VIEN B I A LY - VIEN KHOCN VIET NAM HOI BIA LY VIET NAM
Sir DUNG CONG NGHE VIEN THyUvl VA GIS TRO GIUP CONG TAC QUY HOACH VA QUAN LY CAY XANH DO THI
Nguyen Bd Duy', Le Vdn Anh', Pheim Diic Thiiej^
SUMMARY
Nowadays, addition lo the socioeconomic development, issues of the environmental protection and ecological balemce also have high allention. Vegelulion syslem as the lungs ofi urban areas plays an imporlunt role in the urbun plunning cmd management. In recent years, the integralion of remote sensing and GIS technology has been increasingly applied and widely used in many fields and civil purpose. This paper introduces methods ofi digital processing combined with spatial analysis in GIS lo support urban vegelalion slalislic and management.
1. DAT VAN DE
Mdi mgt cdng trinh, du an bao gid cung ed mdt phan khdng gian xanh duge thiet kc trong bdn ve quy hoach nham tao ra canh quan dep, hdi hod giiia kien triic cae cdng trinh vdi thien nhien cldng thdi dem lai mdt mdi trudng trong sach, giam thieu d nhiem.
Hien nay, cimg vdi sir phat trien kinh te - xa hdi, qua trinh dd thj boa dang dien ra nhanh chdng. De thire hien muc lieu dd, cdng lac quy hoach, dau tu xay dung, nang cap CO sd ha tang dd thj da va dang dugc cbii trgng quan lain. He thdng cay xanh ddng vai trd quan trgng trong viec xay dung dd thj van minh, hien dai. Trong Dd an Quy hoach chung xay dung thii dd HdNdi den nam 2030 va lain nhin den nam 2050 mdi day nhdt ma lien danh PJJ bao eao Thudng true Chinh phu, quy hoach cay xanh se chiem 62%
dien tich Fla Ndi. Cd the thay cdng tdc qudn ly, thdng ke cay xanh dd thj chiem vai trd rat quan trgng trong quy hoach, phat trien dd thj.
Trudc day, viec qudn ly, thdng ke sd lugng, dien tich cay xanh dd thj thudng dugc tien hanh bang each do dac va kiem tra Ihuc dja hoac do ve, tinh loan tir anh hdng kbdng. Tuy nhien, cdc phuong phap truyen thdng nay thirdng tdn nhieu thdi gian, cdng sire va chi phi. Vi the viec cap nhat nhidng bien ddng ve dien tieb eiing nhu eo' cau cay trdng la rat khd vd lau.
Ngdy nay, vdi su phat triidn vugt bac eiia cdng nghe vien tham dae biet la su ra ddi ciia cac loai anh cd do phan gidi sieu cao nhu Quickbird (0,61 - 2,4in), Ikonos (1 - 4m), GeoEye (0,41 - 1,65m) v.v... da dem lai nhieu irng dung mdi trong cdng tac quy hoach dd thj. Ben canh dd, cdng nghe GIS cung da va dang dugc img dung nhieu trong cdng tac thong ke, quan ly, quy hoach dd thj va hd trg ra quyet djnh.
Bdi bao nay tap trung gidi thieu phuong phdp chiet tach va phan loai eac ddi tirgng cay xanh dd thj bdng cdng nghe vien tham ket hgp vdi he thdng lin dja ly (GIS), thir nghiem vdi tu lieu ve tinh Quickbird va khu vue nghien ciru la mdt quan ndi thdnh Hd Ndi
' Dai hgc Md Dja chdt Ha Ndi
- vien Dia ly, Vien Khoa bepc Cong nghe Viet Nam
^ Nha Xuiit ban Ban dd
Hdi nghi Khoa hgc Dia ly Toan cjud'c lan thu'5 - Ha Ndi, 2010 1355
VIEN BLA LY - VIEN KHOCN VEET NAM HOI BIA LY VIET NAM
2. TU LIEU V.A. P H U O N G P H A P 2.1. Tu lieu nghien cuu
Nghic;n cuu na\ su dung cac tu lieu ddu vdo sau:
- Anh \ e tinh Quickbird. dcd phan gidi cao O.dlin, do triim pbii 40kin x 40kin thu chup nadv 08/11/2007 quan trac khu vuc trung tam thanh phd Ha Ndi (hinh 1).
' 4 ' 1 ^ ' •—-*•"—^*-'-—"''^ ''•' ' I 3 ,
t''^ A Ho Dons Da
Ho Ba Miu
! lo 3 h mil Coiu
Hinh 1. .-inh Quichbiid quan trac khu i uc Qudn Ddng Da, Hd Ngi (td hop 4:3:2) - Bdn dd dja hinh I Id Ndi ty le 1/2000 be toa do Quoc gia V N - 2 0 0 0 .
- Bdn dd du Ijch thdnh pho H d N d i nam 2008 t>' le 1/15000 2.2. P h u o n g phap
Ddi tu'ong khong
t b i r r nbi'i
Anh ve tinh Flieu chinh hinh
T
3~ao anh tv solMDVl
Dien tich
Ca\' xanh cone
Doi tugng thuc nhn
j- V r r t n 111 Ca\ ,\anli do thi
Khodiu
Phan tirh k b n n " "ian C I S
Cay xanh
i
Bai cd
Ban J('i c;u' xanh do
Hinh 2. Sa do quy trinh phdn locii city .xanh iio thi
1356 Hgi nghi KJioa hgc Dia ly Todn qud'c ldn tb&S - Hd Ndi, 2010
VIEN BIA LY - VIEN KHOCN VIET NAM HOI BIA LY VIET NAM
Nghien ciru su dung ket hcip cdng nghe \ ie;n thdm vd GIS de; chic:t tdch vd phdn loai cae nhdm cdy xanh dd thi. Quy trinh xir ly phdn loai cay xanh dd thj dugc tien hdnh lheo so dd sau (/;/;;// 2):
Nhdm ldc gia da sd diiiig cdng nghe xir ly dnh sd de chii;! tdch cdc doi tugng thuc plui. Dua trcMi bdn dd dja hinh lid Ngi ty Ic 1/2000, dnh ve tinh dirge hiidu ehinh hinh hoc lir he toa do lodn cdu \VGS-84 \e he toa do VN-2000. Sau dd sd dting ranh gidi lidiih chinh edp (|udn cua bdn do dia hinh Hd Ndi de cat dnh lheo ranh gidi. Do kich Ihii'dc dnh cd ban, chi cd duv nhdl khu vuc qudn Ddng Da Id don vj hdnh chinh dugc triim phu trgn ven nc;n nhdm ldc gia da qu\i;t djnh lua chgn qudn Ddng Da de tlui nghiem nghien cuu (hinh 3).
Hinh 3. Anh cdt theo ranh gidi quim Hmh 4. Anh ty sd NDVl Ddng Da
Anh sau khi cat duge dua \'do tinh toan de tao dnb ty sd NDVl de tren eo' so' dd chie;l tdch cdc ddi tugng tlurc plui vd ddi lugng khdng tlurc phu.
NDVl (NIR - RED) (SIR + RED)
Ji'cn dull ty sd NDVl, edc ddi tugng cd tdng mdu trdng Id thuc phu vd tdng mdu den Id cdc ddi tugng khdng tlurc phu (/;//;/; 4).
Sail khi tdch dugc edc ddi lugng thirc phu vd ddi tugng khdng tlurc phu. \eclo hod cdc de^ii tirgng ihirc phu de lien hdnh budc phdn loai cay xanh dd thj, ()ua iham khdo mdl sd nghien cuu. nhdm tdc gia dd phdn loai cdy xanh dd thi theo 3 mirc:
-h Cdv xaiili cdng \ iciii: cdy xanh trdng tap trung trong cdc cdng v ien + Cdv xanh diroug pTid: he thdng ed\ xanh trdng dgc dirdng giao thong + Bdi cd: cdc kliu \uc ddt trdng cd co \d bdi cd trong khudn vien
D I phdn loai cdc doi lugng cd_\ xanh dd ihj, iigliii;n ciru da su dung phuo'ng phdp phdn tich khdng gian GIS (Spatial Analysis). Cdc Idp thdng tin chuyen dc: nhu \ j tri cdc bed nude, vj tri cdng vii-ii, dudng pho, ddn cu trong ban dd du ljch vd ban dd dja hinh lid Ndi dugc su dung trong phdn tich khdng gian. Thdng thudng, nhdm cay xanh cdng \ ien thudn" tap trung lai edc khu cdng vien. cd dien tich ldn. Nhdm cdv xanh dudng phd tliudnu phdn bd rdi rac. dien tich nho le. nam dgc edc tuyen dudng. Nhdm bai co Hdi nghi Klioa hgc Dia ly Toan cjudc lan thu'5- Ha Ndi, 2010 1357
•VTEN BIA LY - VIEN KHOCN VIET NAM HOI BIA LY VIET NAM
thudng tap Irung gdn eac khu dan cu hoac gan hd, cd dien tich trung binh. Dua trc;n nhung nhan djnh dd, nhdm tac gid da tien hdnh xac djnh cae tieu ehi sau:
Bdng 1. Chi tie}u phdn locil
Khoang cdch tdi cdng vien Khoang each tdi dudng phd
Khoang each tdi hd bode khu dan cu Dien tich
Cay xanh cdng vien
< 50 m
> 10 m
> 100 m
> 150 m-
Cay xanh dudng phd
> 50 m
< 10 in
> 100 m
< 15 m-
Bai cd
> 50 m
> 10 111
< 100 m 1 5 - ISOnr Sau khi thdng ke dien tich va do khodng each tir cae ddi tugng polygon tdi cdng vien, dudng phd, hd hoac khu dan cu gan nhat, su dung cdng cu Spatial Analysis trong phdn mem ArcGIS de thuc hien eac tinh loan, phan tich xac djnh cac nhdm cay xanh dd thj dua tren bang chi tieu phan loai tren (bang 1)
3. KET QUA VA THAO LUAN
Hmh 5 la ban dd ket qud phan loai cay xanh dd thj va thdng ke loan bd dien tich cua cdc nhdm ddi tugng (bdng 2). Cap nhdt them cac thdng tin khac ciia cdc ddi tugng nhu dien tich, chu vi, vj tri cay xanh hd trg them cho cdng lac thdng ke, quan ly. Sau khi chgn ngdu nhien mdt vai vj tri de kiem chirng ngodi thuc dja, ket qua sau phdn loai cd do chinh xac khoang 90%. Tuy nhien do dieu kien cd ban nen nghien ciru mdi chi dirng lai d mirc don gidn la kiem chirng ve ki§t qua phan loai cac nhdm ehir chua kiem cbiriig chi tiet ve sd lugng, dien tich edy xanh.
Ban do phan loai cay xanh quan Dong Da
.1
C h u g 11 ^ \Oi/6ng ph6 i B M C3y xanfi iiing vi6n ii.'.L. C^y xanh duang ph6 \
Th.im c6
•'vmix.
Hinh 5. Bim do cdy xanh do thi quim Ddng Da thdnh phd Hd Ngi
Qua thdng ke, tdng dien tich cay xanh chiem 19,49% tdng dien tich todn quan Ddng Da trong dd dien tich cay xanh cdng vien chilm 18,29%), cay xanh dudng pho
Hdi nghi Klioa hgc Dia ly Todn qud'c ldn th&S - Hd Ndi, 2010 1358
VIEN BIA LY - VIEN KHOCN VIET NAM HOI DIA LY VIET HA-M
eiiieni 0,85%), bai cd chicim 0,35%. Nhu vdy cay xanh thude khu vuc qudn Ddng Da ve CO ban cdn il, ddc biet nidi chi lap trung nhieii vao cdc khu vi^rc cdng vien cdn cd)' xanh dc.ic cdc tuyidn duiTng clura nhii;u. Trong tuong lai can tang cirdng irdng ihein cdy xanh dudng phd vira ldng cdnh quan dd thj vua ddm bdo gidm thieu d nhiem khdi bui.
Bdng 2. Bdng thdng kd dien tich cdc loed cdy xanh quiin Ddng Da
Dien tich (ha) Ty le (%)
Cay xanh cdng vien 182,954
1 8,29%
Cay xanh dudng phd 8,518
0,85%o
Bai cd 3,556 0,35%
Tdng 195,028
1 9,49%
4. KET LUAN
Nghien ciru cho thdy sir dung cdng nghe vic;n tham ket hgp vdi cdng nghe he thdng tin dja ly (GIS) giiip cho cdng tdc qudn ly, quy hoach cay xanh dd thj hicju qua ban rat nhieu so vdi cac phuong phdp truyen thdng. Tuy nhien cdc chi lieu dugc dua ra trong bai bao mdi thanh lap ehi dua tren edc ddc diem rieng ciia khu vue nghien ciru, de dp dung thdng nhat cho cdc khu vuc dd thi ndi chung can phai nghien cuu tiep tren midt quy md rdng va ehi tiet hon. Ben canh dd, can phdi cd them cdc sd lieu thuc dja de kicm chirng ddnh gid do chinh xdc.
Bang cdng nghe GIS, de tdi cd the md them nhieu hudng nghien ciru mdi. Cu the, td chirc thu thdp, cap nhdt, luu tru' cdc thdng tin ve sd lugng, cluing loai, chdt lugng, mat did cay xanh, chieu cao, ludi ddi, khoang each giua cae cay v.v... hd tig them cho cdng tdc qudn ly, duy tri va bdo ve edy xanh. Dira tre;n cdc thdng tin luu ti id, cdc nhd qudn ly cd the tinh loan, xdc djnh duge thdi gian nao edy can eat tia hoac nam bat dugc chat lugng de biet cdy ndo cdn phdi thay tin: dam bao an todn cung nhu canh quan dd thj. Ben canh dd, ki§t hgp cdc thdng tin quy dat, loiii thd nhudng, ciing vdi hien trang thdnh phd vd cdc chi tieu ky thudt de tinh todn khdng gian, thiet ke va quy hoach cay xanh mdt each hgp ly va hieu qud.
TAI LIEU THAM KHAO
1. Le Van Trung - 2005 - "Gido trinh Vien thdm"'- NXB Dai hgc Qudc gia TP. Ho Chi Minh.
2. Nguyen Thanh Minh, Pham Bdeh Viet - 2005 - Phdn Vien Vui ly thdnh phd Ho Chi Minh - "Xdc dinh khu vuc cdy xunh do lhi bdng dnh vien thdm cd eld phun giui sieu cuo " - Fldi nghj Khoa hgc vd Cdng nghe Idn thir 9, Trudng Dai hgc Bach Khoa TP.
Hd Chi Minh.
Hdi ng-hi Khoa hgc Dia ly Todn cpid'c lan thd 5 -Ha Ndi 2010 1359
