Sự hình thành các nguồn nước và một số giải pháp bảo vệ môi trường nước khu vực thành phố hồ chí minh

ngubn nuTdc cung cap chinh cho sinh boat va san xua't cua TP.Hb Chi Minh Id nu'dc song Dbng Nai.. lifu hrdng vd do man du'dc tie'n hanh tai mdl so'Uam Uen sdng Idn, mdi ndm vdi thdng, mo

Myc LVC

CHLfdNG 1: LICH SLf VA PHLfdNG PHAP NGHIEN Cl?U CAC NGUON

1.1 LICH SLf NGHIEN CLfU 4

C H U C J N G 2: SI/ H I N H THANH CAC NGUON NL/(3c KHU Vl/C TP HO

CHf MINH VA DAC DIEM CUA CHUNG 14

2.1 CAC NGUON NlJ(3c KHU VUC TP.HO CHI MINH 14

2.1.1 Ngubn nu'dc den liif he Iho'ng song Dong Nai 14

2.1.2 Ngubn nu'dc bien 25

2.1.3 Ngubn nu'dc ngam 30

2.2. N H O N G N H A N TO ANH HUCJNG DEN SU H I N H THANH 33

2.3.4 Thanh phan ion chhih ciia nirdc mat 47

2.3.5 Phan bo' cac loai dong vat thuy sinh 48

CHl/aNG 3: O NHIEM MOI TRacJNG NlJCfC MAT TP.HO C H I MINH 52

3.1 CAC LOAI 6 NHIEM VA MLfC DO 6 NHIEM 52

3.1.1.6 nhi6mhiTucd 54

3.1.2 6 nhiem do vi sinh 57

3.1.3 6 nhi6m do chat ran Id lung 59

3.1.4 O nhi6m do cac chaft dinh du'dng cho thuy suMi vat 61

3.1.5 O nhiem do hoa chat bao vc thi/c vat 64

3.1.6 O nhiem do kim loai nang 65

3.1.7 6 nhiem dau 67

3.2 NGUON GAY 6 NHIEM MOI TRl/CfNG Nl/CfC 70

3.2.1 Nirdc thai CN & TTCN, sinh boat v^ dich vu 71

3.2.2 Ngubn chat thai sinh boat 77

3.2.3 Cdc bai dd rdc cua Th^nb pbd 78

3.3 NGUYEN NHAN GAY 6 NHIEM MOI TRLfCJNG NLf(3C 80

3.3.1 Nguyen nhan khdch quan gay 6 nhilm moi IruTdng nu'dc 80

3.3.2 Nguyen nhan chu quan gay 6 nhiSm moi tru'dng nu'dc 81

3.4 PHAN VUNG 6 NHIEM MOI TRLfCfNG Nl/CfC , 87

3.5.1 Tac dong cua nu'dc tbSi CN & TTCN, sinh boat va dich vu 91

3.5.2 Tac dong cua nu'dc hi 6 nhiSm dau 94

3.6 ANH HLfdNG CUA NGUON Nl/CfC 6 NHIEM DEN CLf DAN 98

3.7 ANH HLfCJNG N\J6c MAT BI 6 NHIEM DEN NUCfC NGAM 100

CHLfdNG 4: M O T SO GIAI PHAP GIAM NHE 6 NHIEM VA BAO VE

4.1.1 O nhi6m bu'u cd ng^y c^ng n^ng do tiing chat thdi sinh boat 102

4.1.2 O nhilm nu'dc ng^y ckng gia t3ng do tSng chat thai cong ngbiep 105

4.1.3 Thu hep dien tich be mSt cac thuy vi/c & bie'n ddi dong chay mat 107

4.1.4 Gia tang khai thdc cdc ngubn nuTdc cho cap nufdc dan sinh 107

4.1.5 Mi/c nu'dc bien gia ting va man xam nhap sau vao noi dia 108

4.2 M O T SO GIAI PHAP GIAM NHE 6 NHIEM VA BAO VE MTN 109

4.2.1 Dinh hu'dng khai thdc hdp 15^ cdc vDng nu'dc TP.Hb Chi Minh 109

4.2.2 Phan loai cdc giai phdp giam nhe o nbiSm moi tiiTdng nu'dc 115

4.2.3 Giai phdp ky thuat 115

4.2.4 Giai phdp kinb te 121

4.2.5 Giai pbap xa hoi 126

4.2.6 Cac giai phap khac 130

KET LUAN 138 TAI LIEU THAM KHAO 141

PHU LUC 157

BANG C H O VIET T X T TRONG LUAN AN

chat lu'dng nUdc cong ngbiep & tieu thii cong ngbiep cong ngbiep hda

Chemical Oxygen Demand-Nbu cau 6 x y boa hoc Disolved Oxygen -Lu'dng 6 xy boa tan

ddnb gid tdc dong moi tru'dng

do thi bod gidi ban cho ph^p long s^t

khu cong nghiep mufc nu'dc

H b C h l M i n h Thuy ngan kim loai nang kinb te'- xa hoi moi trifdng ni/dc tdng Nitd

Chi long Pbolpho lu'u lu'dng Solid suspended - chat r^n Id liJng

do man tiung blnh Tieu chuan Vict Nam tlianh pbo'

thuo'c truf sau van tdc

ve sinh moi tiu'dng

DANK SACH cAc B A N G TRONG LUAN A N

ChUdng 1

Bang 1.1 NhSng noi dung chinb vh pbiTdng phap nghien cu'u trong luan dn

CbiTdng 2

Bang 2.1 D^Lc tri/ng binh Ibli ciia lu\i vUc be tho'ng s6ng Dbng Nai

Bang 2.2 Dae trU*ng d5ng cb5y cua he thong s6ng Dbng Nai

Bang 2.3 Cdc hb chu'a d thUdng ngubn he thong song Dbng Nai

Bang 2.4 LUu lu'dng xa cua Tri An xudng ha du trong mila kiet

Bang 2.5 Lu'u lu'dng xa cua Tri An xuo'ng ha du tiong mOa lu

Bdng 2.6 Can bang niTdc hb Tri An cdc thdng muk kiet

BSng 2.7 Can bSng nu'dc d hb Tri An cdc thdng mua lu

Bang 2.8 Dae tru'ng lu'u li/dng v^ pbil sa ngubn niTdc song Dbng Nai

Bang 2.9 Dae diem cua thuy Uieu cua cdc cang ven bien Viet Nam

Bdng 2.10 Dae UiTng bod hoc nu'dc bien Ba Rja - Vung Tau, 7/1994

Bang 2.11 Lu'u liTdng tram Kho xdng C song Nha Be, 1987-1988

Bang 2.12 MUc nu'dc Hmax, Hmin blnh quan tram Phu An song Sii Gon

Bang 2.13 Mi/c niTdc Hmax, Hmin Uam Thu Dau Mot va Phu An

Bang 2.14 Phan bo'do mdn (S), oxy boa tan (DO) va van tdc (V)

Bang 2.15 Cdc vilng niTdc va diLrc vat cbl tbj CLN d TP.Hb Chi Mhih

Bang 2.16 Cdc vung niTdc vk lo^i torn cbl thi CLN d TP.Hb Chi Minh

Bang 2.17 He sdluTdng quan giffa cdc ion d buycn Can Gid, nam 1989

Bang 2.18 He sdliTdng quan giffa cdc ion TP.Hb Chi Minh (truf Can Gid), 1989 Bang 2.19 Hbi quy tuye'n linh da bien cua cac ion TP.Hb Chi Minh, nam 1989 Bdng 2.20 Phan bddong vat thuy sinh Uieo cdc loai iru the d TP.Hb Chi Minh Bang 2.21 Phan viing nen chat lufdng nt/dc mat khu vu*c TP.Hb Chi Minh

Chu-dng 3 Bang 3.1 6 nhiSm bu'u cd v^ SS Iren kenh Tan Hda

Bang 3.2 Ket qda do dac DO khu vi/c Nh^ Be-Binb Cbdnb ndm 1990

Bang 3.3 O nhiim vi sinh vat cdc kenh rach noi th^nh, thdng 1/1993

Bang 3.4 Hdm IiTdng vi sinh vat, tai cdc Uam gidm sdtCLN, 1-12/1995

Bdng 3.5 Ham lu'dng chat r^n Id liJng (SS) tai cdc tram gidm sdt MTN

Bang 3.6 Chat lUdng niTdc kenh Tham Lu'dng vd kenh An Ha, 8/1995

Bang 3.7 Nbng dd Thudc trir sau U:ong nUdc mdt TP Hb Chi Minh, ndm 1995

Bang 3.8 Nbng do thudc XiiS sau trong nu'dc hb Tri An, ndm 1993

Bang 3.9 So'lan vil tan suat xuat bien kim loai nang ndm 1989

Bang 3.10 Ham lufdng kim loai ndng trong nu'dc kenh Tdn Hda 1993

Bang 3.11 NbCtng su* co' trdn dau Uen song rach TP.Hb Chi Minh

Bang 3.12 Ham lu'dng dau trong nu'dc va trong dat ngay 7-8/10/1994

Bang 3.13 Ham lu'dng dau tiong ntfdc song rach, thdng 1-12/1995

Bang 3.14 He thong kenh rach thodt nu'dc noi thanh TP.Hb Chi Minh

Bang 3.15 Lu'dng niTdc thai CN&TTCN, sinh hoat.benh vien ndm 1994

Bang 3.16 Dac tru'ng tliiiy vdn cdc tuye'n lieu thoat nu'dc thai

Bang 3.17 Nbng do BOD5 tiong nuTdc thai cua mot so nha mdy CBTP

Bang 3.18 Chat lu'dng nu'dc thai cua Xi ngbiep cbe bien tliuy san VI

Bang 3.19 Chat luTdng nUdc Uiai tuf bai rdc Dong Thanh (ing/l)

Bang 3.20 NhiTng nguyen nhan gay 6 nhiem MTN d TP.Hb Chi Minh

B a n g 3 2 I Diln bien khdi liTdng rdc TP.Hb Chi Minh 1 9 8 3 - 1995

Bang 3.22 Dign bien dan so TP.Hb Chi Minh 1983-1995

Bang 3.23 He thdng thodt nu'dc do tiVi TP.Hb Chi Minh

Bang 3.24 So'phiTdng lien giao thong van tai du'dng song d TP.Hb Chi Minh Bang 3.25 Phan vilng sdluTdng dong vat thuy sinh d TP.Hb Chi Minh

Bang 3.26 Phan vdng 6 nhiem MTN mat TP.Hb Chi Minh

Bang 3.27 Anh budng cua nu'dc tliai KCN Bien Hda ddn tbiiy sinh

Bang 3.28 Hdm luTdng dau gay liJ vong 50% lu'dng dong vat Ihi ngbiem

Bdng3.29 SdngiTdi benh diTdng niTdc d TP.Hb Chi Minh

Bdng3.30 Sdngirdi benh"dirdng nirdc", tai TP.HCM 1990-1994

Bang 3.31 Ty le ngu'di benh tieu chay va sdt xuathuyetd TP.Hb Chi Minh

ChUdng 4

Bang 4.1 D\i bdo kbdi luTdng chat thai cua dan cuT TP.Hb Chi Minh, 1996-2010

Bang 4.2 Danh muc qui hoach 10 khu do thi Idn d TP.Hb Chi Minh

Bang 4.3 DiT bdo liTdng niTdc thai cQa TP.Hb Chi Minh, 1995-2010

Bang 4.4 Di/ bdo lifdng niTdc Uiai cua 12 KCN d TP.Hb Chi Minh,1996-2010 Bang 4.5 Mot so'nguyen vat lieu can thay thdde ngdn cbdn 6 nhiim MTN Bdng 4.6 M6t sd giai phdp giam nhe o nhilm vd bao ve MTN TP.Hb Chi Mini

DANH sACH cAC HINH TRONG LUAN A N

ChiTdng 2 Hinh 2 1 Mang lu'di he thdng song Dbng Nai

Hinh 2.2 Vi tii cdc tram gidm sdt chat lu'dng nu'dc vd cdc diem thu mau Hinh 2.3 Lu'u lu'dng tiung blnh ciia cdc tram Iren he thdng song Dbng Nai Hinli 2.4 Lu'u lu'dng den Tri An trUdc vd sau kbi cd hb chu'a

Hinh 2.5 Thdi gian truyen dinh Irieu vd cdc gidp niTdc d TP.HCM

ITinh 2.6 DiSn bidn vd tUdng quan mifc nu'dc, luTu lu'dng song Dbng Nai Hinh 2.7 Du'dng qua trinh mi/c nu'dc cdc tram d TP.Hb Chi Minh

Hinh 2.8 Dac UiTng mi/c nu'dc va lu'dng quan H&Q cua song Sai Gon Hinh 2.9 Ban db kbi hau luTu vu'c be thong song Dbng Nai

Hinh 2.10 Ban db phan vQng do mdn cua nu'dc mat mud kbo d TP.HCM ITinb 2.11 Ban db phan vOng do man cua nUdc mat mua miTa d TP.HCM Hinh 2.12 Bieu db do man cua cdc tram he tho'ng song Dbng Nai, 1989 Hinh 2.13 DiSn bic'n Smax doc song Vam Cd, Nba Be, Can Giuoc

ITinb 2.14 Qud tiinh do man cua mot so' tram tuT ven bien vao trong song

Hinh 2.15 Qud tiinh m\ic nuTdc va do man tram Nha Be

Hinh 2.16 Dien bien dp mdn Idn nhat cua mot sdtram IdT 1983-1990

Hinh 2.17 Dien bien Smax cua mot sdtram cdc nam 1983,1986,1990 Hinh 2.18 Tu'dng quan Smax va Qxa Tri An d buycn Can Gid

Hinh 2.19, Ban db phan vung do chua cua nuTdc mat, mua kbo d TP.HCM Hinh 2.20 Ban db phan vung do chua cua nu'dc mat, inua mu'a d TP.HCM Hinh 2.21 Dien bie'n do pH va do man tram An Ha^ rach Tra

Hinh 2.22 Dac liu'ng do pH cdc tiam d TP.HCM

Hinh 2.23 Bieu db do pH tai dinh vd chan Uieu cac tram ciia song Vam Cd Hinh 2.24 Ban db phan vQng nhom cua nu'dc mat, mua kho d TP.HCM Hinh 2.25 Bdn db phan vung nhom cila ni.'dc mdt, mua nufa d TP.HCM

Hinh 2.26 Ban db phan vDng sdt cua nUdc mdt, mud kho d TP.HCM

Hinh 2.27 Ban db phan vilng sal cua nu'dc mdl, mua mifa d TP.HCM

Hinh 2.28 Dien bie'n cdc ion d huyen Can Gid, mua kho ndm 1989

Hinh 2.29 Cau hue cdc ion trong nu'dc huyen Can-Gicf, mila kho nam 1989 Hinh 2.30 Dign bie'n cac ion d TP.HCM (UuT Can Gid), mila miTa nam 1989 Hinh 2.31 Phan b d d o n g vat noi theo cdc lodi u'u the mila kbo d TP.HCM Hinh 2.32 Phan b d d o n g vat noi theo cdc loai Uu the, mila mu'a d TP.HCM Hinh 2.33 Phan bo'dong vat day theo cdc loai u'u the', mQa mu'a d TP.HCM

Chu'dng 3 Hinh 3.1 Dien bie'n BOD, COD tram Hod An song Dbng Nai

Hinh 3.2 Diin bie'n va tiTdng quan BOD & COD tai dhih trieu, 1/1993 ffinh 3.3 Dien bie'n va tUdng quan BOD & COD ciJa xa vd kenh NLTN Hinh 3.4 Ban db phan vilng DO cua nu'dc mat, mua kho d TP.HCM

Hinh 3.5 Ban db phan vOng DO cua nu'dc mat, mua mu'a d TP.HCM Hinh 3.6 Dien bie'n va lu'dng quan Coliform & E.coli nam 1995

Hinh 3.7 Ban db phan vQng SS cua nu'dc mat, mua kbo d TP.HCM

Hinh 3.8 Ban db phan vQng SS cua nu'dc mat, mud mu'a d TP.HCM

Hinh 3.9 Tu'dng quan SS & sdt vd Nt & Pt, mila miTa ndm 1989

Hinh 3.10 Ban db phan viing Nt ciia nu'dc mat, mud kho d TP.HCM

Hinh 3.11 Ban db phan vDng Nt cua nu'dc mat, mud mu'a d TP.HCM

Hinh 3.12 Ban db phan vung Pt cua nu'dc mat, mua kho d TP.HCM

ITinh 3.13 Ban db phan viing Pt ciia nu'dc mat, hUia mu'a d TP.HCM

Hinh 3.14 D i l n bie'n SS, Nl, Pt Uam Phu An va Nha Be, 12/1994

Hinh 3.15 D i l n bie'n Nt, Pt vd tu'dng quan cua chilng tram Nha Be,1995 Hinh 3.16 Dien bie'n cdc dac tru'ng CLN kenh Tham Lu'dng va An Ha

Hinh 3.17, Dien bie'n hod chat bao ve thi/c vat tai cdc tram gidm sal CLN

m n h 3.18 Dan sd, mat do dan BOD,SS liong nude thai sinh boat TP.HCM

Hinh 3.19 Dien bie'n dan sd va khdi liTdng rdc TP.HCM luT ndm 1983-1995 Hinh 3.20 Ban db phan vQng sd luTdng dong vat noi, mua kho d TP.HCM Hinh 3.21 Ban db phan vDng sd lu'dng dong vat noi, mud mu'a d TP.HCM Hinh 3.22 Ban db phan vDng sd lu'dng dong vat ddy, mud mu'a d TP.HCM Hinh 3.23 Ban db phan vQng 6 nhiem MTN, mud kho d TP.HCM

Hinh 3.24 Ban db phan vOng 6 nhiem MTN, mud wUad TP.HCM

Hinh 3.25 Ty le ngu'di benh tieu chdy vd sdt xua't buye't d TP.HCM

Chu'dng 4 Hinh 4 1 Dien bie'n H, BOD, SS Uong nifdc rach NLTN nam 1969

Hinh 4.2 Phan bd cdc cd sd cong ngbiep chu ye'u Dia ban KTTD PN

Hinh 4,3 Hien Irang vd dU kie'n hb chu'a tren be thdng song Dbng Nai

M d D A U

TP.Hb Chi Minh cd vj tri dia ly 10^38' de'n 1 TlO' vl do Bac vd 106*^22' den 106°55' kinb do Dong, nam Uong dai chuyen tie'p giffa vilng nang len ciia Dong Nam Bo va vQng tiung tha'p cua Tay Nam Bo

TP.Hb Chi Minh la mot trong nhifng trung lam Idn ve vdn boa, chinh Uj, khoa hoc ky thuat, kinb te' vd tbu'dng mai cua Viet Nam Thanh pho' cd dien tich 2056km^ dan s6'4,7uieu nguTdi, 12 quan noi Ihdnh va 6 huyen ngoai thanh,

mat do dan c\X cao nhat d quan 5 len de'n 62.100 ngUdi/km^ va Ihap nhat d

huyen Can Gid 62 ngUdi/kml

TP.Hb Chi Minh cd 680 nha mdy, xi nghiep va 22.500 cdc cd sd san xua't lieu thu cong nghiep, U-ong so'dd cd 70% phan bd' d noi thanh Nbieu cd sd d xen Uong cdc khu dan cu' Nu'dc thai cong nghiep va sinh boat hau nbu' khdng dUdc xiJ ly nu'dc khi thai ra kenh rach Qud Ulnb do thj hod xay ra nhanh da lam

gia tang dan so' vdi cac ddt di dan iU do vao TP.Hb Chi Minh, da gay sii'c ep

Idn len cd sd ha tang, dac biet la nha d, cap, thodt nuTdc va ve sinh moi tru'dng (VSMT) dd thi Hien tu'dng xay ca't nha Udi phep lan chie'm kenh rach va xa cdc chat thai bufa bai xuo'ng dong nUde con kbd pho bie'n NuTdc uen cdc kenh rach noi thanh cd mau den, mQi hoi Ibo'i kbd chju da lam mat my quan dd Ihj, anh bu'dng xau de'n ddi song, site khde cong dbng, gay nen nbiyng hau qua moi U'U'dng tru'dc mat va lau ddi,

TP.Hb Chi Minh nam Uong vQng ciJa song ven bien ciia he thong song Dbng Nai vdi cdc nhanh song Idn la La Nga, Sai Gon, song Be va song Vam

Cd Ngoai ra, tren dia ban TP.Hb Chi Minh con cd mang lu'di song ngdi, kenh rach chang chit nbu' mang nben Che' do ban nhat trieu khong deu cua bien Dong da lam giam kha nang lieu thodt niTdc ciia song rach, kenh mu'dng, gia

tdng bbi lang, ibn tich d nhiem d cdc viing ibap trung sau trong ndi dbng, hinh thanh cdc gidp nu'dc va tao nen si/ phitc tap trong che'dd tliuy vdn-lhuy lu'c

TP.Hb Chi Minh nam U-ong vilng khi hau nhiet ddi, gid niDa can xich dao md dac UriTng cd ban la cd mot nen nhiel do cao, tu'dng ddi on djnh Uong

ndm va sir phan hod mu'a, gid theo mud rat ro reL S\i phan hod nay da anh

hudng manh de'n cha't lu'dng nen moi Uudng nu'dc (MTN) TP.Hb Chi Minh Phan Idn dien tich nu'dc mat bi nhiem mdn trong mDa kbd, khong the dDng cho

dn uo'ng sinh boat vd trbng Ida Trong kbi dd nuTdc ngam d lang khong cd dp hoac dp life ye'u cung bj nbiSm man Nu'dc mat hi d nhiem, bode nu'dc mu'a cudn trdi cdc chat d nhilm uen be mat, nga'm xuo'ng dat, hodc chay theo cdc khe nu'l xudng nifdc ngam lam 5 nhiim ngubn nu'dc ngam NuTdc ngam bi khai Ihac qud mite, se bi nirdc man lan vdo, gay nhiem mdn ca ngubn nuTdc ngam Vi vay, uen dia ban TP.Hb Chi Minh, chat lu'dng nUdc mat vd nu'dc ngllni cd moi quan

he vdi nhau rat chat che

Hien nay ngubn nuTdc cung cap chinh cho sinh boat va san xua't cua TP.Hb Chi Minh Id nu'dc song Dbng Nai Ngubn nu'dc nay dang du'dc dieu lie't theo mua vdi cdc cong Uinb thuy Idi, thuy dien d tbu'dng ngubn vdi cdc hb Dau Tie'ng uen song Sai Gon, hb Tri An uen song Dong Nai va Tbdc Md tren song B^ Cac viing chuyen canh ndng nghiep xung quanh TP.Hb Chi Minh da gia lang siJ dung ngubn nu'dc song phuc vu cho cap nu'dc, lu'di lieu, riJa chua, rii'a man vd gia tang lu'dng nu'dc thai, cbal thai vao MTN Nbif vay, ngubn nu'dc ngol

ve TP.Hb Chi Minh cang ngay cang bi ban che', Uong khi dd cdc chat pbd' thai cang ngay cang gia tang ve chiing loai va mii'c do doc hai va ne'u khdng cd nhifng giai phdp hifu hieu ngan cbdn kjp thdi Ihi kha ndng tie'p nhan chat ihai cua MTN se qua tai, ngubn nu'dc se bi d nhiem liam trong, moi Uu'dng bi suy thodi, kbd cd kha ndng phuc bbi va chi phi cho vice lam sach se rat ton kdm

Cd the ndi rang TP.Hb Chi Minh la mdt Uong nhffng "diem ndng'* d Viet Nam

ve suy thodi ngubn nuTdc va d nhiem MTN Vi vay, de tai "Si/ hinh Ibdnh cdc ngubn nu'dc vd mot so'giai phdp bao ve moi Uu'dng nu'dc khu vi/c TP.Hb Chi Minh" la can thie'l vd cap bdch

Muc lieu ciia de idi Id nghien cu'u si/ hinh thanh vd ddc diem cdc ngubn nu'dc ( nu'dc mat, nu'dc ngam), d nhiem MTN va de xuat mdi sd giai phdp bao

ve MTN khu vi/c TP.Hb Chi Minh Luan dn nay lap Irung nghien cu'u ngubn nu'dc mat d TP.Hb Chi Minh De dat du'dc muc tieu tren, luan dn can giai quye't cdc nhiem vu sau:

• Phan tich dac diem cdc ngubn nu'dc va nhiTng nhan to' anh bu'dng de'n si/ blnh thanh cbiing

• Ddnh gid mii'c do d nhiim MTN, qui lual phan bd' vd didn bie'n d nhiim theo thdi gian

• De xua't cdc gidi phdp kha thi bao ve MTN khu vi/c TP.Hb Chi Minh, Cdc ke't qua nghien cu'u ciia de tai cd ^ nghia khoa hoc va thi/c lien:

1 Xdc lap linh phan bd' theo khdng gian va thdi gian nhiyng ye'u to' dac Ui/ng CLN mat trong dieu kien kbi hau nhiel ddi gid mDa can xich dao va bdn nhat trieu khdng deu

2 Lam sang id cdc ngubn vd nbffng nguyen nhan gay d n h i i m MTN mat khu vi/c TP.HCM Hinh thitc d nhiim da dang, pham vi d nhiim md rong Tru'dc he't, TP.HCM can lap Uung xiJ 1^ d nhiim bu'u cd, 0 -ihiim vi sinh va cd cac giai phap ngdn chan d nhiim dau, hd Ird di chuyen cdc cd sd san xua't gay d n h i i m

va xi? ly nu'dc thai theo tu'ng khu vi/c

3 Luan dn la cd sd khoa hoc cho vice quy hoach phal Uien KTXH, khai thdc sii" dung hdp 1^ cdc ngubn nu'dc, giam nhe d nhiim bao ve MTN vd phdt trien

ben vifng TP.Hb Chi Minh gin vdi loan bo lu'u vu'c be tho'ng song Dbng Nai

CHl/dNG 1

MOI TRL/CfNG N\J6C TP.HO CHI MINH

1.1 LICH SLf NGHIEN CLfU

Lich siJ nghien cu'u va'n de neu tren (bao gbm nUdc mdt, nu'dc ngam va nghien cu'u ve MTN khu vi/c TP.Hb Chi Minh) cd the chia thdnh 3 giai doan:

irudc Giai phdng mien Nam nam 1975; tir 1975 de'n 1990 vd tuf 1991 de'n nay

Tai lieu nghien cirii cd 2 nhom: tai lieu ve Tbiiy vdn, Hai vdn, Dia chat thuy vdn va tdi lieu ve Mdi Uufdng, trong dd tap Uung chu ydu ve d nhiim MTN

LLL Giai doan triidc Giai phdng mien Nam, ndm 1975

Tdi lieu quan trong nhat Uong giai doan nay la Di/ an kha thi thodt nUdc Sdi Gon cua Cong ty LYON cua My, dirdc Ibi/c hicMi vdo thdng 2 ndm 1971 [130] Di/ dn nay gbm ban Ihuye't minh va phu luc Khu vi/c Di/ dn chie'm dien lich khoang 170km^, gbm phan Idn ndi thanh hien nay vd mdl phan phia Bac huyen Nha Be Trong bdo cao cd nhiTng tai lieu ve KTXH ciia Sai Gon tiiT ndm 1960-1966, so' lieu do dac chat lu'dng nuTdc, mi/c nu'dc uen kenh rach ndi thanh trong 2 ndm 1968-1969 Ngodi ra, cd sd lieu ve he thdng thodt nu'dc va qui

hoach thodt nifdc dd ihj Sai Gon den nam 2000 theo phifdng dn taeh rieng nu'dc

mu'a vdi nu'dc thai Tat ca nu'dc thai se du'dc thu gom ibi chuyen tai theo be did'ng cd'ng cd du'dng kinb 4 mdt ve nha mdy xiJ IJ' nuTdc thai di/ kie'n se ddt tai

xa Phu My huyen Nha Be Sau khi xii' \^, nu'dc thai se thodt ra sdng Nha Be

Tdng kinb phi de hoan tat he tbd'ng thodt nu'dc la 150 U:ieu USD (theo thdi gid ndm 1970)

Ngoai tai lieu Di/ dn kha thi thodt nu'dc Sai Gon con cd cdc tai lieu vc khi hau- tbiiy vdn nhuT lu'dng miTa d Tan Sdn Nhat luT ndm 1917, mi/c niTdc d Phu

An, Thu Dau Mot iDT nam 1960, Bien Hda tir ndm 1966 bien dang lu'u tru' d Dai Khi tU'dng-Tbuy vdn Nam Bd; tai lieu ve ca'p nu'dc Sai Gon cua Bd Cdng Cbdnb Sdi Gon; cdc tai lieu ciia Desk (1972) vd Lieu Kim Sanh (1973) md la

sd luTdc ve he thdng sdng Dbng Nai

Ve Dia cha't thuy vdn, ndm 1873 cdc chuyen vien Nhat Ban da lien banh khao sdt tham dd ngubn nu'dc ngam d Hoc Mdn vdi 5 Id khoan sau Kdt qua da phdt hien 5 lang chu'a nu'dc vd da lap de dn khai tbdc vdi cdng sua't 200.000mVngdy dem De'n ndm I960, ngoai 2 Id khoan sau d Tan Sdn Nba'l cho liTu liTdng khai Uidc 1080m^/ngay dem vd 2.400mVngdy ddm, Tbi/c dan Phdp

da cho khoan them 40 Id khoan khde vdi cdng suat 162.000m^/ngdy ddm Nam 1959-1960, cdc tdc gia nhu' Karpoff Roman, Brashears M L da lam bdo cdo cbl ro viec khai Ibdc nt/dc dudi dat vdi qui md Idn nbU vay da viTdt ngu'dng

an loan cho phdp, lam cho ngubn nu'dc bi nhiem man, du'dng mi/c nu'dc bi ha sau gan 10m va can phai dinh cbl khai thdc mdl sd' gidng Ngoai ra, mdl so' chuyen gia khde nghien cu'u ve liem ndng nu'dc du'di da'l tren pham vi ca phia Nam da db cap ddn cha't lu'dng nu'dc ngam vilng Sai Gdn-Gia Dinh Cdc tdc gia cho r i n g nu'dc ngam d phia Tay Nam TP.Hb Chi Minh, vung Can Gid Nha Be

bi n h i i m man khdng the khai thdc diing cho sinh boat Nhu' vay budc dau cdc lac gia da cho thay suT ban che' trong viec khai thdc ngubn nifdc ngam d khu vi/c TP.Hb Chi Minh [66] Trong giai doan nay cdc tai lieu tap trung vao van de cap thodt nu'dc chu'a cd nbifng nghidn cu'u ve MTN d TP.Hb Chi Minh

LL2.mndm 1975 den ndm 1990

Sau Giai phdng mien Nam, tiT ndm 1975 dd'n ndm 1980, Uy Ban Khoa hoc & Ky Thuat nay la Sd IClioa hoc, Cdng nghe & Mdi Uudng da thanh lap

ChiTdng U-inh nghiSn cu'u "Dieu tra cd ban" ChuTdng trinh nay cd cdc de tai nghidn cu'u ve cac ye'u idli/ nhien nbiT : dia cha't, tlid nhu'dng, kbi hau, tbiiy vdn, chat lu'dng niTdc (CLN) va sinh vat Vien Kinb le phdi bcjp vdi Dai Khi luTdng-Thuy vdn TP.Hb Chi Minh da tie'n banh Uien khai de tai "Md rong mang lu'di quan trac khi urdng-thuy vdn" do dac chi tiet cdc ydu to' mu'a Uen dia ban TP.Hb Chi Minh vd do mdn, do pH tir nam 1982-1986 tren cdc sdng rach chinh Sau dd, ndm 1986 Uien khai chu'dng U:inh nghien cu'u "Anh bu'dng ciia cdng trinh Tri An, Dau Tid'ng de'n ha du sdng Dbng Nai-Sai Gon" Cdng tac do dac theo djnh ky cdc ydu to' mi/c nu'dc lifu hrdng vd do man du'dc tie'n hanh tai mdl so'Uam Uen sdng Idn, mdi ndm vdi thdng, moi thdng do 3-5 ngdy trieu cirdng, Trong chu'dng Uinh nay, de tdi "Mdt sd' van de tliuy vdn tbiiy Ii/c vOng ha du Dbng Nai-Sai Gon tiuTdc vd sau kbi cd cdng Uinh Tri An-Dau Tie'ng" do GS.Nguyin Sinh Huy chu nhiem va tdc gia luan dn triTe lidp tham gia da hoan thanh vao cud'i ndm 1986 [32],

Ngoai ra, de tai "Nghien cu'u Sinh thdi canh quan thuy vi/c TP.Hb Chi Minh" do Vien Kinb te'chii Ui phdi hdp vdi Phan vien Sinh thdi va Tdi nguydn Sinh vat tbu'c hien Uong nhffng nam 1988-1991, trong dd tac gia la mot trong nhCfng thanh vien Iri/c lid'p tham gia thu man vd xuT ly so' Ueu [38] De tai da tie'n banh do dac chat lu'dng nu'dc, ddng-lhi/c vat thuy sinh tren cdc kieu hinh thuy vi/c (sdng, rach, ao dam, rudng liia) tai 500 diem trdn dja ban TP.Hb Chi Minh theo mDa tir miia muTa nam 1988 de'n miia kbd 1991, Ke'l qua dieu Ua khao sdt, nghien cii'u Sinh thdi canh quan thiiy vi/c la nbiTng tdi lieu cd sd duTdc siJ dung linh todn, phan tich trong luan dn nay

Nam 1987-1988, Vien Kinb le trien khai chu'dng trinh ca'p Nha Nirdc

"Dieu tra tdng hdp Dong Nam Bo" (60G) Uong dd, cd cdc de tai nghidn cu'u vc kbi hau, da'l, rung va nirdc [59.25,108] Day Id nbu'ng yd'u id' li/ nhien cd lien

quan ddn si/ blnh thanh ngubn nuTdc mat ngubn nu'dc ngam Uen lu'u vi/c be thdng sdng Dbng Nai

De tai "Dieu Ua ling ngap diTdng pbd do mUa" du'dc Phan vien KJii lu'dng

- Thuy van tbi/c hien da tie'n bdnh do dac muc do ngap ling tu'dng u'ng vdi thdi gian va cuTdng do mu'a Uong 2 miia mu'a, ndm 1988 va ndm 1989 Kdt qua dieu

Ua Id cd sd khoa hoc cho vice cai tao ling ngap vd thodt nu'dc TP.Hb Chi Minh

Nam 1988-1990, de tai "Xay di/ng ban db d nhiim mdi tru'dng TP.Hb Chi Minh" do Trung lam Mdi Uu'dng TP.Hb Chi Minh tbi/c bien da ebon 8 cbl lieu ( EC, SS, DO, BOD5, NH4, PO4, SO4 va long E.coli) de lap sd db d n h i i m MTN d TP.Hb Chi Minh, ty le 1/100.000 [98] O nhiim nuTdc cbl nghien cu'u Uen cdc sdng Idn nhiT Dong Nai-Nha Be va du'dc phan thanh 6 loai Mdi loai du'dc to mau Uen tirng doan sdng theo cdc mu'c 0 nhiim khde nhau Viing nirdc

"khdng d n h i i m " tuy duTdc phan loai nbu'ng Ihi/c te'khdng cd va khdng bieu

d i i n uen ban db Tai lieu ndy chi de cap de'n sdng chinb, nbu'ng ngubn nu'dc sdng, rach, bai Uieu, ao, rudng lien quan vdi nhau rat chat che tao thanh mot the tho'ng nba'l Tren lu'u vi/c sdng, dac biet pba Uieu len, nuTdc khdng gidi ban Irong long sdng ma Iran bd vao vung bdn ngap Do dd, phan loai d n h i i m nu'dc Udn cdc sdng Idn kbd siJ dung tidn Ibi/c id va cbiTa phan dnh day du d i i n bie'n CLN mat uen dja ban TP.Hb Chi Minh

Nam 1990, de tai cap Nha Nu'dc 40B-04-02 "He sinh thdi vOng ciJa sdng Dbng Nai-Sai Gon" dirdc lien banh d khu vi/c TP.Hb Chi Minh Tdc gia cua luan an la thanh vidn cua de tai da iham gia nghien cu'u va thu thap sd'lieu ve CLN va thijy sinh vat Uong ddt khao sat chi lie't vao ihang 6 ndm 1990 [9]

Nbin chung trong giai doan nay, cac cdng Uinh nghien cii'u chu ye'u thudc Ilnh vi/c dieu Ua cd ban ve cdc ye'u id* ti/ nbidn va sinh thai Uong khu vu'c Bu'dc dau da nghien cu'u ve 0 nhiim MTN d TP.Hb Chi Minh

LL3 Tii ndm 1991 den nay

Giai doan nay dac UuTng bing si/ chuyen bie'n nghien cii'u dieu Ua tai nguyen thien nhien sang nghien cu'u ve d nhiim MTN mot cdcb ibi/c thu Ndm 1991 la ndm dau cua giai doan qui hoach 5 ndm vd 10 ndm phdt U-ien kinb td'-xa hoi (KTXH) cua TP.Hb Chi Minh, cbiTdng Uinh "Dieu Ua cd ban" ddi thdnh cbiTdng Uinh "Tai nguyen va Mdi Uu'dng" Chu'dng Uinh nay, ngoai viec khao sdt, do dac nbir triTdc con cd them nhiem vu nghien citu ve mdi tru'dng vd gan no vdi thuTc te' san xuat, ddi sdng cua ngu'di dan Thanh pbd' Trong giai doan nay cd nbieu tdi lieu ve thodt nu'dc, cap nirdc, tdng ket dieu tra cd ban, gidm sat CLN

va ddnh gid tdc dong mdi tru'dng (DTM)

Ndm 1991-1993 cd 2 luan cbifng kinb te' ky thuat ve cai tao he tho'ng thodt nUdc Nhidu Ldc -Thi Nghe vd Tan Hda-Ld Gom cua Sd Thuy Ldi [125]

va Trung lam DHl-Trudng Dai hoc Thuy Ldl thi/c hien Ndm 1992-1993, Sd Ndng Ngbiep trien khai db ldi "Nghien cu'u cdc ydu to' cd ban lam cd sd khoa hoc cai tao lam sach he tbd'ng kenh rach TP.Hb Cbi Minh" Cdc de tai ndu Iren

da phan tich hien trang be tho'ng kenh rach va mang lu'di thodt nu'dc ndi Ihanh;

sd db Ihijy van-lhuy li/c vd de xua't mot sd' bien phap thuy ldi cai tao be tbd'ng thodt nirdc dd thi TP.Hb Cbi Minh Kd't qua nghien cu'u ciia cdc de tai tren da tap hdp du'dc nbu'ng so' lieu ve muTa gay ra ling ngap du'dng pho', CLN kenh Nbieu Loc-Thi Nghe vd nirdc tliai mot sd'cd sd san xua't cdng ngbiep va lieu thu cdng nghiep (CN & TTCN) khu vi/c kdnh Tan Hda -Ld Gd'm Bai loan thuy li/c vd lan truyen d nhiim (cbl lieu BOD5) tren mot s d k e n h , rach noi thanh la

cd sd khoa hoc cho viec nghien cii'u cai tao be tho'ng tieu thodt nu'dc thai TP.Hb Chi Minh [123] Nghidn cu'u ve lliodl nu'dc con du'dc de cap Uong "Db dn qui hoach long the thodt nu'dc dd thi TP.Hb Cbi Minh" ndm 1991-1994 [15] Trong

Db dn nay, ldc gia luan dn da tham gia do dac chi tid't, ve cdc ban ve ky thuat

bien soan thuyet minh ddnh gid kha ndng lieu thodt nu'dc ciia he didng thodt nu'dc vd de xua't phuTdng dn thay he thdng kdnb bd bang he tbd'ng cd'ng ngam duTdc Cdng ty Tbdat nu'dc dd thj cha'p thuan va dp dung vdo IbuTc te', nam 1994-

1995 [44] Trong Db dn qui hoach tbdat nu'dc cd nbu'ng sd' lieu do dac CLN

kenh rach theo Uieu, miia kbd ndm 1993 va sd bo nhan x6i ve linh hinh d

nhiim MTN kenh rach ndi thdnh do Trung lam Nu'dc va Cdng nghe Mdi Uu'dng Dai hoc Bach khoa thi/c hien [102]

Nam 1993-1994, Vien Qui hoach Xay di/ng ke't hdp vdi Trung lam bao

ve Mdi Uu'dng, Trung lam NuTdc vd Cdng nghe Mdi tru'dng da nghien cii'u "Ii/a ebon, ddnh gid cdc pbirdng phdp thodt vd xu" 15^ nuTdc thai cho lu'u vi/c Nbieu Ldc

- Thi Nghe" Ke't qua nghien cii'u da de ra phu'dng dn thu gom nu'dc tliai du'a

ve n h a m a y x u ' 1 5 ' d d t l a i N a m N h d B e , [123]

Ndm 1991, de tai "Tdng kd'l tdi nguyen Sinh vat TP.Hb Cbi Minh" da lap danh muc thdnh phan loai, gid tri tai nguydn va cbu'e ndng sinh thai ciia cdc loai sinh vat d nu'dc, [96]

Nam 1992, Uy Ban Mdi Tru'dng TP.Hb Cbi Minh da to cbu'e mang lu'di cdc tram gidm sat CLN Udn sdng Sai Gon, Dbng Nai, Nbd Be vd Chd Dem, mdi thdng 2 fan, mdi fan la'y mdu d chan va dinh trieu; ngoai ra con soan Ihao

vd ban banh "Qui djiib ve kiem sodl d nhiim TP.Hb Cbi Minb",[I17] Nam

1994, Uong "Sdch Den", cd daub muc 43 cd sd san xua't cdng nghiep Idn, gay

d nhiem mdi Irirdng d TP.Hb Cbi Minh, [118], Nam 1993-1994, Di/ an xay di/ng nbd mdy nu'dc thu' 2 trdn sdng Sai Gon tai Ben Than do Cdng ly khai thdc nu'dc sdng Sai Gon thi/c hien do dac CLN va thuy van trdn sdng Sai Gon [113]

Mot cdng viec mdi nba'l Uong giai doan tir nam 1993 dd'n nay la DTM cdc di/ an dau ur [5] Trong cdc bdo cdo nay cd the tham khao so' lieu do dac

9

bien U^ang d cdc nbd mdy cilng vdi nbifng bien phdp khde phuc d n h i i m MTN

vd cbi phi cho viec lap ddt be tbd'ng xuT 15^ nu'dc thai

Ngoai ra, ndm 1991-1995 Chu'dng trinh KT-02 ngbidn cii'u vc "Bao ve mdi tru'dng va phdt Uien ben viTng" du'dc trien khai vdi 17 de tai [3] trong dd

cd cdc de tdi lien quan de'n cdc ngubn nu'dc vd MTN d TP.Hb Chi Minh nhu': Ddnh gid tdc dong mdi tiuTdng cua cdng Uinb Tri An (KT-02-15) [29], cdng nghe xiJ ly d nhiim indt sd nganh cdng ngbiep d TP.Hb Chi Minh (KT-02-04) [103] va tdi nguydn nuTdc (KT-02-10), [61] Trong luan an nay, ldc gia da tham khao sd' lieu do dac chat lu'dng nu'dc hb Tri An va mot so' diem tidn sdng rach TP.Hb Chi Minh cua bao cdo long ke't ChiTdng trinh KT-02

Nbin Chung, MTN d TP.Hb Cbi Minh du'dc cdc lac gia ngbidn ciiu theo

nbieu khia canh khde nhau So lieu ve CLN luTdng ddi nbieu, song do dac

khdng dbng bd, cdc cbi lieu ddnh gid khde nhau vddo nbieu cd quan phan tich nen mi?c do tin cay cung khac nhau Cac tai lieu neu tren mdi chi dCrng d viec phan tich md ta hien trang d nhiim MTN, nbieu tai lieu di sau vao linh todn ihie't ke' ky thuat, chu'a di sau vdo phan lich ngubn va nguyen nhau gay d nhiem; chu'a xdc dinh val Ud ciia ngubn nu'dc bicMi va tbiiy trieu ddi vdi MTN TP.Hb Chi Minh Viec phan tich anh bu'dng ciia d nhiim MTN de'n ddi song, san xua't ciia ngu'di dan va sinh val con rat it

1.2 PHLfOfNG P H A P NGHIEN C 0 U

Cd sd cua phuTdng phdp luan nghien cii'u trong luan 6.n di/a tren quan

diem " Phdt trien ben vifng" |6,8] va nguyen tac "Ngudi gay d niiiim phai tra lien" [135], phan lich he tbd'ng Uong mdi quan he giua cdc ye'u Id'cd ban dac Irirng cho cha't lu'dng MTN Phu'dng phap nghien citu Irong luan an gbm cd :

10

1 Dieu tra khao sdt vd nghien cii'u ngodi thi/c dja ve dac diem li/ nhien va

KTXH, cdc ngubn gay d nhiem, thu mdu thuy hda, v.v., su* dung anh vidn tbdm, ban db va sinh val cbl thi de phan vDng CLN,

2 Kinh te- moi triiifng (Environmmental Economics-EE): Id cdc phu'dng phdp

su* dung cdc cdng cu kinh Id' de kiem sodl, khdng chd va giam tliieu d n h i i m MTN Nbu'ng chinh sdch quan 1^ tai nguyen nu'dc, kiem soat d nhiim di/a Udn nguyen lac "Ngu'di gay d nhiim phai tra lien"(Polluter Pays Principle -PPP), chinb sdch Ihud' phdt thai mdi tiirdng "Emission charge", thud' siJ dung tai nguyen nirdc, cap gia'y phep d nhiem va chuyen nhu'dng cac giay phep nay, phal lien va chuyen ldi san chung (Open asset) Ihanh tai san cd chu quyen cua xa, huyen (Common property rigbl) bode ldi san ciia lu' nhan, v.v Ap dung phu'dng phdp Nglu nhien (Contigent Method) the hien qua mii'c do san Idng tra lien cai tao d nhiim mdi uu'dng, bode mu'c do san long chap nhan de chiu di/ng mu'c do d nhiim ciia dan dja pbirdng (WilUngness

To Pay & Willingness To Accept) [7 132,134,136,137]

3 Ddnh gid tdc dong moi /n/'(0^/ig^-(Environmental Impact Assessement -EIA): /

siJ dung cdc phu'dng phdp: Lap danh muc ldc dong mdi trirdng "Check list ", ddnh gid tdc dong ciia nu'dc d nhiim vd hau qua d nhiem mdi truTdng; cbbng xe'p ban db "Overlay'* iCr cdc ban db ddn linh de xay du'ng ban db tdng hdp phan vOng CLN d nhiim MTN Phu'dng phdp "Ad hoc" Id Irao ddi vdi dan, di/a vao dan vd dap u'ng nguyen vong chinh dang cua bo do d n h i i m MTN gay ra va gido due mdi Uu'dng de cdng ldc bao ve mdi Uu'dng (BVMT) la cdng ldc cua quan chiing [4,5,6]

4 Dieu tra xa hoi hgc: theo cdc bang hoi, phdng van cac ho gia dinh ve mitc

sd'ng, nhiTng thdi qucn sinh boat VSMT, nbu'ng ban che va kha nang cua

bo tham gia cai tao d nhiim MTN vd BVMT [116]

14

• Cdc phMng phdp khde

Thu thap tbd'ng kd sd'lieu vd cdc kdt qua nghien cu'u cd lidn quan de'n cdc ngubn nu'dc vd d nhiim MTN lam cd sd cho viec phan tich vd de xua't cdc giai phdp bao ve MTN d TP.Hb Cbi Minh

• Li/a ebon cdc cbl tidu d nhiem so sdnh vdi cdc Tidu chuan Nha nirdc Viet Nam ve mdi Uirdng ndm 1995 ddi vdi CLN mat (TCVN 5942), CLN bien ven bd (TCVN 5943), CLN ngam (TCVN 5944) vd CLN thai cdng nghiep (TCVN 5945), [2]

• Di/a tren 1^ ihuye't "Tu'dng li/" va long hdp hda qui lual diin bidn cdc ydu td

d nhiim; qui luat Nban-Qua Irong qud Uinh dd thj hda (DTH), cdng ngbiep hda (CNH) do ydu kdra ve quan 1^ mdi tru'dng va nbu'ng hau qua mdi tru'dng cua Uong vd ngodi nu'dc, ddt biet Id ddi vdi cdc khu dan ngheo ndi thanh va vDng ven dd TP.Hb Chi Minh nbam canh bdo cdc van de mdi tru'dng trong phdt trien, ngdn chan d nhiim, tbi/c hien"Phdng benh bdn chu'a benh" va chi phi cho phdng ngira d nhiim se kinh Id'bdn khac phuc d nhiim

• Li/a ebon cdc chi tidu, phan tich mdi lufdng quan bang linh todn, Ihdng kd bbi qui da bie'n uen may vi linh (SPSS for Windows-multiple regression) Ke't hdp vdi viec dp dung cdc phu'dng phap DTM, Kinh te'-Mdi Irirdng, di/

bdo xu the' bie'n ddi de phan tich cdc ye'u to' on djnh trong trang tlidi dong,

xdc dinh ye'u tdchu dao, ydu Id'dieu kbien Uong he sinh thdi ihiiy vu'c TP.Hb Cbi Minh

• SiJ dung chu'dng Uinh "Map Information'' la mot phan men trong "He tho'ng thdng tin Dja 15^-Geographical Information System-GIS" de ve cdc ban db CLN vd d nhiim MTN ciia TP.Hb Chi Minh trdn mdy vi linh, ly le 1/450.000, Nbu'ng ndi dung va phu'dng phdp ngbidn ciiu trong luan dn du'dc tdng hdp trong bang 1,1

12

Bang 1.1 Nhifng ndi dung chinb va pbirdng phdp nghien cii'u trong luan dn

• Phan viing d nhiim

• Ngubn gay d nbidm

• Nguyen nhan d nhiim

Anh birdng ciia ngubn nu'dc

bi d nhiim ddn khu be

dong tbi/c vat thuy sinh va

ngu'di dan Thanh pbd'

Mot sd' giai phap giam nhe

d nhiim mdi tru'dng nUdc

TP.Hb Cbi Minh:

• Giai phap ky thuat

• Giai phdp kinh te'

• Giai phdp xa hoi

• Giai phdp khac

PbiTdng phdp

• Thdng ke tai lieu

• Kd tbira cdc ke't qua nghien cu'u

• Kliao sdt ngoai ihi/c dja ve dia blnh, dia mao, ihiiy vdn, CLN va tbiiy sinh val

• Phan lich be thdng si/ hinh thanh cdc ngubn nuTdc

• Tbd'ng ke so' lieu li/ nhien va KTXH

cd lidn quan de'n cdc ngubn nu'dc vd dac diem ciia cbiing

• DTM: Lap danh muc, cbbng xe'p ban

db, ma Uan, v.v

• So sdnh vdi TCVN 5942,TCVN 5945

• Phan tich hbi qui da bidn

• Viin tham, ban db sinh vat cbl thj

Ve ban db cdc cbl lieu d nhiim va tdng hdp phan viing d nhiem MTN tren may vi linh (Map Infomalion) DTM: Lap danh muc tac dong ciia ngubn nu'dc bj 0 nhiem dd'n :

• Kliu he dong vat thuy sinh

• Su'c khde cdng dbng my quan dd thj, khai thdc va s'l dung ngubn nuTdc

• Ndi suy, so sdnh, kd' ihira ke't qua nghien cii'u

• Kinh te' - Mdi Uu'dng: thud' phdt thai, Ihue' si? dung tai nguyen nirdc chuyen nhirdng gia'y piidp d n h i i m , xiJ phal banh cbdnb, mu'c do san long chi tra lien (WTP) de cai tao d n h i i m MTN, phi mdi tru'dng

13

C H I / O N G 2

S\J HINH THANH CAC NGUON Nl/(JfC KHU Vl^C

TP HO CHI MINH VA DAC DIEM CUA CHUNG

Mdi irirdng nUdc khu vi/c TP.Hb Chi Minh, cung nbuT d cdc ndi khde, diTdc blnh thdnh tir 2 ngubn nuTde chinb: nu'dc mdl va nu'dc ngam Tuy nhidn, vi TP.Hb Chi Minh nam trong vung tiTdng tdc Sdng-Bien ciia mot ciJa sdng blnh pheu (estuary) dien hinh ndn nUdc mat d day, gbm: ngubn nirdc ngol ciia be tbd'ng sdng Dbng Nai chay ve, ngubn nu'dc bien tir bien Ddng do Ihiiy trieu du'a Icn Nu'dc bdn hdp ngot-mdn tbn tai trdn cdc sdng, rach, ao bd vd cdc kieu hinh thuy vi/c khac Nu'dc ngam cung la mot ngubn nu'dc quan trong ddi vdi TP.Hb Chi Minh nba'l la Uong viec cap nu'dc cho dan sinh, Ngubn nu'dc ngam d day da duTdc nghien cii'u tu'dng ddi day dii trong cdc cdng trinh [14, 64, 66,v.v.].Vi vay, U'ong luan dn nay tap trung cbii yd'u vao ngubn nirdc mat

NhuT vay, mdi tru'dng nu'dc TP.Hb Chi Minh du'dc hinh thdnh tir nbieu ngubn nu'dc khde nhau va du'di day lan lu'di xem xdl cdc ngubn nu'dc chinb

2.1 c A c NGUON Nl/CfC KHU V^C TP.HO CHI MINI!

2.7.7 Ngiion niidc den tii he thong song Bong Nai

* Mang lu'di sdnt; Dbnt; Nai:

Sdng Dbng Nai la mdl Uong nhilng sdng Idn ciia Viet Nam phan bd' d viing Ddng Nam Bo va mot phan mien Tay Nam Bd vdi long dien tich lu'u vu'c 44.100 km^ gbm phan Idn dien tich cdc linh Dbng Nai, Sdng Bd, Tay Ninh, Long An va TP.Hb Cbi Minh, Sdng Dbng Nai bai ngubn tir viing niii cao thudc day Lang Biang cd do cao tir 1500-2000m d Nam TruTdng Sdn vdi hai nhdnh

14

chinb Da Nbim vd Da Dung, chieu dai dd'n ciJa Soai Rap la 635km Dien tich hru vi/c ddn tbdc Tri An I4.800km^ do udn khde long sdng doan chinh 1,3; do ddc uung binh 4,6"/oo[70 7 1 , 9 1 ]

He tbd'ng sdng Dong Nai gbm cd sdng chinh la sdng Dbng Nai-Nhd Sodi Rap vd 4 phu liru Idn (hinh 2.1) la sdng La Ngd (bd U-di), sdng Bd, sdng Sdi Gon va sdng Vam Cd (bd phai) Sdng La Nga bdt ngubn tir vQng niii thudc cao nguydn Di Linh-Bao Ldc vdi chieu dai 272km ; dien lich lu'u vi/c 4.170km ,

Be-be sd' udn khiic 3,0; do ddc long sdng 5.6°/oo CiJa sdng La Ngd hdp vdi sdng Ddng Nai tai diem each Tri An 38km

Sdng Be cd ngubn tir cdc sud'i phia Nam cua tlnh Dac Lac, cd chieu dai 344km, dien tich lu'u vi/c 7.170km^ ; dp ddc trung binh 5.37oo CiJa sdng Be cdcb Tri An 6km

Sdng Sai Gon bat ngubn tir cdc viing dbi thap d Ldc Ninh thudc linh Tay Ninh vdi do cao 210m, cd do ddi 256km, dien tich lu'u vu'c S.OlOkm^ trong dd phan Idn la dbng bang Do dd'c Uung blnh long sdng Sai Gon 0.5°/oo , d ha lu'u

hb Dau Tie'ng, dd ddc Idng sdng rat nbd Sdng Sai Gon ddn Dau Tie'ng dai 132km, khi de'n ndi Ihdnh sdng rong 100-200in, d cang Sai Gon rdng 300-500m, sau 15-20m Tru'dc nam 1984, khi chu'a cd dap Dau Tid'ng ihuy trieu len qud Dau Tie'ng 10km ve phia tbu'dng lu'u

Sdng Dbng Nai hdp vdi sdng Sai Gon tao thanh sdng Nha Be vdi do rong 1.300-1.500m, sau 10-18m Tai miii Nha Be nirdc Ihoal ra bien theo 2 [lu'dng chinh : sdng Long Tdu - Nga Bay rdng 400-600m, ciVa sdng rdng 800-1500m, sau 10-21m; sdng Nha Be-Sodi Rap rdng 2.000-3.000m, sau 6-8m Sdng Vam

Cd du'dc binh thanh tir 2 nhanh Idn la Vam Cd Ddng va Vam Cd Tay, dai 30km

va chay ra sdng Nha Be, each ciJa Soai Rap 15km Sdng Vam Cd Ddng bat ngubn tir Cam-Pu-Chia d do cao 100-150m, dai 220km dien tich lu'u vu'c

15

8.500km^ do dd'c long sdng ra't nbd 0.027oo Sdng Vam Cd Tay cung bat ngubn tir Cam-Pu-Chia, dai 196 km, dien lich lu'u vi/c 4.000 km^ [33 67], Tdng chieu dai cdc sdng chinh cila he tbd'ng sdng Ddng Nai Id 1816km va cdc ddc UuTng binh thdi ciia lu'u vi/c the bien trong bang 2,1 TP.Hb Cbi Minh cd mang luTdi sdng rach chang chit Mat do ddng chay d cdc huyen ngoai thanh phan bd' khdng deu: huyen Hoc Mdn 0,5-l,0km/km^ Cii Chi 0,8-l,4km/km^ Binh Cbdnb 3,0-5,0 km/km^; Thu Dd'c 3,8-4,5km/km^; Mat do ddng chay kha cao tap uung d 2 huyen Nha Be 5,0-7,0 km/km^ va Can Gid 7,0-11,0 km/km^ 113] Vdi mang liTdi sdng rach nhiT vay cDng vdi che do bdn nhat Uieu khdng deu ciia bien Ddng da tao ndn si/ pbiJc lap Irong che' do thiiy vdn, tbiiy li/c vDng ciJa sdng Dbng N a i

Viec phan cap sdng du'dc cdc ldc gia de cap dd'n trong nbieu tai lieu Theo Varnob [142] he tbd'ng sdng gbm cd: sdng cbinh vd phu lu'u cdc ca'p, Phu lu'u ca'p I dd vao sdng chinh; phu lu'u cap II dd vao phu lu'u ca'p I, v.v Cap sdng khdng ban che, tiiy thudc vao mang lu'di sdng vd sdng cd ca'p cao nhat la nhiing nhanh sdng xa nba'l, it phdt Uien nhat Ngirdc lai vdi Varnob, Kliorlon goi sdng, sud'i cung ca'p nu'dc dau lidn cho he tbd'ng sdng la sdng cap I va sdng cap I dd vdo sdng cap II, v.v va sdng chinb cd cap cao nhat Trong cdcb phan chia nay cdc sdng sud'i cd cung do dai va lu'dng nu'dc gan bang nhau tbi cd ca'p nhu nhau Tuy nhidn sdng chinh se giu' cap ciia minh uen mot doan dai ngay ca sau kbi cd nhO'ng nhdnh sdng Idn khac dd vao va lu'dng nu'dc gia lang gap bdi,

O Viet Nam, theo tai lieu ciia Tong cue Klii tUdng-Thiiy vdn phan chia cap sdng theo cdcb phan chia ciia Varnob va qui dinh nhdnh sdng ca'p 1 chay vao sdng chinh Nhu' vay, loan bo he tho'ng sdng Dbng Nai cd bdn 250 sdng sud'i cd chieu dai 10km lid Idn, bao gbm 1 sdng chinh, 61 nhanh sdng ca'p I, 126 nhanh sdng cap II, 53 nhdnh sdng ca'p III, v.v [91 ]

16

Ddi vdi khu vi/c TP.Hb Chi Minh theo GS.Nguyin Sinh Huy (1996), sdng chinb Dbng Nai-Nhd Be-Soai Rap la sdng ca'p I, sdng Idn cd ngubn la sdng cap II nhir sdng Sai Gon, sdng Be, Vdm Cd Cdc sdng rach nbd khde dii cd

dd Ui/e tie'p vao sdng cap I cung Id sdng cap III bode cap IV, [37] Cdcb phan chia theo cdc tai lieu thiiy vdn ciia Lidn Xd (cu) vd ciia Tong cue Klii tirdng-Tbiiy vdn tbich hdp vdi mang lu'di sdng cd ddng chay 1 chieu Ddi vdi mang lu'di sdng TP.Hb Chi Minh, nuTdc chay 2 chieu, cdcb phan chia ndy khdng phD hdp, VI d day cd rat nbieu sdng rach vdi do dai Idn bdn 10km chay vao sdng chinb, nhirng khdng cd ngubn, n i m d khu giiJa la nhdnh cua sdng cbinh nen khdng the la phu lu'u ca'p I

Bang 2.1 Dac Uirng hinh thdi ciia lu'u vi/c be tbd'ng sdng Ddng Nai

Tdn sdng Cdc dac Uu'ng

Do ddc bq lu'u vi/c, 7oo

He sd'tap trung nirdc

He so'binh dang

He sd'ud'n khuc

Mat do song suoi, km/km

He so'khong can bang

liTdi song

Dong Nai

635 44.100

1700

470

98 4.60 1.75 0.26 2.20 0.64 0.72

Da Dung

La Nga

Sai Gon

Ke't hdp giffa cac cdcb phan chia nhir U*en, chung ldi phan cap sdng ciia

he tbd'ng sdng Dbng Nai theo cbu'e nang cac ngubn nu'dc dd'n TP.Hb Chi Minh

va mang sdng rach Udn dia ban TP.Hb Chi Minh nhir sau: sdng Dbng Nai la sdng chinh, bao gbm lien lie'p nbieu sdng : sdng Dbng Nai-sdng Nha Be-Soai Rap Phu luTu cap I la cdc sdng Idn cd ngubn, bao gbm 5 sdng: Da Dung, Sai

r-^ir

17

Gon, Sdng Bd, La Nga, Vdm Cd Ddng - Vam Cd; phu lu'u cap II la cdc sdng: Vam Cd Tay, Tbi Tinb, Ben Lu'c - Chd Dem, Can Giuoc - Rach Cdt v.v Phu luTu cap II ddng vai tid quan Irong trong viec chuyen nu'dc giffa cdc sdng cap I, bode giifa sdng chinh vdi sdng cap I, bode sdng chinh vdi bien Con lai Id cdc sdng, rach cap III va IV Mot ddc diem can lu'u ^ ddi vdi cdc phu lu'u liT cap II de'n ca'p IV uen dia ban TP.Hb Chi Minh la cdc sdng cd tdn khde nhau, nbu'ng nd'i lidn tid'p uen cDng mot tuyd'n se cd cung 1 cap va ten tuye'n sdng tbu'dng Id ten ghdp ciia 2 hay 3 sdng rach gan nhau

Vi du : tuye'n sdng rach phu lu'u cap II tiT sdng Sdi Gon sang sdng Vam

Cd Ddng gbm Kdnb Te-Kenh Ddi-sdng Chd Dem-Bdn Lu'c, bode tuye'n chuyen nirdc liT sdng cbinh Nha Be ra bien nhu' Vam Sal-Dbng Tranh, Long Tau-Nga Bay, v.v Vdi cdcb phan chia nhu' vay nhieu sdng rach la phu luTu ca'p III nhuT sdng rach d Nha Be-C"an Gid, van thoat nu'dc Iri/c lidp ra sdng chinh Vi vay, Uong cdcb phan chia nay cd hien tirdng nhay bac cap sdng va day cung la mot dac diem ciia be thdng sdng Dbng Nai Trong cdc chUdng sau, de thuan lien cho viec xdc dinh vi tri thu mau va cdc tuye'n sdng, tdn vi Ui tram gidm sdt va ten sdng du'dc goi theo tdn gbi Uen ban do Vi du: tram Binh Dien sdng Chd Dem, Uam An Thdi Ddng khdng gbi sdng Dbng Nai, md gbi sdng Nha Be vd luyd'n sdng rach, kenh mu'dng se cd ten ghdp nbu' kenh Tan Hda-Ld Gd'm, kenh Nbidu Ldc -Thj Nghe, v.v gbm cd ten kdnb d dau va ten rach d sau Ten sdng rach d TP.Hb Chi Minh gan lien vdi dja danh, si/ kien lich siJ va ca cbu'e ndng ciia no Vi du: sdng Nha Be do cd nbieu nha be d tren sdng, sdng Long Tau vl

cd nbieu tau Idn di lai, kenh Thay Cai sau ddi thanh kenh Thdi My d Cii Chi du'dc dao trong thdi ky Phdp thudc, v.v

Tdm lai, vdi cQng mot ca'p sdng, cdc sdng se cd cung chiTc nang nbu" nhau, ddc biet la dd'i vdi phu lu'u sdng cap 1 la nbu'ng sdng cung ca'p ngubn nuTdc

IS

de'n khu vi/c TP.Hb Cbi Minh vd phu liru sdng cap II la cdc sdng chuyen nu'dc

giffa cdc phu lUu sdng cap I, bode tCr sdng chinh ra bien Vdi each phan chia cap

sdng nhir vay se thuan lien cho viec khai thdc siJ dung ngubn nu'dc sdng rach U^dn dia ban TP.Hb Chi Minh

* Ddc tru'ng thiiv van ngubn nu'dc sdng Dbng Nai vd hb chu'a :

Trdn be tbd'ng sdng Dbng Nai cd cdc tram tbiiy van (binh 2.2 vd phu luc 1) vdi cdc ydu Id' quan Uac gbm: mi/c nu'dc, lu'u lu'dng, pbQ sa vd thuy hda Cdc ddc Uu'ng ddng chay ciia be thdng sdng Ddng Nai duTdc tdng hdp Uong bang 2.2,(108]

Bang 2.2 Ddc UuTng ddng chay ciia he thdng sdng Ddng Nai

Go Dau Ha

Lu'dng miTaTB nam

35.4 34.7 32.0 26.7 36.2 22.9 21.1 16.4

Lrfu lircfng TB

Qo, m'/s

496.0 779.2 895.3

1076 203.0 61.8 88.6 97.2 Sdng Dbng Nai, sdng La Ngd vd sdng Bd la nbu'ng sdng cd liem nang ve tbiiy dien vdi long cdng sua't trdn 2.000 MW gbm nbieu bac thang, Uong dd Tri

An la bac cud'i cung Cdng trinh Trj An du'dc xay di/ng liT ndm 1984-1988 cung cap ngubn dien l,7ly KWh Tuyd'n dap chinb ciia cdng Uinb bd' Iri lai tbu'dng lu'u tbdc Tri An cd dien lich lu'u vuTc 14.800km^ chenh lech do cao ti/ nhien la 40m Dap Iran xa lu ciia cdng trinh duTdc xay di/ng vdi liru lu'dng Qo.i% la 2I.000mVs u'ng vdi mi/c nu'dc Id'i da trong hb la 63,9m Nha may thuy dien

19

Hinh 2.2 BAN DO VI TRI CAC TRAM

I V) tri Ir.'irn mirc mrOc Qudc gia

jm > • Mirfiiii: trjcii \&n

• • • y MinViii: t i i a i xnrtng

, • (•.'it kliii ilu'r.T mriVc

R j s S ^ * ^ Vhiii.' (Ini p() khftiig v6 nwfv inSt

•••f.l&'f' 'M

ivOn Ihj l.an Viyii Kinh I c ' I I M I o Chi Minh 1996

Thdc Md dirdc xay di/ng tai huyen Phu'dc Long, tinb Sdng Bd vao ndm 1995 cd dien tich hb chu'a 103km^ dung tich l,26km^ , 2 id mdy phdt dien, cdng sua't 150MW, hang nam nha mdy cung cap cho lu'di dien Qud'c gia khoang dOOtrieu KWh dien

Trdn be tho'ng sdng Dbng Nai da xay di/ng nhieu hb chu'a: Tri An, Thdc

Md, Dau Tie'ng (bang 2.3) Hb chu'a Uiuy dien Tri An duTdc van banh theo che'

do dieu tid't nam, mua mu'a tuf thdng 6 de'n thdng 12 lich nu'dc vdi mi/c nirdc dang blnh tbu'dng la 62m va xa nu'dc ve ba du, Uong mud kbd de'n mi/c niTdc che't 50m phu thudc vao ngubn nu'dc dd'n hb Tri An

Bang 2.3 Cdc hb chu'a d tbu'dng ngubn he ihd'ng sdng Dbng Nai

Dien lich hb vdi H bl

Lu'u lu'dng lb nam -Q

Q dinh lu 0.1 % xa Iran

Q xa mua icho TB

Q xa mua mu'a max

Tong lu'dng dong chay

Dung lich Uung blnh

Dung lich hilu ich

Mi/c nu'dc dang bl hb

Mu'c nu'dc gia cU'dng

Mu'c nirdc che'l

Cong sua't nha may

San lu'dng dien lb

Nam xay du'ng

Ddn vi km^

km^

mVs mVs mVs m'/s km' km' km'

-2.800

20 100-200

-1,45 1,06 24,4 25,1

17 lu'di

83.500ha

-1984

Tri An 15.400 323,4

477 21.000

200

880 15,02 2,76 2,55 62,0 63,9 50,0

400

1,76

1987

Thdc Md 2.200 103,0

60

- - -

-1,26 0,97

20

tha'p Theo tbid'tke'liru lu'dng xa ve mDa kbd 200mVs, va mDa mu'a 800m7s, TiT

1989-1994, bidn do mi/c nu'dc hb Tri An dao dong trung binh l l m / n d m Mi/c nu'dc tha'p nhat tbu'dng xay ra vao thdng 5, trung binh Id 50,83m; tai La Nga 50,98m, cbdnb lech mi/c nu'dc giffa 2 tram 15cm Mi/c niTdc tiung blnh cao nhat cua hb IhuTdng xay ra vao dau thdng 11 (61.8m), tai La Nga Id 62m, chenh lech mi/c nu'dc giifa 2 tram 20cm

Hb chu'a Tri An da lam thay ddi chd' do nu'dc ciia sdng Dbng Nai va ngubn nirdc ve TP.Hb Chi Minh Tru'dc khi cd hb Trj An tai tram thuy van Cay Gdo, mi/c nu'dc dao ddng 39-43m Sau khi cd hb chud mi/c nuTdc dao ddng trung blnh 50 - 62m, cd kbi liT 48,5-62,5m, bien do 14m, kd't qua tao ra viing bdn ngap khd rdng Ddng chay miia can, sdng Ddng Nai ve ha du tru'dc khi cd

hb chu'a phu ibudc cbii ye^u vao cdc ngubn nu'dc sdng sudi d Ihirdng ngubn vd nirdc ngam tiong luTu vi/c Lu'u lu'dng mda can trung binh giam liT dau mua dd'n cud'i mua tiT 470niVs xud'ng 40mVs Thdng 4 la thdi gian nu'dc kiet nba'l trong nam (hinh 2.3) Tuf thdng 5 da cd mu'a dau nma, lu'u lu'dng de'n bd Tri An liT sdng La Ngd vd tbu'dng ngubn sdng Ddng Nai da gia tdng nbu'ng mi/c nu'dc hb chu'a tang vl con phu thudc vao lu'dng nu'dc xa ve ba lu'u (blnh 2.4) Liru lu'dng

xa ve ba du trong mDa can trung binh 200-300 m'^/s, Ihdng 6 ndm 1989, lu'u lu'dng xa dat de'n 650mVs (bang 2.4) Hb ebiia Tri An da Idm gia tdng ddng chay mua can ciia sdng Dbng Nai ve ha lu'u Lu'u lu'dng mQa can gia lang cd tac dung day IDi xam nhap man tren sdng Dbng Nai O buycn Thii Dd'c ranh gidi mdn 47oo bi day lui lijT Long Dai xud'ng ngang Cdt Ldi ; khu vi/c Thii Dd'c ngubn nu'dc ngol gia tdng tiong mQa khd tao dieu kien thuan ldi cho phdt trien

Ida vij He - Thu Ddng chay mQa lu IQ* thdng 7 de'n thdng 11 Iren sdng Dbng

Nai phu ihudc vao lu'dng mira trdn lu'u vi/c Lu'u hrdng Idn nba'l (Qmax) de'n hb Tri An tuf nam 1989-1992 lang dan liT thdng 7 den ihang 9 iQT 975mVs-1873mVs

21

lluili 2.3a Litulift]fngtrungbuih

Phtfdc Long s6ng Be (1977 -1992)

500

I 2 3 4 5 6 7 8 9 10 U 12

Th^ng Max Min •TB

Hlnli 2.3c LuTu liA/ng irung buih

Tbaug -Max • Min A TB

Hinh 2.3d LUu liTtfng trung buih Ddu Tie'ng s6ng Sai Gdn (1976-1979)

Tbaug Max Min —A—TB

Hinh 2.3f LUU liSffng trung buih

Trj An s6ng D6ng Nai (1978-1987)

Tbdog -•—Max Min TB

Nguyin Thf Lan Vi^/i Kinh teTP.Ho Chi Minh, ndm 1996

Sau do gidm dan trong thdng 10 va 11 Lu*u lu'dng xa qua tuoc bin va qua dap Uan trung blnh 530-1242 m^/s (blnh 2.4) NbiT vay trong mDa IQ do tich nu'dc, iUu lufdng xa ve ha du nho bdn lu'u lu'dng tru'dc khi co hb

Bang 2.4, LiTu krdng xa cua Trj An ve ha du Uong mila kiet 1989-1992 (mVs)

Bang 2.5 LuTu lifdng xa cua Tri An ve ba du trong mQa In 1989 -1992 (m7s)

Thdng

Dac Uu'ng

Lu'u lu'dng Qbq

Lu'u lu'dng Qmax

LUu lu'dng Qmin

2

-854 -552 -480 -548

3

-317 -486 -680 -458

4

-511 -456 -592 -371

5

-569 -182 -417

-90

6

844

946 -96

304

Cac gia tri can bang nu'dc trong cac Ihang mua kiet hau nbu' deu am, tir

22

ITinh 2.4a D 3 C iriyng lUu lU^ng

nir<?c de'n Trj An tif nam 1983 -1987

•Qlu, •Qtiiax 'Qniiii

irmh2.4bt)5c triTng liAi Ii^tfng nifdc d§'n hd Tri An tCf nSm 1989 -1992

Thang

'Qbq ' n ' Qtiiax i^ Qiiiin

H

ITinh 2.4c LUtJ lUring nU(?c den

Tri An triidc khi co ho

1984 —«—1985 —A—1986 - ^ « - l 9 8 7

irinh2.4d.LUu lUt/ng nii^c den

Tri An sau khi cu h6

1989 1990 1991 1992

\

-Nguyen Thi Lan, Vien Kinh TeTP.Ho Chi Minh, 1996

tbang 12 de'n thdng 5, ngoai trCr thdng 2/1989 la 2 1 0 W , nbu'ng sang Ihang 6,

CO miTa, lu'dng nu'dc de'n hb gia lang, cdn can nu'dc cd gid tri diTdng (bang 2.7) Bang 2.7 Can bang nu'dc d hb Tri An cdc thdng mud IQ (10^ m^)

Chat lu'dng ngubn nu'dc song Dong Nai the hien qua cac cbl lieu ihiiy hda, do due, lu'u liTdng phii sa va va thuy sinh Mac dil long bb da du'dc don khd lot, nu'dc hb vdn bi 6 nhi6m bu'u cd khd nang tiong 2 nam dau (1988-1989), dac biet la d lang ddy nu'dc cd mau den, miii hoi Hien lu'dng phu du'dng hod xay ra trong bb va vilng ba lu'u cua bb vdi si/ xuat bien nhieu tao, rong reu anh bu'dng xau de'n cac tiam bdm Tai cdc be chu'a va loc nUdc d nha mdy nu'dc Thu Due

cd rat nhieu tao sdi, nu'dc cd miii hoi Nha mdy phai thau be thiTdng xuyen tir 15 ngay/lan xuo'ng 5 ngay/lan, gia tang su" dung lu'dng phen, hoa chat loc nu'dc Nu'dc bb Tri An cd bam lu'dng sat kha cao (2-3mg/l), nbu'ng thuoc loai nu'dc men, do cd'ng thap, do pH tir 6,8-7,3, DO=6,5-6,8mg/l, COD<10mg/l, nbd bdn gid tri cho pb6p do'i vdi ngubn nu'dc mat (TCVN 5942-A) cbu'ng to mu'c do 6 nhiim hCfu cd thap Nbng do long Nild (Nl) dao dong tir 0,6-l,0mg/l Nu'dc d hb phu va nha mdy Tri An cd Nt khd cao (1,2 -l,6mg/l); tdng Pbolpho (Pt) tir 0,01-0,04 mg/1 Nhu' vay, nu'dc hb Trj An da cd dau bieu 6 nbidm do cdc chat dinh du'dng cho Ihuy sinh val Ham lu'dng vi sinh the hien qua cbl so" Tong Coliform

d md-c 150-2400MPN/100ml, ihap bdn TCVN 5942-A, nen cd the ndi rang nuTdc

bb chu'a bi o nhiSm vi sinh Hien nay nu'dc hb Tri An bi 6 nhiem d khu vi/c chan cau La Nga do nuoi cd be (300 be), do chat thai cua nhd mdy du'dng La Nga va

dan ciT d \h\ ban La Nga Ham lu'dng tdng Coliform tai chan cau La Nga thdng

23

3 nam 1993 tdng len 24000MPN/100ml cao gan gap 5 fan gid trj cho pht^p, Irong kbi dd d cdc ndi khde trong hb Trj An bam liTdng Coliform rOft thap (30-90MPN/100ml) Trong miia mu'a tdng Coliform tdng ra't cao, max Id llO.OOOMPN/lOOml (ngay 20-21/9/93) Tuy nhien do diTdc pba loang nen nirdc song Dbng Nai sau Trj An chiTa bj 6 nhiim

Cha't lUdng nirdc tir Tri An de'n Hda An cd si/ thay ddi the bien d si/ giam dan ham lirdng Si02 tir long hb (8-12mg/l) xud'ng dap Tri An (7-lOmg/l)

ma nguyen nhan la do mot phan pbQ sa lang dong lai tiong bb LuTu lufdng phO

sa tuf tbu'dng ngubn song Dbng Nai de'n hb Trj An cd gid Ui thap nhat vao thdng

3 d tram Ta Lai 0,02kg/s, d La Ngd 0,10 kg/s, sau dd tdng dan trong cdc thdng 8 de'n thdng 9 (50kg/s) Dac Uu'ng hru luTdng va phii sa ngubn nu'dc song Dbng Nai va song La Nga the hien d bang 2.8

Bang 2.8 Dac Uu'ng lu'u lu'dng va phii sa ngubn nuTdc song Dbng Nai

v a s o n g La Nga (tir 1/1/1990 den 31/12/1993)

u'dc

La Ngd 34.0 23.0 15.3 19.2 71.9 127.3 217.2 379.7 384.7 372.1 188.2 94.4 163.0 839.0

Harr

Td Lai 7.10 5.80 5.41 9.89 20.1 40.3 64.4 68.9 57.5 61.1 44.7 16.2 26.6 70.51

1 lu'dng phii sa g/m'

Phu Dien 12.2 9.63 8.72 17.2 23.2 41.8 50.1 43.3 39.6 41.2 36.7 17.4 20.8 140.3

La Ngd 9.97 7.18 6.18 14.4 52.6 60.4 55.0 50,3 52.8 35.5 38.2 22.8 34.1 137.5

LuTu lu'dng phu sa

Ta Lai 0.54 0.28 0.20 0.49 1.71 11.3 24.7 49.4 45.1 43.1 16.4 2.83 16.4 295.0

kg/s Phu Dien 0.27 0.14 0.10 0.28 0.65 3.59 8.69 12.8 15.3 11.1 4.62 0.84 4.94 55.8

La Nga 0.33 0.17 0.10 0.56 4.91 8.38 11.6 15.7 17.3 12.6 8.24 2.54 6.97 61.0

24

Theo ke't qua do dac 5 mdu nufdc 6 tram ihiiy vdn Cay Gdo nam 1993, Uong nu'dc bb Trj An 4,54% la phii sa Id lung cd dirdng kinh hat trung binh (O)

<0,005mm; 20,35% cd 0=0,05-0,01 va chi cd 2,78% pbQ sa cd O>0,5mm Nbir vay phan Idn bDn cdt Irong nu'dc song Dbng Nai, La Ngd lang dong d dau bb Tri An Theo tinb todn, bbi Idng phii sa xay ra manb d long hb Tri An, Uung blnh 3-6cm/nam, (Nguyin Hu'Q Nhan 1995)

Nhu' vay ngubn nu'dc song Dbng Nai, song La Ngd qua bb cbda Trj An

ve ha du Ud nen Uong bdn, ngheo bdn ve chat dinh du'dng cho thuy sinh vat, tir

dd ddn den gia tang mu'c do ngam bun cdt Uong qud Uinb chay Lu'dng biin cdt nay du'dc bd sung do xdi Id bd vd xam ihi/c sau long song

Si/ blnh thanh hb cbda nu'dc da lam thay ddi thanh phan loai va cau Uuc khu he dong Ihi/c vat Ihuy sinh ngay trong long bb va ha du, Cac loai i/a moi Uu'dng nu'dc chay manh duTdc thay the bang cdc loai Ufa moi UUdng nu'dc chay cham, giau dinh du'dng, cdc loai tao Silic, tao Lam phdt Uien manb Ngoai ra tir Ihdng 1 de'n thdng 5 khi nu'dc rut tir 62m de'n 50m se tao ra vDng bdn ngap vdi dien lich gan 15.000ha cay co phdt Uien Klii nu'dc ngap Ud lai, cdc cay nay la ngubn bd sung chat biTu cd cho hb chu'a De tan dung cdc san pham nay va ngdn chan 6 nhiim MTN nen ihu hoach cay cd dDng cho cbdn nuoi bo, de Tdm lai, cha't lu'dng ngubn nu'dc song Dbng Nai, La Ngd cho de'n nay cbl bj 6 nhiim hiTu cd cue bo, nbin chung dam bao tieu chuan cap nu'dc dan sinh, nuoi thuy san, du lich Nbu'ng tai Hda An nu'dc song Dbng Nai bj 6 n h i i m nhe do nu'dc thai KCN Bien Hoa vd dan cU ven song

2.1.2 Ngiion nu'o'c bien

VQng ven bien cua TP.Hb Cbi Minh cd bd bien tir Can Gid den Dbng Hda ddi 11km vdi cdc ciJa song Idn la Soai Rap, Dbng Tranh, Nga Bay va Cdi

25

M(5p, la ndi tie'p nhan ngubn nu'dc liT bien Ddng do thiiy Uieu du'a vao O vung bien Ba Rja-Vung Tau cd che do ban nhat Uieu khong deu, bien do Idn tuf 3,5m-4,2m so vdi cdc vilng bien khde cua Viet Nam (bang 2.9), do cao sdng Uung blnh 2-3m Che'do dong li/c manb d day gay nen xdi Id bd bien Qua tai lieu khdng anh chup trong cdc nam 1957, 1969, 1977 1981 va 1985 cho Iha'y si/ bie'n dang dUdng bd bien

Bang 2.9 Dac diem cua diuy Uieu ciia cdc cang ven bien Viet Nam

7.Cu'a Thuan

8.DaNang

9.Qui Nhdn lO.Nba Trang

11.V/7/IJP Tail

12.Ganh Hao

n C a M a u 14.Racb Gid 15.HaTicn

Tinh chat Qiuy uieu

Nhat trieu deu

Nbal Uieu khong deu Ban nhat Uieu khdng deu

Bdn nhat trieu deu Bdn nhat trieu khdng deu

Nhat trieu khdng deu

Bdn nbal Uieu khdng deu Nhat trieu khdng deu hoac nhat Uieu deu

Do Idn Ihuy uieu (cm)