FIELD STUDY OF EFFECT OF STREET AND ITS TREES ON THERMAL ENVIRONMENT OF SIDEWALKS

Abstract

In 電 his stUdy ， the e 丘 l of the street and its trees on the sidewalk thermal environmen 重 has been exarnined by carrying out the summer and winter measurements in重 he four重 ypes of the u 由 跚 yon ． ［ ［ 1ie 即巳 sultS can be concluded as fo 】 10ws， 1） 丁血estruct ロre of lhピ streel affeds its enviro 皿men 量 sig 皿 ificantly ． Tlle wi 皿 量 er result has shown tha重tlle wider the s重 reet is ， the higher ah tempcrature is duriug the day ． 2 ） 丁11e air tempe瓰 tore山 血 g the 皿 igh重 is mainly affected by the skyview faCtors ． The namwer S eet resultS in a rela1ively highe 田 ir lemper 飢 urc t血a 爪 he wid 巳r stree 且 ． 3 ） Fmm the s" er resu1 い he street trees have a sign 面 cant e臘 on 亀 he sidewalk thermal environmen 重 ． 1［1e ah tempemture d d with the amou 皿 t of 山 e street trees planted ． 4 ） The ah empera 町 c has a closc relation with the sidewalk su 血 tcmpera 璽 ure ． The IDwer s皿 rface tempeta 重 ure ， 竃 hc lower air temperatUre ． K8y ｝ り 0745 」 5r厂ee 'sttuctzare ， Stree'舵 es ） lhe厂脚 陀 η v ' ro π η霊8 鵬 Field stUtly 街 路 形 態 、街 路樹 、熱環 境 、実測 1． Introduction High density land use in many parts of the cities has caused an mcomfo 丘ablc enviro ent tol pedes ans on the street ． High buildings bu丑t along thc strcets prevcnt dhrect sunlight cspccially in wintcr whcn dcsired ． On the other hand ， wider s鵬 cts 鮴 。 sunshine during summer evcn though shading is dcsircd to implovc thc human comfbrt ． addition ， the air temperature hl the urban beoDmes much higher during the day due to increase of a 宜丗 cial surface such as ooncrete or asphalt and a 控i 丘cial heat release ． In order to hnprove 血 e ulban therrnal environment ， a lot of methods have been dcvclopcd． One of thosc is to introduce thc grecn plant to 血 e urban canyon to provide pedestdans with a shading hl summer and cnough sunlight 洫 w 血teL Thc 血emlal enviro ent 血 山e 田 b-m canyon is detem血ed by its physi αhaturc such as height of buildings and width of the street ． Thc shading effヒ ct of the street trees can be expected to mitigate the CanyOn envirOnment in Sumrner to some cxtent ． Thcrefbre ， thc intcndon i【l this study is to exam e 血 e h1 且uence of 廿1e urban canyon structure and the strcet trees on the sidewalks environment ． Although numerous studies have bccn carried out over the years which deal With thc urban canyon environment by using the numerical mcthods1 ・ 2・ 3・ 4 ） ， somc 且eld studics has also bccn ca π ied out to emphas レe on the energy balance in the urban canyon5 ・ 6・ 7・ 8） ． Nakamura6 ） and Ybshida7 ） a 賃empted to explain thc hcat hansfbr mechanism of the urban canyon based on mcasurements in Kyoto ． Miura8 ） exarnined the therrnal environmcnt 血 血c extclior space ． Katayalnag ） tded ． to examine the