HE THONG GIAI PHAP PHAT T R I E N BEN VUNC KHONG GIAN XANH THANH PHO HUE
TRAN THI TUYET MAT- TRUONG CONG TIEN NGUYEN TRONG QUAN - DUNG VAN SON
DANG THI THANH, VO THI HOAI THU Trudng Dgi hpc Supham - Dgi hpc Hui Tom tat: Ket qua nghien curu khao sat ve hien trang ldp phii thuc vat d thanh pho Hue da chi ra cac dac diem co ban ciia ldp phu thyc vat trong thanh pho cung nhu xac djnh miic dp dat dugc ve cay xanh so vdi tieu chuin cay xanh cua mpt do thi sinh thai. De phat trien ben vung khong gian xanh do thi d thanh pho Hue, can tien hanh ddng bp cac giai phap nhSm phat triln cay xanh theo cac muc dich nhu sau: Cai tao khi hau, bao ve moi truang; Tao my quan cho thanh pho; Tao su on dinh cho boat dong tring va bao ve cay xanh.
Tu khoa: hien trgng, ldp phu thyc vat, tieu chudn cay xanh, phat triln bin vung, giai phap.
l.DATVANDJE
Qua trinh do thi bda (DTH) dang diln ra ngdy cdng manh me. DTH nlu khong qudn li tdt, djnh hudng quy hoach do thi hieu qua se lam suy gidm cay xanh. Cdc nghien cim da chi ro tdm quan trgng cua cay xanh, nhat la cay xanh do tbj (CXDT), viec bao dam su hai hda giOa tien trinh DTH vdi canh quan thien nhien la muc tieu ma tdt cd cac nude tren the gidi cung nhu Viet Nam mong mudn dat dugc. Tii Idu danh tir "'thdnh phd vir&n " da gdn lien vdi Hue, la mdt tiong nhung dd thi (DT) ciia Vifit Nam cd mat dp cdy xanh cao vdi 10 m^/nguai (2005) [9], cay xanh thanh pho Hue la mpt bg phgn khdng the thieu dugc trong kiln triic canh quan dd thi Hue. Thanh pho Hui ia noi cd dilu kifn ty nhien khd khac nghiet, vdn dd cai tao ty nhien bdng cay xanh de tgo mdi trudng sdng tdt cbo con nguai da dugc chii y tir lau va dd cung la mgt trong nhirag dinh hudng phat trien CLia thanh phd Hui trong tien trinh tia thdnh do thj logi 1 tryc thudc hnng uang.
Ket qua nghien ciiu thuc trgng cdy xanh sii dung cdng cgng dd thi (mgt bp phdn cua CXDT) g thanh phd Hui budc ddu cung cdp ca so cho viec de xudt h^ thdng giai phap de gdp phdn duy tri, bdo v? va phat trien bin vung cdy xanh dd thi d thanh pbd Hui.
2. VAN DE PHAT TRIEN KHONG GL\N XANH 6 THANH PHO HUE 2.1. Khai niSm
2.1.L Khong gian xanh do thi
Theo Pham Ngpc Ddng, Chu tich Hpi Mdi tiudng Xdy dung Viet Nam, mgt dd thi chi cd thi dugc coi la xanh khi dap ung 7 tieu cbi; khdng gian xanh; cdng trinh xanh; giao thdng xanh; cdng nghiep xanh; chat lugng moi trudng do thj xanh; bao tdn cdnh quan thien nhien, danh lam thdng cdnh, cdng trinb ljch sir, vdn hda; cgng ddng dan cu sdng than thi?n vdi mdi b-u6ng vd thien nhien. Khdng gian dd thj xanh khdng chi cd cdy xanh
Tap chi Khoa hgc va Giao due, Truong Dai hoc Su pham Hue ISSN 1859-1612, S6 04(28)/2013: tr. 56-65
TRAN TUYET MAI va cs.
duong phd, cdng vien, mat nude ma phai co cai nhin toan dien ban, bao gom cac hanh lang xanh, vdnh dai xanh, thi tian sinh thai, khu sdn xudt nong nghiep chdt lugng cao...
Khdng gian xanh con dugc hieu la: "Ngdi nhd ndy dugc xdy dung v&iy tudng chinh Id tgo ra khdng gian md con ngudi sdng trong do cd ciing nhip ddp v&i thien nhien. Diing sit thay ddi theo rniio ciia mdt cdi cdy kit hgp v&i kiin trite di dieu tiet dnh sdng, khdng khi, mdu sdc cho phii hgp v&i tiin nghi sdng cita con ngudi theo thai tiit va qua dd. con ngu&i se nhdn thi'rc thien nhien ro rdng hah" [7].
2.1.2. Cdy xanh do thj
Co nhilu each hieu khac nhau ve khai niem CXDT. Theo nghi dinh Sd 64/2010/ND - CP cua Chinh phii ngdy 11 thang 6 nam 2010, khdi ni6m dugc hieu nhu sau: CXDT la cay xanh sii dyng cdng cpng, cay xanh sir dung hgn chS va cdy xanh chuyen dyng tiong dd thi. Trong dd, cdy xanh sir dung cdng cgng dd thj la cac logi cay xanh dugc tidng tien duang phd (gdm cdy bdng mdt, cdy trang tri, ddy leo, tham cd trdng tren he phd, ddi phdn cdch, vong xoay duong giao thdng); cay xanh tiong cong vien, vudn hoa; cay xanh va thdm cd tai qudng trudng vd cdc khu vuc cong cgng khac; Cay xanh sii dyng bgn cbe trong do thi la cdy xanh dugc tidng trong khudn vien cdc try sa, truang hgc, benh vien, nghia tiang, cac cdng trinh tin nguong, biet thy, nhd d va cac cdng trinh cdng cdng khac do cac td chiic, cd nhdn qudn ly va su dung; Cay xanh chuyen dyng tiong dd thi la cac logi cay trong vudn uom hodc phyc vy nghien cuu.
2.2. Tong hgp tieu chuan cdy xanh do thi 2.2.1. Chi tiiu cdy xanh do thi tren dau ngudi
Tiiy tiieo loai dd tiij md yeu cdu vl CXDT khac nhau. Chi tieu cay xanh do thi tren ddu ngudi phu thudc nhieu vao nhilu ket cdu, cbiic ndng ciia timg logi do thi.
Bang I. Tdng hap tiiu chudn diin lich dat cdy xanh DT [3]
Loat dd thj Dac biet I v a l l n i v a l V V
Tieu cliuan d^t ciiy xanh cong C9ng(m-/ng)
12-15 10-12 09-11 08-10
Tieu chuan dat cay xanh cong vien (m" /ng)
7,0 - 9,0 6,0 - 7,5 5,0-7,0 4,0 - 6,0
Tieu chuan d^t c3y xanh viro'n
hoa (m^ /ng) 3,0-3,6 2,5-2,8 2,0 - 2,2 1,6-1,8
Tieu chuan dat cay xanh dirdng ph6{in^/ng)
1,7-2,0 1,9-2,2 2,0-2,3 2,0-2,5 2.1.2. Chang logi cdy xanh do thj vdyeu cdu kT thugt trong bd tri
Theo TCXDVN 362:2005 [3], cac loai cdy trdng ti-ong dd tbi pbai dam bao cac tieu chudn sau:
Cdy phdi chiu dugc gid, bui, sau benh: cay thdn dep, dang dep.
Cdy cd re dn sdu, khdng cd re ndi.
HE THONG GIAI PHAP PHAT TRIEN BEN VUNG KHONG GIAN XANH TP HUE
Cay la xanh quanh ndm, khdng rung la tra cdnh hoac cay cd giai dogn rung la tra canh vdo mua dong nhung dang dep, mdu dep thi chi nen chiem t> le thdp trong tdng sd Ioai CXDT.
Khdng CO qud thjt gdy hdp din rudi muoi.
Ve phdi ket; Nhieu logi cdy, loai boa; cdy cd la, hoa mau sdc phong phii theo 4 mua; nhieu tdng cao thdp, cdy than gd, cdy byi va cd, mdt nude, tugng hay phu dieu va cong tiinh kien tnic; sir dung cac quy luat trong ngh? thuat phdi kit cay vdi cdy, cay vai mat nuac, cay vai cong trinh bgp ly, dam bao tinh he tiidng cua ty nhien.
Bang!. Phdn logi cdy xanh do thj vd cdc yiu cdu ky thugt [&]
STT 1 2 3
Loai cdy Cay lo^i 1
(*)
Cay loai 2 Cay loai 3
Chilu cao s 10m
>10m-l5m
>l5m
Khoang each trong
4m- 8m 8m- 12m 12m-15m
Khoang each toi thieu doi vol le dirjrng
0,6m 0,8m lm
Chieu rong via he 3m- 5m
>5m
>5m (*) cdy logi I. tiiu mgc; cdy logi 2. trung mgc: cdy logi 3: dgi mdc
2.3. Thyc trang cay xanh do thi d* thanh ph6 Hue 2.3.1. Melt dp cay xanh thdnh pho Hue
Vao ndm 2005, thanh phd Hui cd 43 cdng vien, diem xanh vdi di?n tich 89,3 ha vd 54.000 cdy bdng mat cac logi dgc theo cac tuyln dudng va cac diem dan cu. Vdi dan sd ciia thanh phd la 326.000 ngudi, 40.000 sinh vien, hgc sinh va khoang 40.000 khdch vang lai thi dien tich cdy xanh binh quan ddu ngudi khoang 10 m'/ngirdi [9], thudc loai cao so vdi ca nudfc. Theo thdng ke, hien Dd Ndng cd ti IS binh qudn ddu ngudi rdt thdp, chi 0,35 m^ cay xanh/ngudi, tai TP Hd Chi Minh, ti le ndy Id 1,2 m^ cdy xanh/ngudi. Ha Npi 1,8 m^ cay xanh/ngudi. Tuy nhien, de phan dau tid thanh do thj logi 1 tryc thugc tmng uang tieu chudn ddt cdy xanh cdng cgng/ngudi ciia thanh phd Hue phai a muc 12 - 15 m^ /ngudi.
Tuy thdnh phd Hui cd mdt dg cay xanh thugc logi cao nhung phdn bd khdng deu tren todn dia bdn. Ket qud nghien ciiu cdy xanh sir dyng cdng cpng cho thdy: cd nhieu duong phd cd mgt do cay xanh rdt cao, tinh tnmg binh cii 10m, nhu dudng Le Lgi cd 1,8 cdy, Ngo Quyen 2,1 cay... (d bd Nam sdng Huong). Ci Bdc sdng Huong cac tuyen dudng Le Dudn 2,6 cay; Nguyin Trai, Dodn Thj Dilm, Yit Kieu, 23/8 vdi 2,2 cdy; Le Hudn 1,91 cay... nhung cung cd cac dudng cd mat do cdy xanh thdp nhu Chu Van An, Mai Thtic Loan cd 0,8 - 0,9 cdy [1], do cac tuyen dudng ndy hodc mdi dugc mdi ma, hoac vdn dl quy hoach dd thi vdn con chua ddng bg... nen viec bd tri trdng cay vdn cdn ban chi.
2.3.2. cdu triic khdng gian xanh ihdnh phd Hui
2.3.2.1. Dgc diim phdn bd cdy xanh & cdc cdng viin vd du&ng phd & thdnh phd Hui a. Cdng vien
TRAN TVYtl MAI va cs.
Cac cdng vien tien dia ban thanh phd Hue cd dien tich khdc nhau;
Cac cdng vien co dien ticb Idn nhu; cong vien Ho Tinh Tam (109.689 m"), cdng vien Ngp mdn (48.994 m^), cdng vien Thuang Bgc (35.816 m"), tap trung d ba Bdc song Huong.
Cdc cong vien cd dien ticb nhd gdm: cdng vien Tii Tugng (2.643 m'), cdng vien An Cuu (5.000 m^), tap trung d bd Nam sdng Huong.
Dieu nay cbo thdy, khu vyc Nam sdng Huong do co tdc dg dd thj hda mgnh nen dd anh budng den dien ticb ddt cay xanh trong cdc cdng vien.
Bang 3. Hi thdng cdng viin trin dia bdn thdnh phd Hue [2], [6]
S T T 1 2 3 4 5 6 7 8 9 10 11 12
Ca<
T£n c5ng vi£n Pblj Xuan Thutrag Bac TiSn Quoc Toan Nguyen Van Troi Ngo Mon Ho Tinh Tam Phii Cat
Cac Ly Tu Trpng Tti Tugfng 3/2 Kira Dong An Cim
cong vien Idiu virc Bac song H m m g Dl^o ti'ch
(m-) 30.139 35.816 6.385 8.400 48.994 109.689 12.328 cdng vi£n k h u
36.381 2.643 29.680 8.350 5.000
M^ d a t CV/cav 13.9 89,3 3,8 40,6 197,6 1424,5 38,7 vuc N a m
55,2 40,7 47,2 34,4 384,6
Vj t r i Duong Le Duan Duong Ttan Himg Dao Duong Dinh Tien Hoang Duong Dinh TiSn Hoang - Han Thuyen
Duong 23/8 - Doan Thj Diem - Ong Ich Khiem
Dudng Doan Thi Diem Duong Trinh Cong son song Hirimg
Duong Le Lpi Duong Le Lpi Duong Le Lpi
Duong Ha Npi - Hai Ba T n m g - Tran Cao Van
Duong Himg Vuong
Mat dg cdy xanh bdng mat a cdc cdng vien cdn mdt cdn ddi, cac cong vien co mat dg cao gdm: cdng vien Tran Qudc Todn 3,8 m"/cdy, cong vien Pbii Xudn 13,9 m^/cdy; cd cdng vien cd dien tich ldn ma mat dp cay thdp nhu d cdng vien An Cyu trung binh 384,6m" cd mdt cay.
b. Cdy xanh dudng phd
Cay xanh duong pbd cd sir thay ddi ldn ve nhilu phuang dien. Tdng sd cay nhin chung cd sy suy gidm, nhu a dudng Ddng Da, Hai Ba Trung, Dien Bien Phii, Ly Thuang Ki^t, Phan Ddng Luu, Huynh Thuc Khdng... tap trung hdu hit a Nam sdng Huong va mgt sd tuyen dudng d ngoai thanh Bac sdng Hucmg; cac tuyln ducmg cd tdng sd cdy tdng khdng nhieu vd tang it ti-en mdt sd tuyen ducmg d khu vyc thanh ngi, cac tuyln dudng mdi md: Nhdt Le, Mang Ca, Chuang Duong, Nguyin Sinh Cung.
HE THONG G U I PHAP PHAT TRIEN BEN XCNG KHONG GIAN XANH TP HUE
Bang 4. So sdnh su bien ddi sd lugng vd mat dp cdy xanh mdt sd tuyen dudng thdnh phd Hue th&i diim ndm 2000 vd ndm 2013 Stt
Ten dirdng ChiSu diii
2000 T6ng so cay
K h o a n g each cay
(m/cav) Loai
2013 T^ng so cav
Khoiing each cay (m/cav)
Loai K h u vu-c B i c song Hiromg
I 2 3 4 5 6 7 8 9
Doan Thi Diem Dmh Tien Hoang Mai Thuc Loan Huynh Thuc Khang 23/08 Phan Dang Luu N h a t L e Mang Ca Chuong Duong
1.009 1.953 853 2.762 953 812 1.034 575 700
237 262 87 221 226 40 53 2 7
4 7 10 12 4 20 20 288 100
A A A A A B B D D
100 140 49 125 121 16 134 22 29
10 14 8 22 8 51 8 26 24
A A A B A D A C B K h u vuc Nam song Hirong
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Ha Noi Le Lot Ly Thuang Kiet Nguyen Hue Phan Boi Chiiu Biii Thi Xuan Himg Vuong Dong Da Dien Bien Phu Hai Ba Trung Bach Dang Ton That Thuyet Nguyen Cong Tni Nguyen Sinh Cuna Nguyen Du Ham Nghi
854 2.260 860 2.069 2.487 5.323 1.395 760 2.221 900 2.814 329 470 2.500 450 840
170 387 162 481 224 360 205 194 266 237 167 18 19 52 3 3
5 6 5 4 11 14 7 4 8 4 17 18 25 48 150 280
A
.\
A A A A A A A A B B B C D D88 248 69 190 76 265 104 15 103 59 180 12 21 126 6 10
10 9 13 11 33 20 14 51 22 16 16 28 23 20 75 84
A A A A C B A D B B B C C B D D Ngudn: [5] vd theo khdo sdt cua nhdm ldc gid Mat dp cay xanh d- dudng phd Hue cd the chia tbdnb 4 loai A, B, C, D:
Logi A: co cu ly cay binh qudn < 15m/cay.
Logi B; cd cy ly cdy binh qudn >15in/cay den <25m/cay.
Loai C; cd cy ly cay binh quan: >25ra/cdy den <50m/cdy.
Logi D: cd cy ly binh qudn >50iii/cdy.
Qua ddnh gia, cdc duang phd thugc logi C, D chii yeu la cac dudng phd each xa trung tdm \ a mgt sd dudng thugc khu vyc Thanh Ndi. Nhitag duang phd nay cd mat dp cdy
TRAN TUYET MAI va cs.
xanh rdt thua that, cho thdy viec phat trien CXDT con nhieu bdt cap. Hogt dgng do thi hda d thanh phd Hui ti-ong nhiing nam tid lai day tap trung d khu vuc phia Nam sdng Huong, da lam suy giam do che phu.
2.3.2.2. Ca cdu cdy xanh thanh phd Hue a. Thdnh phdn lodi th{rc vgt
Qua khdo sat va nghien ciiu CXDT d thanh pbd Hue, dd xac djnh dugc 143 lodi, thudc 54 bg [4], thdnh phdn lodi a CXDP, cdng vien va g cac dilm xanh rdt da dang.
* Cay xanh dudng phd (CXDP)
Cay xanh duong pho thanh pbo cd 59 loai thugc 23 hp thyc vat. dya vao cdng dyng cd the chia thanh 4 nhom [5]:
Nhdm cdy dn qua cho bdng mdt; chiem sd lupng thdp (6,8% trong tdng sd cay xanh dudng phd), phd bien la; Dira (Cocos nucifera L.), Nhan (Dimocarpus longan Lour), Vu Sira (Chiysophyllum cainito L.). Xoai (Mangifera indica L.), Me (Tamarindos indica L.), Vai (Litcbi sinensis Radik)... Cac cbiing logi nay gdp phdn da dang va cai tao moi sinh cbo thanh phd nhung cac loai cay nay cd nhugc diem Id thu hiil rudi, gdy mdt ve sinh khi qua chin hodc gdy nguy hiem cho ngudi di dudng khi qud rai rihu cay Diia (Cocos nucifera L.) (2% cay d dudng phd).
Nhdm cdy bdng mat: chilm 36,6% ti-ong tdng s6 CXDP, phd biln Id Bang {Terminalia catappa L.), Nhgc ngya (Swielenia macrophylla K. Hook), Nhdi {Bischofia trifolio. Hook.f.), Bd hdn (Sapindus rarak (Hook.f.) Dc), Bd de {Ficus religiosa L.).
Nhom cdy bong mat cbo hoa dep; chilm 50,4% ve sd lugng cay, nhCng loai chiem uu the la Bang lang tim {Lagerstroerrua regirme Roxb), Phugng vT {Delonix regia Raf), Phupng vang {Peliophorum tonkinensis A. Chev). Cac loai nay thuang khdng cao vd cd dudng kinh trung binh khoang 20cm din 60cm.
Nhdm cdy gd quy biem cd gia tri kinh te: Nhiing cdy thugc nhdm nay chilm sd lugng vd thanh phdn loai thdp (6%), dien hmh la Bach ddn trdng (Eucalyptus tereticomis JM.Sm.), Nhac ngya (Swietenia macrophylla K. Hook), Xa cir {Khaya senegdlensis Tuss), Sin (Homalium ceylamicaum (Gardn.) B).
* Cay xanh cong vien
Cdy xanh cdng vien thanh phd Hui xdc djnh duac 74 lodi thupc 37 hp thyc vdt. Vdi tdng sd cdy Id 4.956 cay xanh bdng mat, tbeo 5 nhdm cdng dyng: Nhdm cay dn qua cho bdng mat, nhdm cdy cho hoa dep, nhom cay gd quy vd cd gia trj kinh tl, nhdm cay bdng mat, nhdm cdy canh. (Jua khdo sat cho thay, cay hoa canh chilm uu thi vl sd lugng (51,67% tdng sd lugng cdy xanh cong vien) dien hinh nhu: Hoa gidy (Bougainvillea brasiliensis Rauesch;, Triic ddo {Nerium indicum Will), Lilu ru {Salix babylonica), Tu vi {Lagerstroemia indica), Tiing biit {Juniperus chinensis), Cau byng (Roysionia regia O. F. Cook)... mang lgi gia trj my quan cao cho do tbj, dap iriig cac chiic ndng ciia cong
HE THONG GLM PHAP PHAT T R I E N BEN \T'NG KHONG GIAN XANH TP HUE
vien; tgo cam giac thoai mai, khdng gian thu gian, nghi ngai cho ddn sinh. cay dn qua cbo bdng mdt chiem t\- le thdp (1,9% tdng so lugng cdy xanh cdng vien) [5].
* Diem xanh
Cac diem xanh bao gdm cac khudn vien cong cdng nhu; khach san, tnrdng bgc, nhd thd, cdng sa va benh vien. Tdng sd loai cay xanh da xac djnh la 64 loai thuoc 34 hg trong dd, thanh phdn loai cdy uu the la; Trac ba diep 10,7% {Thujao Tifentalis L.), Tram hoa vdng 5,1% (Acacia auriculiformis), Phugng vang 5,2% {Peltophorum tonkinensis A. Chev), Phugng do 4% {Delonix regia). Bang Ldng tim 5% {Peltophorum tonkinensis A. Chev) [5]. Cimg vai chiic nang phdi tri, cdc Ioai cdy nay da phat huy dugc till mgnh ve my quan cho ducmg pho, cdng sd... tgo cam gidc tiiu gidn cho dan sinh.
h. Tudi cdy
Bang 5. Ty li cdy xanh do thi d thdnh phd Hui phdn theo dudng kinh thdn cdy [4], [6]
TT 1 2 3 4 5 6
Dirdng kinh Dio < 10 cm 10 < D,0 < 20cm 20 < D40 < 40cm 40<D«)<60cm 60 < Dgo < 80cm Dioo > 80cm
Cav xanh Cong vien
(%)
60.8 11.7 19.0 4.4 2.5 1.6
Cav sanh dirimg pho (%) 31,5 15,6 34,7 9,8 2,8 2,0 Dp tuoi ciia phan ldn CX DT d tbdnb pbd Hue deu d giai doan tie. So lieu d bang cbo thdy da so dudng Idnh ciia cay xanh dd thi a cap Dio, D20,D4o (chiem >81.8%).
2.3.2.3. Phoi tri cgy xanh & thanh phd
CXDT a thanh phd Hue chua phdt trien dong bp nhdt Id cdy xanh dudng phd. Sy bd tri cac cdy chua ddng nhdt ve khoang each, con cd nhieu khodng trdng khdng cay. Nhieu tuyen duong ven song mat dp cay day dac, gdy ban che tdm nhin cdc khiic quanh \'en song nen d l gdy tai nan giao thdng. Nhilu tuyen duang khac cd qud nhieu loai cdy gay mat my quan nhu dudng Hai Ba Trung, Ben Nghe... Tuy co mat dp cdy xanh khd cao nhung thanh pbd Hue van con nhieu tuyen dudng cd CXDT khdng bdo ddm cac tieu cbudn ve sd lugng, miic do cho bdng mdt, kha nang cai tgo mdi trudng, khd ndng trang tri, lam dep nhu cac tuyen dudng Trdn Phu, Bin Nghe, Chu Van An,...[1]
3. HE THONG GIAI PHAP PHUC VU PHAT TRIEN KHONG GIAN XANH THEO HL'^dNG BEN V C K G 6 THANH P H 6 HUE
CXDT gdp phdn cai thien vd bdo ve mdi trucmg, tao nen ban sac rieng ve vdn hda, kien triic my quan cua mgt DT Hue mgt thai la kinh do cua trieu Nguyen. Do vdy, cdn cd nhimg bien pbap nham huang tdi xdy dung thanh phd Hue tid thanh do thi sinh thai theo huang bin vihig.
TRAN TL^YET MAI va c
3.1. Giai phap phat trien cay xanh phac vu cai tao khi hau, bao ve moi trutmg 3.1.1. Han chi vd loai bd cay xanh khong phii hop v&i dgc diim cua thdnh pho Thanh pbd Hui la nai chiu anh hudng thien tai nen cdn ban che nhirng logi cdy khdng dn dinh nhu, cay xa cir (Khaya senegdlensis Tuss): than cao, tan Ion, gid gdc, de do ngd tiong miia mua bao hay cd he thdng te an ngang lam hu hgi cac be mdt cdng trinh, ducmg phd; Keo la tram {Acacia auriculiformis): cd tan la ram \a nhanh Id de bi tach khdi than trong miia mua bao
3.1.2. Lira chgn cay xanh co khd nang cdi tgo vi khi hgu
Cac ket qua nghien ciiu [4], [5] da chi ra mpt sd loai cdy co chiic ndng c;ai tao vi khi hdu nhu: Cau {Areca catechu L), Van tue (Cycas revoluta Thumb), Thiet mgc lan (Dracaena fragrans (L.) Ker.Gawl), Che tau (Acalypha siamensis Dhv ex Gagn)... dac biet nen
tidng d nhung dia diem cdng cdng nhu cdng vien, tnrdng bpc, benh vien.
3.1.3. Tang d le dien tich ldp pha thuc vdt
Ldp phu thyc vat, trong dd cay xanh cd vai trd quan trpng dilu hda khi hdu vd cdi thifin cdnh quan do tbi. Kinh nghiem d cdc nuoc phat trien, qud trinh cdng nghi$p hda, nhip sdng cdng nghiep dat ra mdt nhu cdu tid lgi vdi thien nhien. Thanh phd phai cd nhung bien phap nhdm tdng cudng ldp phii thyc vat tren cac khu ddt tidng, hanh lang an toan giao thdng, cac vung each ly cdng tiinh xir li rac, d cac khu cdng nghiep... Cdn bao dam ty le cay xanh theo TCVN. Miic bao dam tdi thieu ddi vai ddt cay xanh sii dung cdng cOng tiong dan vi d la 5.000m^, ngoai dan vi d la 6-7m^/ngudi, ty le ddt cay xanh danh cbo nhd d, nha cong cdng, nha may tir 20-30% [3], [8].
3.2. Giai phdp nang cao tinh my quan
3.2.1. Lua chgn cay trong theo cdc dgc tinh cua lodi phu hop vdi kien trdc cdnh quan a Hui
* Cdc logi cdy trdng thich hgp v&i li dudng dgc ven sdng
Ddi vdi ll dudng cdch xa bd sdng: Tang cudng va bd sung cac iogi cay phat tiiln tot d do dm cao, be thdng rl vung chac va cd dang dep, nhu: Ddu rdi {Dipterocarpus alatus Roxb), Lim set (Peltophorum pterocarpum Back ex Heyne), Long ndo {Cinnamomum Camphora L), Me {Tamarindus Indica L).
Ddi vdi le duang gan Ixr sdng; bo tri trdng cac loai cay cd dang dep, gitJ- ddt khdi sgt Id va chiu dugc myc nude cao, nhu; Bd dl {Ficus religiosa L), Bdng ldng tim (Lagerstroemina indica L), Cua (Ficus Microcarpa L), Dodt (Arenga pinnata Merr). Mung {Barringtonia racemosa Roxb), Si (Ficus benjamina L).
Nhung cay iihd tao dang, hoa dep hay cdy byi cd boa co thi tidng dgc ven song, nhu: Cau kieng vang {Chrysalidocarbus lutescens Wendl), Chudi nggc (Duranta repens L). Ke {Licuala grandis H Wendl), Lilu ru (Salix babylonica), Mdng bo tim (Bauhiniapurpurea L), Mudng hoa mai (Cassia splendida Vogel)... [5]
HE THONG GIAI PHAP PHAT TRIEN BEN VUNG KHONG GIAN X ^NH TP HUE
* Khoi phyc nhiing tuyin dudng gdn vai ten cdy: Nhilu con dudng d Hue gan lien vdi ten cdy da an sdu vdo tiim tbiic cua nguai dan xu Hue nhu: Hang Me (Pbam Ngu Lao), Hang Dodc (Ddng Da), Phugng bay (Le Dudn)... den nay cung da pha tipn nhilu loai.
Vi vgy, can cd kl hoach khdi phyc cac loai cdy don Ioai gdn vdi nhiing ten ducmg da dugc tdn tai trong tiem thiic cua ngucri dan xii Hue, de tao nen nhOng dgc sdc rieng cho timg tuyen pho.
* Vi gam mdu: Hien nay, cay xanh Hue cho boa theo ba gam mau chinb; mau tim (Bdng Idng tim {Lagerstroemina indica L)), man vang (Phugng vdng {Peltophorum tonkinensis A. Chev)), man do (Phugng vi {Delonix regia Raf)). Can da dang hem vl mau sdc tren ca sd tdn trpng nguyen tdc hai bda, phdi tri hgp li, tranh dilm xuylt tiiy tien, khdng trdng pha tap nhieu loai cdy cd boa vdi man sdc khac nhau tien mpt tuyln phd. Can cii vao dia dilm ciia khu vyc, tuyen dudng ma bo tri cdy xanh vdi gam mau tao nen dac trung rieng ciia timg khu vyc. Su da dang vl gam mau cua cac loai hoa vira tao ra mot do tbi da sac mau, vira tranh dugc tinh trgng thanh phd vdng man hoa vdo mpt thdi gian tiong nam, do mdi loai hoa cd mgt mau sdc khdc nhau va cd thdi gian ra hoa khdng tning nhau. Y tudng nay da dugc Trung tam Cdng vien Cay xanh thanh pbo Hui thyc Men d mdt sd tuyen dudng nhu Phan Chu Trinh, Phan Dinh Phung...
* Ve miii hirang: Ddi vdi nhung cdy cd miii huang dam, neu dugc trdng vdi mat dp cao, sg tgo nen mui khd chiu cho ngudi dan, vi du: cay boa Sira {Alsionia scholaris R.Br), Sdng ran (Acaciapluricapitato ste.exBenth).,.\\ vay ddi vdi Hue, nen gidi han cac logi cdy trdng cd miii huong ddm ndy [5].
b. Phdi tri cdy xanh theo cdc kien true
* Md hinh du&ng phd mdt hdng cdy: Cay xanh dugc trdng tien via he cua mgt phia ll dudng (dudng Le Huan, Huynh Thiic Khdng, Phan Dinh Phiing...). Md Mnh nay mang mpt net dep rieng, vi vdy; can bd tri cac chiing logi cdy bdng mat thudng xanh, cd do tdn ldn, phu rdng ve hai pMa bd sdng vd long dudng nhu Sung (Ficus glomerata Roxb), Bd dl {Ficus religiosa L), Cira {Ficus microcarpa L.f)...), xen ldn nhung cay cd dang manh, thon cao nep minh ben ddng sdng nhu cdy Doat (Arengapinnata Merr)). Bd tri cdc cay cdn cd su ddng nhdt vl khoang each, sdp xep cac chiing loai cdn tgo ra net ddc trung rieng cho mdi con dudng.
* Md hinh du&ng phd hai hdng cdy: Vdi cdch nay mdi via he dugc tidng mgt hang cdy.
Ddy Id md hinb kha phd bi&n d phudng Phii Hdi. De tgo tinh my quan va mdi sinh cho cac tuyen dudng nay, cdn bd tri cac logi cay bdng mat cbo hoa dep, cd tan rdng nhu Phugng vdng {Peltophorum tonkinensis A. Chev), Bdng lang tim {Lagerstroerrua regirme Roxb), Nhgc ngya {Swietenia macrophylla K. Hook), Hdng IQ' {Spathodea campanulata) cd kha nang tao tinh ddng nhdt ve chilu cao, chung logi [5].
3.3. Gidi phdp phdt trien cay xanh theo hvdng phuc vu ndng cao tinh on dinh trong hoat dgng trong, bao ve cay xanh
* Ap dgng tiin bg kT thugt vdo viec trong vd bdo vi cdy xanh
TRAN T L ^ T MAI va cs.
Chi tidng nhung cay xanh "gidng" khde mgnh, chac chdn sdng 100%, da cd bp re tdt, dugc tao tan mdt cdch bai ban, phu hop vdi vi tri tidng trong do thi. Chdng hodc bugc ddy chdng cho cdy mdi trdng tiong 2 nam ddu de cdy bam chat re vdo ddt. Hang ndm cdn tiln hanh tao tdn, tia canh it nhdt mdt ldn vao ddu miia bao. Viec tgo tan pbai dgt dugc dp cao quy djnh va tgo cho cay xanh cdn ddi thudng xuyen. Khi cua canh phai son bit mdt, de han chi ca hdi ndm benh xdm hai.
Ddu tu cdng nghe de di ddi nhirng cdy ldn, tranh tinh trang chat bd va tidng lai nhiing cay non, cay phat trien khdng ddng deu, dl phat sinh viec trdng dgm thay the gdy tdn kem, mdt m j quan.
Ung dyng cdng nghe GIS de bdo ve cdy xanh. GIS la cdng cu dac lyc de tich hgp cac thdng tin ve be thdng cay xanh hien cd, cung cap diJ lieu de ddi cMeu, so sanh nhdm dua ra cdc kl hoach phdt triSn CXDT nhanh chdng, kjp thdi.
* Xa hdi hda viic chdm sdc
Phat ddng phong tiao trdng cdy vd tiln hdnh dinh ky hang nam tren cdc dia ban dugc cdc CO quan cd thim quyen phe duyet; giao nhiem vy trong va cham sdc cbo cac doan the, td dan phd dudi su hudng dan ky thugt ciia can bg chuyen mdn.
Khuyin khich ngudi dan tidng cdy tien ddt d tbeo quy hogch chung de tranh tinh trang ngudi ddn ty y trdng cdc loai khdng dam bdo ve mdi trudng, my quan dd thj hogc cac lodi CO khd nang xdm hai ndm tiong danh muc cdm [1].
4. KET LUAN
Thdnh phd Hue ndi bgt vdi tinh chdt "vudn". Tuy nhien, tinh chdt ndy phy thupc nhilu vao boat dgng sdng cua con ngudi. Qua trinh do tbi hda dang diln ra ngay cang mgnh me, khdng gian xanh dd thi se ngay cang bj thu h?p nlu khdng ddu tu, bdo ve. Khdng gian xanh d thdnh phd Hue cMem ti le dang ke vdi mat do tap tnmg cao dgc cdc dudng phd, cdng vien, diem xanh. Tuy vdy, vdn cdn nMeu vdn de ve cdy xanh cdn dilu chinh nhu; sd Ioai cdn it, nMeu logi cay dugc trdng hon giao, phdi tri cdy chua cd sy gdn kit vdi nhau, chua tbeo mpt nguyen tdc phdi tri nap nen chua tgo ra hieu qud cao vl thdm my do thj. Cac vdn de trudc mdt cdn dac biet quan tdm dk phat tiiln bin vthig CXDT d thdnh phd Hue:
Dilu tra cac khu vyc thieu cdy xanh hay cac khodng trdng vl bd tii cdy xanh, ddc biet tiong cdc cdng vien, diem xanh. Trdng them cay xanh, nhdm tao ra sy can bdng bai hda giOa cdc cdng vien va diem xanh tiong dd thi.
Tang cudng dien tich cd cay xanh, do che phii ciia cdy xanh, bao dam ty le cay xanh theo tieu chuan Viet Nam. Cac khdng gian xanh trong dd thi phai gdn kit vdi nhau bdng cdc dudng phd dl tgo nen cac dai xanh, hinh thanh mdt he thong xanh lien tyc, tan dyng mgi dien tich ddi (ven bd, kenh rgch, dai phdn each, dilm xanh...) dl phat tiiln cay
HE THONG GIAI PHAP PHAT TRIEN BEN Xt.'NG KHONG GIAN XANH TP HUE
TAI LIEU THAM KHAO
[I] Trdn Thi Tuyet Mai, Trdn Nggc Bay, Tran Van Cat (2013). Hien trang cdy xanh do thj Hue va cac giai phdp de Hue trd thdnh mpt do thi xanh mdu myc, Tgp chi Nghiin cuu va Phdt triin sd 2 (100).2013, Sd Khoa hoc va Cong ngh? Thira Thien Hui.
[2] UBND Tinh Thira Thien Hui (2004). Nien gidm thing ke. Cue Thdng ke Thua Thien Hui.
[3] Nghj djnh 08/2005 vl quy hoach xay dung (2005). Quy hogch cdy xanh su dung cdng cpng trong cdc do thi - Tiiu chudn thiit ki, TCXDVN 362:2005.
[4] Pham Mmh Thinh, Ton thdt Phap, Mai VSn Phd (2002). Nghien ciiu cay xanh do Uii trong kiln tnic canh quan ciia thdnh phd Hui, Tap san Khoa hgc Kf thugl Ndng Ldm Nghiep, Trudng Dai hoc Nong Lam TP Ho Chi Minh.
[5] Pham Minh Thinh (2000). Nghiin cuu cdy xanh do thi (urban ti-ees) & ihdnh phd Hui, Ludn van Thac si khoa hpc, Trudng Dai hpc Khoa hpc Hui.
[6] Bp Xay dung (2005). Thdng tu sd 20/2005/TT-BXD ngdy 20 thdng 12 ndm 2005 cua Bg Xdy dung, Hudng ddn qudn ly cdy xanh do ihi. Ha Npi.
[7] Cdng ty V-Architecture (2010). Khdng gian xanh - nhd theo miia, kienviel.net >
ArchTV > Kien tnic su.
[8] Tnmg tam Cdng vien Cay xanh thanh ph6 Hui (2012). Bdn tdng hap cay xanh dudng phd, cdng viin, diem xanh. khu dinh cu, cdc ca quan, trudng hpc, Thira Thien Hue.
[9] Uy ban Nhan dan thanh phd Hue (2007). Bdo cdo so kit cdng tdc trdng cdy xanh thdnh phd Hui giai doan 2001 - 2006, Thira Thifin Hue.
Title: SOLUTIONS FOR SUSTAINABLE DEVELOPMENT OF GREEN SPACE IN HUE CITY
Abstract: Survey findings on the state of vegetation cover in Hue city has pointed out the basic characteristics of vegetation cover in the city, and has established the level of trees comparing to trees standard in an eco - city. In order to develop sustainable urban green space in Hue city, it needs to cany out sync solutions, for developing Uees following the purposes: Improving the climate and protect envuonment; Creating landscape of the city; Creating stability for planting and protecting trees.
Keywords: show stams, vegetation cover, green standards, sustainable, development, and solution.
ThS. TRAN THI TUYET MAI
Khoa Dja ly, Trudng Dai hpc Su pham - Dai hpc Hui TRUONG CONG TIEN
NGUYfiN TRONG QUAN DUNG VAN SON DANG THI THANH v 6 THJ HOAI THU
Sinh vien Khoa Dja ly, Truong Dai hpc Su pham - Dai hpc Hui
