The Summer Microclimate Test Report Of Fully Enclosed Street With "Continuous Arch" In Xi’an -Gongyuanmen Street,Shuangrenfu Street And Hanguanglu Street In Xi’an

Rapid economic development results in the increase of urban heat island effect and the decline of urban comfortable outdoor space. At the same time, the constant improvement of social living standard leads to great demand for urban outdoor public space, which produces a huge contradiction with the shrinking healthy outdoor public environment. Urban street space is an important part of the urban outdoor activities. The microclimate test of city streets enables us to deeply understand the streets and provides data support for improving the street environment. The improvement of the microclimate in streets allows people to get good experiences in the streets and increases the space-time utilization of outdoor public environment. Therefore, such a natural way to improve microclimatic factors in the city streets, such as temperature and humidity, radiation and wind, is the inevitable choice for the future of urban development.Based on climatic characteristics of Xi’an, this paper conducts microclimate test and data analysis of Xi’an streets. Firstly, it investigates streets within the second ring of Xi’an and divides space types of tree-lined streets. Secondly, the tree-lined streets in the typical type are selected for field measurements. Thirdly, it conducts data analysis mainly for fully enclosed tree-lined streets with "Continuous Arch". Fourthly, two fully enclosed tree-lined streets with "Continuous Arch"-Gongyuanmen Street and Hanguanglu Street and the fully enclosed tree-lined street with "Single Arch"-Shuangrenfu Street were selected for the analysis of microclimate temperature data under the tree of 1.5 meters. Fifthly, the temperatures of 1.5m are compared under the sophora japonica in Gongyuanmen Street and under the platanus orientalis in Hanguanglu Street.For north-south tree-lined Gongyuanmen Street with "Continuous Arch" in Xi’an, the following conclusions are obtained:In terms of cooling effect in summer, Gongyuanmen Street is better than Shuangrenfu Street; the temperature under the crown on the south side of Gongyuanmen Street is lower that on the tree-lined corridor; there are heating phase, flat phase of high temperature and cooling phase in the morning, noon and evening in Gongyuanmen Street, Shuangrenfu Street, and Hanguanglu Street, but they are different in the time of appearing and duration. The flat phase of high temperature appears in the afternoon in fully enclosed tree-lined Gongyuanmen Street and lasts 1.5h longer than in Shuangrenfu Street, which shows that heat preservation effect is better in Gongyuanmen Street; in the same fully enclosed tree-lined streets with "Continuous Arch", different types of trees have different cooling effects.