Đánh giá tác Động môi trường - phạm ngọc hồ - hoàng xuân cơ, 304 trang

Gio trnh nh gi tc ng mi trng

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BNG CH VIT TT

ADB : Ngn hng pht trin Chu BVMT : Bo v Mi trng

CHXHCN : Cng ho x hI ch ngha CCN : Cy cng nghip CN : Cng nghip CTGT : Cng trnh giao thng

DSH : a dng sinh hc GRR : nh gi rI ro

TM : nh gi tc ng Mi trng TMC : nh gi tc ng Mi trng chin lc FAO : T chc Nng lng Th giI

GIS : H thng thng tin a l GTVT : Giao thng vn ti

KHCN : Khoa hc cng ngh KHKT : Khoa hc k thut

KT-XH : Kinh t x hI

MT : Mi trng

MTST : Mi trng sinh thi NN : Nng nghip

PCD : C quan Bo v Mi trng Singapo QA/QC : m bo cht lng / kim sot cht lng QH : Quy hoch t QHMT : Quy hoch Mi trng QHSD : Quy hoch s dng

B GIO DC V O TO TRNG I HC NNG NGHIP I

PGS - TS. NGUYN NH MNH

NH GI TC NG MI TRNG

(Gio trnh cho ngnh Mi trng v ngnh Qun l t ai)

H ni - 2005


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BNG CH VIT TT

ADV Ngn hng pht trin chu BVMT Bo v Mi trng

CHXHCN Cng ho X hi Ch ngha CCN Cy cng nghip CN Cng nghip

CTGT Cng trnh Giao thng DDSH a dng Sinh hc

GRR nh gi ri ro TM nh gi tc ng Mi trng

TMC nh gi tc ng Mi trng chin lc FAO T chc Nng Lng Th gii

GIS H thng Thng tin a l GTVT Giao thng vn ti

KHCN Khoa hc Cng ngh KHKT Khoa hc K thut

KT-XH Kinh t -X hi

MT Mi trng

MTST Mi trng Sinh thi NN Nng nghip

PCD C quan BVMT Singapre QA/QC m bo cht lng/ kim sot cht lng QH Quy hoch t QHMT Quy hoch Mi trng QHSD Quy hoch s dng

SDD : S dng t

SH : Sinh hc TCCP : Tiu chun cho php

TCCL : Tiu chun cht lng TCN : Tiu chun Nghnh

TCVN : Tiu chun Vit Nam THC : Tng lng Hydrocacbon


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TN : Ti nguyn t

TNMT : Ti nguyn Mi trng

TNTN : Ti nguyn thin nhin

TNSV : Ti nguyn Sinh vt UNECO : T chc Gio dc Vn ho th giI

UNDP : Chng trnh pht trin LHQ UNEP : Chng trnh Mi trng LHQ USEPA : Hi ng nghin cu BVMT Hoa k VH : Vn ho

VQG : Vn Quc Gia WB : Ngn hng th gii

WHO : T chc sc kho th gii


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LI NI U

Cun gio trnh nh gi tc ng mi trng

ny c bin son ging dy

cho sinh vin ngnh Mi trng v sinh vin ngnh Qun l t ai. Vi i tng , chng ti c gng trang b phn kin thc c bn ca phng php, cng c, bc i trong nh gi tc ng mi trng v ly mi trng t - c bit l t Nng nghip v cc hot ng trn t Nng nghip lm trng tm. Chng ti hy vng gio trnh ny c th lm ti liu tham kho cho nhng ngi cn nghin cu.

V bin son ln u, sch s gp mt s khim khuyt c v ni dung v hnh thc. Rt mong nhn c cc kin ng gp ca bn c. Mi nhn xt xin gi v: Khoa t v Mi trng, Trng i hc Nng nghip I

Tc gi

Theo nhu cu ca cng tc o to, theo kinh nghim ging dy. gip cho nhiu

i tng sinh vin cc ngnh s dng, chng ti tin hnh sa cha, b sung cun sch ny vi mong mun cp nht cc tri thc v cc vn bn php quy ca nh nc trong nhng nm gn y. Chng ti hy vng rng : bn in t ny s gip ch nhiu hn cho ngi c v ngi tham kho. V nguyn nhn , chng ti s a thm vo sch mt s

ph lc v v d v DTM. Xin trn trng cm n bn c gp phn lm cho sch tt hn.

H ni ngy 10 thng 1 nm 2008 Tc gi.


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MC LC

Li ni u Danh mc ch vit tt

Bi m u 1

1. Mi trng v TM 1

2. Cc yu cu i vi cng tc TM 2

Chng I: Cc ch th, ch s mi trng v lp k hoch TM 5 1. B tc kin thc 5 2. Cc nh ngha v khi nim v mi trng 5 3. Lp k hoch cho TM 9 3.1. Nguyn tc chung 9 3.2. Nhng TM ring 9 4. Ni dung chnh trong vic thc hin TM 10 4.1. Lc duyt 10 4.2. Lp cng 11

4.3. Xc nh mc cn nh gi tc ng 11 4.4. nh gi tc ng n mi trng sinh thi v ti nguyn TN 12

4.5. Xc nh bin php gim thiu tc ng v qun l 12 5. Cu hi bi tp chng I 13

Chng II: Trnh t thc hin nh gi tc ng mi trng 14 1. Lc duyt 14 2. nh gi TMT s b 16 3. nh gi TMT y 17

3.1. Quan h gia mi trng v pht trin 17 3.2. nh hng ca TMT quy m ln 17

3.3. nh gi TMT 17 3.4. Quan h gia d n v TM 17 3.5. iu kin thc hin TM 18 4. nh gi TMT chi tit (theo kiu rt gn) 21 5. nh gi TMT chi tit (theo kiu y ) 22 5.1. Cng tc chun b 22 5.2. Xc nh cc hot ng quan trng ca d n 23 5.3. Xc nh tc ng ca hot ng n mi trng 24 5.4. Xc nh tc ng n ngun TNTN v cht lng cuc sng 24


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5.5. D bo din bin ca tc ng 25 5.6. Xc nh cc bin php gim thiu v qun l chng 25 5.7. xut cc ni dung v yu cu monitoring mi trng 26 6. Lp bo co TM v thng bo kt qu 6.1 Khung BC ( Mu bo co DTM ) 6.2 Ngh nh 80 ( xem ph lc) 6.3 Quyt nh 08.( xem ph lc)

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7. Cu hi v bi tp chng II 30

Chng III. Cc phng php dng trong TM 32

1. Phng php danh mc cc iu kin mi trng 32

2. Phng php ma trn MT 33

3. Phng php chng ghp bn 36 4. Phng php phn tch chi ph - li ch m rng 37

5. Hng dn nh gi tc ng mi trng n cht lng nc mt 39

6. nh gi tc ng n cht lng mi trng t v nc ngm 42

7. nh gi ri ro 43

8. Cu hi v bi tp chng III 48

Chng IV: Mu cng TM v mt s TM Vit Nam 49

4.1. Mu cng nh gi tc ng mi trng

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4.3. Gii thiu mt s tm tt kt qu TM Vit Nam 50 Cc s liu mi trng quan trng 68 Tiu chun Vit Nam 71

Bng tra cu thut ng 83


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BI M U

1. Mi trng v nh gi tc ng mi trng Mi trng l tng hp cc iu kin bn ngoi c nh hng n mt vt th hoc

mt s kin no . C th hiu mt cch khc theo nh ngha ca B Quc phng Hoa K: Mi

trng bao gm tt c mi yu t v nh hng ca chng n mt h sinh quyn. Theo lut Bo v mi trng ca nc CHXHCN Vit Nam (2003) th Mi trng

bao gm cc yu t t nhin v yu t vt cht nhn to quan h mt thit vi nhau, bao quanh con ngi, c nh hng n i sng, sn xut, s tn ti pht trin ca con ngi v thin nhin (iu 1 Lut BVMT-2003).

Mi trng theo cch hiu tng i c th l rt rng (nh v tr, tri t, khng kh...) v cng c th l hp (mi trng nc b mt, mi trng sng, mi trng sng trong cn h...)

Cc yu t to ra mi trng c gi l thnh phn mi trng. Trong khi nim v mi trng ngoi yu t t nhin, phi lun lun coi trng cc

yu t vn ho, x hi, kinh t... bi v chng l thnh phn ht sc quan trng to ra mi trng sng.

Trong mt mi trng c th bao gm mt hay nhiu h thng sinh vt tn ti, pht trin v tng tc ln nhau. V vy, mt h sinh thi l mt h thng cc qun th sinh vt, sng chung v pht trin trong mt mi trng nht nh, quan h tng tc vi nhau v vi mi trng (iu 2-9 lut BVMT-2003).

a dng sinh hc l s phong ph v ngun gen v ging, loi sinh vt (ng vt, thc vt, vi sinh vt...) v h sinh thi trong t nhin. S a dng ca sinh hc nhiu khi c xem xt mt cch rt tng qut v cc h sinh thi trong mt mi trng nghin cu. a dng sinh hc nhiu khi cng c xem xt ht sc chi tit, t m trong mt h sinh thi - l qu trnh xem xt, nh gi n cc loi, ging v k c nh gi c im v di truyn ca chng (Gen)

Mi trng c thnh phn ht sc quan trng, l con ngi v cc hot ng ca con ngi k c t nhin v vn ho - x hi. Con ngi, trong qu trnh tn ti v pht trin d bng ngu nhin hay c tnh cng lun lun tc ng vo mi trng. Ngc li, mi trng cng lun tc ng n con ngi. Qu trnh pht trin lun lun km theo s dng (t, g, nc, khng kh, nhin liu ho thch, ti nguyn cc loi ) ng thi cng thi vo mi trng cc cht ph thi (cht thi rn, lng, kh t sinh hot , t cng nghip, t nng nghip, giao thng, y t...). Nhng cht thi dn dn lm nhim mi trng. Chnh v vy, ngi ta cho rng: pht trin l ng hnh vi nhim.

S phn hu cht bn trong mi trng t nhin l mt quy lut hng vn nm. Qu trnh phn hy cht bn nh vy nh tc ng rt tch cc ca t, vi sinh vt, nc, bc x mt tri, ng v thc vt cc loi... V vy, qu trnh c gi l qu trnh t lm sch. Cc qu trnh t lm sch tun theo mt quy lut ring ca chng v ng vi mt tc lm sch xc nh.

Nh vy, con ngi mun tn ti v pht trin c trong mi trng ca mnh th nht thit phi xc lp tt mi tng quan gia pht trin vi t lm sch ca mi trng.

lm c nhim v trn, cn hiu c nh hng ca cc hot ng kinh t - x hi, hot ng sn xut n cc yu t cu thnh mi trng. Ngc li cng cn hiu c cc phn ng ca mi trng n cc thnh phn mi trng. Qu trnh hiu, xc nh nh gi c gi l nh gi tc ng mi trng (TM hay EIA).

Do , Lut BVMT 2003 (iu 2-11) nh ngha: nh gi tc ng mi trng l qu trnh phn tch, nh gi, d bo nh hng n mi trng ca cc d n, quy hoch pht trin kinh t x hi ca cc c s sn xut, kinh doanh, cng trnh kinh t, khoa


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hc, k tht, y t, vn ho, x hi, an ninh, quc phng v cc cng trnh khc, xut cc gii php thch hp v bo v mi trng.

Vo khong cui nhng nm 60 ca th k 20, khi nim nh gi tc ng mi trng c hnh thnh r nt v c thc hin M. Sang nhng nm 70 ca th k, TM c s dng nhiu quc gia nh: Anh, c, Canada, Nht, Singapo, Philippin v Trung Quc...

Vit Nam , nhng vn mi trng bc xc bt u xut hin kh r t nm 1990. V vy, khi nim nh gi tc ng mi trng (TM-EIA) khng cn l khi nim ring trong i ng cc nh khoa hc na. Khi nim TM chuyn vo i ng cc nh qun l v khoa hc - k thut rng hn ng thi c a vo Lut BVMT (1994).

Trong lut BVMT (2003) Nh nc quy nh mt s iu cht ch l: iu 17: T chc, c nhn qun l c s kinh t, khoa hc, k thut, y t, vn

ho, x hi, an ninh, quc phng hot ng t trc khi ban hnh lut ny phi lp bo co nh gi tc ng mi trng ca c s mnh c quan qun l Nh nc v bo v mi trng thm nh.

iu 18: T chc, c nhn khi xy dng, ci to vng sn xut, khu dn c, cc cng trnh kinh t, khoa hc, k thut, y t, vn ho, x hi, an ninh, quc phng, ch d n u t ca nc ngoi hoc lin doanh vi nc ngoi, ch d n pht trin kinh t - x hi khc phi lp bo co TM c quan qun l Nh nc v mi trng thm nh.

Nh vy, thc hin mt TM cho d n tr thnh yu t rt quan trng trong khoa hc mi trng, hn th na tr thnh yu t bt buc trong cng tc qun l Nh nc v BVMT.

Do hon cnh kinh t cha mnh nn t khong 1985 n 1992 cc d n ln v trung bnh ca ta v c bn cha c lp bo co TM m ch cp s b n mt s vn mi trng c th xy ra. Sau 1992 mt s d n quan trng c nh gi tc ng mi trng nh thu in Sn La, Sng Hinh hoc nh my ma ng i Loan (Thanh Ho), nhiu cng trnh khoan thm d du kh cng c lp bo co TM. Gn y, cc d n c lp bo co TM ngy cng nhiu nh: ng mn H Ch Minh, khu cng nghip Dung Qut, cng nc su Ci Ln v nhiu cu ng khc...

2. Cc yu cu i vi cng tc nh gi tc ng mi trng Vi ni dung, mc ch v ngha nh ni trn, cng tc TM ni chung v bo

co TM ni ring, phi t c nhng yu cu sau: 1. Phi thc s l mt cng c gip cho vic thc hin quyt nh ca c quan qun

l. Thc cht ca TM l cung cp thm t liu c cn nhc, phn tch c quan c trch nhim ra quyt nh c iu kin la chn phng n hnh ng pht trin mt cch hp l, chnh xc hn.

2. Phi xut c phng n phng trnh, gim bt cc tc ng tiu cc, tng cng cc mt c li m vn t c y cc mc tiu v yu cu ca pht trin. C th ni rng, khng c hot ng pht trin no c th p ng nhng li ch v yu cu cp bch trc mt ca con ngi m khng lm tn hi t nhiu n TNMT. TM phi lm r iu , khng phi ngn cn s pht trin kinh t - x hi m to iu kin thun li nht cho cc hot ng . V vy TM c trch nhim nghin cu, gp phn xut bin php bo v, thm ch ci thin c tnh hnh TNMT. Khi phng n xut khng th chp nhn c v gy tn hi qu ln v TNMT th phi xut phng hng thay th phng n.

3. Phi l cng c c hiu lc khc phc nhng hiu qu tiu cc ca cc hot ng c hon thnh hoc ang tin hnh. Trong thc t, nht l ti cc nc ang pht trin nhiu hot ng pht trin c tin hnh hoc c hon thnh, nhng lc xut cha h c TM. Do , hnh thnh nhng tp th khoa hc c kin thc, kinh nghim v phng php lun cn thit, ph hp vi ni dung v yu cu ca TM trong tng trng hp c th l ht sc quan trng.


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4. Bo co TM phi r rng, d hiu. Khoa hc mi trng rt phc tp, ni dung khoa hc c xem xt trong TM rt phong ph. Tuy nhin ngi s dng kt qu cui cng ca TM c khi khng phi l nh khoa hc, m l ngi qun l. V vy bo co TM phi r rng, d hiu, dng ngn ng , thut ng ph thng. Cch din t v trnh by phi c th, thit thc, c sc thuyt phc, gip cho ngi quyt nh nhn thy vn mt cch r rng, khch quan, t quyt nh ng n, kp thi.

5. Bo co TM phi cht ch v php l, bo co TM khng nhng l c s khoa hc, m cn l c s php l gip cho vic quyt nh nhng vn quan trng v pht trin kinh t - x hi lin quan n i sng vt cht, tinh thn ca nhn dn trong c nc, hoc mt vng, mt a phng.

6. Hp l trong chi tiu cho TM. TM l vic lm tn km, i hi nhiu thi gian. Kinh nghim cc nc pht trin cho thy vic hon thnh mt bo co TM cp quc gia i hi thi gian t 10 n 16 thng, chi ph t hng chc nghn n hng triu la.

3. Mc tiu ca gio trnh Gio trnh nh gi tc ng mi trng (TM) ny c bin son ging dy cho sinh vin ngnh Mi trng, sinh vin ngnh Qun l t ai. Cun sch cng c th lm ti liu cho nhng ngi mi nhp mn nh gi tc ng mi trng. Vi i tng nh vy, chng ti c bit ch trng n phn b tc kin thc v mi trng nht l sinh vin ngnh Qun l t ai. lm c iu ging vin c th s dng phn ph lc 1, khai trin cc vn ngi hc hnh dung c bc tranh tng qut ca mi trng t nhin. Ngi hc cn hiu r kh quyn thu - quyn - a quyn - sinh quyn, trong phi nm chc c:

Hin tng suy gim cht lng MT v yu t tc ng. Hiu ng nh knh v yu t tc ng Bn cha CO2 trong i dng Vai tro v qua h ca sinh quyn vi kh quyn, thy quyn v cc nh hng lm

suy gim tng zn dn n l r zn. y l mn hc tng hp nhiu khoa hc, mt khc thc hin mt TM y l

rt kh khn, v th ngi hc phi hiu c quy trnh tng qut. Nm vng c th thc hin c phn n gin l xy dng mt lc duyt, nh gi tc ng mi trng s b. Yu cu v thc hin mt TM y cha t ra m ch dng mc c v hiu c mt bo co TM y do nhm tc gi, t chc no thc hin.

4. Cu trc v khi lng kin thc Gio trnh TM gm phn m u, chng I (trnh by v mt s i lng, ch th,

ch s ca mi trng v mi lin h gia chng. Khi nim v tm quan trng v thi gian, v kinh t khi lp k hoch thc hin mt nh gi tc ng mi trng). Chng II cung cp cho ngi hc nm c tri thc, trng trnh thc hin mt lc duyt, mt TM s b, mt TM chi tit nhng theo kiu rt gn v mt TM chi tit, y . Chng III gii thiu cc phng php tin hnh thc hin mt TM trong la chn i su vo 4 phng php c dng nhiu Vit Nam c bit l phng php c lin quan, hay c s dng thc hin TM i vi t ai, QHSD t ai v s dng t ai. Chng IV l mu cho cng ca TM, mu ny cung cp cho ngi hc kiu xy dng cng tt, ph thng.

Phn cn li ca chng IV l gii thiu (tm tt) mt s kt qu nh gi tc ng mi trng Vit Nam, phn ny c tm tt kt qu thc hin TM v gip cho ngi c: Mt c s l lun, phng php lun. Gii thiu cc TM cho khu vc bo tn vn quc gia, mt TM cho xy dng ng giao thng, mt TM cho m rng c s y t v mt TM cho quy hoch s dng t v.v...

Phn yu cu quan trng nht m sinh vin phi lm c l:


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Hiu r ch th, ch tiu mi trng thy nh hng ca hnh ng d n lm thay i, lm nh hng n n.

Bit xy dng mt cng gn cho TM. Bit cch thc hin iu tra, ly mu v thu thp d liu tng hp cc kt qu

thnh mt sn phm lm c s d lii cho cc bc tip sau. Bit lm mt lc duyt v mt TM s b theo phng php lit k v phng

php ma trn n gin. Bit xy dng mt bo co TM trn c s lut nh. Vi yu cu , gio trnh mc d l 3 trnh song phn vit v l thuyt v phng

php y ch c thc hin trong 2 trnh. Mt trnh cn li, sinh vin s c gio vin hng dn thc hin xy dng mt TM theo mt d n nh (QHSD t, xy dng mt khu th t, cho mt bi chn rc, cho s dng t cp huyn, cho mt x nghip ch cng nghip bin, mt nh my loi nh..). Gio vin cng sinh vin tin hnh la chn d n c sn thc hin TM . lm tt phn ny, sinh vin cn nghin cu k l lun, nm k chng IV v gio vin c trch nhim phn tch hnh ng ca d n sinh vin tm ra cc tc ng. Phn tc ng bc 2 v d bo lu di cha i hi.

Vi sinh vin chuyn ngnh Mi trng, cn thm mt tn ch v Thc hnh DTM. y l phn sinh vin phi tin hnh ti mt c s CN, NN, Giao thngdo gio vin hng dn. Trong phn ny sinh vin phi thc hin mi giai on ca mt DTM v bn bo co nh gi tc ng Mi trng.

5. Gio trnh nh gi tc ng mi trng ny c vit ln u. Qu trnh vit tham kho mt s ti liu (xem phn ti liu tham kho chnh). Sinh vin c th c thm gio trnh ca Phm Ngc H, Hong Xun C: nh gi tc ng mi trng ca Nxb i hc Quc gia H Ni (2001). Ngoi ra c th c cc sch hng dn v thng xuyn cp nht trang Web ca B Ti nguyn Mi trng: http://www.nea.gov.vn. Trong cc nm gn y, nht l t 2005 chng ta c nhiu thay i ton din, v vy cc thay i cp nht v hon chnh v DTM cng c b sung. Ngoi DTM, chng ta cn thc hin cc nh gi tc ng MT chin lc (DTMC), cc Cam kt BVMT, cc K khai pht thi l cc thanh cng c quan trng trong h thng vn bn php quy BVMT. Tuy nhin cng cn ch phm vy, yu cu, iu kin ng dng cc cng c ny vo thc t sn xut.


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Chng I

CC CH TH, CH S MI TRNG V LP K HOCH CHO TM

Chng I ny nhm cung cp cho ngi c mt s khi nim v nh ngha v mi trng nh: mi trng, trng thi, thnh phn mi trng, ch tiu, ch s v.v... y l nhng nn c bn c th hiu c ngha v vai tr ca TM.

Phn gii thiu v lp k hoch TM l phn trang b bc chun b ban u, n gip cho nh chuyn mn nhn r tng yu t i su thc hin mt TM va nhanh va tit kim v ph hp.

1. B tc kin thc v mi trng (theo ngnh o to, xem ph lc) 2. Cc nh ngha v khi nim v mi trng 2.1. Mi trng + Mi trng bao gm cc yu t t nhin v yu t nhn to quan h mt thit vi

nhau, bao quanh con ngi, c nh hng ti i sng, sn xut, s tn ti, s pht trin ca con ngi v thin nhin (Lut BVMT.2003).

+ Mi trng l tng th nhng iu kin bn ngoi tc ng n cuc sng, s pht trin v s tn ti ca mt sinh th (c quan bo v mi trng M -EPA-Enviromental Protection Agency)

2.2. Trng thi (State): Trng thi hoc tnh trng mi trng ca mt khu vc hoc quc gia chnh l trng thi ch yu ca mi trng trn hai phng din: tnh trng vt l - sinh hc v tnh trng kinh t - x hi.

Mi trng lun c mt trng thi no v khng hon ton n nh di tc ng ca t nhin v hot ng sn xut.

Cc hot ng ca t nhin v con ngi to ra p lc (Pressure) lm thay i trng thi mi trng. X hi (v c yu t t nhn) phi p ng (Response)vi hin trng mi bng s pht trin, s vn ng tip theo.

2.3. P lc (Pressure): ca t nhin v con ngi ln trng thi mi trng chnh l cc vn ng, hot ng sn xut pht trin, v vy, n lm thay i trng thi c.

2.4. p ng (Response): p ng vi p lc chnh l nhng thay i trong mi trng (nh hiu ng nh knh - do kh thi CO2 tng; t l ngi cht tng khi pht sinh dch bnh, nhim c mi trng) v p ng ch ng ca con ngi (nh: x l thi, bo v a dng sinh hc, s dng nc v nng lng tit kim, thay i th ch v lut, p ng c th trong cng ng...) Nh vy khi nim p ng phi hiu rng, y theo c hai mt l bn thn t nhin p ng li p lc (dn n tt v cha tt) v s p ng c tri thc ca con ngi ph hp hoc gim thiu cc p lc ca mi trng.

Trng thi - p lc - p ng l gn lin, l mt khung lin kt (Environment Framework) m t chc hp tc v kinh t v pht trin xut nm 1993 (Ogranization for Economic Cooperation and Development).


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Hnh 1.1. Khung lin ktTrng thi - p lc - p ng

2.5. Thnh phn mi trng: L cc phn vt l, ha hc, sinh hc ca mi trng kh quyn, thy quyn (trn bin v lc a) ca mi trng thch quyn v sinh quyn (nh kh hu, thnh phn vt l, thnh phn ho hc, a cht, sinh ho hc v mi tim nng v ti nguyn) to ra mi trng .

B phn rt quan trng trong thnh phn mi trng l a dng sinh hc.

2.6. Ch tiu mi trng (Environment factors) Ch tiu mi trng hoc ch th mi trng (Factors, Indicators) l nhng i lng

biu hin cc c trng ca mi trng ti mt trng thi xc nh. V d: Suy gim tng zon, axit ho t, ngun nc, ph dng, cht thi, ti

nguyn rng, ti nguyn nng nghip, a dng sinh hc, nhim cht c, ti nguyn c, cht lng mi trng th, s thay i kh hu...

Cn hiu rng: Cc ch th mi trng l ht sc phc tp - n khng phi ch l mt tham s ring bit m l mt tp hp ca nhiu tham s (Parameters) trong . Mt khc theo nhiu quan im, theo nhiu iu kin mi trng khc nhau v mc nh gi cn n u m cc tc gi, cc t chc a ra cc ch th .

Vi mi trng t - ch th ph cp nht cho t ai (Land) c s dng nhiu, phn ln cc cng trnh s dng ch th t ai l:

Ti nguyn g v ng c (theo NCFEA (1995) - (National Center for Economic Alternatives).

Ti nguyn g, t nng nghip, cht lng mi trng th v cht thi (theo Nordic Council of Ministers - 1997).

Trng hp th 3, xut pht t quan im s dng bn vng t ai, ngi ta a ra cc ch th gm: Nng sut cy trng, cn bng dinh dng, s tn ti ca lp

p lc Nng lng Cng nghip GTVT Nng nghip Ng nghip Khc Thin tai, s c MT

Trng thi Ti nguyn nc Ti nguyn t ai (Land) Ti nguyn t (Soil) a dng sinh hc Khu dn c, cht thi Khu CN, ng x Di sn vn ha Khc

p lc

Ngun lc

p ng - Kh nng t phc hi - Cng c k thut CN mi - Cng c kinh t - Lut php - Quan h cng ng - Rng buc quc t - Khc

Thng tin

Cc p ng x hi (cc quyt nh hnh ng)

Thng tin

Cc p ng x hi (cc quyt nh hnh ng)


13

ph t, cht lng t (Soil) v qu t (Land), cht lng v tr lng nc, kh nng sinh li ca h thng trang tri, s tham gia ca ngi dn v x hi trong bo v mi trng (Dumanski. 1994 v DSE - ZEL (1996) - Sustanable Land use in Rural Areas: Tool for Analysis and Evaluation).

Trong cc trng hp nghin cu c th, hp hn ngi ta s dng mt s thng s khoa hc lm nhim v ca thng s mi trng ng thi cc thng s ny (parameters) cng c xem nh cc ch th mi trng (Indicators) v d: lng t si mn, nhim thuc bo v thc vt, nhim kim loi nng trong t trng, vi sinh vt gy bnh...

2.7. Thng s mi trng (Parameters) L nhng i lng vt l, ha hc, sinh hc c th c trng cho mi trng ni

chung v mi trng t ni ring c kh nng phn nh tnh cht ca mi trng trng thi nghin cu (k c t v t ai).

V d: pH, dn in (EC), mn, t trng, % hu c (OM), phn b kim loi nng (Cu, Pb, Cd, Zn...), hm lng dinh dng N, P, K..., dy lp ph tn d hu c, kh nng tr nc, % cp ht, cht, m, nn kt cu cng trnh, loi v hng t.

Cc thng s mi trng c th l ring bit, c th c s dng cc thng s KHKT ca nhiu ngnh khoa hc khc.

Cc thng s mi trng l cc tham s ca ch th mi trng (Indicators) hoc ch tiu mi trng (Factors). Nhiu trng hp bn thn mt thng s mi trng c dng nh mt ch th MT.

2.8. Tiu chun MT (Standards) Cc tiu chun MT ca mt quc gia c xy dng ph hp vi iu kin v trnh

pht trin ca n. Tiu chun MT chnh l s chun ha cc thng s MT ti mt gi tr (hoc mt

khong gi tr) no . V d: TCVN v t nng nghip: Cd l 2 mg/kg; Zn l 80 mg/kg (TCVN 7902 -

2002)

2.9. Gi tr nn (Alternative Value) Gi tr nn (ca mi trng) vi mt i lng no (v d Cd) l gi tr nguyn

thu ca n trong MT ang xem xt. Gi tr nn ca Cd l gi tr nguyn thy ca Cd trong t. Tuy nhin, gi tr ny

khng xc nh c khi MT t cn "nguyn thu". V vy, thng ngi ta tin hnh kho st hng lot mu v ly gi tr c xc nh l nn khi gi tr l gi tr (hoc khong gi tr) c xc xut tn sut xut hin t 95% s mu phn tch (hoc php o).

2.10. Ch s mi trng (Indices, Indexes) Ch s mi trng l gi tr c tnh ton trong mt iu kin mi trng no

(kh, nc, t) theo mt s thng s mi trng c mi trng . Gi tr cc thng s mi trng ny thu c nh cc php o lin tip trong mt khong thi gian di hoc mt s php o ln.

Ch s mi trng c nhiu tc gi hoc t chc a ra trong cc iu kin khc nhau phc v cho mc tiu nghin cu, qun l. Xin nu mt s ch s lm dn liu:

Ch s cht lng kh (Air Quality Index - AQI - Ott 1978) AQi= Wi * Ii , y i l loi cht kh gy nhim (i =CO, SO2, tng ht bi rn)


14

Ch s cht lng nc ca Horton (1996)

2*1Wi

Ii*Win

1i

1 MMQi

n

i

=

=

=

y Wi l lng gy nhim ng vi kiu cht i, M1, M2 ng vi kiu nhim c s dng (bn thi, du, nc thi c mu...) Cc ch s v t (Soil) v nc ti thng gp nh: phng trnh mt t ph

dng (Universal Soil Loss Equation - Wishmier 1976). A = R * K * L * S * C * P Ch s v xi mn t c th s dng m hnh xi mn da vo GIS m Pilesjo

gii thiu 1992. Nh vy, ch s mi trng c th c nhn nhn nh mt ch tiu mi trng

c nh lng ha thng qua kho st, o c thc nghim n mt gi tr no ph hp vi iu kin mi trng ti khu vc kho st.

(Trong mc 2.10, chng ti ch s dng cc ch s lm dn liu, khng i su phn tch. Nu cn i su, xin c gi thng qua cc ti liu dn).

2.11. Phng php v cng c nghin cu. y l vn cn thng nht trong qui nh chung c th t cng ng v sai

s cho php vi cc php o, php tnh ton. Lm c iu ny mi c kh nng so snh i chiu cc s liu mi trng.

2.12. m bo cht lng v kim sot cht lng (QA/QC) (Quality Assurance/Quality Control). QA l h thng kh thi cc hot ng qun l v k thut lin quan n nhn s, phng tin, phng php trong cc trm, cc c s lm cng tc quan trc v phn tch mi trng t nhm m bo cho tt c cc cng vic t c kt qu m bo cht lng mong mun.

QC l cc th tc, bin php, vn bn, chng trnh nh gi c tin hnh song song vi hot ng c th ca cng vic quan trc, phn tch mi trng t t mc tiu, thit k, mng li, cng tc hin trng, phng TN n bo co, x l thng tin, xy dng v chia s ngun c s d liu.

2.13. Quy hoch mi trng (QHMT) (Environmental Planning) C th dng nh ngha ca Alan Gilpin (1996): QHMT l s xc nh cc mc tiu

mong mun i vi mi trng t nhin bao gm mc tiu kinh t - x hi v to lp c cc chng trnh, qui trnh qun l t c mc tiu .

Cng trong nm 1996 Toner cho rng: QHMT l vic ng dng cc kin thc v khoa hc t nhin v sc khe trong cc quyt nh v s dng t.

Gia QHMT, TM v vng sinh thi c lin h mt thit.

Hnh 1.2. Khung lin kt sinh thi - Quy hoch mi trng - TM

ST

QHMT

TM


15

R rng gia QHMT, TM, t v vng sinh thi (ST) c lin h mt thit. V l khi tip cn nghin cu TN khng th no qun lng mi lin h ny.

2.14. Quy hoch s dng t (QH) (Land use planning) QHSD t l vic xc nh, phn b hp l qu t cho cc mc ch s dng t

nng nghip, lm nghip, chuyn dng (xy dng, giao thng, thy li, KHKT, vn ha, gio dc, y t, th dc th thao, quc phng, an ninh...), t th, nng thn... theo mc tiu pht trin kinh t - x hi ca quc gia.

2.15. S dng t (Land use) S dng t (SD) l qu trnh thc hin cc hot ng kinh t, x hi, sn xut an

ninh, quc phng... theo mt QHSD t hoc t pht din ra trn mt khu vc hoc vng lnh th c tc ng n t ai (Land) v c tc ng n t (Soil) cng nh cc hp phn ca chng (nc mt, nc ngm, thc vt...)

2.16. Tnh bn vng (Sustainablity) Theo nh ngha ca FAO (1992) - trnh by trong phn nh gi TN theo thnh

phn sinh - ha - l (nh ngha cho nng nghip bn vng v pht trin nng thn).

3. Lp k hoch cho TM 3.1. Nguyn tc chung: Nguyn tc chung c gii thiu sau y (UNEP, FAO)

Hnh 1.3. Khung lin kt lp k hoch cho TM

iu kin u + Chun b d n; s cn thit ca d n; cc c s cho s ph hp. + Thu thp ng thng tin t c quan qun l. + Nhn bit cc tc ng tim tng

Cc tc ng + D bo tc ng + nh gi tc ng + Vic lm nh tc ng

Quyt nh cn + S la chn cc hot ng + La chn cc hnh ng d nh

Cung cp t liu chng minh

+ Chun b t liu vit + Monitoning mi trng


16

3.2. Nhng TM ring La chn, nh gi s b

La chn c im ring Xc nh ng thng tin ca d n tip theo cn xc nh ng cng ngh. S b xc nh tc dng tim tng s xy ra.

nh gi tc ng, xut nh gi cc tc ng s xut hin (5 nm, 10 nm, 20 nm sau) xut phng hng gim nh cc tc ng

(Bng vic thay i cng ngh, thay i phng php, thay i trnh t ca d n) a ra quyt nh

La chn cc hot ng ca d n. D kin hot ng thay th v chn la ng

Xy dng d liu, cung cp t liu chng minh Cc d liu chng minh cc tc ng Cc d liu xut, t phng hng Monitoring mi trng v tng kt La chn cc hot ng ca d n. D kin hot ng thay th v chn la ng

Xy dng d liu, cung cp t liu chng minh Cc d liu chng minh cc tc ng Cc d liu xut, t phng hng Monitoring mi trng v tng kt

3.3. Chun b cc bc TM Lc duyt (xy dng: phng php, bc i) nh gi s b (chn phng php, chn yu t cn i su, nh gi nh lng) nh gi chi tit (chn phng php, yu t cn i su, nh gi nh tnh) Xy dng c s d liu (Database) Bo co (nh gi, d bo tc ng, xut khc phc gim nh) Monitoring

4. Nhng ni dung chnh trong vic thc hin nh gi tc ng mi trng 4.1. Lc duyt: y l bc u nhm xc nh s cn thit hoc khng cn thit

phi thc hin mt TM y . C s thc hin lc duyt l: Danh mc lit k cc vn cn phi lm TM ca d n. Gii hn v quy m, phm vi kch c ca d n. Vi quy nh ca Chnh ph, quy

m no, phm vi no ln s phi thc hin TM. Mc nhy cm ca ni thc hin d n (mc nhy cm v mi trng t

nhin nh t, khng kh, nc, h sinh thi v mc nhy cm v mi trng x hi, nhn vn).

Nhng vng nhy cm thng l: vng c ngha lch s vn ho, kho c, khoa hc. Vng t ngp nc. Khu vc vn quc gia, khu bo tn thin nhin, vng c h sinh thi c bit. Vng cn bo v gen ca ng, thc vt him. Vng t dc, ni cao c rng u ngun. Vng thng xy ra s c mi trng, ri ro thin tai. Vng c cht lng mi trng c bit, d thay i cc tham s mi trng

Mt s d n thuc phm vi quy nh quc gia khng cn phi thc hin TM. Mt s d n quy nh thuc loi lun lun phi thc hin TM d loi d n quy m ln hoc quy m nh.


17

Thng quyt nh cn hay khng cn thc hin TM y m dng li mc mt lc duyt l: Nh nc, c quan ch d n hoc Cc Bo v mi trng. Mt s trng hp khc c th da vo quyt nh ca mt hi ng t vn do Chnh ph u thc.

c th quyt nh cn mt lc duyt hay phi lm TM y ta c th phi thc hin mt s hot ng l:

Bn bc trao i gia ch d n vi c quan qun l Ly kin cc chuyn gia Ly kin ca c quan BVMT v kim sot nhim Tham kho cc d n tng t khc. Ly kin cng ng Nh vy, nu d n khng cn thc hin mt TM y th cho php thc hin d

n. Trong trng hp cn thc hin mt TM y th phi chuyn sang cc ni dung khc.

4.2. Lp cng (theo k hoch nu trn) v chun b t liu. Nhng vic cn phi c l:

Ni dung d n, t xc nh: + Hin trng mi trng + Phng n ca d n + So snh cc yu t gia phng n v hin trng.

Xc nh cc hnh ng ca d n Xc nh cc bin i mi trng do cc hnh ng ca d n gy ra (c bin i

xu v tt) v cc mt: Vt l, Ho hc v Sinh hc v Kinh t vn ho x hi. Xc nh cc tc ng ti ti nguyn thin nhin, sinh thi, cht lng mi

trng v cuc sng cng ng (k c tc ng bc 1, bc 2). D bo din bin tc ng mi trng Xc nh phng php cn s dng thc hin TM xut phng n gim thiu tc ng hoc phng n thay th. Bo co TM Vic lp cng chi tit theo nhng vic cn lm nht nu trn s c gii thiu

chng 4 (mc 4.1)

4.3. Xc nh mc cn nh gi tc ng Trong ni dung ny, cn lm r cc vn sau y: Mc cn thit chi ph ti chnh ph hp nht Tp trung c vo cc tc ng c nh hng nht khng th b qua. To c s ho hp gia quyn li ca d n (ch d n) vi cng ng v to

c kh nng khc phc, lm gim thiu cc tc ng c hi i vi mi trng. t c tt nht v hiu qu kinh t cho d n v cho c cng ng v lu di.

Ph hp vi Lut v cc chnh sch. lm tt vic xc nh mc v phm vi cn nh gi tc ng, ta nht thit phi

lm tt, y , chnh xc 4 bc l: + Xc nh r kh nng tc ng ca cc hnh ng ca d n n mi trng v

ngun ti nguyn thin nhin. + Phi xut c phng n gim thiu hoc thay th. Nhim v ny c cn

nhc trn Lut, Ngh nh, TCVN, trnh khoa hc v cng ngh cn phi c, nhu cu v c im ca sn phm ca d n, hiu qu thc v kinh t, bin php khc phc cht thi v cui cng l giai on theo di, kim tra, monitoring v phng ri ro.


18

Sau khi thc hin cc vn nu trn, hai vic quan trng k tip phi thc hin na l:

+ Ly kin cng ng: Vic ly kin cng ng gip cho cc nh qun l, cc nh khoa hc pht hin c nhng vn cng ngh cn cha ph hp. Mt khc quan trng hn l gip cho ch d n - nh qun l - cng ng c th b sung nhau, ho nhp d n t hiu qu cao nht.

+ Cn nhc v ra quyt nh: y l vic cn li ca c quan qun l ti nguyn mi trng. Vic ra quyt nh ng v nhanh chng, ph hp s lm d n thc hin tt v tc ng i vi mi trng c th chp nhn c sau ny.

4.4. nh gi cc tc ng n MTST v TNTN Xc nh cc hnh ng ca d n (hay trng thi ca mi trng) c th gy ra

tc ng mi trng sinh thi. y, chng ta cn phi xc nh rt y v tc ng n c mi trng t nhin, mi trng kinh t - x hi v nhn vn. Xc nh cc tc ng c th c n cc h sinh thi: khng kh, sinh thi t; sinh thi nc mn, nc ngm, cc h sinh thi sinh vt v c bit phi ch n h sinh thi nhy cm nh (sinh thi t dc, sinh thi rng, sinh thi t ngp nc).

Xc nh c cc bin i bc 1 tc l cc hnh ng ca d n s phi dn n cc tc ng tng ng. Cc tc ng tng ng a dn cc bin i trc tip ca mi trng. Nu c nhiu hnh ng th s dn n nhiu tc ng v tt nhin s c nhiu bin i bc 1.

Xc nh cc bin i bc 2: Cc bin i bc 1 lm cho trng thi mi trng thay i t trng thi 1 sang trng thi 2. S tn ti, cc hot ng ca trng thi 2 c th s dn n mt s tc ng tim n i vi trng thi 2 ca mi trng. Nh vy, trng thi 2 ca mi trng s c th (hoc khng th) thay i dn n mt s bin i mi. Nhng bin i mi ny c gi l bin i bc 2.

Phn tch k cc tc ng, xc nh cc tc ng a n bin i bc 1 v bc 2 (nu c) t y phn tch v d bo cc tc ng c th i vi mi trng sinh thi v ngun ti nguyn thin nhin (ti nguyn t, ti nguyn nc, ti nguyn sinh vt, a dng loi, ti nguyn kh tng thu vn, ti nguyn khong sn). lm tt phn ni dung ny, thng nhm chuyn gia thc hin TM phi tin hnh tham kho rng cc chuyn gia, cc t chc trong v ngoi nc, t liu lu tr, cc tiu chun cho php (TCCP) c bit l TCVN. Trong phn tch, nh gi mt vn ht sc quan trng l cn i gia d n v cc tc ng m tiu ch ln nht l hiu qu kinh t ca d n v hiu qu kinh t mi trng. y l mt vn rt quan trng song rt t nh, v th cn b sung cp nht cc quy nh, ngh nh ca quc gia v mi trng v da vo kinh t mi trng quyt nh.

4.5. Xc nh c bin php gim thiu tc ng v qun l chng y l mt vn kh, i hi tng hp tri thc theo cc d n khc nhau. Nhn

chung, c th theo mt s vn sau y: a ra mt s phng thc mi thay i ph hp vi yu cu ca D n v ho

hp vi mi trng sinh thi (v d: thay i cng ngh ph hp, b sung cng ngh, b sung hng mc).

Thay i hn thit k, quy hoch pht trin (nh my nhit in s dng than sang nh my s dng hi t)

xut mi hoc b sung kim sot hot ng nh ch d n hoc chuyn v tr ph hp hn.


19

Tt c cc vn ny u nm trong bc Xc nh cc ni dung chnh ca TM tc l xy dng k hoch chi tit. Nu bc ny lm tt chng ta s c th b qua mt s vic khi thc hin TM chi tit, trnh c lng ph v ti chnh v thi gian.

5. Cu hi bi tp chng I 1. Thnh phn mi trng l g? C th ch ra nhng thnh phn ca mi trng

trong mt h thng t nhin - kinh t - x hi mt huyn? 2. Mi quan h gia Trng thi (hin trng) - p lc - p ng l mt mi quan h

n hay a chiu? V sao? ngha ca hiu bit vn ny? 3. Phn bit khi nim thng s vi tiu chun v gi tr nn ca mi trng. 4. Ch tiu mi trng, ch s mi trng l i lng nh th no? 5. Lp k hoch cho mt TM l cn thit? V sao? 6. Cc bc chun b cho mt TM th no? C th gim bc no c? 7. Th no l hot ng ca d n? Th no l hnh ng? Th no l tc ng? 8. V sao nh gi tc ng n MTST li cn nh gi tc ng n TNTN?


20

Chng II

TRNH T THC HIN NH GI TC NG MI TRNG

nh gi tc ng mi trng l mt vic rt quan trng c ch, c ngha thc t i vi hot ng kinh t - x hi ca mt quc gia, mt khu vc. Mt khc, cng tc nh gi tc ng mi trng li l mt qu trnh tng hp va phn tch va nghin cu rt phc tp vi nhiu lnh vc khoa hc kinh t v cng ngh khc nhau do rt tn km v ti chnh. Hn th na thc hin mt TM thng phi s dng nhiu chuyn gia c kinh nghim v trnh cao v mt nhiu thi gian hon tt. Nhng vn ny xut pht t khi nim v Cy tc ng nh sau:

Chnh v vy ch cn thc hin TM cho mt s d n quan trng sau khi tin hnh xem xt y nhiu mt. Mt s d n khc hoc cc hot ng kinh t - x hi khc khi xem xt thy cc hnh ng ca d n tc ng khng nhiu n mi trng sinh thi v ti nguyn thin nhin c th b TM hoc thc hin TM mc s b cng c. Theo quan im ca chng trnh mi trng Lin hip quc (UNEP- United nations Environment programme)

Qu trnh nh gi tc ng mi trng thng c thc hin theo 3 bc ln: Bc 1: Lc duyt cc tc ng mi trng (Screening) Bc 2: nh gi s b cc tc ng mi trng (Preliminary Assessment) Bc 3: nh gi y cc tc ng mi trng (Full Assessment) Chng II s gii thiu chi tit cc ni dung . Sinh vin cn s dng c phn

lc duyt v phn nh gi s b tc ng mi trng, mt khc phi hiu c phn nh gi y tc ng mi trng.

B.3

T Bc 2

Tng bc 1

Tc ng gc


21

1. Lc duyt: y l yu cu ti thiu phi thc hin cho cc d n nm trong khun kh bt buc

phi xt n cc tc ng mi trng ca chng. Qu trnh thc hin mt lc duyt v nguyn tc phi c thc hin khi d n bt u hnh thnh, bt u chun b v mc tiu, quy m, khu vc d n, trnh cng ngh, trnh qun l thc hin v c im ring v vn ho, x hi, tp qun ca khu vc ln cn.

Vi iu kin Vit Nam, do trnh pht trin v kh nng ti chnh hn ch, nhng nm qua chng ta cn nhiu khim khuyt. V vy, nhiu d n (c bit l cc d n v quy hoch s dng t v s dng t) vic lm ny cha m bo. Trong rt nhiu trng hp, chng ta phi thc hin chm, thc hin vo thi k sau khi d n hoc ang vn hnh.

Mc tiu ca lc duyt l gip cho vic hnh thnh, xy dng d n t tt hn, y hn. V th, lc duyt do ch n thc hin.

Ni dung ca lc duyt l: R sot, im li nhng d n tng t n trc y c thc hin khu vc hay gn khu vc gy ra nhng hnh ng g? Nhng hnh ng ca d n li gy ra cc tc ng g n MTST v ngun ti nguyn thin nhin cng nh kinh t - vn ho - x hi. Trn c s xt sot nh vy, chng ta d on nhng tc ng c th xy ra ca d n s thc hin. Vic d on ng v cc tc ng ny s gip chng ta kp thi iu chnh, b sung hoc thay i mt phn d n mt cch nhanh chng, trnh lng ph v ti chnh v thi gian.

Phng php thc hin mt lc duyt l:

So snh chi tit quan trng ca d n ang xem xt vi cc d n tng ng c thc hin. Cn ch trng mt s yu t ln nh kiu d n, a im thc hin, quy m, cng ngh.

So snh d n ang xem xt vi hai loi d n khc trong : + Loi thng c php khng cn phi lm TM. + Loi th hai nht thit phi thc hin TM (loi ny thng l x nghip, nh my,

khu CN, ng giao thng, sn bay, bn cng, khu x l cht thi) Trn c s so snh , ta xc nh yu cu cn hay khng cn phi thc hin TM.

on trc bng suy lun trn c s KHCN, trn c s kinh nghim cc tc ng ca d n s gy ra vi mi trng v nh gi kh nng chu ng ca mi trng t nhin, x hi. Cn ch trng n kh nng p ng ca mi trng v ph hp vi chnh sch.

Phn tch kinh t, chi ph v li nhun trn c s cc ch tiu kinh t v x hi ang sn c ca d n v ca cc iu kin khc.

Thm nh mt lc duyt l chc nng ca c quan qun l mi trng. C quan ny c th trc tip thc hin hoc u thc cho mt t chc, cc nhn, nhm chuyn gia thc hin.

Mt trong cc quc gia c cu trc t chc v kinh nghim lm tt nht cng tc BVMT khu vc ng Nam l Singapo. Singapo c c quan qun l mi trng, c quan kim sot nhim mi trng (PCD). C quan ny c nhim v v quyn hn rt ln thm ch h c php ra quyt nh thay i phng n, thay i cng ngh v ngay c nh ch hot ng ca d n hoc nh ch hot ng sn xut ca mt c s gy nhim mi trng qu mc cho php.

Vit Nam, mc d mi pht trin lnh vc BVMT gn y song chng ta c Cc Bo v Mi trng, V Mi trng v V Thm nh v nh gi tc ng mi trng.


22

Nhng c quan ngy c nhim v gip Chnh ph hon chnh cc quy nh, qun l mi trng chng ta c mt bc i tt trong cng tc nh gi tc ng mi trng ni ring v BVMT ni chung.

lc duyt n c cc nh qun l, cn c mt vn bn quyt nh bc lc duyt. y l vn bn quyt nh cui cng. Vn bn ca lc duyt phi a ra c kt lun: c cn thit phi tip tc thc hin TM hay khng cn? Tip theo cn c quyt nh tip theo gii quyt nhng vng mc, nhng khuyn ngh cha thng nht gia ch d n v c quan kim sot.

Bn cnh , thc hin c hiu qu, mt s hot ng hu ch i n quyt nh bc ny l:

+ i thoi gia ch d n v c quan qun l + Ly t vn ca c quan kim sot nhim, c quan BVMT, bo v ngun ti

nguyn thin nhin (Cc BVMT, V Mi trng, V Thm nh v nh gi tc ng mi trng, Thanh tra mi trng...)

+ Ly t vn t cc nh khoa hc, cc c quan khoa hc khc. + Kho st cc TM tng t khc + Ly kin cng ng Tm li, c mt lc duyt, cn theo cc bc sau y:

D n pht trin (Chun b c d n)

Bc 1: Kim tra danh mc ca d n - Theo Lut - Theo quy nh

Bc 2: Kim tra a im ca d n C vng phi thc hin TM khng?

Bc 3: Tham kho sch, ti liu t liu hng dn nh gi tc ng mi trng

Bc 4: Thu thp thng tin (cc loi)

Bc 5: Lp danh mc cu hi lc duyt

Bc 6: Lp vn bn lc duyt


23

Hnh 2.1. Cc bc ca mt lc duyt

2. nh gi tc ng mi trng s b (IEE) nh gi tc ng mi trng s b (Initial Environmental examination - IEE) cn

c gi l nh gi tc ng mi trng ban u hay nh gi nhanh cc tc ng mi trng (Rapid Environment Impacts Assessment - REIA).

nh gi s b tc ng mi trng gm cc bc sau: Xc nh cc tc ng chnh ca mi trng (t cc hnh ng quan trng ca d

n) ti khu vc d n s xy ra. M t chung cc tc ng , d bo phm vi v mc ca cc tc ng trong

khi nh gi TM. Trnh by v lm r c tnh cht cc tc ng, tm quan trng ca cc tc ng

i vi mi trng. Yu cu ca bc ny l phi r v ngn gn c quan qun l c th a ra cc quyt nh ph hp.

TM s b cn c tin hnh ngay trong giai on lun chng s b (nghin cu tin kh thi). nh gi ny gip cho ta thu hp s tranh ci v mt s vn quan trng, nh v v tr, quy m ca d n. Trong mt s trng hp do lm tt nh gi s b, kp thi iu chnh khi nim v d n, lm cho vic TM y tr nn khng cn thit na.

TM s b do c quan ch tr d n thc hin theo cc hng dn ca quy nh TM ca quc gia hoc ca cc t chc quc t. Cc phng php thng dng l phng php danh mc v phng php ma trn tc ng mi trng.

Vic thm nh bo nh gi bi c quan qun l mi trng c th dn ti 2 kt lun:

Khng cn thit lm TM chi tit Cn thit lm TM chi tit. Vic thc hin nh gi tc ng mi trng s b l mt cng vic kh v phc tp

hn vic thc hin mt lc duyt. V vy, khi thc hin nh gi tc ng mi trng s b (hay nh gi nhnh) chng ta cn la chn mt nhm chuyn gia c trnh cao hn, nhiu kinh nghim hn v ng, phm vi chuyn mn m d n ang xem xt c lin quan n.

quyt nh mc tin hnh trong mt nh gi mi trng s b, cng c th da vo cc bc trong TM chi tit sau ny v nhm chuyn gia s quyt nh s dng phn bc no l cho cng vic ca mnh. 3. nh gi tc ng mi trng y (Full Environment Impacts Assessment)

nh gi tc ng mi trng y l khung c bn ca TM. y l bc thc hin sau lc duyt hoc TM nhanh kt lun cn phi lm.

hiu c nhim v ny cn nm r: 3.1. Mi quan h gia mi trng v pht trin 3.2. nh hng ca tc ng mi trng quy m ln a. Suy thoi TNSV:

a dng sinh hc Xi mn Kinh t - x hi

(Ngun [4] 2001)


24

b. Hiu ng nh knh Nc bin dng Ngp lt

c. nhim mi trng Ma axit Tng Ozon Sc khe con ngi

3.3. nh gi tc ng mi trng (TM) l nhim v xy dng mt bo co trong phi ch r c

a. TM tin hnh: Phn tch, xc nh qu trnh gy nhim, gy thit hi n mi trng. D bo cc tc ng n mi trng ca mt d n, mt chnh sch. xut cc phng n thay th. Xy dng chng trnh gim st v qun l d n

b. TM phi lm c s khoa hc thm nh d n. c. TM l kt qu ca s nghin cu a ngnh. 3.4. Mi quan h gia d n v TM (EIA)

Nghin cu tin

kh thi ca D n

Nghin cu kh thi

ca D n

D n

s b

TM s

b/nhanh

TM chi tit

a. nh gi tc ng v

sa i kh thi.

b. Duyt cc ch tiu c

bit. c. Duyt cc phng n.

d. Hn ch mi trng

a ra khuyn co

Duyt v la chn cc

phng n thc thi (cp giy php)

Nghin cu tin

kh thi ca D n

Tin hnh

d n

iu khin

mi trng


25

Hnh 2.2. S cc bc ca TM v d n pht trin. 3.5. iu kin thc hin TM a. C s php l (Lut MT, cc lut khc c lin quan, Ngh nh, Quy nh, Ch th,

Thng t, Cng c quc t, Tho thun ) b. Tiu chun mi trng (TCVN, TCN, WHO) c. S liu mi trng vng d n bao gm: Mi trng vt l, ho hc

+ a hnh, a cht + Cht lng khng kh + Kh tng thu vn

+ Cht lng nc

Mi trng sinh hc + Cc h sinh thi + Qun th thc vt, ng vt + Sinh vt qu him.

iu kin kinh t x hi (mi trng vn ho - x hi) + Dn s, dn tc + Hin trng s dng t + Sc kho cng ng + Ngnh ngh + Thu nhp + Vn ho gio dc + Cc tiu ch c trng ring.

d. Quy m d n, Cng ngh c s dng trong d n. Cn ch ra trnh CN, kh nng tip cn hin i trong tng lai, cc loi cht thi, cc nh hng trc mt v lu di

Nh vy, mun c mt bo co TM y , vic chun b v tri thc TM, v tri thc hiu bit ni dung d n pht trin hoc hot ng kinh t - x hi l ht sc quan trng. Bn cnh nhm chuyn gia thc hin TM y cng phi tin hnh chun b mi iu kin chi tit cho vic nh gi TM mt cch thn trng v bao qut.

Cng cn nhn thc r nguyn tc l: nh gi tc ng mi trng y (hoc TM chi tit) l hot ng ch c thc hin do mt s c quan c thm quyn tin hnh. Theo Ngh nh 80/ 2006/N- CP ngy 09 thng 8 nm 2006 v cc quy nh trong Ph lc cc danh mc cn thc hin DTM km theo. Cng cn phi tun th cc bc, cc quy nh v mu hng dn v cng, bo co, thm nh, ph duyt trong Thng t 08/2006/TT- BTNMT ngy 8/9/2006.

C quan ch d n hoc cp khng thm quyn ch c thc hin cc lc duyt hoc cc TM s b.


26

nh gi tc ng mi trng y phi theo mt trnh t quy nh. Trnh t ny phc tp, xin c gii thiu sau y:


27

Hnh 2.3. Trnh t ca mt TM y Ngun [5]-1994)

Trong mt s trng hp, ngi ta thc hin mt cch ngn gn theo 4 bc chnh l:

Xc nh cc hnh ng quan trng ca d n Xc nh cc bin i mi trng do cc hnh ng a n. Xc nh cc tc ng n TNTN v cht lng sng con ngi D bo din bin ca cc tc ng nh gi tc ng mi trng mt cch chi tit nhng c trnh by ngn gn theo

4 bc c gii thiu di y nhm gip cho ngi cha c iu kin i su c th hiu, tip thu v bc u thc hin mt TM.

D n - tm hiu d n

Quy nh khng cn TM

Cn lc duyt

Lc duyt ca cc tc ng MT

Tc ng MT khng ng k

Cn c nh gi MT

nh gi tc ng MT s b

Khng cn TM y

Cn chun b cho TM

Chun b cho TM y

Lp nhm nghin cu nh gi Xc nh phm vi nh gi (Scoping) Xc nh cc ni cn lin h Xc nh cc ni, thi gian np bo co Xc nh cng nh gi

nh gi tc ng MT y

Xc nh cc hnh ng quan trng ca d n ( Activities) Xc nh cc bin i MT (Env.Changes) Xc nh cc tc ng n MT (Indentifications) D bo cc tc ng tim n (Forecast) nh gi cc tc ng n TNTN (Evaluation) xut bin php (gim thiu, x l) (Mitigation measures) xut yu cu quan trc, theo di (Monitoring) Bo co v thng tin kt qu (Communication)

S dng kt qu nh gi tc ng MT


28

Cn phi hiu rng: y l mt kiu thc hin TM chi tit (khng phi l TM s b) 4 Bc c chn trong cch lm ny l nhng bc quan trng nht trong c qu

trnh. Sau ny khi i su hn, chng ta s tin hnh phn tch k tng bc v b sung, chia ct cc bc ra tu thuc vo yu cu ca TM v tnh phc tp nhiu hay t ca d n ang xem xt.

Ch : cn phn bit TMCvi TM v KTMT nh s di y.

TMC TM Kim ton mi trng (KTMT) Xc nh v tr ca TM trong tin trnh pht trin Vit Nam hin nay theo kinh nghim ca Th gii

4. nh gi tc ng mi trng chi tit (theo kiu rt gn) Gm nhng ni dung sau: nh gi c tc ng ca mt hot ng pht trin, v d ca mt d n pht

trin, trc ht cn xc nh (identification) cc tc ng m vic thc hin d n c th xy ra.

Vic xc nh ny thng i theo mt qu trnh phn tch logic, xut pht t mc tiu ni dung ca d n pht trin, cc hot ng c th s din ra trong qu trnh thc hin d n, tin n xc nh cc tc ng ca d n ti mi trng. Qu trnh ny c th din ra theo trnh t nh sau:

Bc 1 Xc nh cc hnh ng quan trng ca d n Xem xt ni dung ca lun chng kinh t k thut (cn gi l bo co nghin cu

kh thi/Feasibility Study) t xc nh cc hot ng quan trng nht s xy ra trong qu trnh thc hin d n.

V d d n mt cng trnh thy in s c cc hot ng quan trng nh: xy dng ng dy cao th ti in, xy dng cng trng thi cng, di dn vng h ti cc khu nh c mi... Mt d n nh my sn xut xi mng s c cc hot ng ln nh: lp cng trng khai thc vi, lp cng trng khai thc t st, vn chuyn nguyn liu, vn chuyn nhin liu ti nh my, xy dng nh my, xy dng khu lm vic, khu nh ca cng nhn...

Bc 2: Xc nh cc bin i mi trng do cc hnh ng Mi hnh ng ni trn u gy ra nhng bin i mi trng vt l, sinh hc, x

hi ti a bn hnh ng. Cn xem xt xc nh nhng bin i quan trng nht. V d hnh ng xy dng p chn nc trong d n thy in s to nn mt s

bin i nh: hnh thnh h cha vi mc nc dao ng trong phm vi ln theo chng trnh iu tit nc trn khu vc thng lu p, hnh thnh ch thy vn mi ti khu vc h lu p. Cc bin i ln ny, c th gi l bin i bc mt, cc bin i ny s gy nn bin i bc hai. V d s hnh thnh h c iu tit s to nn vng bn ngp, vi ch thy vn c bit.

Chin lc, Chnh sch

Hot ng thc t

D n u t

Quy hoach, K hoch


29

Bc 3: Xc nh cc tc ng ti ti nguyn thin nhin v cht lng mi trng sng ca con ngi.

Cc bin i mi trng ni trn s c tc ng (Impact) ti ti nguyn thin nhin, cc h sinh thi, sc kho v cc iu kin sng khc ca con ngi. Mc tiu ca nh gi tc ng mi trng l xc nh mt cch ng n, nh tnh v nh lng cc tc ng ni trn, d bo din bin ca cc tc ng trong tng lai.

V d bin i mi trng ln l vic hnh thnh h cha ti thng lu p s gy nn nhng tc ng nh sau i vi ti nguyn: mt t nng nghip vng thp, mt rng ti cc vng ngp, lm cho khong sn b ngp kh khai thc hn, tn ti a dng sinh hc, ti nguyn vn ho, to nn nhng iu kin mi v ti nguyn nc, to nn ti nguyn du lch... Bin i ni trn cng c nhng tc ng i v cht lng mi trng sng ca con ngi nh: thay i a bn sinh sng ca dn di chuyn t vng b ngp, thay i ch nhit m, v kh hu, ngun cp nc cho sinh hot v sn xut, phng thc sn xut to ngun dch bnh lan truyn theo nc.

Cc hnh ng cp 2, v d di dn, to lp a bn sinh sng v sn xut mi ti vng ven h, s c kh nng gy nn ph rng lm nng ry ti vng cao, t dc, to nn xi mn vng ven h, gia tc bi lng, gim hiu qu, rt ngn thi gian pht huy tc dng ca h.

Mt d n pht trin thng c thc hin qua rt nhiu hnh ng c th, mi hnh ng gy nn bin i mi trng khc nhau, nhng bin i ny l to ra nhng tc ng gy nn nhng tc ng mi trng khc nhau. Tc ng chung ca d n i vi ti nguyn v mi trng ti a im thc hin d n l s tng hp ca hng lot tc ng tng tc cht ch vi nhau.

Bc 4: D bo din bin ca cc tc ng mi trng D n pht trin thng xuyn hot ng trong mt thi gian, trong qu trnh

cc tc ng mi trng s din bin. V vy, tip theo bc xc nh cc tc ng v trn c s ca vic xc nh cn d bo din bin ca cc tc ng mi trng. Vic d o cn tin hnh trong phm vi khng gian v thi gian nh trc. D liu d bo l cc d liu dng trong xc nh tc ng, c th tham kho thm d bo ca cc ngnh lin quan v s liu kinh nghim ca cc d n tng t thc hin trc y. Phng php c th s dng l cc phng php m hnh (m hnh ton, vt l), phng php chuyn gia, phng php so snh. Trong trnh by kt qu d bo cn ni r tin cy ca s liu tnh ton, s liu thng k hoc tin cy ca php so snh.

Cui cng l vic lp mt bo co nh gi tc ng mi trng trnh duyt, thm nh v c quan qun l s ra quyt nh cng nhn. Trong bo co TM phi nu ra c cc kt lun, kin ngh vi cc ni dung ht sc ngn gn, r rng. C nh vy, ngi qun l (c quan qun l) mi c th nh gi nhanh v chnh xc. Quy nh ca mt s bo co TM s c gii thin y sau.

5. nh gi tc ng mi trng chi tit (theo kiu y ) 5.1. Cng tc chun b: Sau khi c lc duyt v nh gi tc ng mi trng s

b xt thy cn phi thc hin TM chi tit, ta thc hin cc cng tc chun b. Cng tc chun b gm cc vic sau y (chi tit ho ca mc 3 -3 chng 1). Thnh lp nhm chuyn gia (hay quyt nh nhm chuyn gia) thc hin

vic nh gi tc ng mi trng y . Trong nhm phi m bo chuyn gia v TM, chuyn gia v cc lnh vc khoa hc - kinh t m ni dung ca d n cp n. Nhm chuyn gia ny phi c lp v quyn lc c lp vi nhm xy dng d n (hoc ch d n nu d n ang c thc hin).


30

Xc nh phm vi cn thc hin TM (c v khng gian, thi gian v mc su (nng) m d n cn c TM. y cn da vo quy m m khung d n a ra v hot ng trc mt v lu di. Nhm nh gi cn i vo nhng vn trng im, quan trng v cc mt khoa hc, cng ngh, ti nguyn thin nhin, a dng sinh hc. Nhng vn a ra phi da trn lun c khoa hc m c quan qun l Nh nc chp nhn c. Khi xc nh vn ny, cc chuyn gia ca nhm TM li phi cn c trn yu cu t ra v thi hn thc hin TM, v iu kin ti chnh cho php.

Trong mt s trng hp c bit, nu pht hin cc im ring cn i su m lc duyt v TM s b cha xem xt nhng c th gy ra nhng tc ng mnh n mi trng, cn c kin ngh b sung.

Tm ngun kinh ph (c th l kinh ph d n c lp t quc gia, c th t ngun ti tr v c th t t l % ca d n pht trin kinh t - x hi).

Xc nh c quan kim tra thc hin d n thm quyn v thm nh bo co nh gi tc ng mi trng c lin h, hng dn trong qu trnh nhm chuyn gia thc hin TM.

Xy dng cng cho nh gi tc ng mi trng y . cng phi c ni dung sau: (mu cng chi tit trnh by chng 4) 1. Gii thiu v TM Mc tiu cc iu khon tham kho Trch nhim bin son, bo co TM 2. Cc ti liu hng dn TM chung 3. Cc thng tin c bn ca d n Cc nghin cu chnh ca bo co chuyn ngnh Cc nhn dn v bo co chung 4. Cc hng dn TM chuyn ngnh Cc nh hng ca mi trng Cc gii php hiu chnh, sa cha, thay th 5. Nhng d kin v quan trc (monitoring) MT. 6. D kin v k hoch hot ng ca nhm TM. Cc nhim v phi lm K hoch v chng trnh lm vic K hoch hi tho, trao i chuyn gia K hoch xy dng bo co, in ti liu, cng b kt qu Thi gian biu 7. Ngn sch (vin tr, ti tr) 8. Cc yu cu khc, ph lc hng dn.

5.2. Xc nh cc hnh ng quan trng ca d n Mt d n thng c cc hnh ng quan trng cn xc nh r t giai on tin hnh

xy dng v giai on d n i vo hot ng. Trong mt s trng hp khc, chng ta ch xc nh c cc hnh ng m d n i vo hot ng v qu trnh thc hin TM chm hn.

Cc hnh ng ca d n (hay ca hot ng kinh t - x hi) chnh l cc ngun gy tc ng n mi trng sinh thi v ngun ti nguyn thin nhin.

C th nu ra cc ngun tc ng chung nht l: San lp mt bng; o t, ph ni, lp ao h (n mn)


31

Tho nc lm kh mt t, ly nc vo h cha Ngn sng, i dng chy Xy dng ng giao thng v c s h tng Vn chuyn thit b vt t Lp t thit b, vn hnh th Di dn, thnh lp khu nh canh nh c mi, xy dng th Chuyn mc ch s dng t Di chuyn ti sn Khai thc qu mc ngun ti nguyn thin nhin (c bit quan trng l nc

ngm, nhin liu ho thch, khu bo tn quc gia, khu vc t ngp nc, rng) Vn chuyn hng ho (nhp, xut) Tiu th nguyn liu, sn phm v x l cht thi S dng khng hp l v d tha cc cht ho hc (bn phn ho hc, thuc BVTV, thuc dit c, cht thi v thc n tha ca chn nui, thc n tha v khng sinh trong nui trng thy sn) Cc cht thi kh (SO2, CO2, NO2...) ca giao thng, kh d r khi vn hnh cc thit b lnh, bc x , , ca cc trm y t, l cao my pht in, trm in, quc phng.

5.3. Xc nh cc tc ng ca cc hnh ng n mi trng y l bc quan trng nht i hi trnh y , tng hp ca cc chuyn gia

trong nhm cng tc TM. Mi hnh ng ca d n u tc ng n mi trng v ty theo mc s lm thay i tnh cht ca mi trng v vt l, ho hc, sinh hc, x hi v kinh t vn ho trn a bn.

V d 1: Lm cn nc mt phn din tch khu vc t ngp nc s thay i h sinh thi, thay i hoc suy gim ngun gen sinh vt. Nc cn, mt p lc b mt s lm kh metan (CH4) bc mnh dn n nguy c chy rng. Mt nc mt i lm mt ngun d tr nc b sung vo ti nc ngm v.v... Nh vy, thay i v nc dn n CH4 bc ln mnh, h thc vt thay i... l nhng thay i bc 1. K tip cc thay i l mc nc ngm gim, tnh cht nc ngm thay i theo, l cc thay i bc 2.

V d 2: Hot ng ca nh my Giy thng gy ra mt s thay i bc 1 l: mi hi kh chu (mercaptan) - cht lng khng kh bin i. Khi lng cht thi lng rt ln cha bt giy, lignin, kim d tha... lm cht lng nc mt thay i. Khai thc cy nguyn liu lm cht lng rng thay i, che ph thc vt gim xung.

Tt c cc bin i bc 1 v khng kh, nc mt, che ph ca thc vt s dn n cc thay i bc 2 l: sc kho cng ng gim do khng kh, t rung b thi ho do Lignin v kim d, gia sc b bnh, c cht hoc nhim c, t b ra tri mnh hn v che ph gim.

Nhn chung xc nh c tc ng ca cc hnh ng t mt d n n mi trng cn phi ch :

Xc nh , ng hnh ng ca d n Hiu bit tt xc nh bin i bc 1 cho tng d n c th Xc nh bin i bc 2 da vo mc , phm vi ca cc bin i bc 1. Phi xem xt ton din c bin i mi trng t nhin ng thi bin i v

kinh t - vn ho - x hi nhm bo tn vn ho. Mi cng vic thc cht l nhm xoay quanh pht trin. V vy cn lun lun so snh, i chiu c s ho hp gia pht trin vi kh nng chu ng tn thng ca mi trng.


32

5.4. Xc nh cc tc ng n ngun ti nguyn v cht lng cuc sng lm r vn , ta cn xc nh la chn cc hnh ng ca d n c kh nng dn

n nh hng cho ngun ti nguyn thin nhin (v ngay c ngun ti nguyn vn ho), ngun ti nguyn bao gm: kh tng, ch thu vn, tnh cht t, nc mt, nc ngm v tnh cht ca chng. Cc ngun ti nguyn rng, sinh vt, ti nguyn c, ti nguyn khong sn, ti nguyn bin v.v... Cn phi thy r, pht hin c cc tc ng bc 1 v c tc ng bc 2 (c khi xy ra rt chm) bo m pht trin bn vng.

Cht lng cuc sng, v c bn l cht lng cuc sng ca con ngi khng ch v mt vt cht m phi y , ton din c v vn ho, khoa hc, dn tr, truyn thng trong pht trin bn vng. Mt ln na nhc li: mc tiu ca chng ta l pht trin song nguyn tc l phi bn vng.

C th minh ho qu trnh nh sau:


33

Hnh 2.4: Phn tch xc nh cc tc ng MT ca d n pht trin (Ngun. R. Carpenter - 1993)

Sau khi xc nh cc tc ng nh hng n ngun TNTN v cht lng cuc sng ca con ngi, cn thit phi xc nh r ngun gc tc ng . Tip theo nh gi mc tc ng, ta phi s dng cc phng php phn tch v xp hng (s trnh by chng 3).

5.5. D bo din bin ca cc tc ng y l qu trnh d on theo thi gian (5 nm, 10 nm, 20 nm) theo khng gian

(tc ng c b m rng phm vi a gii khng) v theo cng (tc ng din bin theo chiu hng tng hay gim). Qu trnh d bo din bin ca tc ng n MT v ti nguyn c th thc hin c bng phng php c bn l phng php chuyn gia da trn cc kt qu monitoring MT nh gi. Cng c thc hin thng l phng php m hnh ha, phng php Ma trn ,k thut bn hoc k thut GIS.

Trong qu trnh nh gi tc ng MT, d bo din bin ca cc tc ng ti MT, chng ta cn xc nh r cc tc ng, mc v mc quan trng ca loi tc ng n MT t nhin, n ti nguyn mi trng v n cht lng MT sng. lm tt vic ny cn phi da vo lut, Ngh nh, quy nh, cng c quc t, tho thun quc t, cc loi tiu chun, qui nh c bit (khu bo tn quc gia, khu d tr sinh quyn, khu vc nhy cm ca MT t nhin cng nh kinh t- x hi, v.v..).Cui cng phi xc nh c s ph hp v tho thun tt ca cng ng.

5.6. Xc nh cc bin php gim thiu v qun l tc ng. Mc tiu ca bin php gim thiu tc ng l: Trnh cho MT chu nhiu tc ng nhng d n vn phi c hiu qu. Xc lp s ph hp gia tc ng v mc chu ng ca MT Lm cho chi ph khc phc mc m cng ng, ch d n c th chp nhn

c so vi li nhun. lm tt vic , phi c cc thng tin y sau y:

Mc tiu: Pht trin kinh t - x hi

D n pht trin, hot ng pht trin

Hnh ng thc hin d n pht trin

Cc bin i MT do hnh ng pht trin gy ra

To ra tc ng lm bin i ngun TNMT

Cn cc p ng: bin php phng trnh v gim thiu

i

ch

iu

Thng

tin phn

hi


34

+ Kt qu nghin cu tng ng v phng thc, cng ngh, qun l c th gim thiu tc ng (vn ny c th tham kho cc d n tng t vi cc cng ngh pht trin hn cn cc cht thi c th s dng cc tuyn tp, s tay hng dn[6]

+ Tip nhn cc t liu, ti liu, kinh nghim t nhiu c s khc. + Cc ngun thng tin khc t cng ng. Trn c s tin n vic la chn mt s hng c bn gim thiu, x l v

khc phc cc tc ng n MT v TNTN. + Chn phng thc mi, cng ngh mi thay th. + Thay i mt s chi tit trong quy hoch, thit k. + Thay i v tr, phm vi, qui m d n. + B xung cc chi tit ca d n. + Tng cng cng tc qun l v phng thc ph hp. Cn lm tt cc vic trn y km theo phng tin thc hin, c nh vy th cc

phng n gim thiu v khc phc mi c th kh thi.

5.7. xut cc ni dung v yu cu monitoring mi trng Mc d d n TM thc hin xong trong thc t, nhng cc d bo, cc php o

c, cc phng php so snh v nh gi khng bao gi khng gp cc sai s. Mt khc mi trng t nhin, kinh t - x hi lun lun c bin ng do chu nh hng t nhiu tc nhn bn trong cng nh bn ngoi.

V nguyn nhn , m bo cho nhim v kim sot MT ngy cng tt, cn thit phi c mt k hoch monitoring tip tc. Nhim v ca Moniring l pht hin cc sai st m TM gp phi do nguyn nhn bn trong v bn ngoi.

Yu cu ca Monitoring l:

Xc nh a im, v tr thc hin Monitoring.

Xc nh cc phng php, cng c thc hin theo tiu tr nh trc. Xc nh thi gian monitoring v cc bc monitoring. So snh, i chiu kt qu monitoring vi TM lm. Cui cng l s dng cc kt qu ca TM iu chnh, gip cho d n c

thc hin y vi kt qu tt nht.

6. Lp bo co TM v thng bo kt qu. Mt TM ch c gi tr v pht huy c tc dng nu thng bo n c quan c

thm quyn kp thi v y . Nhng thng tin ny c gi i trong mt khung quy nh ca " bo co TM". Tu theo quy nh, bo co TM c gi v cc s ti nguyn Mi trng, cc BVMT, v thm nh v nh gi tc ng MT.

Cc c quan ny s t chc thm nh (khng trnh by y) v ra quyt nh. Trnh t mt bo co TM gm c cc phn sau y theo nguyn tc chung trn th gii l:

M u.

6.1. Mc ch ca vic lp bo co TM - Tnh hnh mi trng chung. - Khi qut tnh hnh mi trng khu vc. - Tm quan trng ca d n. - Tnh cht quy m ca cng trnh. - Vn bo v mi trng ca d n t ra hay cha.

6.2. Phm vi trin khai nghin cu, tnh hnh ti liu, s liu. - Xc nh vng nh hng.


35

- Quy m v mc nghin cu. - Xc nh nhng thnh phn mi trng cn nghin cu. - La chn phng php TM. - Nhu cu v ti liu, s liu (nu l cng trnh ang hot ng, c th thm).

6.3. Khi qut hot ng ca cng trnh - Khi qut qu trnh hot ng. - Quy m cng trnh - Cng sut cng trnh - Nguyn vt liu, sn phm. - Nhng bin php k thut.

M t d n: 6.4. Gii thiu chung.

- Loi d n, cng trnh - C quan ch qun - Cc bn lin doanh - Nhu cu pht trin KT-XH - Cc nhu cu khc

6.5. V tr cng trnh - V tr hnh chnh - Ranh gii -V tr tng th - S mt bng - B cc ton th cng trnh.

6.6. Nhng ni dung hot ng c bn ca d n: - Qui m d n - Mc hot ng ti a - Phm vi nh hng ca d n. - Nng lng s dng. - Ngun ti nguyn sinh vt. - Cc loi cht thi. - Vn u t, thi gian hot ng. - Hiu qu kinh t - kt lun.

M t v hin trng mi trng 6.7. V iu kin t nhin, ti nguyn vt l

- V a hnh khu vc lp bo co TM- Ti nguyn t. - iu kin kh hu - Ch thy vn. - Vn a cht, a cht cng trnh - a chn hc.

6.8. Ti nguyn sinh vt - Cc loi c - sinh hc, thy vn.


36

- i sng hoang d- Rng v cc loi qu him. - Cc khu bo v, bo tn, cnh quan hang ng.

6.9. V pht trin con ngi v c s h tng - Dn s v i sng cng ng - Cc chnh sch v th ch. - Ngnh ngh v xu th pht trin - Giao thng, quy hoch t ai - Nc ung, s dng in - Pht trin nng, lm, ng nghip - Pht trin du lch, thng mi - Sc kho cng ng

nh gi tc ng n mi trng ca d n Cc ch tiu nh gi:

6.10. Cc thnh phn mi trng vt l: - Kh quyn: nh gi tc ng ca d n n cht lng khng kh, n kh hu v

thi tit xung quanh. - Thu quyn: Tc ng ca d n n ngun nc ( nc mt, ngm, phn bnc,

khu vc nhy cm v.v...) - Thch quyn: Tc ng ca d n n ti nguyn t v cc ti nguyn khng ti

to khc.

6.11. Cc ti nguyn sinh vt, h sinh thi; - Cc h sinh thi - Ti nguyn sinh vt cn - Ti nguyn sinh vt di nc (thu sinh)

6.12. nh gi tc ng n c s h tng. (ng x, cu cng, giao thng thu b, nh ca, cng trnh phc li, mng li

thu nng, thng tin lin lc, cc c s h tng khc.v.v...)

6.13 . Tc ng n cc cnh quan

Di tch lch s, hang ng, kho c, khu gii tr. Khu d tr nhin liu, vn rng v.v...

6.14. n cht lng cuc sng v sc kho cng ng. - V cht lng cuc sng, thu nhp bnh qun. - Sc kho y t, pht trin ngun lc. - Pht trin vn ho, th thao, du lch.

6.15. n cc ngnh ngh: (Cng nghip, nng nghip, lm nghip, ng nghip, thu li, th cng nghip,

dch v thng mi, cc ngnh ngh khc...

6.16. n nhng s c, d bo ri ro c th: D bo v nhng s c c th xy ra, nhng ri ro c th gp phi, nhng tai bin

mi trng ca d n (v tr, quy m, cng ngh, thit k thi cng, qu trnh sn xut, cc nguyn nhn khc...)


37

6.17. nh gi v d on tc ng n cc ngun? ti nguyn khng ti to ca quc gia (cc ngun lc) (Ti nguyn rng, ti nguyn sinh vt, h sinh thi, cc ngun nc, cc vng nhin liu, nguyn liu, di tch lch s hang ng, khu gii tr, khu lu tr, tp qun sn xut, vn ho, kinh t - x hi ...)

6.18. nh gi tn tht chung ca d n: - Tng hp cc ch tiu. - Phn tch li, hi (c, mt). - Phn tch hiu qu ca d n.

Kt lun: - nh gi chung v mc tin cy ca d n v u t thng mi. - Cn phi lin tc, nghin cu thm nhng phn no c kt lun tin cy hn. - D n cn phi iu chnh nhng g.

Phng n gim thiu v gii php thay th 1. Thay i phng n. 2. Thay i v tr. 3. Thay i cng ngh (hoc b sung) 4. Cc gii php k thut. 5. Cc gii php t chc. 6. Cc c hi tng cng gi tr mi trng. 7. Cc gii php v gi tr ngun lc, tng cng li ch cng ng 8. xut cc phng n thay th 9. Cc gii php, kin ngh khc...

Phn tch chi ph - li ch

Bao gm : Tng ton b ngun thu ca d n Tng vn u t + tng gi tr thc ca tt c thit hi.

(Bao gm c vic tnh cc chi ph ca cc bin php gim thiu).

Tng gi tr thc ca tt c cc thit hi bao gm: - Thit hi v ti nguyn, cc h sinh thi. - V c s vt cht h tng. - Kinh t - vn ho - lch s.

Cc yu cu cn thit v th ch v chng trnh gim st mi trng 1. Cc quy nh, quy phm, tiu chun mi trng ca Nh nc, a phng

- Quy m kim sot (mng li monitoring) - Cht lng gim st mi trng (QA/QC). - Yu cu thit b, dng c. - Yu cu v nhn lc, k thut.

2. K hoch v yu cu v cht lng bo co


38

- Bo co theo nh k chung. - Bo co ring c bit. - Yu cu v s liu. - K hoch, chng trnh quan trc, kim sot cht lng mi trng. - p ng s liu cho c quan qun l mi trng quc gia.

Cng ng lin quan 1. Quyn hn v trch nhim ca cng ng

- Tin hnh cc cuc trao i , ly kin ca nhn dn - Ca cc t chc x hi - Ca chnh quyn a phng v vic hnh thnh d n v cc vn mi trng

m cng trnh gy ra.

2. iu tra x hi hc - Phm vi iu tra. - kin ca cng ng v vic tun th cc quy nh v lut l Nh nc. - Din n ca cc phng tin thng tin i chng v vn mi trng trong khu

vc s c d n. - Tng hp v nh gi mi quan tm ca cng ng.

Kt lun v kin ngh 1. Cc kt lun: - Kt qu nghin cu lp bo co TM. - Cc hot ng li v hi trc mt, lu di. - Cc kh nng gim thiu nhng nh hng xut. - nh gi vvic n b thit hi i vi gi tr mi trng khu vc (c bit i vi

ti nguyn khng ti to). - Bi thng vi nhn dn. - Hiu qu vic s dng ti nguyn quc gia - Hiu qu kinh t,x hi - Cc chng trnh gim st v kho st tip theo

2. Cc kin ngh: - Cc kin ngh i vi cc c quan ra quyt nh, cc nh lm chnh sch - Kin ngh trong vic bo v mi trng khu vc Sau khi lp bo co TM chi tit phi c bn tm tt bo co TM trnh t theo cc

mc tiu nu trn (xem mc 6 - t 6.1 n 6.18 trn) c mt bo co tt v TM, nhm nh gi tc ng mi trng cn nht nh

phi thc hin y cc bc quy nh. Tuy nhin, trong qu trnh thc hin nh gi TM v xy dng bo co phi lun lun bm st thc tin d n tp th chuyn gia quyt nh dng li mc no? hoc tip tc thc hin y . Mt khc, nhm thc hin TM lun phi a ra quyt nh ng, c li nht khi s dng phng php ch yu tin hnh thc hin TM (c th phng php ma trn, ma trn nh lng, m hnh ho, chng ghp bn , phn tch chi ph - li ch... (xem chng III). Cui cng trong bo co TM, ngoi cc yu t mi trng t nhin, chng ta lun phi lu n mi trng kinh t - x hi bi v l mc tiu pht trin.


39

Hin nay, mt khung bo co TM c quy nh ti Vit Nam theo B Ti Nguyn v Mi Trng ( Xem ph lc 12 )

7. Cc cu hi bi tp chng II 1. Th no l mt lc duyt 2. Hy thc hin mt lc duyt cho d n s dng 200 ha t trng i ni trc

pht trin kinh t nng - lm kt hp. 3. Th no l mt TM s b 4. c mt TM s b cn xc nh cc hnh ng ca d n nh th no? Hy

xc nh cc hnh ng quan trng ca d n QHSD t cho 200 ha vo mc ch nui thy sn t t chuyn canh la - mu.

5. Trong mt TM y c bc d bo cc tc ng mi trng tim n. Anh (ch) hiu th no l yu t tc ng tim n .

6. Yu t tc ng tim n v tc ng bc 1, tc ng bc 2 khc nhau v ging nhau ch no?

7. Vai tr ca quan trc theo di mi trng (monitoring) trong mt TM l g? 8. Vai tr ca cng ng trong mt TM? 9. Vai tr ca cng tc qun l cht lng v kim tra cht lng trong mt TM

nh th no? 10. Th no l nhim v thm nh v ph duyt TM? Cp c th thc hin thm

nh ph duyt mt TM c ph thuc vo d n khng? 11. Ch d n c c thc hin mt TM khng? 12. Anh ch c th d bo cc yu t mi trng b tc ng n nc h Ty nu s

dng n vo nui thu sn v vo du lch sinh thi?


40

Chng III

CC PHNG PHP DNG TRONG NH GI TC NG MI TRNG

Mc tiu ca chng III l trang b cc phng php (cng c) tin hnh thc hin nh gi tc ng TM. Cc phng php ny c th nghim v tng kt, d sao vic thc hin n cng ph thuc vo trnh ca i ng chuyn gia. Do cc bc thc hin l rt quan trng, n c nhim v m bo cht lng, kim tra cht lng cho TM (tc l c mt QA/QC) y .

Sinh vin cn hiu, nm c phng php danh mc iu kin mi trng, phng php ma trn mi trng v phng php phn tch chi ph - li ch m rng. Ba phng php ny thng dng, c hiu qu v thng b khuyt cho nhau rt tt.

tin hnh thc hin mt TM, ngi ta thng s dng 7 phng php bao gm: Phng php lit k s liu v thng s mi trng. Phng php danh mc cc iu kin mi trng Phng php ma trn mi trng Phng php chng ghp bn mi trng Phng php s mng li Phng php m hnh Phng php phn tch chi ph - li ch m rng.

Trong 7 phng php trn, xin gii thiu 4 phng php thng c s dng nht ( c th nghim nhiu Vit Nam) l:

+ Phng php danh mc cc iu kin mi trng c lng ho + Phng php ma trn mi trng + Phng php chng ghp bn + Phng php phn tch chi ph - li ch m rng

1. Phng php danh mc cc iu kin mi trng y l phng php c s dng kh rng ri n c vai tr rt ln lm r cc tc

ng xy ra. Phng php danh mc thng da trn c s: cc danh mc c trng v cc danh mc c phn chia theo mc phc tp.

Nguyn tc thc hin l: lit k mt danh mc tt c mi yu t mi trng lin quan n hot ng pht trin (n d n) cn nh gi. Gi danh mc n cc chuyn gia hoc t chc ly kin nh gi.

C nhiu loi danh mc (danh mc n gin, danh mc m t, danh mc cu hi, danh mc c ghi mc tc ng, danh mc c ghi trng s)

1.1. Phng php danh mc cc cu hi. Phng php ny c s dng bng cch xy dng cu hi, phiu tr li s nhn c t chuyn gia v c cng ng. T tng hp, nh gi.

V d: trch dn danh mc nh gi tc ng mi trng ca cng trnh ti nc cho sn xut nng nghip (theo Ngn hng Pht trin chu -1987)


41

Bng 3.1. TM ca cng trnh nc cho nng nghip

nh gi mc tc ng Tc ng ca d n (do v tr cng trnh)

Tn hi ti TNMT

Bin php bo v TNMT K Kh.K

1. Mt rng Mt ti nguyn Ch khi thit k * 2. Ngn cn i li ca ngi, ng vt

o ln i sng ngi dn, ng vt Ch khi thit k *

3. Xung t quyn li v ngun nc Bt bnh ng x hi

Ch khi thit k v qun l *

K: ng k KK: khng ng k

1.2. Phng php danh mc c ghi trng s Phng php ny hn phng php lp bng danh mc n gin khc l: trong danh

mc tc ng c mc tc ng nh phng php trc, ngoi ra cn c thm trng s (hay mc quan trng ca tng yu t mi trng chu tc ng vo). y, ta tin hnh cho im v cht lng v mc quan trng ca cc yu t. Tip theo c th tng hp mi yu t li thnh ch s nh gi tc ng

Ch s (hay n v nh gi) ==

=

m

i

m

iWiViiViE

11*2)(W*1)(

y E l tc ng mi trng (Vi)1: Gi tr cht lng thng s mi trng th i khi c d n (Vi)2: Gi tr cht lng thng s mi trng th i khi cha c d n Wi: Trng s - mc quan trng (gi tr tng i) ca yu t i m: tng cc thng s mi trng c xem xt. V d: nh gi chi tit ch tiu cht lng nc h cha (theo 5 phng n)

Bng 3.2. TM ca cng trnh h cha nc cho nng nghip (5 phng n)

Phng n x l lng h cha nc khi thi cng Thng s mi trng PA1 PA2 PA3 PA4 PA5

1. pH 5 2 3 4 1 2. Tng Fe Mg 5 2 3 4 1 3. cng tng cng 2 5 3 4 1

PA1.... PA5 l 5 phng n x l lng h khi thi cng Kt lun: Phng n 1 chu tc ng ln nht, phng n 5 chu t nht. 2. Phng php ma trn mi trng y l phng php phi hp lit k cc hnh ng ca hot ng pht trin (hay

hnh ng ca d n) v lit k cc yu t mi trng (ch tiu mi trng) c th b tc ng v a vo mt ma trn. Tin hnh nh gi.

Ngi ta s dng hai loi: 2.1. Phng php ma trn n gin (nh tnh v bn nh lng)


42

Trong ma trn ny ct ng l cc hnh ng (hot ng) ca d n, hng ngang l cc yu t mi trng. Trong ma trn, tu theo mc c th lm c ngi ta s dng du (+) biu th hnh ng c tc ng n yu t mi trng (i khi r hn, ngi ta cn chia tc ng theo mc (v d ++, +, o, -).

Phng php ny n gin nhng cho php ng thi thy tc ng ca mt hnh ng ca d n n nhiu yu t mi trng, mt khc phn nh c bc tranh y trong tng tc ca nhiu yu t

Bng 3.3 Ma trn phn loi a dng cho qun l ngun ti nguyn hin ti ca c quan bo v rng Hoa K

(Ngun> [7]-1996)

Mc nhy cm

tg1 mga bg1 bg2 mg2 bg2 3 Loi A R R R PR PR PR PR Loi B R PR PR PR M M M

(MM) Loi C PR PR M M M MM MM

Ghi ch: tg (1,2): Vng gn mga: Vng gia bg (1,2): Vng c s R: Cn duy tr PR: Cn duy tr cc b M: Bin i MM: Bin i mnh

Bng 3.4. V d v nh gi TMT theo ma trn cho mt n ci to thnh ph - Theo Westman, Walter E.1985

Cc hnh ng c tc dng n mi trng

Thi cng Chuyn tip Sua khi hon thnh em vo s dng Cc nhn t mi trng

Chuyn ch

Chuyn ch lm

vic

Ph sa lm mi

Nh dng tm

C s dch v

mi

Nh

mi

Ca hng mi

Bi xe

Cng vin

Di tch vn ho

i vi

ng ph

Yu t vt l a cht th nhng kr kr Kr kr kr kr kr kr ++ kr kr

Cng rnh v sinh kr kr - - + + + kr kr kr +

Cp nc kr kr - - ++ + + kr kr kr +

Cy xanh kr kr - - kr ++ + kr ++ kr kr

ng vt kr kr Kr kr kr kr kr kr - kr kr

Cht lng kh kh kr kr - kr kr - - - + + kr


43

S dng t ln cn kr kr - - kr ++ kr kr ++ ++ 0

Thot nc ma kr kr - - ++ + + kr + kr +

ng ph kr - - - + + + ++ kr kr + Giao thng cng cng kr kr - - kr 0 0 kr 0 0

B hnh - - - - kr ++ ++ + ++ 0 0

Khong trng kr kr kr kr ++ - - ++ 0 0

Yu t x hi

C tr - - - - + ++ + + ++ ++ 0

Trng hc kr kr - - kr + kr kr + + 0

....

M quan

Cnh p kr kr - - kr + + - ++ - kr

Di tch lch s kr kr - - + kr kr 0 + ++ r

....

Ch thch: kr = khng r tc ng 0 = khng tc ng + = tc ng tch cc ++ = tc ng rt tch cc - = tc ng tiu cc -- = tc ng rt tiu cc

2.2. Phng php ma trn nh lng Phng php ny l cch nh lng ho phng php ma trn n gin. Ct ng

cng ghi cc hnh ng ca d n hoc hot ng kinh t - x hi ang c xem xt. Hng ngang ghi cc yu t mi trng c th chu tc ng ca hnh ng gy ra.

Mi nh gi khng ch ghi c hoc khng tc ng m c nh lng theo im. Nh vy, ma trn ny khng nhng cho php tm ra c tc ng c hay khng m cn cho thy mc ca tc ng do hnh ng no ca hot ng kinh t - x hi n yu t mi trng no . Da trn c s ny, nhm thc hin nhim v TM c th m rng thm hnh ng theo thi gian, khng gian xc nh cc tc ng bc 2, d bo tc ng c th din ra sau ny.

C th phn chia mc tc ng t 1 n 5 im (hoc chn khong no ph hp yu cu), thng thng ngi ta dng thang 10 im (quy tc Leopold xut). Trong thang , tc ng thp l 1 im, tc ng cao nht l 10 im.

Trong mi ca ma trn, ngi ta trnh by c 2 i lng l mc ca tc ng v tm quan trng ca tc ng

Tm quan trng ca tc ng c ghi pha di bn phi ma trn Mc tc ng ghi bn tri gc cao trong ma trn Tm quan trng ca tc ng nh gi vai tr, v tr ca tc ng n yu t mi

trng trng thi no ca d n. Thng thng l trng thi thc hin d n v trng thi d n ang vn hnh (ti thi im 5 nm, 10 nm hay 20 nm). Vic xc nh tm quan trng ca tc ng nh hng rt ln n kt qu TM.

Mc ca tc ng (quy chiu tng i) cho thy kh nng nh lng ca tc ng n mi trng.

Vic xc nh mt tc ng c tm quan trng n u trong cc tc ng d n v xc minh mc ca tc ng n mt yu t mi trng trong d n l nhiu hay t, l mnh hay yu l vn rt kh. Lm vic ny thng l cc chuyn gia c trnh v kinh nghim cao.


44

Bng 3.5: Ma trn tc ng mi trng nh lng ca d n nh my bt giy

Cc hot ng d n

Thnh phn mi trng

Xy

dng

Trang

tr i tr

ng

Kenif

S

dng

th

uc

su,

phn

ho

hc

Vn

ch

uyn

nguyn

li u th

Cp

nc

Rc thi

N

c thi

Kh

th i

To

vic lm

Tng

Cht lng nc mt 6 7 4

4 2

8 5

5 17

24

Thy vn nc mt 1 7 1

7

Cht lng khng kh 3 6 2

6 4

5 9

17

Thy sn 2 5 2

7 4

12 Mi trng sng ca sinh vt nc

2 8

2 5

4 11

Mi trng sng sinh vt cn

3 4

3 4

Sinh vt cn 2 5 2

5

M hnh s dng t 5 6 8

7 13

13

ng cao tc/ng st 6 5 6

5

Cung cp nc 3 6 2

7 5

13

Nng nghip 7 7 7

7

Cung cp nh 7 6 7

6

Sc kho 3 5

2 8

2 6

7 19

iu kin kinh t - x hi 10 8 8

8 18

16

Tng 13 21 25

22 13

24 8

11 1

7 7

9 10

35 6

11 20

19

3. Phng php chng ghp bn y l mt phng php tt c s kt hp vi cng c hin i GIS, vin thm( cc

phn mm c trng). Mt khc vn c th thc hin c TM theo phng php ny bng cng c n gin

Xy dng cc bn mi trng n tnh (yu t mi trng ring) nh bn nhim kim loi nng trong t, bn phn b rng, bn dc, bn mt nc v.v...

Chng gp cc bn Xc nh cc tc ng do cc hnh ng gy ra Phng php chng ghp bn hin nay thng c thc hin vi k thut cao

(computer, my nh v, my o in t). V vy c th t cht lng cao. Bn cnh chnh xc tt, phng php ny cho php quan st hnh nh do c th nh gi tc ng mt cch c th, mt cch nhn bao qut. Phng php ny thng c p dng khi nh gi tc ng mi trng cho d n quy hoch chi tit, quy hoch s dng t, nng lm nghip, t th v giao thng.

Hnh nh minh ho kt qu trong vic la chn thc hin d n s dng bn vng.


45

Hnh 3.1. Kt qu TM s dng t bng phng php chng ghp bn

4. Phng php phn tch chi ph ---

- li ch m rng Cc phng php trnh by trc y c s dng tu theo yu cu ca TM v

tu theo cc yu t mi trng c chn lc xem xt tc ng n n. Tuy vy, cc phng php thng thc hin tt vi yu t ti nguyn, mi trng t nhin. Khi cn nh gi tc ng ca cc hnh ng d n n mi trng kinh t, x hi th rt kh. Trng hp ny ngi ta s dng phng php phn tch chi ph - li ch m rng. Phng php ny gip cho cn i s dng ngun ti nguyn thin nhin trong pht trin bn vng.

Trnh t tin hnh: Lit k tt c cc ti nguyn c chi dng trong mi hot ng k c ti nguyn

nhn lc. Lit k tt c cc sn phm thu c k c ph thi c gi tr hon nguyn. Xc nh tt c mi hnh ng tiu th, hnh ng lm suy gim ti nguyn, k

c hot ng sn xut gy nhim. Lit k cc kha cnh c li cho ti nguyn nhng cha c xt n trong n

hot ng, cc kh nng nng cao hiu qu s dng ti nguyn. Lit k vo d n hot ng nhng vn cn b sung cho d n s dng hp

l v pht huy ti a ngun ti nguyn. Din t kt qu phn tch nu trn vo bo co nh gi TM. S dng phng

php trnh by kiu bng so snh chi ph - li ch (thng dng trong tnh ton kinh t). Tt c mi phn tch chi ph - li ch phi c tnh ton sn trc khi thc hin d

n. Nhng kt qu tnh ton s gip cho nh qun l hiu r, hnh dung ra hot ng quyt nh cho php hay khng. y l phng php TM cho thy tnh kh thi c hay khng.

Cn lu rng: S dng phng php phn tch chi ph - li ch m rng phi tnh ton thc hin cho ton b d n sau ny s hot ng (v d 30 nm). Tt nht l tnh ton theo tng giai on trong ri tin hnh tng hp cho ton b.

Cc i lng thng c s dng trong phn tch chi ph - li ch l:

4.1. Gi tr li nhun hin ti (gi tt l li nhun) C th gi l li rng. i lng ny k hiu l NPV (Net Present value)

])1([)1(1 2 ++

+=

=

tt

o

n

t r

CCr

BtNPV

y Ct: l chi ph ca nm th t Bt : li nhun nm th t C0: l chi ph ban u ca d n


46

r: l h s chit khu t: l thi gian tnh ton (nm th t) n: l tui th thit k ca cng trnh Gi tr NPV chnh l gi tr li nhun tch lu n ph thuc nhiu yu t bin ng

c bit l h s chit khu (r) v thi gian (nm). Thng thng NPV tng dn t m khng mt gi tr no .

Khi tin hnh so snh, thc hin TM ca mt s d n cng loi, s dng NPV ca d n so snh. Nu NPV nh nhau, ta chn phng n c u t ban u (C0) b - nh vy ch hon ton da vo kinh t. Trong trng hp ta phi tip tc tham kho ma trn mi trng xem xt y cc kha cnh khc.

Cng c th chng ta i thm yu t kinh t khc t kt qu hn.

4.2. Sut li nhun hoc t sut li ch chi ph (B/C) i lng NPV trnh by trn cho thy c li rng tc l lng li (tnh theo tin)

trong khong thi gian hot ng no . Gi tr ny c th cao, thp song cha phn nh c hiu qu ca d n so vi ng vn u t. vn ny r hn, chng ta s dng i lng sut li nhun (B/C)

++

+=

==

n

tto

n

tt

r

CtCr

BtCB11 )1(

/)1(/

ngha cc i lng B, C, C0, r... y ging biu thc trnh by mc 3.4.1. Theo thi gian hot ng, theo yu cu tip cn th trng, trnh sn xut v cc

yu t khc, gi tr B/C tng dn. Lc u c th ch t B/C


47

Phng php phn tch chi ph - li ch ch yu xem xt trn kha cnh kinh t v kinh t ti nguyn mi trng. Trong rt nhiu trng hp, cc d n quan trng cn c thc hin TM theo mt vi phng php kt hp.

c th phn tch y v ng v chi ph - li nhun ca mt d n pht trin hoc mt hot ng kinh t - x hI, cn c hiu bit y hn na v cc vn :

Phn tch chi ph - li ch Phn tch kinh t ng dng Phn tch kinh t mi trng Phn tch mi trng Tiu ch mi trng v phng php tip cn Phn tch bin ng theo thi gian S gim thu nhp theo thi gian Ri ro Tnh ton chi ph phng nga Phn tch nh gi ri ro Phn tch tc ng x hi ca d n pht trin Ngoi nhng vn trn, chng ta cng lun lun phi cp nht cc thng tin sau y Lut, quy nh, ngh nh, cng c mi Cc tiu chun mi (TCVN, TCN) Cc cng ngh mi s dng trong monitoring, o c mi trng Phng thc qun l cht lng h thng (QA/QC) v cc tiu ch tin hnh

cc d n, cc hot ng kinh t - x hi. Ngoi 4 phng php thng dng c trnh by trn, trong cc trng hp khi thc

hin TM cho mi trng - nht l cht lng mi trng t - nc, ngi ta cn hay s dng phng php m hnh v phng php s mng li. i su vo hai phng php ny, ngi hc cn c trang b k hn v mt s tri thc trong chuyn ngnh Ho t, Ho nc, Ho mi trng v nhiu thut ton khc. C th tham kho v nng cao trnh da vo cc ti liu tham kho [5] [6]

5. Hng dn nh gi tc ng MT n cht lng nc mt. Bc 1: Nhn din cc tc ng ca d n ti lng v cht ca nc b mt. thc hin c bc ny, trc tin cn thu thp nhng thng tin y v cn

thit v bn thn d n nh loi ny v quy m d n, thi gian thc hin, u vo v d kin u ra mi trng ca d n trong pha xy dng cng nh vn hnh, thit k d n v cc gii php nhim ca n, c im a phng ni trin khai d n, nhng yu cu cn a phng p ng cho thc hin d n, v d nh kim sot l, pht trin cng nghip, kinh t...

Nhng phng php nghin cu c th s dng nhn din tc ng t hiu qu l cc phng php bit.

Trong qu trnh nhn din tc ng, cn phi nghin cu cc ti liu lu tr v loi bo co nh gi tc ng mi trng tng t cng nh nhng nghin cu lin quan ti cc cng trnh tng t ang hot ng.

Nhng t liu lm sng t nhiu vn . V d nh s tch nc p Vaiont dn n lm trt t, gy cht 2000 ngi. S c 13 p ca M trong thi gian t 1874 n 1997 lm cht ti 3500 ngi. Ti liu lu tr lin quan n cht thi d n v cc tc ng mi trng ca n cng rt nhiu v c gi tr. V d nh cc thng tin v kho


48

nc k thut ca M cho bit 18% ca 442 kho nc cha cht hu c lin quan n pH v axit ho, 33% c vn vi kim loi nng khng phi st v mangan, m nh cadmi, ng, ch, thu ngn, 24-25% kho nc c vn vi st v mangan. Con s y v cc vn nu trn thc t phi cao hn, v c khong t 29 n 54 % cc d n khng c nh gi theo cc vn .

Trong cng nghip, i lng dn s tng ng thng c dng m t lng cht thi. y l mt ch s c th tnh c cho nhiu loi cht thi khc nhau ca cc ngun thi im cng nh mt (xem ti liu [6])

Chc nng ti c xc nh nh cc biu thc ton hc n gin tnh ton sn phm v/hoc s chuyn dch ca cht nhim trong mt vng xc nh theo phng thc s dng nh.

Nhng thng tin lin quan n c im, dng tn ti, bin i ca cht nhim cng nh kh nng tch lu ca chng trong b phn mi trng no nh trm tch, thc vt, ng vt cn c thu thp y v s c nhng gi tr ng k cho qu trnh nh gi tc ng.

Nu d n c s dng nc th cn c nhng thng tin v tng lng nc cng nh bin trnh nc dng theo thi gian.

i vi d n ti nc nng nghip cn phi lp cn bng nc nh gi lng nc i vo tng ngm. y l mt vic nht thit phi lm m bo tnh bn vng .

Bc 2: M t cc c im ca ti nguyn nc mt t nhin trong vng d n v h lu.

Trong bc ny cn thu thp c cc thng tin lin quan ti lng v cht ca ti nguyn nc khu vc cng nh xu th bin ng ca chng trong lch s. xc nh dung lng thng tin thu thp cn phi xc nh phm vi kim sot. Cc c trng nc c bit nhy cm hoc c th b tc ng ca d n u phi c nh lng. Ti liu lu tr th cp l ngun thng tin lin tc v thng xuyn v nc do mng li thu vn v h thng trm kim sot cht lng o c c, cc xut bn phm nh tnh ton x l s liu v ti nguyn nc, atlat ti nguyn nc, thng tin v bn a cht thu vn, nh v tinh.

Nhn din cc vn nhim n nh cht c, pht trin to, phn tng u c th thc hin bng vic s dng cc thng tin ca cc n v nghin cu ti nguyn nc trung ng v a phng. Ngoi ra bo ch a phng cng l mt ngun c kh nng cung cp thng tin loi ny. Hin nay cn b thc hin DTM cn cp nht thng tin quaVitnet.

Thng tin kh tng cn thit cho qu trnh tnh ton cn bng nc, nh gi tc ng ca cc yu t kh tng ln ti nguyn nc t nhin cng nh nghin cu vai tr ca cc yu t kh tng trong vic lm thay i xu th hoc mc ca tc ng d n ln mi trng nc, hoc c dng nh gi ngun thi mang tnh din t lu vc vo thu vc. V d yu t nhit khng kh c lin quan ti nhit nc mt v qua tc ng n cc qu trnh l, ho, sinh trong nc, ma c th mang axit v gy nn qu trnh axit ho thu vc.

Tng quan v cc ngun nhim v s dng lng nc trong khu vc cn phi lu tm xem xt ti mc chi tit v nh lng. V d, nu d n tng lai c x thi ni t v pht pho th trong nh gi tc ng mi trng d n cn tnh c lng thi cc cht ny trong khu vc do cc ngun ang hot ng ca n. Tng t nh vy, trong bo co phi tnh nhu cu tiu th nc c tnh ton cho c nhn, cng ng v cng nghip trong cc hot ng n ung, sinh hot, sn xut, lm ngui ng c nhit .

Bc 3: Tm kim cc tiu chun, quy nh, chnh sch v cht v lng nc mt ph hp.

Cc tiu chun, quy nh, chnh sch lin quan ti ti nguyn nc c th c tm thy nhiu cp c quan qun l v nghin cu khc nhau, t a phng, trung ng n


49

cc t chc quc t. Cn phi lu rng, a phn cc ch tiu cht lng nc v cc hn ch dng nc c lin quan ch yu vi thi k nc kit. Tt nht, nn da vo Trung tm TCCL Vit Nam.

Chnh sch qun l nc trong d n cn phi c la chn mt cch hp l v c mc tiu ng n, v d nh nhm mc ch lm sch nc, gim nh nhim, bo v sinh thi nc. Ngoi ra cn phi tnh n iu kin nhm bo m duy tr c h sinh thi nc trong thi k kit.

Bc 4: D bo tc ng Trong bc ny, cc tc ng ca d n n nhng yu t mi trng v ti nguyn

nc khc nhau phi c nh lng ho, hoc ch t cng phi c nh tnh chi tit nhng ch c th. Lng nc tiu th cng phi c quy v % so vi lng nc thu vc mc cao, trung bnh v thp. Tng t nh vy phi tnh c phn trm bin i cc tham s cht lng nc ng vi cc mc dng chy khc nhau. Vn s tr ln c bit nghim trng khi vic x thi ca d n thayi theo thi gian v bin trnh x thi ca d n c xu th trng vi bin trnh x thi ca cc d n khc trong khu vc hoc ngc vi bin trnh lng nc trong thu vc. Khng c php qun s dng TCVN cho vic x nc thi vo thy vc.

D bo tc ng vi m n mt s yu t c th c thc hin thng qua vic s dng m hnh ton gn ng. Mt trong s cc m hnh loi ny l m hnh Streeter Phelps, ra i nm 1925 dng tnh ton bin ng xy ho tan gy nn do tiu th xy ca vi khun trong qu trnh phn hu sinh hc. Trn c s m hnh ny, nhiu tc gi pht trin cc m hnh cht lng nc mt khc nh Biswas (1981), Grimsrud, Finnemor v Owen (1976). Ngoi ra cn c cc m hnh tnh ton nhim du, nhit ..

D bo bin ng c tnh ca h sinh thi nc, nng sut sinh hc nc, tc ng ca trm tch ti h sinh thi y, tch lu mt s kim loi nng trong chui thc n c nghin cu v t c nhng kt qu nht nh c v phng php lun cng nh thc t. Chng ta c th ng dng nhiu phn mm c trng khc rt thun li cho d bo bin ng.

Bc 5: nh gi tc ng mi trng nh gi tc ng c tin hnh da trn vic p dng mt cch h thng khi nim

v tnh ng k, s dng cc chun cht lng v tiu chun cht thi. Phn tch chuyn mn c s dng nh gi phn trm bin ng cc tham s la chn so vi iu kin t nhin ban u. Nhng thng tin b sung c th c thu thp t cng ng thng qua cc cuc hp hoc iu tra ti ch. Cng ng c th m t c nhng ngun ti nguyn quan trng v nh gi chng trn tng a bn v iu ny phi c tnh ti trong qu trnh nh gi.

Bc 6: Tm v tng hp cc gii php gim nh tc ng. Gii php gim nh tc ng ph thuc hon ton vo loi d n v c im a

phng. Gii php gim nh tc ng c th bao gm cch thc lm gim ln ca tc ng hoc n b tc ng. Tuy nhin di y s dn ra mt s gii php chung nht:

1.Gim s dng nc v gim x thi bng vic ci thin iu kin phc hi ti nguyn, lm sch nc thi, ti s dng.

Chn la s x l nc thi nhm lm sch nc trn c s gii bi ton chi ph, li ch. i vi cc ngun im, cn x l nc thi ti bc 2 v trn na bng cc bin php l, ho v sinh hc.

2. Trong cc d n nng nghip c s dng ho cht cn tin ti t c vic s dng thuc hp l, ng k thut. Cc tiu ho xi mn bng vic b tng ho hoc ph xanh b mt lu vc.


50

3. Pht trin chng trnh kim sot nhim vng ca sng do ngun mt t ton b phn t lin a ra. S dng vng t ngp nc lm cng c kim sot nhim mt. Qun l cc ngun thi mt thng qua vic ng vin ton th cng ng tham gia bo v mi trng.

4. La chn nhng d n c tc ng mi trng t nht hoc a vo d n nhng gii php cng trnh c tc dng ci thin mi trng tt nht.

Ngoi tc ng n hai thnh phn mi trng khng kh v nc nu trn phi nh gi tc ng ca d n n cc thnh phn khc nh nc ngm, t, sinh vt v cc thnh phn kinh t, x hi, ri ro mi trng. Nhng hng dn nh gi tc ng n cc thnh phn ny c th xem thm Ph lc 1 v cc ti liu tham kho. Khi c iu kin, chng ti x tip tc bin son tip ni gio trnh ny.

Tuy nhin, c th thy r rng, cc bc nh gi hai mc trn l nhng gi hu ch cho vic nh gi tc ng n cc thnh phn mi trng khc.

(ngun: 4, 5, 6. )

6. nh gi tc ng n cht lng MT t v nc ngm t v phng din tnh cht ca mnh c phn loi. Mi loi t u c c

im ring v c c trng bi cc ch s ca chng (nh pH, me, % vt l, xp, t trng, % hu c, dn in EC, thnh phn dinh dng khc nhau nh N, P, K, Si, Ca...) Nhng thng s (hay ch tiu) ring ca cc loi t dn c hnh thnh qua thi gian.

S tn ti ca kh quyn, thu quyn v sinh quyn gp phn to nn cc c im ring ca tng loi t (Soil) .

Trong qu tnh pht trin, con ngi v cc hot ng sn xut, sinh hot phn no tc ng vo t. Khi mc tc ng cn yu, nh th tnh cht ca t t thay i (c v vt l, ho hc, v sinh hc). Nu nhng tc ng mnh th kh nng ti to ca t (kh nng phc hi - t lm sch) khng sc chng li v tnh

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