A Research Of Microclimate Effects Of Plant In Urban Outdoor Spaces Of Xi’an City

Microclimate problem such as urban heat island effect is increasingly prominent,urban public space of garden plant has a positive role to the improvement of the urban microclimate, current research focus on garden plants in ecological design, plant landscaping and plant community in recent years for garden plants, cooling and humidifying dust detention of ecological function has become a research hotspot, but lack in xi ’an city under the climate characteristics of urban garden plant microclimate effect of system research. Xi ’an city in the design of outdoor public space, on the basis of aesthetics and ecology, plant microclimate effect design, will greatly promote outdoor public space of xi ’an city comfort, increase the comfortable place for residents outdoor activities, to extend the time of residents outdoor activities, promote the emotional communication between people, to create a harmonious society has positive significance.The study from the national natural science fund project named “Research on Design Theory and Method of Landscape ArchitectureRespons to Microclimate Suitability in Urban Livable Environment"(NO. 51338007).The research method of this study is mainly through the model by computer simulation technology, to explore the different basic form canopies and deciduous plant way with solar radiation, which type of tree can achieve more light in the winter. Through to the Da’yan pagoda scenic area and green space form different field testing, summed up the summer and winter microclimate comfortableness better space form and made the space form of plants.Through the comparison of common garden plant leaf area index in Xi’an dust detentions guessed the transpiration rate, good tree species. Establish plant microclimate effect evaluation index system, analyzes the relationship between the indicators, plant microclimate effect is proposed to design strategy, plant microclimate effect and the evaluation index was applied to landscape architecture design, provide a reference basis for plant selection.The study has achieve the following conclusions:(1) Based on xi ’an city climate,summer shade effect is good, the winter sun penetrating effect of poor tree species includes Platanus orientalis Linn., Sophora japonica Linn., Ailanthus altissima(Mill.)Swingle. Summer shade effect is poorer but winter can achieve sunshine tree species with good effect includes Ginkgo biloba,Populus tomentosa, Populus X hopeiensis Hu& Cho, Sophora japonica, Metasequoia glyptostroboides.(2)Winter and summer microclimate in xian city outdoor public space is the most comfortable space layout "center open grass forest terrain around" spatial layout pattern.(3) composed of plant space form small summer climate comfort degree good, high space utilization rate of “a savanna(evergreen) + bare earth space”, “central shop + three trees surround close space”; Winter composed of plant space form of small and medium-sized climate comfort and high space utilization rate includes” a hedge(evergreen) + the shop installs the square space”, “central shop + peripheral arbor tree pool(leaves) space”.(4)Microclimate effect design index system can be divided into plant microclimate effect subject index and plants microclimate effect index, as well as plant planting design parameters. Indicators are the most important indicator of leaf area index,transpiration rate, plant community canopy density.Special thanks to the national natural science fund project "Research on Design Theory and Method of Landscape ArchitectureRespons to Microclimate Suitability in Urban Livable Environment"(NO. 51338007).