u im g bie"n. Tij,p zyxwvutsrqponmlk
IX

suat MTDC xuat hien tai bien, d(>ng luc sinh tai bien, dang tai bien va hau qua
kinh te' - xa h(>i cua tai bien.
Tai bien MTDC
nang

n~ va thach

pha phat

tri~n

thuc

trong

khu vue darn pha TG - CH gay hau
nang

luc ling xli. IOn nhat

giai dean trudng'

thanh,

qU:8.kinh

la su khong

Iii va ngap

lut

te' - xa hi?i

6n dinh

cua d§.m

hang

nam.

Tuy

nang cao nang luc ling xli. tai bien d6ng nghia vdi gia tang chi phi thay the'

nhien,

ban d§.u, d6 la di~u c§.n xet de'n trong cac quy hoach

phat

tri~n

kinh

te' - xa h(>i

khu vue.

2. Cac dang tal nguyen chii yeu lien quan too cac ki~u mol truong dia chat
khu vue dam pha Tam Giang - Cau Hai

Bang

KieuMTDC
khu

V\!C

Hi nguyen sinh vat

Hi nguyen phi sinh vat

ponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

"

Kieu MTDC con

Luu giU nguon gien cua he sinh thai

- Tiem nang phat trien du lich bien

- dun va bai bien

vung cat

- Noi sinh elf cua cong dong lang nghe khai
thac bien va dam pha
.. Sa khoang yen be, (t6 hop titan - zircon monazit . dac bier i::J Vinh My, Vinh Hien)

Kieu MTDC
lagun ven bo

- Nguon gen thuy sinh vat da dang

- Nguon cat xav dung
tieu bieu cho he sinh thai lagun yen
bo va dien hlnh cho he thong dam

- Dieu lfl, duy trl chirc nang va gia tri cua
24 000 ha dat ngap nuoc co lien quan. giU
guong nuoc ngam khu vue

pha yen bo mien Trung Viet Nam,

- Dieu hoa vi khf hau

voi 221 loai thuc vat noi, 95 loai rang
co ruroc va thuc vat bac cao, 66 Ioai

- Chon vui chat thai nguon luc dia va kha
nang nr lam sach

dong vat n6i, 76 Ioai dong vat day.

- Tiern nang phat trien cang, ben thuyen va

230 loai ca, 54 loai thuc vat nho song
day va 73 loai chim mroc [I 6.21]

giao thong thuy
- Noi tni dau cua tau thuyen trang bao

. - Nhieu loai co gia tri kinh te cao,
nhieu loai quy hiern diroc ghi trang
Sach do Viet Nam
- Tiem nang nguon lei to Ian voi san
hrong khai thac thuy san 2000 - 2500

- La co

sa hau

can nghe ca khoi

- Mat nuoc nuoi trong thuy san ruroc Iq
- Co tiem nang bao ton dat ngap noc lagun
ven bo co tam quan trong quoc te
- Co tiern nang phat trien du lich sinh thai

tan/nam, do la chua ke rang cau. co
mroc
Kieu MTDC
dong bang yen

Duy trl tiern nang cac he sinh thai
dong bang. dac bier trang do la dong

bien

bang cat yen bien

- Cung cap noi sinh cir va cac dieu kien sinh
cu cua cong dong lien quan rei 5 huyen:
Phong Dietl. Quang Dien, Huang Tra, Phu
Yang va Phu Loc
- Cung cap dat nong nghiep chu yeu cua
tinh
- Cung cap mat bang, giao 1¢ chu yeu giua
cac tinh yen bien mien Trung

III

Tuyin

tij,p Tdi nguyen va M 6i t.ruong bien. Tij,p IX

Bdng zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
3. Tal bien lien quan totmoi truong dia chat khu vue dam pha Tam Giang -

Cau Hai
>,

Cae kieu MTDC ponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Tai bien
khu V\IC
Kieu MTDC con dun
va bai bien

- X6i 10 bo bien. Bo bien 6n dinh nrong doi Trang nhieu narn nay boi can bang boi
tu - x6i 16 theo mua thay the nhau nhung xoi 16 dot bien nr nam 1999. Do thay d6i
hinh thai dong I\ICvung cira Thuan An Trang thai gian 11/1999 - 11/200 L be cat
lang Thai Duong (Hai Duong) bi x6i 10 lui toi 37m gay sap d6 hai dang va cong
Trinh phu can, xoi 16 day lui blii Thuan An toi tren 40m gay sap d6 nha nghi ca cu
va moi xay. Dien bien x6i 16 van can phirc tap. Xoi 10 lien tuc gay bien dang hlnh
thai dong hrc va cau tnic de cat nam giiia cira Tir Hien va Hai Binh
- Cat bay. Hien nrong cat bay thirong xuyen xay ra tren ca he thong con - dun,
dac bier dean tir Dien Loc toi Hai Duong, Ill' Phu Dien toi Vinh Hien gay bien
dang be mat, con cat di dong, vui HIpcay coi, boi Ian khu dan ctr

v« rnua rmra. cat chay

- Cat chay.

dan

CLT

xay ra hau khap h¢ thong con cat. boi. Ian khu

va da"tcanh tac tren them lagun do chay tran, boi lap ven dam pha do dong

chay tam thai. Dang tai bien nay gay anh huang Ian toi dieu kien sinh cir cua
cong dong vung cat
Kieu MTDC lagun

- Lfi va ngap lut. Do hinh the thai tiet cue doan gay mira Ian keo dai tren dien
rong, de sinh 1i1.ket hop voi trang thai thu hep mat cat u61 qua cira dam pha Trang

ven bo

mua kho, ngap lut de xay fa, gay hau qua true tiep va gian tiep toi kinh te - xli hoi
khu

VUC,

trong do c6 kinh te rhuy san

- Khong 6n dinh cira dam pha. Do ket hop dong luc san bang 00 cua bien xay ra
manh me ve mua kho va dong luc song manh ve rnua 1i1,cira dam pha khong 6n
dinh vi trf, hlnh thai va trang thai ton tai. Cira Tu Hien co xu the bien d6i chu ky
ngan voi hien nrong lap, me, thay d6i vi trf gifra Vinh Hien va Hai Blnh. Cira
Thuan An co xu the bien dong chu ky dai voi hien urong dich chuyen ve phfa tay
bac. Hau qua cua khong 6n dinh cira rat nang ne, gan day nhat phai ke toi sir kien

Hip cira Tu Hien vao thang 12/1994, su kien mo cira Tu Hien, mo cira Hoa Duan
lap lai vi trf lich sir dau tien nam 1404 va vao thang 11/1999
Kieu MTDC dong

- Lli va ngap lut ve mua mua

bang ven bien

- Sinh han va xam nhap man ve mua kho. Daria hai dang tai bien ph6 bien thee
mua, gay hau qua kinh te - xli hoi nang ne, dac bier doi voi cat dieu kien sinh CLT
cua cong dong ven bien mien Trung n6i chung

~

A?

",,,'"

4. TAC DQNG
KHU

vtrc

Thong

CUA CON NGUOI

,,'

TOI MOl TRUONG

DAM PHA

qua cac hanh

dong phat

tri~n cua minh

duoi ba't cu hinh

can nguoi cung tac dorig tdi MTDC khu vue, noi can nguoi
gian, sinh song nho vao khai

thac cac dang tai nguyen

dang

MTDC.

qua che dQ dia dong luc, MTDC tac dong trd lai tdi can nguoi,
112

D~A CHAT

thuc nao,

chiern cu khong

Nguoc lai, thong

noi sinh cu va cac


T uyln

dieu kien sinh

cu dudi dang

va M 6i truang bien. T gp zyxwvutsrqpo
IX

tai bien. Du tn;te tiep hay gian tiep, can nguoi tac

dong tdi MTDC 113. tac dQng tdicac
nguyen

tgp T ai nguyen

don vi cau true,

che' dQ dong luc, co cau tai

yeu to' dQng luc MTDC sinh tai bien. Dudi day
va tharn chi kieh thich cacponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

113. cac hanh

dong chuyeu

cua conriguoi

tac dQhg tdi MTDC

khu v'1e d~m pha

TG - CH.
4.1. Khai

thac

Iiru vue

M9i hanh
dong luc nhan

dQng phat

tri~n kinhte'

- xii hQi di~n ra tren luu vue deu 113. yeu to'

sinh tac dong true tiep tdi MTDC khu vue d~m pha hay gian tiep

tdi MTDC d~m pha dudi dang khai
tac dong tdi MTDC thong

thac

sli dung da't va nude. Ca hai dang nay

qua su thay d6i dQng thai nude mat d~m. Du r&ng nude

khi quy~n rei trong khu vue khong 6n dinh theo thoi gian

va

theo khong

nhan

gian, tham

chi Ia cue dean,

do chu yeu 113. su bien d6i khi hau, nhung
ye'u do can nguoi.
tinh

trang

chung

Khai

thac

do nhieu

nguyen

lam giarn kha

d tf(t ca cac ti~u luu vue dong Truong

BQ, lam giam chirc nang

ngarn,

d§.n den tinh

trang

b6 khong deu

khac

nhau

trong

su thay d6i dQng thai nude mat d~m chu

rung 'd~u nguon

Trung

phan

nang

sinh

Son khong

rieng

dieu tiet dong chay mat va ha thap

nhu v§.n thuong

thuy

xay ra: dong chay mat

113.

dBi'ic

guong nude
mua ki~t trd

ne.i qua kiet va gia tang xarn nhap man theo song, gia tang ldp dong chay mat va
h~ so' t~p trung

nude ye mua mua, d~ sinh hi vangap

lut, gia tang kha nang xarn

thuc - boc mon va ri1a. troi be mat. Hien nay, nhimg n6 luc to IOn baa v~ va phuc

h6i tu nhien

rung dau nguon nharn khoi phuc lai cac chuc nang t1;lnhien von quy

cua no chua

dap ung' nhu

phu xanh

da't trong,

nang

sinh

thuy

truct

ld hau

nhu

cauthuc

te trong

khi ph at tri~n

d6i troc va eung cap nguyen

va giu vo phong
ch ixay

hoa; trong

ra d vung co rung

tran

rung

trong

lieu. Loai rung
lii thang

tr6ng,

loai-rirng

chu yeu

nay it co kha

11/1999,

lu bun da,

khong

co cau true

nhieu tang.
Nham
hien eo tren

dap ung nhucau
10 h6 ehua

nude, chu yeu 113. nude nong nghiep,

IOn nho vdi nang

dang co nang luc bioi 50ha trd len, 56 tram
cho g:in 10000 ha (chua
thay

d6i can bangrnrdc

k~ h6 Trudi).

luc thifit ke tudi 100ha

trong

trd len, 6 d~p

born tudi, tieu, du nang

d muc dQdo,

luu vtJ.c

cac cong trinh

luc tudi tieu
nay cimgdu

cac song co cua dieu tiet dftn den can kiet nhanh

nguon

nude, ha thap muc nude cac song va xam nhap man sau theo song trong khi vai tro
dieu tiet dong chay (dong chay lu, dong chay kiet) chua. phat huy hieu qua eao (Ha
Hoc Kanh , 1996 [14]). La san pharn cua tuong tac luc dia - bi~n, h~ d~m pha TG CH khong tranh

khoi nhimg thay d6i ve ehe d9 dQng luc, gia tang dang k~ su anh

hudng cua bi~n vemua

kho, thu hep mat clit udt qua clia d~m pha do dQng luc bi~n

san bang bo. Do can.bang

nude thay d6i, can h&ng b6i tich va dinh dudng cung thay

d6i, se tac dQng lau dai toi qua trinh phat tri~n h~ d~m.pha

TG - CH.

113
,
, I

.


T uyin

tijp Tiii. ng uyen. va M 6i t.ruang biin.

T tip IX zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPON

4.2. Chiem ell khong gian moi truong dja chat khu vt:!cdiim pha
Can nguoi chiern cu khcng

gian MTDC d~ tien hanh

minh la tat yeu qua cac the h~ n6i tiep nhau
hop vdi.quy luat phat
giam d9 nhay

nhung

cac hoat d9ng s6ng cua

van d~ Ia d ch6 sao cho phu

tri~n dia chat, it ra la cac qua trinh

earn tai bien toi muc thap nhat,

chat cua tai bien chi don gian la hien

tuong

dia chat ngoai sinh, d~

tuc la thiet
bat thuong

hai thap

nhat.

gay thiet

Ban

hai cho can

nguoi vuot qua h~ thong tri thuc, kha nang du baa va nang luc ung xi'i cua ho.
Hinh thai phan

b6 dan cu chiern cu khong gian MTDC khu vue hien nay la

ket qua cua ba yeu to':
- Sire hut do thi huang

v~ co' do Hue va cac ti~u do thi.

- Suc hut giao luu luc 19.
- Sue hut giao luu thuy

19 va van h6a lang nghe (trong

nay, tac gia xin dung laioyeu
Tu lau,

to' thu ba).

dan cu d6ng bang

thong' song d6 vao d~m pha
H uong, song Dai Giang,

TG - CH, dac biet

doc theo thung

6

Ia song

Lau,

phan b6 tap trung

cac bai b6i ven song, bai b6i chau

hoa khi hau

C\lC

earn lu va ngap lut hang nam. HQ t~p trung

b9 d vung khac nghiet,

ma vo tinh bo qua quy luat phat

song B6; song

tien loi nhieu

mat,

th6 lagun

thoi theo mua, nhieu

t~p quan

d~n den con qua it co h9i thoat

lang nghe

tri~n dia chat cua song va d~m pha, b6 qua cac

d6i nhung

corig trinh,

va bai

d day vi su di~u

yeu to' d9ng luc sinh tai bien. C6 th~ coi h~ thong de hien nay la ranh
vanh dai an toan tuong

cac h~

mat nude.ponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFE
0 nhieu noi trong so' d6, dan cu

cu tren

b6i lagun von nhay

lung

va ven bo d~m pha vdi cac ki~u quan cu

rat da dang, k~ ca ki~u quan
ngay tren

kh6 bai viet

.

ph an b6 t~p trung

va song Truci,

khuon

thay vi chiern cu vung trong

co Sd san xuat c6dinh

gidi xac l~p

d~ si'i dung tarn

va nha d lai dat tren do,

khoi anh huong cua lu va ngap lut va tai bien da

tung xay tdi.
Tinh trang

tuong

tu ciing xay ra d vung cua d~m pha nhung

con phuc tap

hen. Hinh thai cua d~m pha, ea hinh thai cau true va hinh thai d9ng luc, d~ thay
d6i bdi ea dong luc song va dong luc bi~n san bang bo. Cac dang tich tu lien quan

tdi cau true vung

cua d~m pha it ra la khong

khong gian si'i dung

dat c6dinh.

Trang

c6 ti~n d~ dia chat

lich si'i phat

tri~n

cua minh,

d~ chiern cu
cua Thuan

An bien d9ng chu ky dai. Sau l~n md cua d~u tien vao narn 1404 tai Hoa Duan, vi
tri cua nay da tai l~p lai khong

it hon hai l~n vao khoang

narn 1999, va toan b9 vung cua Thuan
cira dan v~ phia

An d~y bien dong, trong

tay bac tU vi tri Thai Duong HI;l trong

1904). Tren co sd cac dac di~m hinh

1498 - 1504 va
d6 c6 co che dich

suot the ky qua (tu narn

thai dong' luc bo khao sat duoc trong

narn 1993 - 1996 va dien bien lich si'i, vi trf Hoa Duan

114

nam

nhfmg

da timg duoc canh

baa


Tuyin

tijp Tat nguyen. va M 6i trudng

biirii, Tij.,pIX, zyxwvutsrqp

xung yeu va canh bao l~n dau tien trong khuon kh6 d~ tai d(k lap cap nha nude
DKTL - 95 - 09 [14]. Khong chi r ieng trong su kien md cua Hoa Duan vao thang
11/1999, ca trong lich sli bien dong vung clia Thuan An, nhung thiet 'hai true

tiep, gian tiep d mire d9 khac nhau hiin da tung xay ra.ponmlkjihgfedcbaZYXWVUTSRQPONML

o

ven bo darn pha, khong gian MTDC bi chiern cu chu yeu nharn phat tri~n

nong nghiep, thuy san va md rorig di~m dan cu. Hanh dong nay tac d(5ng true
tiep vao moi tru9~g lang' dong trarn tich bai b6i ven bo va bai b6i chau th5lagun,
lam giarn dien tic'h mat nude va sue chua thuy vue va giarn chuc nang dieu hca
lii. Nhanh song La

Y, song Phe' L<;Ii(Phu Thanh) va nhanh song Tan Myytirng' la

cac chi luu quan trong trong c~u true thuy van vung cua song Huong, da bi chan
dllp, gay thieu hut b6i tich mot vung narn giira Phu Thanh, Phu Duong, Phu Tan
va darn Thanh'Lam, kern theo su t~p trung b6i tich phat tri~n bai b6i nhanh v~
phia Thuan An va gia tang su phat tri~n phan di gifia pha Tam Giang va d~m
Thuy Tu ..
4.3. Xay dungedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
c d sd ha tftng tb.uy 19i ven bo dftrn pha
Nharn dap ung nhu c~u phat tri~n kinh te - xa h9i khu vue d~m pha
TG - CH, mot co sd ha t~ng thuy loi nhieu hang muc cong trinh da duoc xay dung
c6 lien quan tdi t~t ca cac don vi cau true MTDC d~m pha. Ngay tU nam1931,
d~p Thuan An dai 1900m da duoc xay dung nharn giu ngot va ngan man. Trong
khi chua

k ip

phat huy hieu qua, dap Thuan An lai trd thanh vat can lii va da c6

bon l~n pha dd ha thap cao d9 cong trinh tU 2,0 m tdi O,Om vao cac narn 1932,
1934, 1942 va 1953 tren t6ng chieu dai 1050m. Sau tran Iii ngay 22/9/1953 va
tran lii narn 1954, dap Thuan An xem nhu bi vd [23], nay con s6t lai dean noi bo
Thai Duong Dong. Sau nay, dap c6 chuc nang tuong tu duoc xay dung tai Thao
Long chan cua song Huong, cac dap khr c t:•....Ic xay dung tai vung cua song Tru6i
(dap Cong Quan) va vung cua song

6

Lau (dap Cua Lac). Ngoai h~ thong kenh

muong, cong, hien c6 tdi 162km de bao ven bo d~m pha va mot cau be tong IOn c~u Thuan

An noi li~n bo trudc va bd sau d~m pha. Trong tran

bao thang

12/1994, cua 'I'u Hi~n (tai Vinh Hi~n) bi t~i lap, ngay sau do da duoc gia co-b~ng
da granit. Tran Iii thang 11/1999, cua Hos Duan md lai theo cd che' buc xung, r6i
mot nam sau d6 da dU<;IC
han kh:lu cudng b.tc bang cong trinh cirng.
T~t ca cac cong trinh duoc xay dung nharn bao v~ noi sinh cu va cac di~u
kien sinh cu cua cong d6ng ven bo darn ph a nhung d6ng thoi can thiep true tiep
vao cau true va d9ng luc MTDC khu vue d~m pha, tac d9ng vao qua trinh phat
tri~n lagun ven bo von bien d9ng phuc tap va cang phuc tap hon. Cac dap ngan

man, giu ngot, h~ thong de bao ngan lu I-.i~uman bao v~ 2 vu dong xuan va he
thu nhung d6ng thoi cung trd thanh vat .~an Iii, gay ngap lut mot vung chirng
4000ha trong mua Iii chinh vu. La san pharn tuong tac luc dia - bien, d~m pha
115


Tuyin

tij,p Tat ngu,yen va M 6i truang

bien. Tij,p IX zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM

TG - CH ra doi va tra thanh b6n hQi luu cua hau het cacsong cua tinh Thua
Thien - Hue, noi phan anh su anh huong cua bien gia tang ve mua kh6 va cua luc
dia gia tang ve mua mila, d~n den cua d~m pha luon bien dong cau true hinh
thai theo rnua, thay d6i vi trf va dong, md theo chu ky nhieu nam. Lap cua 'I'u
Hien g~n day nhat VaGthang 12/1994 la ket qua cua qua trinh dQng luc san bangedcbaZYXWVU
'b d trong mot chu ponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
ky nhieu narn, t~a lai vi tri cua Hai Binh cho d~m c~u Hai, mot
cua nho d sat mui Chari May tay. Trong lich sir, su chuyen d6i vi tri clia gifia
Vinh Hien va Hai Binh, hoac cung t6n tai trang thai dong, md dii tung xay ra.
Nhung trong tran lfi IOn thang 1111999', chinh su gia c6 tuong d6i vimg chac cira
Tu Hien sau khi bi la'p va su hien dien phan s6t lai cua d~p Thuan An narn xua
dii trd thanh mQt trong nhimg nguyen nhan lap lai vi tri Iich sli cua Hoa Duan
bdi dong lu luon tim duong thoat ngan nhat b noi xung yeu nhat [20]. Duong
nhien trong tran Hi nay, cua Tu Hien d Vinh Hien md lai, la'p cua Hai Binh, lam
thay d6i co ban cau true hinh thai delta trieu len d cua Tu Hien khi mot luong
cat d6 sQ tran vao, d6ng thoi cung gay bien dang dang k~ cau true delta trieu
xuong d cua Thuan An, ach tllc giao thong thuy, va cang Tan My hie do hau nhu
khong c6 tau ra vao.

4 A . Khai thac titi nguyen dihn pha

Tai nguyen d~m pha rAt da dang, duoc khai thac tU lau dudi nhieu hinh
thuc khac nhau va tac dQng tdi MTDC diim pha a rmrc dQ khac nhau, trong d6
rmrc dQ dang k~ can de cap tdi la thay d6i co che hoan luu 11Qitai va giam kha
nang thoat hi. Hai tac dQng dang k~ nay deu bllt nguon tu khai thac tiem nang
nuoi trong va danh bat thuy san tt! nhien trongdampha.
Tinh tdi narn 1995 [11],
c6 tdi 4694 thuyen khai thac vdi hang ngan ngu cu nhieu chung loai, dang luu y
trong d6 c6 1674 trQ sao, 1958 mieng day, 805 chuom va 202 mieng roo Cac ngu
cu nay la vat can quan trong lam anh huong cd che hoan Iuu b6i tich theo phuong
nam ngang, trao d6i nude va dinh dudng theo ca phucng tharig dung va nam
ngang, gia tang tinh chat kin C\lC bQ trong qua trinh phat tri~n d~m pha. 6 ven
bo d~m pha, 1530ha d~m nuoi thuy san (tinh tdi nam 1997) cung g6p phan quan
trong thu hep dien tich va sue chua thuy vue, thu hep moi truong lang dong tdm
ti~h, tang cuong b6i la'p nen day d~m pha, giam chuc nang dieu hoa III va 6n dinh
guong nude ngarn khu vue.
Tren day la bon hanh d'Qng tieu bi~u trong s6 nhieu hanhdong phat tri~n
khac nhau cua con nguoi tac dong tdi MTDC khu vue diim pha. Tuy nhien, cac
tac dQng tU hoat dQng nay khong tach roi va thuong t6 hop vdi nhau hoac d~n
suat tac dQng tdi qua trinh phat tri~n dia chat lagun ven be. Trong nhieu truong
hop thong qua hanh dQng phat tri~n kinh te - xii hQi cua minh, tac dQng cua con
'
nguoi trd thanh yeu t6 ktch thich tai bien MTDC.

116


T uyln

tijp T ai nguyen. va edcbaZYXWVUTSRQPONMLKJIHGF
M 6 i t . r u a n g b ie n . T ijp IX zyxwvutsrqp

5.KETLU~
ã

a

H~ dĐ.m pha TG - CH, ki~u MTDC lagun venponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGF
bo
mien -Trung Vi~t Nam di~n
hinh v~ cau true, dong' luc hinh thanh,
dung nguon tai nguyen

phat tri~n va tien h6a phuc tap, chua

to IOn va giau tiern nang phat tri~n, va di~n hinh v~

tai bien dia chit vung bo bien.
•

Tac dQng cua con nguoi, thong qua hanh dQngphat tri~n kinh te' - xii hQi cua
minh, tdi khu vue d§.m pha 1'G - CH du true tiep hay gian tiep la tac dQng
vao cau true va che' dQ dQng luc MTDC, can thiep vao su phat tri~n tv nhien
cua mot lagun ven bo dang phat tri~n phan di

a

giai dean truong thanh

van

bien dong phuc tap, lam cho bien dQng phuc tap hen, dac biet doi vdi vung

cua Thuan An va Tu Hien. Nguoc lai, thong qua che' dQ dQng luc MTDC sinh
tai bien, nhirng bien dong nay tac dQng tdi con nguoi, gay hau qua kinh te' xa hQi

a muc

dQ khac nhau.

TAl Ll¢U THAM KHAo
1.

Brovko,

P.F., 1990.

Su phat tri~n lagun ven bo. NXB Dai h9C T6ng hop Vi~n Dong, 147 tr. (tieng
Nga) ..
2.

-Coates, D.R., 1977.
Environmental

3.

Geology. John Wiley and Sons. 701p.

Nguy~n Hfru Cli, 1995.

\

H~ thong d§.m pha ven bCimien Trung Vi~t Nam. Cac cong trinh nghien cuu
Dia chit va Dia vat ly bi~n, NXB Khoa h9C va Ky thuat, Ha NQi, tr. 113 - 120.
4.

Nguy~n Huu Cli, 1996.
Di~u kien dQng luc hinh thanh va phat tri~n h~ d§.m pha Tam Giang - C§.u
Hai. Cac cong trinh nghien cuu Dia chit va Dia vat ly bi~n, NXB Khoa h9C va
Ky thuat, Ha NQi, tr. 234 - 240.

5.

Nguyer; Huu Cli, 1996.
D$.c di~m dia chit h~ d§.m pha Tam Giang - Cau Hai trong Holoxen va phuc
h~ Trung 16 chua trong chung. Luan an ph6 tien sy dia chit h9C. .

117


su«

Tuye"n tiJ,p Tai nguyen. va M 6i tr edcbaZYXWVUTSRQPONMLKJIHGFEDCBA
u im g
TiJ,p IX zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK

6.

Nguyen Hiru Cli, 1999.

T6ng quan tinh hinh nghien cuu tai nguyen va moi truong d~m pha ven bo
mien Trung Vi~t am. 'I'ai nguyen va Moi. trucng bi~n, T~p VI, NXB ponmlkjihgfedcbaZ
Khoa
h9Cva Ky thuat, Ha Qi, tr. 126 - 142.
7.

Nguyen Hiru Cd, 2000.
Dia chat moi trucng trong danh gia tac dQng moi truong. Tai nguyen va Moi
truong bien, Tap VI, NXB .Khoa h9C va Ky thuat, Ha: NQi~;tr. 143 - 151.

8.

Ng~y~n Hiru Cli, 2001.

-r

Dinh huang chien luoc ki~m scat hi mien Trung Viet Nam. Tai nguyen va Moi
truong bi~n"T~p VII, NXB Khoa h9C va Ky thuat, Ha N{h, tr. 289 - 302.
9.

Nguyan Huu Cd, 2001.
Overview of Coastal Hazards in Vietnam. Marine Science and Technology, 6th
Asean Science and Technology Week, Conference Document, p.93. Bandar
Seri Begawan, Brunei Darussalam.

10. Nguyen Huu

co

va Nguye n

vo

Tua'n, 2001.

Tac dong cua con nguoi toi moi trucng dia chat vung bo chau th6 song Hong.
Tai nguyen va Moi truong bi~n, T~p VIII, NXB Khoa h9C va Ky thuat, Ha
NQi, tr. 43 - 53.
11. Nguven Luong Hi~n, 1997.
Hien trang va dinh huang phat tri~n nghe ca pha Tam ..G iang trong moi quan
h~ vdi nghf ca bi~n 'I'hua Thien - Hue. 'I'ai nguyen va Moi tr uong bien, T~p
IV, NXB Khoa h9C va Ky thuat, Ha NQi, tr. 338 - 350.
,F"

12. Nguyen Dinh Hoe, Tr~n Dinh Lan va Nguy~n Hiru Cli, 1995.
MQt so dac di~m dia dong luc noi sinh hien dai va tac dQng cua chung doi vdi
h~ d~m pha Tam Giang - C~u Hai. Ky ye~ HQi thao khoa h9C ve d~m pha
Thira Thien - Hue, Hai Phong, 1111994, tr.i If - 23.
13. Nguye n Chu Hc3i,Tr~n Due Th~nh va nnk, 1995.
Nghien cuu stt dung hop ly mot so h~ sinh thai tieu bi~u d vung bi~n 'ven bo
Vi~t Nam, m a so KT - 03 - 11, phan h~ sinh thai d~m pha ven bd mien Trung.
Luu trft d Phan vien Hai duong h9C tai H3.i Phong.
14. Nguyen Chu Hc3i,Tr~n Due Th~nh va nnk, 1996.
Nghien cuu khai thac stt dung hop ly tiem nang pha Tam Giang. De tai dQC
lap cap Nha nude, ma so KTDL 95 - 09. Luu trft d Phan vien Hai duong h9C
tai Hai Phong.
118

•

T uyln

t~ p T ai ·nguyen va M 6i t edcbaZYXWVUTSRQPONMLK
r u a n g bien. T ~ p IX zyxwvutsrqpo

15. Tran Due Th~nh, 1997.

a

Tac dQng moi truong cua viec lap cira, chuyen cua
he dfim pha Tam Giang Cau Hai. Tai nguyen va Moi truong bi~n, T~p IV, NXB Khoa h9C va Kg thuat,
Ha NQi, tr. 185 - 196.
16. Tran Due Th~nh, Nguy~n Chu H6i, Nguy~n Hfiu Cli, Tran Dinh Lan
. va nnk, 1998.
Danh gia tiern wing va de xuat lua chon khu baa v~dit ngap nude h~ dfim
pha Tam Giang - Cfiu Hai. De tai cap tinh Thua Thien - Hue'. Luu tri1 Phari
vien Hai duong h9C tai Hai Phong.

a

17. Tran Due Tb anh, Tran Dinh Lan, Nguyen Hfiu Cli va nnk, 1998.

a

Nguyen nhan b6i lip cua Tu Hien
h~ dfim pha Tam Giang - Cau Hai. 'I'ai
nguyen va Moi truong bien, T~p V, NXB Khoa h9C va Kg thuat, Ha NQi,
tr. 28 - 43.
18. Tran Due Th~nh, Nguyen Chu H6i, DB Nam, Nguyen Mien, Nguy~n

Hfiu Cli va nnk, 1998.
Dinh huang quan ly tai nguyen va moi trucng h~ dfim pha Tam Giang - cfiu
Hai. Tai nguyen va Moi truong bien, -T~p V, NXB Khoa h9C va Kg thuat, Ha
NQi, tr. 65 - 76.
19. Tran Due Th~nh, 1999.
MQt so va'n'·.de co ban ve dia moi truong bo Vi~t Nam. Tai nguyen
truong bi~n, T~p VI, NXB Khoa h9C va Kg thuat, Ha NQi, tr. 87 - 97.

va Moi

20. Tran Dite Th~nh, Nguy~n Chu H6i va Nguy~n Hfiu Cli, 2000.

Bie'n dong cira dfim pha Tam Giang - Cfiu Hai va hau qua moi truong, sinh
(sa Khoa h9C, Cong nghe va Moi
thai. Thong tin Khoa h9C va Cong ngheponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
truong tinh Thira Thien - Hue), SO'2 (28), tr. 31 - 43.
21. Tr~n Due Thanh, Nguyen Hfiu Cli, Nguy~n Chu H6i va Nguy~n Van
Tie'n,2002. (

H~ d~ni pha Tam Giang - Cfiu Hai: Gia trj tai nguyen va vin de bien dQng
clia. Nghien ciru Hue' (Trung tam Nghien cuu Hue), T~p 3, tr. 124 - 167.
22. Nguyen Quang Trung Tie'n, 1998.
Bie'n dQl1g dia Iy clia Thuan An va du an d~p song Huong trirdc narn 1975.
Thong tin Khoa h9C va Cong nghe (Sb Khoa hoc, Cong nghe va Moi truong
tinh 'I'hua Thien - Hue), sO'2 (20), tr. 73 - 79.
23.

Ngo Dinh Tuan, 1995.
MQt s6vin de cfin xem xet trong bai toan sli dung khai thac hop ly pha Tam
Giang - cfiu Hai. Ky ye'u HQi thao khoa h9C ve dfim pha Thira Thien - Hue',

Hai Phong, 1111994, tr. 81 - 84.

119


/

kjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
T uyin

tijp T ai ng uyen. va M 6i t.ruang bien. T ijp IX

SUMMARYzyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJ
IMPACTS OF HUMAN ACTIVITIES

ON THE GEOLOGICAL

ENVIRONMENT

OF THE TAMGIANG - CAUHAI COASTAL LAGOON
N guyen
N guyen

H uu C u, T ran D ue T hanh,

V u T uan, N guyen

T hi K im A nh

The Tamgiang - Cauhai coastal lagoon is large in size and characteristic

horizontal

structure

of a coastal

lagoon

geological

environmental

of the

type with four

subtypes. The subtype of lagoonal inlets with a role of connec.ting with the sea is
composed of channels and a seasonally changeable ebb tidal delta in the Thuanan
inlet and a flood tidal delta in the Tuhien inlet, to which coastal hazards in from of
replacing, closing and opening often occur. The subtype of lagoonal terraces, a part
of which is inundated in rainy season and the other has been impounded for farming,
and narrow tidal flats along the lagoonal shore. The subtype
called locally Tamgiang,

of lagoonal

basins

Damsam - Antruyen, Thuytu and Cauhai (southward) with a

total of 216 sq.km in area is characteristic

of the accumulation

of lacustrine fine -

grained sediments with a high wetness and organic metter quantity. The last subtype
of lagoonal deltas of the Olau, Huong and Truoi - Daigiang rivers is composed
river mouths with crossing

diverson

dams, dammed

tributaries

and alluvia

of

being

used for agriculture, and even populated.
Human activities affecting the lagoon are in 4 major forms of the exploitation of
catchment areas, multi - use occupation

of geological

environments,

infrastructure

development for land and water use and the exploitation of lagoonal living resources.
Their impacts, though direct or indirect, on the lagoonal geological
to deform its structure,

to change the dynamics of geological

environment

development,

are

natural

resource potentials and, in a way, to intensify the coastal hazard sensitivity due to
the unbalance

of water and reduction

lagoonal inner circulation

of water,

in water exchange

materials

with the sea, deterring

and nutrients,

decrease

reservoir and its role of harmonizing floods, groundwater table, etc.

120

in laqoonal