Luan Van ThuyHC

8/6/2019 Luan Van ThuyHC

1/84

MU

1. Tnh cp thit ca ti

t ai cung cp cho con ngi ti nguyn v ng thi cng lm chc nng

cha ng nhng ph thi sn sinh ra trong qu trnh sinh sng v pht trin ca

con ngi. Nhng khi s lng ph thi ny vt qu mt mc nht nh th vic

cha ng chng tr thnh mt vn phc tp. c bit l khi nn kinh t cng

pht trin, tc th ho nhanh th din tch t ai ca cc th dnh cho cc

mc ch sn xut kinh doanh phi nng nghip cng nhiu, vy nh ca rc su? Vn tm v tr chn lp rc cng l mt trong nhng nhim v quan trng

ca quy hoch s dng t. 1 triu 600 nghn tn l con sc tnh v lng rc ca

H Ni nm 2010 do SKhoa hc v Cng ngh Thnh pha ra. Nu chng ta

khng c bin php x l th khi lng rc thi khng l nu trn s trthnh mt

thm ho ca th. Chn lp rc l bin php x l cht thi rn s dng nhiu

nht v ph bin nc ta. Lu nay, cc bi rc thng c hnh thnh mt cch

t pht, lm mt m quan th, lng ph s dng t v nhim mi trng.

Trong cng tc quy hoch s dng t, vic chn a im xy dng bi chn lp

cht thi l rt cn thit v s la chn ng gip chng ta bo v mi trng v

gim thiu chi ph xy dng, cng nh gii quyt cc vn x hi khc.

Chn a im bi chn lp cht thi rn l mt bi ton phn tch khng gian

phc tp nhm phc v cho mc ch quy hoch s dng t, quy hoch th. N

i hi phi nh gi rt nhiu cc tiu ch khc nhau v t nhin, kinh t, x hi,mi trng. gii quyt vn ny th v phng php lun, phn tch a ch tiu

l mt cch tip cn thch hp nht, v h thng tin a l (GIS) l cng c h tr

quyt nh hiu qu. GIS cho php chng ta phn tch, x l d liu khng gian,

tnh ton n nhiu ch tiu v tch hp cc lp thng tin phc v cho vic xc nh

v tr bi chn lp.

Huyn ng Anh, thnh ph H Ni l mt huyn c tc pht trin tng

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i nhanh v c nhiu khu cng nghip c xy dng trong thi gian gn y. B

mt ca huyn ang dn khi sc nhng bn cnh th vn rc thi ang l ni

lo trong cng tc qun l t ai v mi trng. Trong nhng nm qua, thc hin

ch trng x hi ha cng tc thu gom, vn chuyn v x l rc thi, huyn ng

Anh thnh lp cc t thu gom rc v bi chn lp ti 156 thn lng ca huyn.

Tuy nhin, hu ht cc bi chn lp rc ti ch ca cc thn lng l tn dng nhng

h hay h ao, bi tha ma. Thc trng chn lp rc khng ng quy nh ti mt s

bi rc cc thn lng khng ch gy kh khn cho cng tc qun l t ai m cn

li nhiu nguy c tim n v nhim ngun nc, t ai v khng kh. V th

m bin php lu di l cn phi quy hoch xc nh v tr mt bi chn lp cht thirn c quy m ph h p v p ng cc yu cu v mi trng. y cng l mt

trong nhng nhim v cp bch ca qun l t ai.

2. Mc tiu nghin cu

Xy dng phng php la chn a im b tr bi chn lp cht thi rn sinh

hot trn c sng dng GIS v phng php phn tch a ch tiu. Th nghim

trn a bn huyn ng Anh, thnh ph H Ni.

3. Ni dung nghin cu

- Nghin cu tng quan v vn la chn a im b tr bi chn lp cht

thi rn.

- Nghin cu quy trnh ng dng GIS v phng php phn tch a ch tiu

trong vic tm a im b tr bi chn lp hp l.

- ng dng quy trnh trn xc nh v tr bi chn lp cht thi rn sinh hot

cho huyn ng Anh, thnh ph H Ni. So snh kt qu ca ti vi

phng n quy hoch s dng t ca huyn n nm 2020.

4. Phng php nghin cu

- Phng php phn tch tng hp t ti liu: cc ngun ti liu thu thp c

bao gm gio trnh, sch tham kho, bo ch, mng Internet, cc bi vit, bo co

trong v ngoi nc,sc nghin cu, phn tch, v tng hp cc vn lin

quan n ti.

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- Phng php iu tra thc a: bit c thc t ca khu vc nghin cu

v thu thp thm ngun d liu cho ti.

- Phng php nh gi nh lng a ra nhng s liu c tnh khch quan

cao phc v trgip quyt nh.

- Phng php phn tch a ch tiu xc nh mc nh hng ca cc

yu t v tng hp cc ch tiu nh gi.

- Phng php phn tch khng gian bng GIS nh gi cc yu t nh

hng n vic la chn a im hp l cho bi chn lp cht thi rn.

- Phng php chuyn gia nh gi vai tr ca cc yu tnh hng.

- Phng php th nghim thc t kim chng kt qu nghin cu.5. Kt qut c

- Quy trnh ng dng GIS v phng php phn tch a ch tiu trong la chn

a im b tr bi chn lp cht thi rn da trn mt s ch tiu viu kin t

nhin, kinh t, x hi.

- Phng n b tr v tr bi chn lp cht thi rn sinh hot trn a bn huyn

ng Anh, H Ni.

6. ngha ca ti

- ngha khoa hc ca ti l a ra c quy trnh la chn v tr bi

chn lp cht thi rn sinh hot bng phng php nh lng trn csng dng

GIS v phng php phn tch a ch tiu.

- ngha thc tin ca ti l xc lp cskhoa hc v xut phng

n b tr bi chn lp cht thi rn sinh hot cho huyn ng Anh, thnh ph H

Ni.

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CHNG 1. TNG QUAN V VN LA CHN A IM B TR

BI CHN LP CHT THI RN SINH HOT

1.1. Khi nim v cht thi rn sinh hot

1.1.1. nh ngha

C nhiu nh ngha v cht thi c a ra ca cc tc gi trong nc v

trn th gii nhng xt mt cch tng qut, chng ta c th hiu Cht thi l mi

th m con ngi, thin nhin v qu trnh con ngi tc ng vo thin nhin thi

ra mi trng. Trong qu trnh tiu ho, con ngi thi ra cc cht cn b. Thinnhin v c cy c, ng vt cng thi ra mi trng t l rng n xc cc ng

vt. Con ngi tc ng vo mi trng thc hin qu trnh sn xut thi vo

mi trng v s cc loi cht thi [7].

Tu theo mc ch m c th phn chia cht thi theo cc tiu ch khc nhau:

- Theo tnh cht vt l c: cht thi rn, cht thi lng, cht thi kh.

- Theo ngun gc pht sinh c: cht thi sinh hot, cht thi cng nghip, cht

thi c ngun gc khc trong lnh vc nng, lm, ng nghip v dch v.

- Theo tnh cht, mc c hi c: cht thi nguy hi, cht thi thng thng.

Nh vy, cht thi rn sinh hot c hiu l cht thi th rn pht sinh t

cc hot ng cc khu dn c, hot ng thng mi, dch v th. N bao gm

nhng cht hu c (giy, nha, thc n tha, cao su,), v c (thu tinh, kim

loi,) v cht thi c bit c ngun gc cc h gia nh, cc trung tm thng

mi, cquan, dch v cng cng. Trong thut ng ting Vit, cht thi cn c gil rc.

1.1.2. Cc lung cht thi rn sinh hot

Cht thi pht sinh t mt ngun nht nh c gi l mt lung cht thi [7].

Cng nhcc nc trn th gii, Vit Nam, phn ln (80%) cht thi pht sinh

t cc hot ng kinh doanh v sinh hot, ch yu t cc c s sn xut cng

nghip, thng mi v t dn c th, nng thn. Theo c tnh ca chuyn gia v

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cc nh qun l mi trng Vit Nam th trung bnh Vit Nam lng cht thi rn

tnh trn u ngi thi ra mi ngy khong 1kg, trong lng cht thi rn sinh

hot th chim hn 80%, cht thi rn cng nghip khong 17%, cn li 1% l

cht thi rn nguy hi (gm cht thi rn cng nghip nguy hi, cht thi rn y t v

cc loi thuc tr su).

Hin nay, chng ta ang ng trc nguy ccht thi rn sinh hot ngy cng

gia tng c th ln nng thn. c bit l khi qu trnh th ho din ra mnh

m th cng gy nn nhng vn v lng rc thi, nhim mi trng. Ta c th

phn tch mt s lung pht sinh nh sau:

Th nht: i vi nhng khu vc dn c th ln th do dn s ngy cngtng, trong khi din tch t th th khng p ng kp nn lng rc thi t

cc hot ng n, , gii tr,ca con ngi ngy cng qu ti so vi sc cha ca

th.

Th hai, cc th mi m rng ra cc vng ven v ngoi c nhng s

thay i ln t kiu cu trc lng x ngoi thnh cc nh theo li th. Cu

trc khng gian cng nh cu trc qun l x hi, qun l mi trng cng bo

ln. C th h vn quen theo kiu sinh hot c: rc vt ba bi, lp y h ao, cng

rnh, nn gy ra tnh trng nhim mi trng nghim trng. Cng c th dn c

ngy cng ng vi cc thnh phn khc nhau nn rt kh vn ng, thuyt phc

lm theo quy nh (c th nhcc xm liu).

Th ba, cc khu th mi do Nh nc hay t nhn u t xy dng hon

chnh ri bn cho ngi dn hoc chia t cho cn b. Kiu th ho ny c u

im l khi xy dng ngi ta quy hoch kh y h thng cp thot nc,

cc h rc thi, x l rc thi, Tuy nhin, nhng khu vc ny nu khng c

nhng quy nh nghim ngt th nguy cn tc v nhim rc thi cng d xy ra

v rt nguy hi.

Th t l khu vc ca cc trung tm cng nghip tp trung. Trong qu trnh

cng nghip ho ang din ra mnh m th nhiu khu cng nghip mi xut hin. i

cng vi nhng ni ny l nhng vng ctr mi c hnh thnh. Mt l cc khu

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nh tm, ln tri cho cng nhn xy dng. y l nhng loi nh c xy dng

khng kin c v cuc sng ca c dn trong cc khu ny thng l tm b. V th

v vic x rc v thu gom rc l khng c t chc. Hai l cc khu nh r tin cho

cng nhn t cc tnh xa li. Trong cc khu vc ny, phn ng l dn t x hp

li v lm vic nn vic qun l rc thi cng gp kh khn.

Th nm l rc thi sinh hot pht sinh t cc ni ngh ngi, tham quan du lch

v dch v gii tr. i lin vi qu trnh cng nghip ha v hin i ha l s pht

trin ca cc khu dch v du lch v vui chi gii tr mi mc ln hoc mrng trn

c s cc khu ngh ngi, vui chi sn c. Thc t, thi gian qua cho thy, trong

nhiu khu du lch gii tr, c bit l vng bbin, ni c hot ng l hi tp trungng ngi hu nh cha t chc thu gom rc v hng dn thc hin cc quy

nh v v sinh cng cng mt cch cht ch v hiu qu.

Nh vy, ta c th thy rng rc thi rn sinh hot t p trung ch yu cc

vng th. nng thn th lng pht sinh cht thi sinh hot t hn v phn ln

l cht thi hu cd phn hu. Chng ta cn nm c cc ngun pht sinh ch

ng a ra nhng gii php thch h p v hu hiu nhm m bo v sinh mi

trng v cnh quan chung ca th.

1.1.3. Cc phng php xl cht thi rn sinh hot

a. Ti sdng, ti ch

- Ti s dng (re-use) l em cc vt thi cn c gi tr s dng tr li th

trng. Cc ca hng bn c, cc trm thu mua, bn dng v vt liu cu

nhm mc ch ti s dng. Bin php ny c u im [2]:

+ Tit kim nng lng;

+ Tit kim din tch bi thi;

+ To cng n vic lm cho mt s ngi tht nghip;

+ Cung cp dng cho ngi ngho vi gi r;

+ Gim bt nhim do sn xut.

Tuy nhin khng phi vt liu no cng c tha vo ti s dng. Cc vt

liu c th ti s dng trc tip l: g, t, bn gh c, chai ng nc ung,

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- Ti ch (recycling) l hot ng thu hi li t cht thi cc thnh phn c th

s dng ch bin thnh cc sn phm mi s dng li cho cc hot ng sinh

hot v sn xut. V d thu tinh c cho vo l nu li, kim loi c nung chy

trli. Ti ch khng tit kim bng ti s dng nhng rt c li v:

+ Tit kim ti nguyn thin nhin bi vic s dng vt liu c ti ch vt liu

gc;

+ Tit kim din tch chn lp;

+ C th thu li nhun t hot ng ti ch.

Tuy nhin ti ch rc thi i hi s hp tc ca ton dn trong phn loi rc

thi trc khi vo h thng chung. S tm tt qu trnh thu hi ti nguyn,sn phm, nng lng c biu thhnh 1.1.

Hnh 1.1. S quy trnh cng ngh xl v thu hi ti nguyn,

sn phm nng lng [7]

b. Tip cn u vo

Vic gim bt rc thi cn c thc hin theo hng tip cn u vo (Input

approach). Tip cn ny da trn ba phng php sau [2]:

- Ko di thi hn s dng ca hng ho. Hng ho cht lng tt, c bn

cao s c thi hn s dng di, gim bt lng ph thi;

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- Gim bt khi lng vt liu trong ch to hng ho. Vic chy ua theo cc

hnh thc hp dn trong th trng gy nn lng ph trong ch to hng ho. Ti cc

nc cng nghip pht trin, 40% sn lng giy, 14% sn lng nhm, 8% sn

lng thp c dng cho bao b hng ho, 40% lng rc thi rn l bao b;

- Gim bt s tiu th: Kinh t th trng to ra nhng nhu cu tiu dng mi

nhiu khi khng cn thit, thm ch c hi cho tng c nhn v x hi. C nhiu kh

nng gim bt tiu th tit kim vt liu, nng lng trong bi cnh ti nguyn

v mi trng c nhiu kh khn trn ton th gii hin nay.

c. Xl cht thi rn bng cng ngh p kin

Phng php p kin c thc hin trn cs ton b rc thi tp trung thugom vo nh my. Rc c phn loi bng phng php th cng trn bng ti.

Nhng cht khng thu li ti chc th sc chuyn qua h thng p nn

rc bng thu lc vi mc ch lm gim ti a th tch khi rc v to thnh cc

kin rc vi t s nn cao. Cc kin rc p c s dng vo vic p cc b

chn hoc san l p cc vng t trng ri ph lp t ct ln. Trn din tch ny,

ngi ta c th s dng lm mt bng xy dng cng vin, vn hay cc cng

trnh xy dng nh. S quy trnh cng ngh nh hnh 1.2.

Hnh 1.2. Quy trnh cng ngh xl rc thi bng phng php p kin [7]

d. Phng php sinh hc

sinh hc (compost) c hiu l qu trnh n nh sinh ho cc cht hu c

thnh cht mn, vi thao tc sn xut v kim sot mt cch khoa hc to mi

trng ti u i vi qu trnh.

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Qu trnh c p dng i vi cht hu ckhng c hi, lc u l kh

nc, sau l x l cho ti khi n trnn xp v m. m v nhit c kim

tra gi cho vt liu lun lun trng thi hiu kh trong sut thi gian . Qu

trnh t to ra nhit ring nh qu trnh oxy ho sinh hc cc cht thi ra. Sn

phm cui cng ca qu trnh phn hu l CO2, nc v cc hp cht hu cnh

lignin, xenlul, si. Cht thi hu cny c phn gii ym kh bng cc vi sinh

vt c nn li thnh cc bnh phn hu c. Phn ny c tc dng tng ph nhiu

ca t, lm cho t thm ti xp, thm nc nhiu hn, hn ch xi mn mt t.

Tuy nhin phng php ny cng c mt s nhc im l gy mi hi thi,

c th gy dch bnh, vic phn loi rc thi hu ckhi rc thi chung cng tncng sc, tin ca. Ch yu sn phm l phn hu c tinh, mun c phn hu c

cao cp phi b sung thm cc thnh phn dinh dng N, P, K v mt s nguyn t

ho hc vi lng hoc mt s ph gia kch thch sinh trng.

e. Phng php t

-t c khng kh:

t c khng kh l giai on cui cng c p dng cho mt s loi rc nht

nh khi khng th x l bng cc bin php khc. y l mt giai on oxy ho

nhit cao vi s c mt ca oxy trong khng kh (hnh 1.3 l quy trnh cng ngh

t cht thi rn quy m cng nghip).

Cng nght c nhng u im [7]:

+ Gim ti mc ti thiu cht thi cho khu x l cui cng;

+ X l ton b cht thi th m khng cn nhiu din tch t s dng lm

bi chn lp rc;

+ Nng lng pht sinh c th tn dng cho cc l hi, l si hoc cc cng

nghip cn nhit v pht in.

Nhc im ca phng php ny l:

+ Khi t rc s sinh ra khi c v d sinh ixin nu gii quyt vic x l

khi khng tt;

+ Vn hnh dy chuyn phc tp v gi thnh u t rt ln.

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Hnh 1.3. Quy trnh cng nght cht thi rn quy m cng nghip [7]

-t khng c khng kh (nhit gii):

y l phng php phn gii cc rc thi hu c trong iu kin ym kh

nhit cao. Phng php ny l mt cng ngh sch, nhng cng nh phng

php t c khng kh, n c gi thnh cao hn cc phng php khc.

f. Phng php chn lp

Phng php chn lp l mt hng tip cn x thi trong vic qun l cht

thi. Tc l em rc thi ti ni xa th trnh cc tc ng xu v gim bt

lng rc thi. Theo tip cn ny, ti hng lot cc th, ngi ta chuyn cc

bi thi t nhin, l thin thnh bi thi hp v sinh c lp t. l nhng bi s

dng mt khong t thp t nhin (thung lng, ao h cn) hoc nhn to, lm

bi rc. Hng ngy, rc thi c tp trung v, san i, lp trn mt lp t mng

vi phng tin cgii.Qun l bi chn lp cht thi rn bao gm cc cng vic quy hoch, thit k,

vn hnh, ng bi v kim sot sau khi ng bi. Hnh 1.4 l s th hin cc

quy trnh khi qut v qun l bi chn lp cht thi rn.

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- Chun b mt bng xy dng bi rc.- Ni chn lp rc cn tho mn nhng tiu ch quy nh vquy hoch s dng t v bo v mi trng

Quy hoch

Hnh 1.4. Quy trnh qun l bi chn lp cht thi rn [7]

Trong cc bc trn th quy hoch hay la chn a im l bc u tin v

rt quan trng, quyt nh n thnh cng ca c d n. L do l mt v tr ph hp

s gip gim thiu ng k nhng tc ng mi trng tiu cc c th xy ra trong

qu trnh vn hnh BCL CTR, qua gim nguy cnh hng ti sc kho cng

ng v gim thiu s phn i ca cng ng trong qu trnh vn hnh. Mt v tr

thch hp cng gip gim chi ph u t xy dng bi.

Phng php ny c u im:

+ Chi ph thp nht so vi cc phng php khc;

+ Sau mt thi gian 5 10 nm, lc t lp y c th xy dng cc cngtrnh ln trn .

Nhc im ca phng php l [2]:

+ i hi din tch t nhiu hn so vi phng php khc;

+ C th gy nhim nc ngm;

+ Kh rc khng c kim sot thot ra khi bi gy mi hi. Sn sinh ra kh

metan t qu trnh phn gii ym kh cc cht hu c. Kh ny c th thot ra v

Thit k

Vn hnh

ng bi

Kim sot

o h chn lp v chun b cc k thut y bi cng nhtrn b mt

- Quan trc mi trng- Bo tr b mt bi rc

- rc, ban rc thnh lp mng, nn cht rc.- X l kh rc v nc rc

- Khi bi rc t n chiu cao quy nh th s tin hnh phln trn mt lp t mng. C th trng cy v 1 lp thm

thc vt bn trn lp ph- Lp t cc ng ly kh rc theo phng thng ng

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gy n;

+ Nhn dn a phng c th phn i vic chn bi rc ni gn chca h.

Kinh nghim cho thy chn lp l bin php kinh t trong x l cht thi rn.

Ngy nay, c nhiu cng ngh tin tin c s dng nhm hn ch ti a cc

nhc im ca phng php ny nh [2]:

+ Ht rc bng chn khng kt hp vi phn loi rc ti ch gim bt

din tch bi cha rc. Bin php ny thng c p dng cc khu chung c;

+ Cch ly BCL CTR vi cc dng nc ngm, khoan cc ging quanh bi

cha theo di ng thi ca cc cht c hi t rc thm ra ngoi. Nu c nc

thi c hi th s kp thi x l;+ t cc ng thot kh metan ra kh quyn, hoc thu gom lm nhin liu cho

cc nh gn.

Vit Nam, mt s phng php x l cht thi rn hay c s dng l:

- Phng php thu gom vt liu thi ti s dng, ti ch. y l phng php

tt yu trong iu kin nn kinh t cn kh khn, mc thu nhp ca ngi dn cn

thp. Hu ht cc gia nh Vit Nam u c gng tn dng ti a nhiu loi vt dng

hoc bn li hay em cho ngi khc v h thng thu mua c kh pht trin Vit

Nam. Ngoi ra cn kn i ng sa cha gia dng hng (tivi, t lnh,).

- Phng php sinh hc: Hin ti Vit Nam c 9 nh my ch bin phn

hu c tp trung (Cu Din - H Ni, thnh ph Nam nh, Thi Bnh, Vit Tr,

thnh ph H Ch Minh, B Ra Vng Tu, Trng Ct - Hi Phng, Ninh Thun,

Hu). Cu Din H Ni c mt trm phn compost t nm 1994 n nay vi

cng sut 150 tn rc/ngy. Nguyn liu ch yu l rc ng v rc ch, phn bn

t b t hoi. Cng ngh x l, ch bin v thit b ca Ty Ban Nha [2].

- Cng nght thng dng x l rc c hi nh rc bnh vin v cht

thi cng nghip nguy hi.

- Phng php chn lp l c dng ph bin nht. Kt qu kho st trong

nhiu nm qua cho thy trong s 91 bi chn lp ln trn c nc ch c 17 bi

ng quy hoch, hp v sinh, chim t l rt thp, ch khong 15,5% [20]. S tn ti

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cc bi chn lp t pht cc a phng ang to nn nhng bc xc v qun l

t ai v mi trng, x hi. Chnh v vy m i hi vic quy hoch cc BCL

CTR cng phi c tin hnh theo ng nhng tiu chun nht nh.

1.2. Cc yu tnh hng n la chn a im b tr bi chn lp cht thi

rn sinh hot

La chn a im b tr bi chn lp cht thi rn sinh hot l mt bi ton

phn tch khng gian tng hp, lin quan n rt nhiu cc tham s nh: a hnh,

thu vn, mc ch s dng t, khong cch n cc khu dn c, cc tuyn ng

giao thng, Chng ta cn phn tch r snh hng ny lm cscho vic

xc nh cc tiu ch la chn a im b tr bi chn lp cht thi rn ph hp vitng khu vc.

1.2.1. Cc yu ttnhin

a.a hnh

a hnh l yu tnh hng rt r n v tr bi chn lp. Thng thng th

ngi ta hay tn dng ti a a hnh t nhin nhm gim bt khi lng o lp.

Nu nhng ni no c a hnh trng th vic o h s tit kim hn khi tn dng

nhng ao h cn. nhng khu vc i ni th ngi ta thng quan tm n khu

vc thung lng, sn ni hay hm m c chn lp rc.

a hnh cn lin quan n hng dc v dc ca bi. Vic chn v tr ni

qu dc c th s lm lng nc rc b r r ra ngoi d hn. Nhng nu dc

va phi th c th gip cho vic trnh ng nc ma.

Vic la chn kiu bi chn lp cng ph thuc nhiu vo yu ta hnh. Nu

nhng khu vc min ni cao th bi chn l p chm l thch h p. Ngc li

nhng ni th p th nn lm bi rc ni khng lm nh hng n tng nc

ngm v trnh vic b st ln thm. Cn i vi vng c cao va phi th bi

chn lp na chm na ni li thch hp v s tit kim c din tch bi chn lp

m vn c th tng lng cha hn.

b.a cht

Yu ta cht lin quan n cu trc ca cc loi v sn nh kin to.

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Bi chn lp khng nn xy dng nhng khu vc c nt t gy, ng t, hay l

trn vi nhm bo v nc ngm. Trong trng hp khng c cch la chn no

khc th i vi a im c nn vi, bi chn lp phi xy dng lp chng thm

c h s thm thu k < 1 x 10-7 cm/s, b dy khng c nh hn 1m v phi c h

thng thu gom, x l nc rc [1]. Cc khu vc c cu to a cht phc tp cng

khng thch hp v gy kh khn cho vic quan trc v thc hin cc k hoch d

phng.

Khi tin hnh iu tra a cht, cn phi nm c cc thng tin sau:

- Din phn b ca cc lp t trong khu vc bi chn lp;

- Thnh phn thch hc ca cc lp;- H s thm nc ca cc lp;

- S hin din ca cc t gy khng, mc ng t,

c. Kh hu

Yu t kh hu c nh hng nhiu nht n vic b tr BCL CTR l gi.

Hng gi sa mi ca rc khuch tn xung quanh nn thng thng vic la

chn a im BCL CTR nn nm cui hng gi. Ngoi ra cng cn ch n

lng ma ca khu vc. V nu ma nhiu qu m h thng thot khng tt th s

lm ng nc rc v gim kh nng nn rc, cha rc, r r nc rc nhiu. Cc

khu vc hay xy ra thin tai ngp lt cng phi trnh.

Cc s liu cn thit khi iu tra v kh hu l [1]:

- Lng ma trung bnh cc thng trong nm, lng ma ngy ln nht, nh nht;

- bc hi trung bnh v ln nht trong thng;

- Hng gi v tc gi trong nm;

- Nhit trung bnh, ln nht, nh nht trong thng,

d. Thu vn

H thng thu vn bao gm nc mt v nc ngm. Cc khu vc nh h,

sui,khng ph hp xy dng BCL CTR v rt d gy nhim ngun nc.

Khu vc c nc ngm cng phi ch n khong cch ti thiu theo quy nh.

Nguyn nhn l do bi chn lp c th b r cc cht thi c hi v thm thu qua

14


15/84

t nn snh hng n tng nc ngm. Kt qu l d ly lan cc mm bnh

nguy him cho con ngi thng qua ngun cung cp nc ny.

Khi iu tra v thu vn, cn phi lm sng t cc vn sau:

- Mng li sng sui ca khu vc;

- Quy m ca cc dng chy: rng, su, hng chy v lu vc ca chng;

- Mc nc, cht lng nc, hin trng s dng nc;

- Khong cch t bi chn lp n cc dng chy,

e. Thnhng

Yu t th nhng lin quan n vic la chn a im BCL CTR l loi t

v thm. Ngi ta thng a ra tiu ch l lm sao tng ti a s thch nghi cat ti ch lm nguyn liu lt y bi v che ph bi. Thng thng th t st hay

c s dng v c thm nc km, gim vic r r nc rc hay cc cht thi

c hi khc t bi. Nu t ti ch khng ph h p th cn c gng gim thiu

khong cch t bi chn lp n cc a im c nguyn liu ny.

f. H sinh thi khu vc

Khi la chn a im BCL CTR cn phi tm hiu v h thc vt, ng vt

ch yu v cc loi ng thc vt qu him c trong sch ca khu vc v vng

ph cn. Bi v vic xut hin BCL s lm nh hng n mi trng sng xung

quanh ca cc loi sinh vt. Tiu ch thng l phi tng ti a khong cch n cc

khu vc .

1.2.2. Cc yu tkinh t- x hi

a. Thng tin sdngt

Thng tin s dng t cho php chng ta bit c s phn b ca cc loi

hnh sng t ti 1 thi im nht nh hay dnh trong tng lai. Mt iu tt

yu l a im bi chn lp phi c xc nh cn c theo quy hoch xy dng

c cquan nh nc c thm quyn ph duyt. Thng th nhng loi t cha

s dng sc u tin cho vic lm bi chn lp. Nhng tu trng hp m phi

la chn a im khc th nn tm kim v tr sao cho vic n b gii phng mt

bng t gp kh khn nht.

15


16/84

b. Dn c

y l mt yu t rt quan trng v n nh hng trc tip n sc kho ca

cng ng xung quanh khu vc BCL CTR. Cc vn thng ny sinh khi c bi

chn lp l: mi trng b nhim, mi hi thi, bnh tt d pht sinh, Do ,

gn nh khng c d n xy dng BCL CTR no l khng vp phi thi phn

i quyt lit ca ngi dn. Mt kho st thc t ti 2 bi rc Nam Sn (H Ni)

v bi rc G Ct (H Ch Minh) cho thy rng: ti bi rc G Ct, dn c phn i

mnh m nht (93%), Nam Sn th t lng h ch c 6%, cn 49% khng ng

[22]. Thm ch ngi dn cn chn xe rc, p vknh, khng cho xe ch

rc vo. V th m tiu ch a ra l phi tng ti a khong cch ti cc im dnc v gim thiu s lng c dn trong khu vc nh hng ca bi chn lp. Bn

cnh cc cp chnh quyn v cng ty mi trng cn ch n vic n b tho

ng cho nhng ngi dn ti khu vc bi rc, quan tm n vai tr ca h v c

trch nhim bo v mi trng xung quanh bi chn lp nhm tng ti a s chp

thun ca cng ng.

Cc s liu cn thu thp v dn c bao gm: s dn, mt , tc tng dn

s, c im dn c (lao ng, thu nhp, phong tc tp qun, tnh hnh y t,). T

cc thng tin ny ta c thc tnh c lng rc thi sinh hot pht sinh v cc

bin php qun l, nm bt tm l ca ngi dn.

c. H thng qun l hnh chnh

Vic la chn a im b tr BCL CTR khng ch lin quan n ngi dn m

cn ph thuc rt nhiu vo c p qun l hnh chnh ti khu vc . Vai tr ca

chnh quyn a phng mt mt l s chp thun b tr a im chn lp rc hay

khng v mt khc l vn qun l, phi hp vi cng ty mi trng m bo

cho s vn hnh ca bi.

d. Cc khu di tch lch s, vn ho, du lch

Cc a im di tch lch s, vn ho, du lch thng yu cu v mi trng

phi trong sch thu ht khch thm quan hoc do yu t tm linh (nh cha,

miu, n,). Do vic la chn v tr BCL CTR phi nm cch xa nhng khu

16


17/84

vc trn vi khong cch ti thiu thng l 1km.

e. Hin trng kinh tv kh nng tng trng kinh t

Cn nh gi c tnh hnh pht trin kinh t ca khu vc v n s quyt nh

n quy m ca bi chn lp v loi cht thi ch yu. Mt iu chc chn rng cc

bi chn lp rc cng khng th nm ngay mt trung tm pht trin kinh t (v d

nh ni thnh thnh ph H Ni) m phi nm cch mt khong cch nht nh

nhm hn ch tc ng n nn kinh ta phng v s dng t.

iu tra thng tin v hin trng kinh t cn ch n s phn b v s lng

ca cc khu cng nghip, cssn xut kinh doanh, khai khong, cc ngnh cng

nghip tim nng v sn phm.1.2.3. Cc yu tcsh tng

a. Giao thng

Giao thng l mt trong nhng yu t rt quan trng lin quan n vn vn

chuyn, thu gom cht thi. Nu khong cch ny qu xa s gy tn km v c th

gy nhim trong qu trnh vn chuyn nhiu hn. Thng thng khi thit k BCL

CTR cn tnh n vic gim thiu khong cch vn chuyn rc t thnh ph hoc

khu thn BCL. Bn cnh cn ch n si li thun tin ca cc tuyn

ng dnh cho xe rc.

Khi iu tra v giao thng cn xem xt cc yu t nh rng ca cc con

ng, khong cch n ng giao thng chnh, mc kh khn, thun li trong

qu trnh vn chuyn.

b. Mng li in, nc

vn hnh v duy tr BCL CTR th h thng kim sot kh rc, nc rc,

quan trc mi trng phi hot ng lin tc. Do m mng li in v thot

nc khu vc c BCL rt cn c quan tm. Nn la chn nhng vng c h

thng in v nc tt gim chi ph xy dng csh tng cho bi v phc

v cho vic qun l bi c tt hn.

1.3. Cc ch tiu trong la chn a im bi chn lp cht thi rn

i vi vic la chn a im bi chn lp cht thi rn, ngoi cc phn tch v

17


18/84

mt nh tnh nh trn th cc ch tiu nh lng l rt quan trng. Cc ch tiu ny

cho php chng ta c nhng cs thc hin bi ton tm kim a im thch hp.

tng bc quy chun ho vic xy dng BCL CTRVit Nam, B Xy

dng v B Khoa hc, Cng ngh v Mi trng ban hnh TCXD 261:2001

Bi chn lp cht thi rn Tiu chun thit k, v Thng t lin tch s 01/2001

Hng dn thc hin cc quy nh bo v mi trng i vi vic la chn a

im, xy dng v vn hnh bi chn lp cht thi rn. Trong c mt sim

cn ch nh sau:

a. Quy m din tch bi chn lp

Quy m din tch BCL c xc nh trn cs[1]:- Dn s v lng cht thi hin ti, t l tng dn s v tng lng cht thi

trong sut thi gian vn hnh ca BCL.

- Kh nng tng trng kinh t v nh hng pht trin ca th.

- Vic thit k BCL phi m bo sao cho tng chiu dy ca bi k ty n

nh c th t 15m n 25m, tu thuc vo loi hnh BCL v iu kin cnh quan

xung quanh BCL.

- T l din tch xy dng cc cng trnh ph tr: ng, k, h thng thot

nc, dn nc, nh kho, sn bi, xng, h lng nc rc, h x l nc, h thng

hng ro cy xanh v cc cng trnh ph trkhc trong BCL chim khong 20%

tng din tch bi.

Quy m ca cc BCL CTR cho cc khu dn c thc th hin trong bng

1.1.

b. Yu cu la chn a im bi chn lp

- a im BCL phi c xc nh cn c theo quy hoch xy dng c

cquan nh nc c thm quyn ph duyt.

- Khong cch xy dng t BCL ti cc im dn c, khu thc quy

nh trong bng 1.2.

- Vic la chn a im phi cn c vo cc yu t t nhin, kinh t, x hi,

h thng h tng k thut ti khu vc d kin xy dng BCL.

18


19/84

19

Bng 1.1. Phn loi quy m BCL cht thi rn (ngun: TTLT 01/2001)

STT Loi bi Dn s th hin ti Lng rc Din tch bi

1 Nh < 100.000 20.000 tn/nm < 10 ha

2 Va 100.000 300.000 65.000 tn/nm 10 - 30 ha

3 Ln 300.000 1.000.000 200.000 tn/nm 30 - 50 ha

4 Rt ln > 1.000.000 > 200.000 tn/nm > 50 ha

Bng 1.2. Khong cch thch hp khi la chn BCL (ngun: TCXDVN 261:2001)

Khong cch ti thiu t vnh ai cngtrnh ti cc bi chn lp (n v: m)

Cc cng trnh

c im v quy m cng

trnh BCL nh vva

BCL ln BCL rt ln

thCc thnh ph, th x, th

trn, th t,3000 - 5000

5000 -

15000

15000 -

30000

Sn bay, cc khu cngnghip, hi cng

T quy m nhn ln 1000 - 20002000 -

3000

3000 -

5000

15 h cui hng gi chnh 1000 1000 1000Cm dn cng

bng v trung du Cc hng khc 300 300 300

Cm dn c min niTheo khe ni (c dng chy

xung)3000 - 5000 > 5000 > 5000

Cng trnh khai thcnc ngm

C.sut Q < 100 m3/ng

Q < 10.000 m3/ng

Q > 10.000 m3/ng

50 - 100

> 100

> 500

> 100

> 500

> 1000

> 500

> 1000

> 5000

Khong cch tnggiao thng n BCL

Quc l, tnh l >100 >300 >500

Ch thch: Khong cch trong bng trn c tnh tvnh ai cng trnh n hng ro bi chn lp

Ngoi cc quy nh trn, trong khun kh ca D n Kinh t cht thi do C

quan pht trin quc t Canada (CIDA) ti tr, cc tc gi Mc Nally v Lu c

Cng xy dng b mc tiu, tiu ch, gii hn chi tit c tnh cht tng qut p

dng cho BCL CTR (bng 1.3). Khi a phng thc hin vn c th b sung hoc

iu chnh ph hp vi iu kin khu vc ca mnh.


20/84

Bng 1.3. B mc tiu, tiu chun, gii hn v cc loi sliu trong xy dng bi chn lp ch

(Ngun: Byer, McNally, Luc Cng 2003) [7]

Mc tiu Tiu ch Gii hn Quy nh ca Vit Nam

Gim thiu cc tc ng titng ngm nc

BCL khng nn t ti cc khuvc c nc ngm l nguncung cp nc hin ti hoctng lai

a iqua nc nngm, k

Gim ti thiu thm chtthi vo lp a cht bndi

BCL khng nn xy dng tinhng khu vc c nt t gy, cng, a hnh vi

TT lin b 01/2001: i vi cca im c nn vi v phadi rng, BCL phi xy dnglp chng thm c h s thmthu k < 1x10-7cm/s vi b dykhng nh hn 1m v c hthng thu gom, x l nc rc

c ithm thlng t

Tng ti a khong cch ticc vt nt, rn

Khng c cc cu trc a chtnt, rn ln trong phm vi Xmt BCL

V tr c

Tng ti a khong cch ticc ngun cung cp nc vgim thiu s lng ccngun ny trong khu vc

Cc khu vc c ngun nc(h, sui, m ly,) hoc cckhu vc c bo v khngph hp xy dng BCL

Ti liu thng k m ly qucgia chnh v bo v cc khuvc m ly nhy cm, rngln v mt sinh thi

a icc khu

Gim tithiu cc

tc ngti khu

vc nhycm v c

ncngm

Gim thiu cc ri ro do ltbng vic tng ti a khongcch t bi n cc vng

ng bng trng v d b bo

BCL khng nn t ti cc vngngp lt c tn sut ngp lt 10nm/1 ln. Nu t BCL trong

cc vng c tn sut b lt 100nm/ln th phi s bn thitk gim tim nng b lt

Bn sut lt

Gim thiuchi ph xydng vvn hnh

Tn dng ti a t sn ctrong khu vc cho vic xydng lp lt y bi. Trongtrng hp t th nhng

Cc khu vc c cu to acht phc tp khng thch hpdo nhng kh khn trong vicquan trc v thc hin cc k

TCXDVN 261:2001: a imc t t nhin vi h s thmthu


21/84

Mc tiu Tiu ch Gii hn Quy nh ca Vit Nam

khng ph hp, gim thiukhong cch ti cc a imkhai thc t cho vic xy

dng lp lt y bi

hoch d phng. HDPE. BCL xy dng ti cch t nhin nh m hoc ni cct y bi cao hn mc nc

ngm v t t nhin c h sthm thu


22/84

Mc tiu

22

Tiu ch Gii hn Quy nh ca Vit Nam

Gim thiu cc tc ng tis pht trin kinh t

Khong cch ti thiu ti cckhu cng nghip

Mc thvc, snghip cng nphm

Tng ti a khong cch ticc khu qun s

S lnbi ti quanh

Tng ti a vic s dng bisau khi ng ca

Quy ho

Gim thiucc tc

ng tinn kinh

taphngv s

dng t

Gim thiu cc thay i v sdng t v chi ph n b

S dnnghip,nh v

Gim thiu chi ph thit lpbu chnh vin thng

Khongchnh v

Gim thiu chi ph xy dngh thng cung cp ncphc v bi

Khongnc cng su

Gim thiu chi ph xy dngmng li cp in cho bi

Khongin a

Tng khong cch nng quc l

TCXDVN 261-2001: khongcch t bi n ng giaothng chnh (tnh l, quc l) l> 100m

a ikhong

Gim thiuchi ph xydng c

s h tng

Gim thiu khong cch vnchuyn rc t thnh ph hockhu th

Khongphn


23/84

1.4. Tnh hnh nghin cu trong v ngoi nc v phng php la chn a

im bi chn lp cht thi rn sinh hot

Nhiu nc trn th gii quan tm rt sm n vic quy hoch v tr bi

chn lp cht thi rn hp l bi mt s tc ng tiu cc ca n ti mi trng,

sc kho cng ng, x hi v kinh t. Cc nghin cu l thuyt ca th gii v la

chn a im (LC), trong c LC BCL CTR bt u t nhng nm 70 ca

th k trc, thng qua kinh nghim thc tin M. Cch tip cn trong thi gian

ch yu da trn cc tiu ch kinh t (hiu qu kinh t cao nht) vi cng c ph

bin l phn tch chi ph li ch (Keeney, 1980). Hai cng cc s dng ph bin

nht trong thi k ny l k thut phn tch a tiu ch (Multicriteria analysis) vchng xp bn (Overlapping Map). Cui nhng nm 80 v thp k 90 ca th k

trc l giai on m cc nghin cu v LC khng ch tp trung M m lan

rng sang cc nc khc chu u v mt s quc gia pht trin chu . Cc l

thuyt v LC cng c lng ghp, r sot bng l thuyt ca cc ban ngnh

khoa hc khc nh khoa hc chnh tr, khoa hc x hi, kinh t, mi trng. Bc

sang th k XXI, cng vi s pht trin ca khoa hc my tnh, h thng thng tin

a l (GIS) c s dng nh mt cng c hu hiu trong LC [21].

Trong nhng nm va qua, ni ln mt s nghin cu ng dng GIS trong vic

la chn v tr BCL CTRMalaysia, Hy Lp, Nht Bn, i Loan, Malaysia,

th trn Klang thuc bang Selangor l mt khu vc c dn sng v tc pht

trin nhanh c chn lm a im nghin cu. Cc tc gi s dng phng

php phn tch a ch tiu c tch hp bi 2 thut ton l qu trnh phn tch phn

cp (AHP Analytical Hierachy Process) v lin kt trng s tuyn tnh (WLC

Weighted Linear Combination) gii quyt bi ton ny. Cc d liu u vo gm

11 yu t l cc bn h thng thu vn b mt, khu vc dn c, h thng ng

xe la, dc ca cc vng ngp lt, m ly, cc di tch vn ho, mt dc, th

nhng, hin trng s dng t, h thng giao thng v cc khu th [16]. Hnh 1.5

l quy trnh xc nh v tr BCL CTR do tc gi tham kho nghin cu Malaysia.

C 2 bc chnh trong quy trnh. Bc 1: Da trn cc ch tiu gii hn v v

23


24/84

tr bi chn lp phn tch cc d liu khng gian u vo nhm xc nh cc khu

vc tim nng. Bc 2: xc nh cc trng s cho cc tham s chnh v t tnh

im cho cc v tr tim nng.

Hnh 1.5. Quy trnh LC BCL CTR Malaysia [16]

y c 4 tham s chnh l hin trng s dng t (land use), mt dc (slope),

giao thng (road) v th nhng (soil type). Vic xc nh trng s ny da trn

phng php AHP. y l k thut do Thomas.L. Saaty nghin cu v xut t

nhng nm 1970. Theo phng php ny, chng ta s lp mt ma trn vung vi

hng v ct l cc tham sc chn. Cc gi tr trong ma trn l mc quan

trng ca cc tham s sau khi so snh tng cp vi nhau. Sau s xc nh trng

s tng quan chung RIW (Relative Importance Weight). Hnh 1.6 l bng ma trn

so snh mc quan trng ca cc tham s m cc tc gi th nghim

Malaysia.

Phng php WCL c s dng nh gi v tr (hay cn gi l tnh im)

cc khu vc tim nng thng qua cng thc:

=

=n

j

ijji xwS1

* (1.1)

Trong Si l gi trim chung ca khu vc tim nng i, wjl trng s ca

tham sj,xij l im thnh phn ca khu vc i vi tham sj, n l tng s cc tham

s. Khu vc no c gi tr cao nht th c chn. Phng php phn tch a ch

24


25/84

tiu s dng thut ton AHP v WCL tm khu vc ph hp cng c nghin

cu South Cork (Ireland) v Giroft (Iran).

Hnh 1.6. Ma trn mc quan trng ca cc tham schnh khi LC BCL CTR [16]

Cng theo hng tip cn phng php phn tch a ch tiu, tc gi Basak

Sener (Middle East Technical University) s dng thut ton Simple Additive

Weighting (SAW) nghin cu vng Ankara, Th NhK. Cc bc chnh

trong quy trnh l [11]:

- Xc nh cc ch tiu gii hn v cc khu vc kh thi;

- Chun ho (hay tnh im) cho tng ch tiu ca bn u vo bng SAW;

- Xc nh trng s ca tng ch tiu (dng SAW);

- Xy dng cc lp bn c chun ho v tnh trng s;

- Tnh im chung ca mi khu vc kh thi s dng thao tc chng xp bn ;- Phn loi v la chn khu vc thch hp nht.

K thut SAW l mt thut ton da trn trung bnh trng s. im ca cc

tiu chun sc tnh theo cng thc:

=

=n

j

ijji xwA1

* (1.2)

Trong xij l im ca khu vc i vi ch tiu j, wj l trng s ca ch tiuj.

Nhng nu im ca cc tiu chun xijc xc nh cc thang phn loi khcnhau th cn phi c quy chun. Mt php ton c p dng l [10]:

)/(' minmax jjijjij xxxxx = (1.3)

xij: im c quy chun ca khu vc i vi ch tiuj;

xij: im th (im cha c quy chun);

xjmax: im ln nht ca ch tiuj trong thang chia;

25


26/84

xjmin: im nh nht ca ch tiu j trong thang chia.

Trng s ca cc ch tiu c cc nh chuyn mn a ra nhhnh 1.7. Ct

Data Layer l cc tiu chun, Weight l cc trng s v Normalized Weights l cc

gi tr trng sc chun ho bng cch ly tng gi tr trong ct Weight chia cho

tng cc gi tr ca c ct Weight.

Hnh 1.7. Gi tr trng stheo phng php SAW [11]

Trong mt nghin cu khc [10], A. Karkazi v nnk ng dng GIS vi mt

cch tip cn khc l phn tch d liu u vo theo Lgic m (Fuzzy logic). a

im th nghim l qun Governorate ca Hy Lp. Logic mc ng dng khi

m cc iu kin hay ch tiu a ra khng phi i hi qu chnh xc, c th v

ranh gii ca cc khu vc l khng r rng m l phn cch dn dn. im khc

bit ca phng php phn tch logic ml khng cn xc nh cc trng s cho cc

tham s c th. N sc tnh gin tip thng qua cc quy tc xc nh da trn

khong cch t 1 im n 1 i tng. V d, nu khong cch n khu dn c lln th coi l ph hp (mang gi tr 1). Nu l nh th khng ph hp (mang gi tr

0). Gi tr ln hay nh bao nhiu c tham kho kin chuyn gia. Nu gi tr

khong cch nm trong gii hn ln v nh th mc ph hp sc tnh theo

mt cng thc nht nh. V d bng 1.4 l kt qu nghin cu vi mt siu kin

chnh khi xc nh v tr BCL CTR.

Bc tip l x l tt c cc quy tc a ra. Kt qu sc chuyn sang mt

26


27/84

gi tr tng i gi l qu trnh gim s m(defuzzification process). V d: 73%

khng ph hp, 37% ph hp th kt qu l khng ph hp.

Bng 1.4. Cng thc tnh gi tr vkhong cch ca mt schtiu [10]STT iu kin Cng thc

1Khong cchn khu th

>


28/84

Hnh 1.8. La chn a im BCL CTR theo phng php chng xp bn [15]

Ni chung ng dng GIS xc nh a im b tr bi chn lp cht thi rn

c thc hin kh hiu qu trn th gii. Cn Vit Nam th cng tc ny c

thc hin tng i t pht, ch yu l p dng cc ch tiu n gin. Nm 2001,

Thng t Lin tch 01/2001/BXD - BKHCNMT c a ra hng dn vic la

chn a im, xy dng v vn hnh BCL CTR. Nghin cu ng dng GIS trong

lnh vc ny mi ch c mt s tc gi. V d c th l nghin cu ca tp th tc

gi thuc trung tm Nghin cu Bo v Mi trng - i hc Nng tin hnh

quy hoch xc nh v tr BCL CTRng Nam, Khnh Sn, Nng. Trc

tin, cc tc gi xc nh cc ch tiu ph hp vi quy phm v khu vc nghin

cu. Sau tin hnh xc nh cc vng m pht hin nhng khu vc khng

ph hp. Trn cs chn sb v tr BCL CTR ri tin hnh kho st a chtv iu tra cc vn kinh t - x hi lin quan [5]. Nghin cu ny c pht

trin thnh phn mm Landfill. Tuy nhin vic xc nh c th cc trng s ca cc

ch tiu cha c xc nh r rng.

Ni chung, nhu cu thc tVit Nam hin nay l cn c mt quy trnh v

phng php tnh ton c th hn na h trcho cc nh quy hoch tm c v tr

chn lp cht thi rn hp l, gim thiu tc ng v kinh t, x hi v mi trng.

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CHNG 2. QUY TRNH LA CHN A IM B TR BI CHN LP

CHT THI RN SINH HOT BNG GIS V PHNG PHP PHN

TCH A CH TIU

2.1. Khi nim v GIS

GIS l ch vit tt ca Geographic Information System (H thng tin a l).

GIS l t hp ca cc hp phn c quan h thng nht, lin quan cht ch vi nhau

l: phn cng gm my tnh v cc thit b lin quan; phn mm v t chc con

ngi c hot ng ng b nhm thu thp, lu tr, qun l, thao tc, phn tchv m hnh ho, hin th cc d liu khng gian c nh v theo to dng cho

Tri t v cc d liu thuc tnh nhm tho mn cc yu cu thc t [3]. Hnh 2.1

minh ho tng qut cho mt h thng tin a l.

Th giithc

GIS

CSDLPhn cngPhn mmCon ngi

U RAU VO

Cc yu cu ca ngi s dng

Hnh 2.1. S khi qut vGIS

Tnh ngha trn, ta c th thy cc thnh phn ca GIS bao gm phn cng,

phn mm, con ngi v csd liu. Chng u c vai tr nht nh v c mi

quan h vi nhau cht ch, trong csd liu l trung tm ca GIS.

Cc thnh phn trn ca GIS c nhim v thc thi cc chc nng chnh ca h

thng l: thu thp d liu; qun l csd liu; tm kim v phn tch khng gian;

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hin th ho v tng tc. Mi chc nng l mt khu trong c mt h thng x

l GIS. Trong s cc chc nng trn th tm kim v phn tch khng gian c coi

l mt th mnh ca GIS. Mt s php phn tch khng gian hay c s dng

trong ti l:

a. Buffering

y l nhm thao tc khng gian to vng m nhm khoanh cc vng cch

u mt im, mt con ng hoc mt vng trn nhng khong cch nh trc

(hnh 2.2).

Vngngim

Hnh 2.2. Cc dng vngm (buffer)

Chc nng vng m dng vi mc ch g? Mt vng nhim cn c vch

ra vng cch ly, mt h cha nc cn vch ra mt hnh lang bo v, Ni chung

nhng vng m thng xuyn c vn dng cho s la chn khu vc.

b. Chng xp cc lp thng tin (Overlay)

y l thao tc khng gian trong cc lp chuyn c chng xp ln

nhau to ra mt lp chuyn mi cha ng nhng thng tin mi. C 2 dng l

chng xp lp thng tin raster v chng xp lp thng tin vector.

- Chng xp lp thng tin raster: Mi lp raster l mt ma trn cc pixel c

kch thc nh nhau to s d dng so snh gia chng. Gi tr ti mi v tr trn

mt ma trn c t hp vi gi tr ca v tr tng ng trn ma trn khc rt ra

gi tr mi. Cc php tnh ton c th l s hc (cng, tr, nhn, chia,) hoc

Boolean (And, Or, Xor, Not), hoc php ton quan h (=, >, ) (hnh 2.3).

- Chng xp lp thng tin vector: thao tc phn tch trn d liu vector da

trn vic nh gi mi quan h topology ca cc i tng. V d nh Intersect (tm

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kim v to ra vng giao nhau ca 2 lp i tng), union (tm kim v to ra vng

hp ca 2 lp i tng), V bn cht chnh l cc php ton Boolean (hnh 2.4).

Hnh 2.3. Minh ho chng xp thng tin raster

Hnh 2.4. Mt sphp ton Boolean

Ngoi ra cn c mt s php phn tch khng gian khc trong GIS l:

- Phn tch a hnh: M hnh s cao (DEM), dc,

- Ni suy: ni suy tuyn tnh, ni suy IDW, Kriging,

- Phn tch mng;

- Phn tch dng;

- Phn tch chiu sng;

-

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2.2. Phng php phn tch a ch tiu trong bi ton h trra quyt nh

Phng php phn tch a ch tiu - MCA (Multi-Criteria Analysis) l mt

php phn tch t hp cc ch tiu khc nhau cho ra mt kt qu cui cng. Cc

ng dng ca MCA ch yu l nh gi tc ng ca mt qu trnh n mi trng,

h trbi ton quy hoch la chn v tr ph hp nht cho mt mc ch xc

nh, Cc bc cbn ca MCA nh sau [3]:

2.2.1. nh chtiu

Bc u tin trong phn tch a ch tiu l nh ra cc ch tiu khc nhau

c tnh n. a s cc trng hp mt ch tiu khng phi l mt bin n gin

m l t hp ca cc d liu thuc tnh v hnh hc khc nhau.V da im thch hp cho bi chn lp cht thi rn sinh hot c 3 ch tiu

sau: ch tiu v kinh t (BCL nn xy dng nhng khu vc t cha s dng, t

nng nghip hiu qu kinh t thp; gim thiu khong cch vn chuyn rc t thnh

phn bi), ch tiu v mi trng (tng khong cch n h thng thu vn), ch

tiu x hi (tng khong cch n khu dn c).

Cc ch tiu ny phc v cho vic thu thp cc d liu u vo hay chnh l

cc bn xut pht u tin. Qua cc chc nng phn tch khng gian ca GIS,

chng ta s c cc thng tin cn thit hay l bn chit xut.

2.2.2. Phn khong cc chtiu

Cc ch tiu c tm quan trng khc nhau i vi mt mc ch nht nh v

trong tng ch tiu, mc thch hp cng khc nhau. V vy m chng phi c

xp theo th t cho mt mc ch ring bit. C 2 cch tip cn thc hin s

phn hng ny l cch tip cn kiu Boolean v cch tip cn kiu nhn t phn loi

hoc lin tc.

a. Cch tip cn kiu Boolean

Cch tip cn ny da trn vic phn vng ra thnh 2 nhm: vng thch hp

(gi tr 1) v vng khng thch hp (gi tr 0). V d vi ch tiu l BCL CTR phi

nm cch khu dn c th 3 km. iu c ngha l nhng vng nm ngoi

khong cch 3 km t ranh gii th l thch hp, cc vng khc khng thch hp.

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Trong cch tip cn ny, cc ch tiu u cn c chuyn sang kiu gii hn

Boolean. Cui cng chng c gii m thnh nhng bn v chng ghp cho

ra cc vng tho mn tt c cc gii hn (cc gii hn cn c gi l constraint

criteria). Cch tip cn ny rt c ch khi chng ta bit c mc thch hp trong

mt vi mc ch nht nh v thng l n gin. Trong trng hp cc ch tiu

phc tp v c mc quan trng khc nhau th phng php Boolean khng thch

hp v nhc im ca n l xem xt cc nhn t vi mc quan trng nh nhau.

b. Cch tip cn nhn tphn loi hoc lin tc

Khi cc ch tiu c mc nh hng khc nhau v vn nghin cu th

phng php nn s dng l theo cch tip cn nhn t phn loi hoc lin tc.Nu cc gi tr ca cc ch tiu th hin mc bin thin lin tc v c s

tng quan r rng vi nhau th mt thang t l lin tc c xc lp. to thang

t l ny th d liu gi tr cn c lp li t l. Phng php c s dng l php

nh li t l kiu tuyn tnh:

)/()( minmaxmin iiiii xxxxX = (2.1)

Xi: nh li im s ca nhn ti;

xi: im gc;

ixmin : im nh nht;

ixmax : im ln nht.

Khi im s c gi tr t l nghch vi mc thch hp tc l gi tr cng

thp th cng c im cao th cng thc sc chuyn thnh:

)/()(minmaxmax iiiii

xxxxX = (2.2)

V d nh khong cch t bi chn lp n ranh gii thnh ph cng gn cng tt

th im cng cao gim thiu tuyn ng vn chuyn rc.

Nu cc gi tr ca cc ch tiu l gi tr s lin tc nhng khng c tng

quan r rng vi mc thch hp hoc khi cc gi tr khng c th hin di

dng s th cc gi tr c thc xp hng theo thang t l phn loi. V d nh

ch tiu v hin trng s dng t cho mc ch b tr BCL CTR c th phn loi

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nh sau: 3 im: t cha s dng(rt thch hp), 2 im: t nng nghip hiu qu

thp (thch hp), 1 im: t nh tm, t ngha a (t thch hp), 0 im: cc mc

ch s dng khc (khng thch hp).

Phn loi nh vy c th thc hin cho bt k nhn t no lm cho chng

c th so snh c vi nhau.

2.2.3. Xc nh trng s

Khi cc ch tiu khc nhau m c cng mc quan trng, trng s ca tng

nhn t bng 1. Tuy nhin, trong i a s cc trng hp l khc nhau v cn phi

xc nh mc quan trng tng i ca chng. Trng s ca cc ch tiu c th

tnh thng qua thut ton thng k, php o, hoc da trn kinh nghim, hiu bitch quan ca chuyn gia. Qu trnh phn tch phn c p (Analytical Hierarchy

Process - AHP) l mt trong s k thut tnh trng s. y l k thut do GS. Saaty

nghin cu v sau pht trin t nhng nm 80. Qu trnh ny bao gm 4 bc

chnh [18]:

1. Phn r mt tnh hung phi cu trc thnh cc phn nh;

2. Sp xp cc thnh phn hay cc ch tiu theo mt th t phn cp;

3. Gn gi tr s cho nhng so snh ch quan v mc quan trng ca cc

ch tiu. Vic so snh ny c thc hin gia cc cp ch tiu vi nhau v

tng hp li thnh mt ma trn gm n dng v n ct (n l s ch tiu). Phn

taij th hin mc quan trng ca ch tiu hng i so vi ch tiu ct j.

Mc quan trng tng i ca ch tiu i so vijc tnh theo t l k (k

t 1 n 9), ngc li ca ch tiu j so vi i l 1/k. Nh vy aij>0, aij =

1/aji, aii=1. Hnh 2.5 th hin thang im so snh mc u tin (mc

quan trng) ca cc ch tiu. Hnh 2.6a minh ha cho ma trn mc quan

trng vi s ch tiu n = 4. X l tn cc ch tiu.

4. Tnh ton v tng hp cc kt qu chn ra ch tiu c mc quan trng

cao nht thng qua 2 bc:

+ Chun ho ma trn mc quan trng ca cc ch tiu bng cch ly gi

tr ca mi trong mt ct chia cho gi tr tng ca ct (hnh 2.6b).

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+ Tnh gi tr trung bnh ca tng dng trong ma trn cho ra trng s tng

ng ca tng ch tiu (bng 2.6c).

1 3 5 7 91/51/71/9

Quantrngnhnhau

Quantrnghn

Quantrngnhiuhn

Rtquantrnghn

tquantrnghn

Rt tquantrng

Vcng tquantrng

1/3

tquantrngnhiuhn

Vcngquantrnghn

Hnh 2.5. Thangim so snh cc chtiu

a. Mc quan trng ca

cc chtiu

X1 X2 X3 X4

X1 1 2 1/3 1/2

X2 1/2 1 1/3 1/2

X3 3 3 1 2

X4 2 2 1/2 1

Tng 6.5 8 2.167 4

b. Chun ho ma trn

X1 X2 X3 X4

X1 0.154 0.250 0.154 0.125

X2 0.077 0.125 0.154 0.125

X3 0.461 0.375 0.461 0.500

X4 0.308 0.250 0.231 0.250

Tng 1 1 1 1

c. Trng s

ca cc ch

tiu

X1 0.171

X2 0.120

X3 0.450

X4 0.259

Hnh 2.6. Mc quan trng ca cc chtiu v cch tnh trng s

Ma trn mc quan trng ca cc ch tiu thng c xy dng da trn

kin chuyn gia. i vi ma trn ny cn ch cc vn sau:

- Th nht: y l ma trn ph thuc vo kin ch quan ca ngi ra quyt

nh. V d ch tiu X1 quan trng hn ch tiu X2 nhng gi tr quan trng gp bao

nhiu ln th c th tu tng ngi.

- Th hai: Cn phi xem xt n tnh nht qun ca d liu. Tc l nu ch tiu

X1 quan trng gp 2 ln ch tiu X2, ch tiu X2 quan trng gp 3 ln ch tiu X3 th

v ton hc, ch tiu X1 s quan trng g p 6 ln ch tiu X3. Tuy nhin, kin

chuyn gia trong thc t s khng phi nh vy do h khng bao qut c tnh

logic ca ma trn so snh (v cng khng nn c gng bao qut nhm m bo tnh

khch quan ca nh gi).

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Vy c phng php no nh gi tnh h p l ca cc gi tr mc quan

trng ca cc ch tiu? Theo Saaty, ta c th s dng t s nht qun ca d liu

(Consistency Ratio CR). T s ny so snh mc nht qun vi tnh khch quan

(ngu nhin) ca d liu [14]:

RI

CICR = (2.3)

CI: Ch s nht qun (Consistency Index)

RI: Ch s ngu nhin (Random Index)

1max

=

n

nCI

(2.4)

max : Gi trc trng ca ma trn

n: s ch tiu (trong v d trn n = 4)

+++=

====

44

4

1

4

33

4

1

3

22

4

1

2

11

4

1

1

1max w

w

w

w

w

w

w

w

nn

n

n

n

n

n

n

n

(2.5)

i vi mi mt ma trn so snh cp n, Saaty th nghim to ra cc ma trn

ngu nhin v tnh ch s CI trung bnh ca chng v gi l RI (ch s ngu nhin)

(bng 2.1).

Bng 2.1. Gi tr RIng vi tng slng chtiu n [14]

n 1 2 3 4 5 6 7 8 9 10

RI 0 0 0.52 0.89 1.11 1.25 1.35 1.40 1.45 1.49

Nu gi tr t s nht qun CR < 0.1 l chp nhn c, nu ln hn i hi

ngi ra quyt nh thu gim s khng ng nht bng cch thay i gi tr mc

quan trng gia cc cp ch tiu.

Theo v dhnh 2.6, ta c cc gi tr tnh ton kim tra tnh nht qun ca d

liu l:

n = 4 RI = 0.89

max = 4.083 CR = 0.031 (< 0.1 tho mn)

CI = 0.028

2.2.4. Tch hp cc chtiu

Sau khi phn khong v tnh trng s ca cc ch tiu th vic tch hp

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chng cho ta tnh c ch s thch hp hay kt qu cui cng ca cc ch tiu. y

thc cht l mt t hp ca cc ch tiu khc nhau. Cng thc tnh ch s cui cng

l [3]:

)(1

i i

n

i

XWS ==

(2.6)

S: Ch s thch hp;

n: Tng s ch tiu;

Wi: Trng s ca ch tiu i;

Xi: im ca ch tiu i.

Kt qu cui cng ca phn tch a ch tiu l bn vi ch s thch hp chotng v tr. Trn cs, ngi ra quyt nh s la chn phng n thch hp nht

l mt trong s cc phng n c ch s cao nht.

2.3. Quy trnh la chn a im bi chn lp cht thi rn sinh hot bng GIS

v phng php phn tch a ch tiu

Da trn nhng phn tch trn, ti xin a ra mt quy trnh la chn a

im bi chn l p cht thi rn sinh hot trn c s s dng phn mm ArcGIS

(hnh 2.7). Cc bc ca quy trnh ny nh sau:

Bc 1: Thu thp ti liu, sliu khu vc nghin cu v ti liu chuyn mn

y l bc u tin trong quy trnh la chn a im. Mc ch l tm hiu

vc im t nhin, kinh t, x hi khu vc nghin cu. ng thi thu thp cc ti

liu bn a hnh, bn hin trng s dng t, bn a cht, cc s liu

thng k, bo co quy hoch, ca khu vc.

Cc ti liu chuyn mn cn thu thp l cc quy nh ca php lut, quy phm

k thut v la chn bi chn lp cht thi rn.

Bc 2: Chun b dliu u vo

T cc ngun bn thu thp c, tin hnh chuyn sang nh dng

Geodatabase trong phn mm ArcGIS v tch cc lp cn thit. Nhim v quan

trng ca bc ny l cung cp d liu u vo v m bo mi quan h topology

gia cc i tng. Mun vy, cn thit lp quy tc topology v tin hnh kim tra,

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sa li to ra d liu c cht lng.

Thu thp ti liu, s liu khu vcnghin cu v ti liu chuyn mn

Chun b d liu u vo

Xc nh cc yu cu va im,v chtiu gii hn

La chn s b

Xc nh mt s chtiu c th

nh gi ngay

Phn loi v tnh im cc lp uvo

Xc nh s b cc khu vc timnng

La chn chnh xc

Xc nh nhng chtiu cn li nh gi chnh xc

Tnh trng s ca tng chtiu

iu tra, kho st thc a v ly kin cng ng

nh gi tng hp cc khu vctim nng

La chn khu vc ph hp nht

AHP

GIS

GISv

AHP

Hnh 2.7. Quy trnh la chn a im BCL CTR sinh hot bng GIS v phng

php phn tch a chtiu

Bc 3: Xc nh cc yu cu va im v chtiu gii hn

Vic xc nh cc yu cu ca bi chn lp (quy m, loi bi,) v ra cc

ch tiu gii hn l cs tin hnh la chn a im. Bc ny c thc hin

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da trn cc quy nh, quy phm v c im iu kin t nhin, kinh t x hi ca

a phng.

Bc 4: Tnh trng scho cc chtiu

Nh cp trn, c rt nhiu yu t tc ng n vic la chn BCL CTR

v mc nh hng hay tm quan trngca chng l khc nhau. Do cn phi

sp xp chng theo th t v th hin bng trng s. C nhiu cch tnh, trong

ti ny, tc gi p dng Qu trnh phn tch phn cp (AHP).

Khi s lng cc ch tiu nhiu, chng phi c gp li theo tng nhm. Mi

nhm s bao gm cc ch tiu c cng mt tiu ch. V d nhm A gm c ch tiu

a1, a2, a3; nhm B c cc ch tiu b1, b2. Nhm C c ch tiu c1, c2, c3. Cc nhmv ch tiu c sp xp nh hnh 2.8.

a im tt nht

Nhm A Nhm B Nhm C

Chtiua1

Chtiua2

Chtiua3

Chtiub1

Chtiub2

Chtiuc1

Chtiuc2

Mc 1

Mc 2

Hnh 2.8. Phn cp cc chtiu

a. Tnh trng sca cc nhm

Lp mt ma trn u tin ca cc nhm gm n dng v n ct (n l s nhm),

y theo v d hnh 2.8 th n = 3. Cc gi tr trong ma trn l mc u tin ca

nhm hng i so vi nhm ctj (i = 1 n 3, j = 1 n 3) Chng c lp da trn

cn c vo tnh hnh thc t ca khu vc, kin ca cc chuyn gia, ca ngi ra

quyt nh. Cc bc tnh ton trng sc thc hin theo phng php AHP

trnh by 2.2.3. Kt qu ta c trng s tng ng vi 3 nhm A, B, C l m, l, k.

b. Tnh trng sca cc chtiu trong tng nhm

Ln lt lp ma trn u tin ca cc ch tiu a1, a2, a3 v tnh trng sc

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kt qu l m1, m2, m3.

Lp ma trn u tin ca 2 ch tiu b1, b2 v tnh trng sc kt qul1, l2.

Lp ma trn u tin ca 2 ch tiu c1, c2 v tnh trng sc kt quk1, k2.

c. Tnh trng schung ca cc chtiu

Trng s cui cng ca cc ch tiu c tnh bng trng s ca nhm nhn

vi trng s ca ch tiu trong tng nhm.

Hnh 2.9 th hin kt qu tng hp ca vic tnh trng s cho cc ch tiu.

a im tt nht

Nhm ATS: m

Nhm BTS: l

Nhm CTS: k

Chtiua1

TS: m1

Chtiua2

TS: m2

Chtiua3

TS: m3

Chtiub1

TS: l1

Chtiub2

TS: l2

Chtiuc1

TS: k1

Chtiuc2

TS: k2

Trngs

chung m x m1 m x m2 m x m3 lx l1 lx l2 kx k1 kx k2

Hnh 2.9. Cch tnh trng sca cc chtiu (TS: Trng s)

Bc 5: La chn sb

Vi mt khu vc rng ln, ngi la chn a im s gp kh khn khi xc

nh khu vc no ph hp cho bi chn lp. V vy cn phi sng lc sb lm

gim din tch vng tm kim.

a. Xc nh mt s ch tiu c thnh gi ngay:

Trong s cc ch tiu c t ra, c nhng ch tiu c thnh gi c d

dng qua cc gi tr gii hn theo quy nh. V d nh bi chn lp phi nm cch

khu th t nht l 3 km. Tc l khong cch xung quanh khu dn c th 3 km

l b cm, khng th b tr bi chn lp c. Nh vy la chn sb, chng ta

s chn ra nhng ch tiu c thnh gi trc.

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b. Phn loi v tnh im cc yu tu vo:

Trong tng ch tiu u c nhng mc thch hp vi yu cu b tr bi chn

lp cht thi rn khc nhau. V d: khong cch t bi chn lp n khu dn c cng

xa cng tt, nhng khong cch t bi n ng giao thng th cng gn cng tt

thun tin cho vic vn chuyn rc,... c th phn loi v tnh im cho cc

yu tu vo theo cc ch tiu trn, ta to cc raster cha khong cch ti cc i

tng nh dn c, ng giao thng, V bn cht, gi tr ca mi pixel l khong

cch t cell ti khu dn c gn nht hay ng giao thng gn nht, Trn c

slp raster khong cch ny th chng ta s d dng phn khong v tnh im cho

cc lp.V d, da trn raster khong cch n lp dn c th, ta c th chia ra cc

khong gi tr nh 0 3000m, 3000m 5000m, 5000m 7000m, > 7000m. Vi

tiu ch l bi chn lp cng xa khu dn c th cng tt, ta c th tnh im nh

trong bng 2.2.

Bng 2.2. Bngim minh ho cho khong cch n khu dn c th

Khong cch < 3000m 3000m 5000m 5000m 7000m > 7000m

im 0 1 2 3

c. Xc nh cc khu vc tim nng:

Sau khi cc lp rasterc gn im, chng ta s to ra mt lp raster chung

trn cscng cc lp raster thnh phn li. N s th hin cc pixel vi cc gi tr

t th p nht n ln nht. Nhng khu vc no khng c d liu hoc gi tr qu

thp s b loi b. Thng thng nn gi li t 3 n 4 khu vc. Nu s lng t hnth c th ni lng cc gii hn sao cho hp l. Nu s lng nhiu qu th cn phi

xem xt cc khu vc theo tng ch tiu v lp thnh mt bng so snh, t loi b

bt khu vc. Hoc c th lm cht hn cc gii hn. Nh vy th min tm kim

c gim i ng k.

Bc 6: La chn chnh xc

T mt s khu vc tim nng, tin hnh nh gi v sng lc tip tm ra

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c a im ph hp nht.

a. Xc nh nhng ch tiu cn li nh gi chnh xc:

Nhng ch tiu no cha tham gia vo nh gi sb th sc la chn

nh gi chnh xc. Vic nh gi ch cn thc hin cho cc khu vc tim nng

chn ra bc nh gi sb.

b. iu tra, kho st thc a v ly kin cng ng:

bc ny, cc s liu chi tit c thu thp cho tng a im tim nng.

Vic iu tra kho st a im nhm mc ch kim chng cc ngun s liu thu

thp v b sung nhng thng tin cn thit theo cc ch tiu ra. Quan trng nht

l ly kin t ngi dn v chnh quyn ca khu vc tim nng bit v nhucu v mc chp thun ca ngi dn, chnh quyn.

c. nh gi tng h p cc khu vc tim nng theo tng ch tiu la chn

chnh xc

Cc khu vc tim nng c nh gi tng hp theo ton b cc ch tiu nhm

mc ch la chn khu vc ph hp nht. Hnh 2.10 minh ha vic nh gi tng

hp cho 3 khu vc tim nng theo 7 ch tiu. Vi mi ch tiu nh gi tng hp,

chng ta s lp ra mt bng ma trn so snh mc u tin ca cc khu vc tim

nng v tnh im. V dnh gi 3 khu vc tim nng theo ch tiu a1 c th

hin hnh 2.11. Cch tnh cng theo phng php phn tch AHP trnh by

mc 2.2.3.

- La chn khu vc ph hp nht:

Trn csim thnh phn v trng s ca cc ch tiu, tin hnh tnh im

chung cuc ca cc khu vc tim nng theo cng thc:

)(1

iji

n

i

j XWS ==

(2.7)

n: Tng s ch tiu

Sj: Ch s thch hp (im chung) ca khu vcj

Wi: Trng s ca ch tiu i

Xij: im ca khu vc tim nngj theo ch tiu i

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Kt qu l khu vc no c gi tr cao nht sc la chn v thng tin s

c cung cp cho nh qun l ra quyt nh.

Khu vc 1 Khu vc 2

Chtiua1

Chtiua2

Chtiua3

Chtiub1

Chtiub2

Chtiuc1

Chtiuc2

a im tt nht

Khu vc 3

Hnh 2.10.nh gi tng hp cc khu vc tim nng theo cc chtiu

a. Mc u tin ca 3 khu

vc tim nng

KV1 KV2 KV3

KV1 1 2 2

KV2 1/2 1 1/2

KV3 1/2 2 1

Tng 2 5 3.5

b. Chun ho ma trn

KV1 KV2 KV3

KV1 0.5 0.4 0.571

KV2 0.25 0.2 0.143

KV3 0.25 0.4 0.286

Tng 1 1 1

c.im sca 3 khu vc

tim nng

KV1 0.490

KV2 0.198

KV3 0.312

CR 0.058 (


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CHNG 3. LA CHN A IM BI CHN LP CHT THI RN

SINH HOT TRN A BN HUYN NG ANH

3.1. Gii thiu v khu vc nghin cu

3.1.1. iu kin tnhin

a. V tra l

ng Anh l mt huyn ngoi thnh pha Bc thnh ph H Ni, c din tch

l 182.139 km2, nm trong vng quy hoch pht trin cng nghip, th, dch v

v du lch c Chnh ph v Thnh ph ph duyt, l u mi giao thng quantrng ni Th H Ni vi cc tnh pha Bc (hnh 3.1).

Hnh 3.1. V tr ca huynng Anh trong thnh phH Ni

- Pha ng, ng Bc ca huyn gip tnh Bc Ninh;

- Pha Nam gip sng Hng;

- Pha ng Nam gip huyn Gia Lm, H Ni;

- Pha Ty gip huyn M Linh, H Ni;

44
http://vi.wikipedia.org/wiki/B%E1%BA%AFc_Ninhhttp://vi.wikipedia.org/wiki/B%E1%BA%AFc_Ninhhttp://vi.wikipedia.org/wiki/B%E1%BA%AFc_Ninhhttp://vi.wikipedia.org/wiki/S%C3%B4ng_H%E1%BB%93nghttp://vi.wikipedia.org/wiki/S%C3%B4ng_H%E1%BB%93nghttp://vi.wikipedia.org/wiki/S%C3%B4ng_H%E1%BB%93nghttp://vi.wikipedia.org/wiki/Gia_L%C3%A2mhttp://vi.wikipedia.org/wiki/H%C3%A0_N%E1%BB%99ihttp://vi.wikipedia.org/wiki/H%C3%A0_N%E1%BB%99ihttp://vi.wikipedia.org/wiki/H%C3%A0_N%E1%BB%99ihttp://vi.wikipedia.org/wiki/M%C3%AA_Linhhttp://vi.wikipedia.org/wiki/H%C3%A0_N%E1%BB%99ihttp://vi.wikipedia.org/wiki/H%C3%A0_N%E1%BB%99ihttp://vi.wikipedia.org/wiki/H%C3%A0_N%E1%BB%99ihttp://vi.wikipedia.org/wiki/H%C3%A0_N%E1%BB%99ihttp://vi.wikipedia.org/wiki/M%C3%AA_Linhhttp://vi.wikipedia.org/wiki/H%C3%A0_N%E1%BB%99ihttp://vi.wikipedia.org/wiki/Gia_L%C3%A2mhttp://vi.wikipedia.org/wiki/S%C3%B4ng_H%E1%BB%93nghttp://vi.wikipedia.org/wiki/B%E1%BA%AFc_Ninh


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c. Kh huKh hu ca khu vc c iu kin chung vi kh hu H Ni: nhit i gi ma

m, ma h nng ma nhiu vi gi thnh hnh hng ng Nam v ma ng

lnh, t ma, gi ng Bc thnh hnh. Cc thng s lin quan n kh hu ca khu

vc da ch yu vo s liu ca trm kh tng gn nht l trm Lng H Ni:

- Nhit trung bnh nm: 24.80C;

- m trung bnh nm: 79%;

- Lng ma trung bnh nm l 1700 mm, mi nm c khong 143 ngy ma;

- Thng ma nhiu nht l thng 8 vi lng ma bnh qun l 300 350 mm;

- Thng ma t nht l thng 12;

- Tc gi trung bnh nm: Gi hng ng Nam l 2.7m/s, gi hng

ng Bc l 3.3m/s.

d. Thu vn

Huyn ng Anh chu nh hng bi ch thu vn ca cc sng Hng v

sng ung. Ngoi ra, trong huyn cn c sng C L, sng Thip, sng Ng Huyn

Kh v rt nhiu ao h, trong ng k nht l m Vn Tr vi din tch 130 ha.

Tuy a hnh ca huyn c cao hn so vi ni thnh H Ni nhng vn nm

trong khu vc chu se do ca ngp lt sng Hng. Do vy, tuyn sng Hng

v sng ung l iu kin cbn bo v khu vc. Tnh hnh ng lt thng xy

ra cc x pha ng ca huyn: Thy Lm, Vn H, Lin H lin quan n cc

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sng C L v sng Ng Huyn Kh. Thc trng ny cn phi c lu khi la

chn BCL CTR cho huyn.

Bng 3.1.c im a cht thu vn khu vcng Anh [9]

TT Tn tng K hiu su trung bnh,

dy trung bnhc im

T: 0.0 m

n: 11.6 m

1 Lp cch nc trong

trm tch Pleixtocen

trn

LCN1

St, st

pha Dy: 11.6 m

Phn b rng ri. Ti khu bi ging

nh my nc ng Anh, b dy

ca lp ny trung bnh l 3.8 m

T: 11.0 m

n: 24.9 m

2 Tng cha nc l

hng trong trm tch

Pleixtocen trn

TCNqp2

Ct ht mn

trung ln t

snDy: 13.9 m

Tng cha nc p lc yu,

c phn b rng ri, c gi tr

i vi cung cp nc vi quy

m nh dng cho h dn. Tikhu bi ging nh my nc

ng Anh, su trung bnh l

3.8m, dy l 23 m

T: 22.0 m

n: 31.2 m

3 Lp cch nc trm

tch Pleixtocen gia -

trn

LCN2

St, st

pha ct pha Dy: 9.2 m

Lp cch nc phn b khng

lin tc, c ni b bo mn hoc

mt hn. Ti khu bi ging nh

my nc ng Anh, gp lp

ny sau 24.4m, b dy

c 4.6m

T: 30.1 m

n: 56.0 m

4 Tng cha nc l

hng trong trm tch

Pleixtocen di -

gia

TCNqp1

Cui, si,

sn ln ct,

cui ktDy: 25.8 m

Phn b rng ri ton khu vc.

y l tng cha nc p lc,

rt phong ph nc p ng

nhu cu cp nc sinh hot v

sn xut quy m ln. Ti nh

my nc ng Anh, gp

su t 29m, b dy trung bnh

29.5 m

T: 57.5 m

n: 76.3 m

5 Phc h cha nc

Neogen

PHCN N

Ct kt, btkt kp st

kt viDy: 18.8 m

Phc h ny t c nghin

cu (Cc l khoan cha khoanht tng ny)

T: 53.0 m

n: 81.1 m

6 Phc h cha nc

trong trm tch Triat

trung - bc Ladini -

h tng N Khut

PHCN

T2lnk

Bt kt, ct

kt kp st

kt vi

Dy: 28.1 m

Phc h ny t c nghin cu.

Theo cc ti liu trc th y l

tng ngho nc, khng c

ngha cung cp nc ln (Cc l

khoan cha khoan ht tng ny)

Ngun: Trung tm Quan trc cht lng nc thuc Trung tm Quy hoch viu tra ti nguyn nc

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Theo bo co tng hp v quan trc cht lng, s lng nc ng Anh

ca Trung tm quan trc cht lng nc thuc Trung tm Quy hoch v iu tra

ti nguyn nc th c im a cht thy vn ca khu vc ng Anh nh trong

bng 3.1.

Nh vy thi cc tng nc di t u c lp st bo v. iu ny l rt quan

trng v s trnh c cc ri ro do b thm nc rc.

e. Ti nguyn t

Din tch ca ton huyn l 18 214 ha bao gm c mt phn din tch sng

Hng, sng ung v vng bi t ven sng. t trong huyn bao gm t ph sa

ngoi v t ph sa trong .+ t ph sa ngoi l t c bi p thng xuyn trn cc bi bi ven

sng, bi gia sng.

+ t ph sa trong khng c bi p thng xuyn do c h thng .

ng Anh thuc nhm t bc mu pht trin trn t ph sa c: t chua, ngho

dinh dng, khng kt cu, thnh phn cgii nh, ri rc khi kh hn, kt dnh khi

ngp nc, nng sut cy trng thng thp.

3.1.2. iu kin kinh t- x hi

a. Dn c

Cn c theo s liu ca phng Thng k - UBND huyn ng Anh, dn s ca

huyn l 276 750 ngi (tnh n nm 2003), mt trung bnh l 1544 ngi/km2.

D kin quy m dn s ca huyn n nm 2020 l 672 000 ngi khu th v

158 000 ngi khu vc nng thn. Dn s khu th ch yu l tng chc, cn

dn s nng thn ch yu l tng t nhin.

Hin nay ccu lao ng trong huyn vn cbn l nng nghip (hn 80%),

s lao ng trong lnh vc cng nghip, tiu th cng nghip v dch v cn t.

b. Tnh hnh kinh t

Hin ti, huyn ng Anh c khu cng nghip Bc Thng Long c quy m ln

v khu cng nghip va v nh Nguyn Kh. Theo quy hoch n nm 2020, khu

cng nghip tp trung ng Anh s hon thnh. Ngoi ra, cn c mt s lng ngh

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truyn thng nhng in hnh v tp trung nht l lng ngh gLin H.

c. Csh tng x hi

- Gio dc: Hu ht cc x u c trng ph thng csv trung hc cs.

C x c trng ph thng trung hc. Nhn chung csvt cht cc trng u

kh tt.

- Y t: Ton b cc x u c trm y t nhng quy m nh v trang b cn

ngho nn. Huyn cng c 1 bnh vin huyn ti x Kim Chung v bnh vin ngnh

ti th trn ng Anh.

- Cquan, UBND x: Cc cquan lnh o ch yu ca huyn nh huyn u,

UBND, cc phng ban trc thuc u ng ti th trn ng Anh.- Hu ht cc x u c trung tm thng mi l chvi tng s 24 ch.

- Cc cng trnh di tch lch s v vn ho: Trn a bn huyn c rt nhiu di

tch lch s vn ho gn lin vi cc l hi. Trong c 29 di tch lch s xp

hng (bng 3.2), c bit phi kn l khu di tch C Loa v n Si.

Bng 3.2. Cc di tch lch svn ho huynng Anh c xp hng (n 1999)

STT Tn cng trnh a im (x) STT Tn cng trnh a im (x)

1 Khu di tch lch sC Loa

C Loa, Vit Hng,Dc T, Uy N

15 Miu Mch Lng i Mch

2 nh H V Lin H 16 nh Dc T Dc T

3 Nh th h Lin H 17 Cha Dc T Dc T

4 nh H Hng Lin H 18 nh L Nhn Dc T

5 nh L Kh Lin H 19 Cha L Nhn Dc T

6 Nh th ca cng Lin H 20 nh Phc Hu Dc T

7 nh Ngc Chi Vnh Ngc 21 Cha Phc Hu Dc T

8 nhng Tr ng Hi 22 nh L Giao Vit Hng

9 nh Li ng Hi 23 nho Thc Thy Lm

10 Cha Li ng Hi 24 Chao Thc Thy Lm

11 Miu Li ng Hi 25 nh Thy Li Thy Lm

12 nh Hi Ph ng Hi 26 n Thng Thy Lm

13 Cha Hi Ph ng Hi 27 n Si Thy Lm

14 Miu Hi Ph ng Hi 28 nh Hng Trm Thy Lm

29 Cha Hng Trm Thy Lm

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d. Csh tng kthut

- H thng giao thng: Huyn ng Anh l mt trong nhng u mi giao

thng quan trng ca th H Ni. Mt s tuyn ng chnh i qua a bn

huyn l quc l 3 (t H Ni i Thi Nguyn), ng cao tc Bc Thng Long (i

Thng Long - Ni Bi) v quc l 23. Cc tuyn ng ny kt hp vi ng lin

huyn, lin x to thnh mt mng li lin hon, p ng nhu cu giao lu ca

huyn. ng st qua huyn ng Anh c 3 tuyn: H Ni Thi Nguyn, ng

Anh - Vit Tr v tuyn cu Thng Long n ga Bc Hng. C 33.3 km ng sng

(sng Hng, sng ung, sng C L) v 20 km sng ni huyn (sng Thip, sng

Ng Huyn Kh).- H thng cung cp in: ngun cp in cho cc ph ti ca huyn ng Anh

l mng li in quc gia thng qua trm bin th 110/35/6 KV ng Anh v trm

trung gian 35/6 KV Lm Tiu. Li phn phi gm 2 cp in p l 35 KV v 6 KV.

- H thng cung cp nc: Trong huyn ch c 2 khu vc c h thng cp nc

cng cng l khu vc th trn ng Anh (cng sut 13500 m3/ngy m v khu vc

Bc cu Thng Long (cng sut 3500 m3/ngy m). Hin ti pha Bc cu Thng

Long ang chun b xy dng nh my cp nc vi cng sut 30000 m3/ngy m.

- H thng thot nc trong khu vc th cng nh trong ton huyn ch yu

da vo h thng tiu nc nng nghip. Nc t cc khu th v cc im dn c

c thu gom li hoc x t nhin vo cc knh mng tiu nc nng nghip, sau

thot ra sng bng t chy hoc bm. Ton b huyn c chia thnh 3 lu vc

tiu nc chnh:

+ Lu vc tiu nc ra sng C L qua m Sn Du, cng Xun Nn v trm

bm Mnh Tn;

+ Lu vc trm bm Phng Trch ra sng Hng;

+ Lu vc tiu nc ra sng Ng Huyn Kh.

e. Tnh hnh sdngt

Tng din tch t nhin ca huyn l 18 213.9 ha. Theo s liu thng k t

ai nm 2007 th tnh hnh s dng t ca huyn nh sau (bng 3.3):

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- t nng nghip c din tch 9569.48 ha, chim 45%, ch yu l t sn xut

nng nghip v nui trng thy sn.

- t phi nng nghip c din tch 8273.97 ha, chim 53%.

- t cha s dng chim 2%, ch yu l t bi bi ven sng Hng.

Bng 3.3. Thng k hin trng sdngt huynng Anh

TT Mc ch sdng t M Din tch (ha)

Tng din tch t nhin 18213.90

1 t nng nghip NNP 9569.48

1.1 t sn xut nng nghip SXN 9020.14

1.1.1 t trng cy hng nm CHN 8832.27

1.1.1.1 t trng la LUA 7918.65

1.1.1.3 t trng cy hng nm khc HNK 913.62

1.1.2 t trng cy lu nm CLN 187.87

1.3 t nui trng thu sn NTS 549.34

2 t phi nng nghip PNN 8273.97

2.1 t OTC 2119.29

2.1.1 t ti nng thn ONT 2014.95

2.1.2 t ti th ODT 104.342.2 t chuyn dng CDG 3901.75

2.2.1 t tr s c quan, cng trnh s CTS 246.48

2.2.2 t quc phng CQP 91.32

2.2.3 t an ninh CAN 3.21

2.2.4 t sn xut, kinh doanh phi nng CSK 886.90

2.2.5 t c mc ch cng cng CCC 2673.84

2.3 t tn gio, tn ngng TTN 11.24

2.4 t ngha trang, ngha a NTD 172.27

2.5 t sng sui v mt nc chuyn SMN 2049.48

2.6 t phi nng nghip khc PNK 19.94

3 t cha s dng CSD 370.45

3.1 t bng cha s dng BCS 370.45

Ngun: Phng Ti nguyn v Mi trng huynng Anh

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3.1.3. Hin trng mt sbi rc ng Anh

Vi ch trng mi thn lng u c mt t t qun v 1 bi chn lp rc thi

ti ch, ng Anh l huyn thc hin kh tt cng tc x hi ho v sinh mi

trng. Tuy nhin, do l huyn c tc th ho nhanh, khi lng cht thi rn

pht sinh trong nhng nm gn y tng mt cch ng k. Theo bo co ca X

nghip Mi trng th huyn ng Anh th hin nay, khi lng rc thi pht

sinh trn a bn huyn c tnh khong 130 T/ngy, d bo n nm 2010 l 135

T/ngy (khu vc th trn l 80 90 T/ngy). Trong khi , qut dnh cho chn

lp rc ngy cng hn hp, c ni quy trnh x l cha m bo yu cu k thut

nn rt d gy ra nguy c nhim mi trng. Hu ht cc bi rc u l t pht,tn dng nhng ao h, bi tha ma, l gch,

V d nh bi rc x Vnh Ngc (hnh 3.3a), bi rc y c tn dng khu

l gch c ch cch UBND x khong 200m, cch trng tiu hc v THCS Vnh

Ngc gn 300m. Theo quy nh, bi chn lp rc phi cch khu dn c t 300m tr

ln. Vi khong cch qu gn v rc c l thin cnh ng lin thn li

khng c x l, chn lp nn mi hi thi bc ln nh hng n khu vc

xung quanh, nht l i vi hc sinh ca cc trng hc gn .

Ti x Kim N, mt bi rc xut hin cch cng lng 10m, ko di khong

50m, rt mt v sinh (hnh 3.3b).

a. Bi rc x Vnh Ngc b. Bi rc x Kim N

Hnh 3.3. Hin trng cc bi rc x Vnh Ngc v x Kim N

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nhiu ni, cc x t chc thu gom rc v vn chuyn ln bi rc Nam Sn.

Tuy nhin, s ln thu gom t, ch khong 2 ln/tun dn n tnh trng ng rc

trong khu dn c vn cn ph bin.

Xut pht t thc t trn, nhu cu quy hoch mt bi chn lp cht thi rn hp

v sinh cng trnn cp bch trn a bn huyn.

Nm 2003, UBND Thnh ph H Ni ph duyt d n u t Xy dng

khu chn lp v x l rc thi Huyn ng Anh (giai on 1 tc 2003 2006) s

3822/Q-UB. a im u t l x Vit Hng vi phm vi l 88448 m2. Khu chn

lp rc thi sinh hot ny c xy dng mi nhm mc tiu thu gom x l rc thi

trn a bn huyn v mt s vng ni thnh, ln cn (trong trng hp cn thit)gp phn lm gim thiu nhim mi trng. Hin nay khu chn lp ny mi ch

dng li xy dng cc hng mc cng trnh v h tng k thut. Tng thi gian

vn hnh ca bi l 12.47 nm. y c coi l mt cng trnh mang tnh quy m

ca huyn. Liu v tr ca bi chn lp ny hp l cha? y c phi l phung

n ti u hay khng? Chng ta hy cng kim chng vi kt qu ca ti khi ng

dng GIS v phng php phn tch a ch tiu.

3.2. La chn a im b tr bi chn lp cht thi rn trn a bn huyn

ng Anh

3.2.1. Cn cxc nh vtr bi chn lp cht thi rn trn a bn huyn ng Anh

a. Cn cphp l, kthut v ti liu thu thp

- B Xy dng. Tiu chun xy dng Vit Nam. TCXDVN 261: 2001. Bi

chn lp cht thi rn Tiu chun thit k. Nh xut bn Xy dng, H Ni, 2002.

- B Khoa hc, Cng ngh v Mi trng, B Xy dng. Thng t lin tch s

01/2001/TTLT/BKHCNMT-BXD. Hng dn cc quy nh v bo v mi trng

i vi vic la chn a im, xy dng v vn hnh bi chn lp cht thi rn.

- Cc ngun ti liu bn thu thp c: bn hin trng s dng t huyn

ng Anh nm 2005 t l 1: 15000 dng s, bn a hnh huyn ng Anh t l

1: 25000 dng s, bn a cht v khong sn H Ni t l 1: 200.000 dng s.

Ngoi ra cn c cc ti liu khc nh Thuyt minh tm tt quy hoch chi tit

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huyn ng Anh, Bo co c im a cht thu vn v hin trng khai thc nc

di t huyn ng Anh ca Trung tm quan trc cht lng nc.

b. Xc nh quy m, m hnh bi chn lp

Theo quy nh ca TCXDVN 261:2001 v thng t lin tch 01/2001, cn c

theo din tch, dn s v lng cht thi pht sinh ca huyn ng Anh th quy m

BCL l va vi din tch 10 30 ha.

Da trn c im a hnh, a cht thu vn th m hnh bi chn lp nn l

hn hp kt hp ni chm. y l bi chn lp na chm, na ni, thng c s

dng vng ng bng, c a hnh bng phng hoc dc nh. Cht thi sau khi

lp y h chn, c tip tc cht ng ln trn vi mt cao nht nh, p bao quanh to thnh chn lp. Nh vy s tit kim c din tch chn lp m

vn m bo kh nng cha rc thi.

Da theo quy hoch ca huyn th y khng phi l mt bi chn lp thun

tu m c kt hp vi cng ngh x l.

3.2.2. Chun bdliu u vo

T cc bn ti liu dng s trong Microstation, chng ta s tch ra thnh

nhiu lp i tng chuyn sang phn mm ArcGIS phc v cho vic phn tch,

x l. Bng 3.4 th hin cc lp d liu m ti s dng.

Tuy nhin cc i tng a l khi xy dng trong Microstation khng c mi

quan h khng gian topology. Chnh v vy khi chuyn i d liu sang nh dng

Geodatabase ca ArcGIS, chng ta cn phi thit lp li mi quan h topology v

kim tra, chnh sa li cho cc i tng trong mt lp v gia cc lp theo yu cu

quan h khng gian. C mt s li ch yu nh: cc tha t chng ln nhau hoc

nm chm ln nhau; cc ng giao thng khng kt ni vi nhau ng ba, ng t;

a gii hnh chnh huyn, x khng khp kn, S dng cng c Topology trong

ArcCatalog cho php ta thc hin cng vic ny. V d kim tra quan h topology ca

cc i tng trong lp hin trng s dng t. Nguyn tc l 2 khoanh vi mc ch

s dng t khng c chng ln nhau hoc nm chm ln nhau. Nhng vng mu

l nhng vng khng tun th theo ng nguyn tc. Hnh 3.4 minh ho li 2

khoanh vi mc ch s dng t b chng ln nhau (vng mu ).

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Bng 3.4. Cc lp dliu u vo

Stt Tn lp M t nh dng

1 Diem_thu_gom im thu gom. Th hin v tr cc im thu gom rc Point

2 Tram_dien Trm in. Th hin v tr cc trm cung cp in Point

3 Nuoc_ngam Nc ngm. Th hin v tr ngun cung cp nc ngm Point

4 Gthong_chinh Giao thng chnh. Th hin cc tuyn giao thng chnh(quc l, cao tc, tnh l)

Line

5 Duong ng. Th hin cc tuyn ng giao thng khngphi l chnh

Line

6 Duong_sat ng st Line

7 Kenh_muong Knh, mng Line

8 Dia_chat a cht. Th hin cc t gy Line

9 Thi_tran Th trn. Th hin khu vc th trnng Anh Polygon

10 Dan_thuong Dn thng. Th hin cc cm dn c cc x Polygon

11 Thuy_van Thy vn. Th hin cc sng, m, ao, h, (ncmt)

Polygon

12 Di_tich Di tch. Th hin cc khu di tch vn ho c xphng

Polygon

13 Khu_CNghiep Khu cng nghip Polygon

14 Hien_trang Hin trng. Th hin mc ch s dng t trn a bnhuyn Polygon

15 Dong_anh Th hin cc n v hnh chnh x trn a bn huyn Polygon

16 Tho_nhuong Th nhng. Th hin khoanh vi cc loi t chnh trna bn huyn

Polygon

17 DEM M hnh s cao Raster

Cch sa cc li topology c thc hin bng cch xo i tng, thm mi

hoc l Merge ri xc nh li ng mc ch s dng ca tha t ,

Sau khi chy li Topology xong, csd liu c lm sch v c th s

dng tin hnh phn tch khng gian cc bc tip theo.

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Hnh 3.4. Li topology ca cc i tng trong lp hin trng sdngt

3.2.3. Cc chtiu la chn a im btr bi chn lp cht thi rn

Da trn nhng cn c php l, cskhoa hc v vic la chn a im BCL

CTR v tng hp cc ti liu, nghin cu c im khu vc ng Anh cng nh

tham kho kin chuyn gia, ti a ra cc ch tiu la chn a im BCL

CTR cho huyn ng Anh nh trong bng 3.5 (Mu phiu tham kho kin

chuyn gia th hin phn ph lc).

Bng 3.5. Cc chtiu la chn a im BCL CTR huynng Anh

Nhm chtiu

Tn ch tiu Gii hn

1. Khong cch n ngun nc mt (sng,

h, m,...)

Khng xy dng bi chn lp gn cc ngun nc, ven sng, cc

vng c bo v (h, sui, m ly,...) hoc nhng ni c khnng bo lt thng xuyn nhng cng khng nn xa qu

thun tin cho thot nc thI (tham kho t d n WASTE

ECON ca Canada vi Vit Nam)

2. Khong cch n cng trnh khai thc

nc ngm

Tng ti a khong cch t bi n ngun cung cp nc. Tu

theo cng sut. ng Anh (Q > 10.000 m3/ngy khong

cch > 500m) (theo quy nh ca TCXDVN 261:2001)

A

Mi trng(Gim thiu

tc ng ti

mi trng)

3. Th nhng (tnh cht ca t khu vc

nh loi t, h s thm thu,...)Hn ch ti a s thm thu nc rc t bi vo mi trng t

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4. Khong cch ti ng giao thng chnh

(cao tc, quc l, tnh l, ng st)

(ng st c xp l loi ng giao

thng chnh)

Khong cch t bi n ng giao thng chnh > 100m (theo quy

nh ca TCXDVN 261:2001)

5. Hng gi Hn ch nhim do mi Cng cui hng gi cng tt

6. Khong cch ti cc khu di tch, vn hoKhong cch t bi n khu di tch, vn ho > 1000m (tham kho

t d n WASTE ECON ca Canada vi Vit Nam)

7. a hnh Kt hp vi yu t gi hn ch s nhim khng kh do mi

8. Khong cch n khu cng nghipKhong cch t bi n khu cng nghip > 1000m (theo quy nh

ca TCXDVN 261:2001)

1. Khong cch ti trm cung cp in

Gim thiu chi ph xy dng mng li cp in cho bi cng

gn cng tt (tham kho t d n WASTE ECON ca Canadavi Vit Nam)

2. Khong cch ti ng giao thng

thng (khng phi ng quc l, ng

cao tc, tnh l)

Thun tin cho vic vn chuyn, thu gom rc cng gn cng

tt

3. Khong cch ti im thu gom rc ca

cc n v cp di v cc trung tm pht

sinh rc thi

Gim chi ph v thi gian vn chuyn cng gn cng tt

4. Hin trng s dng t

Gim chi ph n b, gii phng mt bng cho xy dng bi

u tin t cha s dng, t nng nghip hiu qu kinh t thp,cc bi rc ang s dng nng cp phc v cho chn lp v

x l rc trn a bn huyn

B

Kinh t

(Gim thiu

chi ph xy

dng v vn

hnh bichn lp)

5. a cht ( cp n yu t t gy)

Khng xy dng bi nhng ch c cu trc a cht phc tp,

nhng ni c nn nt rn Tng ti a khong cch ti cc vt

nt rn (tham kho t d n WASTE ECON ca Canada vi

Vit Nam)

1. Khong cch n cc khu th

Tng ti a khong cch n cc khu th.

Khong cch n khu th > 3000m

(theo quy nh ca TCXDVN 261:2001)

2. Khong cch n cm dn c thng

Tng ti a khong cch n cm dn c.

Khong cch n cm dn c> 1000m (hng gi chnh)

Khong cch n cm dn c> 300m (hng khc)

(theo quy nh ca TCXDVN 261:2001)

3. Chp thun ca cng ng Tng ti a s chp thun ca cng ng

C

X hi

(gim thiu

tc ng ti

x hi)

4. Chp thun ca chnh quyn a phng Tng ti a s chp thun ca chnh quyn a phng

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3.2.4. Tnh trng scho cc chtiu

Phng php c s dng tnh trng s l Qu trnh phn tch phn cp

(AHP) trnh by mc 2.2.3.

a. Trng sca cc nhm chtiu

- Lp bng ma trn mc u tin ca 3 nhm l mi trng, kinh t v x hi

ri tin hnh chun ha ma trn, tnh trng s ca cc nhm (bng 3.6).

kim tra tnh nht qun ca d liu, thc hin tnh t s CR (Consistency

Ratio). Nu CR < 0.1 l chp nhn c.

Bng 3.6. Ma trn mc u tin v trng sca 3 nhm chtiu

Kinh t X hi Mi tr ng Tr ng sKinh t 1 1/3 1/4 0.126

X hi 3 1 1 0.416

Mi trng 4 1 1 0.458

CR 0.011 (< 0.1) tho mn

(Gi tr mc u tin tham kho t kin ca 3 chuyn gia)

b. Tnh trng scho cc chtiu trong tng nhm

Kt qu so snh mc u tin v tnh ton trng s cho cc ch tiu theo tng

nhm c th hin trong cc bng 3.7 3.9.

Bng 3.7. Mc u tin v trng sca cc chtiu trong nhm Mi trng

Ncmt

Ncngm

Th

nhngGT

chnhHng

giahnh

Di tch KCNTrng

s

Nc mt 1 1/2 1 3 1/2 2 1/2 2 0.118

Nc ngm 2 1 2 3 1/2 2 1/2 2 0.151

Th nhng 1 1/2 1 3 1/3 1 1/2 2 0.102

GT chnh 1/2 1/3 1/3 1 1/4 1/2 1/3 1/2 0.046

Hng gi 2 2 3 4 1 2 1 3 0.222

a hnh 1/2 1/2 1 2 1/2 1 1/2 1 0.086

Di tch 2 2 2 3 1 2 1 3 0.204

KCN 1/2 1/2 1/2 2 1/3 1 1/3 1 0.071

CR 0.023 (< 0.1) tho mn


Ch thch:

Nc mt: Khong cch tbi n ngun nc mt

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Nc ngm: Khong cch tbi n ngun cung cp nc ngm

GT chnh: Khong cch tbi n ng giao thng chnh (quc l, tnh l, cao tc)

Di tch: Khong cch tbi n khu di tch vn ho c xp hng

KCN: Khong cch tbi n khu cng nghip

Bng 3.8. Mc u tin v trng sca cc chtiu trong nhm Kinh t

Trmin

GTthng

imthu gom

HTSD acht

Trng s

Trm in 1 1/3 2 1/5 1/5 0.077

GT thng 3 1 4 1/3 1/3 0.166

im thu gom 1/2 1/4 1 1/5 1/4 0.059

HTSD 5 3 5 1 1 0.356

a cht 5 3 4 1 1 0.343

CR 0.053 (< 0.1) tho mn


Ch thch:

Trm in: Khong cch tbi n trm cung cp in

GT thng: Khong cch tbi n ng giao thng thng (khng phi quc l, tnh l,

cao tc)

im thu gom: Khong cch tbi n im thu gom

HTSD: Hin trng sdngt

a cht: Khong cch tbi n v trt gy

Bng 3.9. Mc u tin v trng sca cc chtiu trong nhm X hi

th Dn c Cng ng Chnh quyn Trng s

th 1 2 1/2 1/2 0.198

Dn c 1/2 1 1/2 1/2 0.140

Cng ng 2 2 1 2 0.387

Chnh quyn 2 2 1/2 1 0.275CR 0.051 (< 0.1) tho mn


Ch thch:

th: Khong cch tbi n khu dn c th

Dn c: Khong cch tbi n cm dn cnng thn cc x

Cngng: Mc chp thun ca ngi dn a phng

Chnh quyn: Mc chp thun ca chnh quyn a phng

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b. Tnh trng schung ca cc chtiu

Thc hin php tnh nhn trng s ca cc nhm vi trng s ca cc ch tiu

trong nhm , c kt qu l trng s chung ca cc ch tiu (bng 3.10).

Bng 3.10. Trng schung ca cc chtiu

Stt Ch tiuTrng s ca

nhmTrng s trong

nhmTrng s chung

1. Nc mt 0.118 0.054

2. Nc ngm 0.151 0.069

3. Th nhng 0.102 0.047

4. Giao thng chnh 0.046 0.021

5. Hng gi 0.222 0.102

6. a hnh 0.086 0.039

7. Di tch 0.204 0.094

8. Khu cng nghip

Mi trng:

0.458

0.071 0.032

9. Trm in 0.077 0.010

10. Giao thng thng 0.166 0.021

11. im thu gom 0.059 0.007

12. HTSD 0.356 0.045

13. a cht

Kinh t:

0.126

0.343 0.043

14. th 0.198 0.082

15. Dn c 0.140 0.058

16. Cng ng 0.387 0.161

17. Chnh quyn

X hi:

0.416

0.275 0.114

Tng 1.000 1.000

3.2.5. La chn sb

a. Xc nh cc chtiu nh gi sb

Vng tm kim v tr bi chn lp rc sc gii hn li khi tin hnh la

chn sb. Cng vic ny c thc hin da trn vic phn tch khng gian i

vi mt s ch tiu c thnh gi trc.

Bng 3.11 th hin tn cc ch tiu v thang phn loi cho tng ch tiu. Cc

mc l: Khng ph hp: 0 im; t ph hp: 1 im; Ph hp: 2 im; Rt ph

hp: 3 im.

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Bng 3.11. Cc chtiu c sdngnh gi sb

STT Tn ch tiu Gi tr im

1. Khong cch n khu dn c th

0 3000 m

3000 5000 m5000 7000 m> 7000 m

0

123

Khong cch n cm dn c nng thn

0 300 m300 1000 m1000 2000 m> 2000 m

0123

2.

Khong cch n cm dn c nng thntheo hng gi chnh

0 1000 m1000 2000 m2000 3000 m> 3000 m

0123

3. Khong cch n ngun cung cp ncngm

0 500 m

500 3000 m3000 5000 m> 5000 m

0

123

4. Khong cch n ngun nc mt

0 500 m500 1000 m1000 3000 m> 3000 m

0123

5. Khong cch n khu di tch, vn ho

0 1000 m1000 3000 m3000 5000 m> 5000 m

0123

6. Th nhng-t ph sa ngoi -t ph sa trong

03

7.Khong cch n ng giao thngchnh

0 100 m100 1000 m1000 3000 m> 3000 m

0123

8.Khong cch n ng giao thngthng

0 100 m100 1000 m1000 3000 m> 3000 m

3210

9. Hin trng s dng t

-t cha s dng-t nng nghip hiu qu thp

-t nh tm, t ngha a- Cc mc ch s dng khc

32

10

10. Khong cch n khu cng nghip

0 1000 m1000 2000 m2000 5000 m> 5000 m

0123

11. Khong cch n im thu gom0 2000 m2000 4000 m> 4000 m

321

12. Khong cch n trm cung cp in0 1000 m1000 3000 m> 3000 m

321

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Khu th Cm dn c nng thn Cm dn c theo hng gi chnh

Ngun cung cp nc ngm Ngun nc mt Di tch

Th nhng Giao thng chnh Giao thng thng

Hin trng s dng t Khu cng nghip im thu gom

Thang im nh gi

Trm in

Hnh 3.5. Kt qu tnh im ca cc chtiu

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b. To cc lp raster vkhong cch

thc hin phn tch khong cch theo cc ch tiu trn, cc lp d liu u

vo c phn tch bng cng c Distance/Straight Line ca Spatial Analyst. Sau

tin hnh phn khong, gn im cho cc lp kt qu bng cng c Reclassify.

Ring cc lp hin trng v th nhng th c chuyn i nh dng t vector

sang raster v tin hnh phn loi li ri gn im.

Kt quim ca 13 ch tiu trn c th hin hnh 3.5.

c. Xc nh cc khu vc tim nng

T nhng trng s tnh c v cc lp rasterim thnh phn ca cc ch

tiu, s dng cng c Raster Calculator, ta to ra mt lp raster tng vi kt qu lim cho tng pixel. Nhng gi tr thp s b loi b. Tuy nhin, cn c mt ch tiu

na phi c xem xt l bi chn lp phi c din tch > 10ha. Thc hin php lc,

ta loi c nhng vng c din tch < 10ha. Kt qu cc vng tim nng c th

hin hnh 3.6.

Hnh 3.6. Kt qu tm kim sb cc khu vc tim nng

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Nh vy, kt qu tm kim sb cho thy c 5 vng tim nng nm trn a

bn ca 4 x l: Vit Hng (2 vng), Vn H, Mai Lm, v Dc T.

3.2.6. La chn chnh xc

3.2.6.1. Chn lc cc v tr tim nng

Theo kt qu tm kim sb, phm vi cc khu vc tim nng vn cn nhiu,

cn phi c thu gim na da trn cc ch tiu dng nh gi chnh xc l:

hng gi, a hnh, a cht, s chp thun ca cng ng, s chp thun ca chnh

quyn a phng.

Sau khi i iu tra, kho st thc a kt hp vi ti liu thu thp c, thng

tin tm tt ca cc a im tim nng c th hin bng 3.12.Bng 3.12. So snh cc a im sau khi tm kim sb

aim(x)

HTSD Hng gi a hnh a cht (xtn yu tt gy)

Mc thuntin v giao

thng

cimkhc

VnH

t nng nghiphiu qu thp (2 vla/nm, nng sut~1.5 t/so)

u hnggingBc

Thp dn vpha ng, cao 5 -7m

Nm nghng t gysu thun don v tgy trt bng

Gn nglin x angc m rng

D bnglt

VitHng

(2vng)

t nng nghiphiu qu thp (2 vla/nm, c trngmu, nng sut ~1.5t/so)

Nm giakhu vc chunh hngca 2 ging Bc vng Nam

Bng phng, cao 5 6m

Cch v tr tgy ~ 1.1 km

Thun tin,gn mtng c rng ~ 3m

DcT

t nng nghiphiu qu thp (2 vla/nm, c trngmu, nng sut ~1.5t/so)

u hnggingNam

a hnhbng phng, cao ~ 6 7m

Nm nghng t gytrt bng

ng t c rng < 2m

Mai

Lm

- Trc l bi rc

thi s dng- Xung quanh l tnng nghip hiuqu thp (2 v la/nm, nng sut ~1.5t/so)

u hng

gingNam

a hnh

thp, phasau bi cng cao chn gi

Cch v tr t

gy trt bng~ 1.5 km

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Luan Van ThuyHC