Study On The Impact Of Urban Green Infrastructure For Thermal Environment Based On Sample Extraction

The importance of urban green infrastructure to solve thermal environment problems grows with each passing day, on one hand urban green infrastructure needs to adapt to climate environment, on the other hand it requires reasonable spatial distribution of urban thermal environmental problems caused by urbanization. Studying the effect of urban green infrastructure on the urban thermal environment has the important meaning: rich quantitative study on the theory of green infrastructure thermal environment influence, has the important meaning in city scale of green infrastructure planning practice. This paper firstly uses the TM satellite remote sensing image and the technology of geographic information system(GIS) and the land surface temperature of Shenzhen City. In consideration of Shenzhen belongs to the subtropical monsoon climate, the study within the urban limits using computational fluid dynamics(CFD) simulation technology, analysis the thermal environment problem of the research area Shenzhen within the scope of urban green infrastructure in the summer the dominant wind direction, under the influence of wind frequency. And analyze the thermal effects of large bodies of water, green spaces etc; finally, propose the space optimization strategy to reduce heat island intensity of large scale space planning in urban scale green infrastructure such as ecological corridor. The main contexts include:(1) numerical simulation of thermal environment based on RS-GIS-CFD;(2) analysis of thermal environmental effect of city green infrastructure;(3) city green infrastructure planning strategy according to the analysis results. Relevant research results are as follows: based on analysis of simulation results and the three aspects of urban green infrastructure effectively cool distance, get the following conclusions: In the same city, the larger urban green infrastructure acts as a good cold island effect throughout the city; and the relatively small size of the surrounding environment in improving their local micro-climate effect is remarkable. In general, the cool distance of parkland with large area and low shape index is further than the parkland with a higher shape index; however, close to the short range boundary of the park, high shape index parkland cooling intensity is better than low shape index parkland. Parkland, water and urban ecological corridor’s cooling effect have some relevance with those geographic locations. The built environment temperature on the upwind is lower than the temperature on the downwind. The closer the park districts to heat island, the greater its influence on urban thermal environment. Large plane domain water has effect on local temperature near the surface region. While on the vertical height, the relieving effect is not significant compared to relative water surface height; and this effect is nonlinear with decreasing distance. City ecological corridor as the air carrier rise to adjust city climate effect in a certain range. Finally, according the analysis results, here the planning Policy 1) for large parkland: adopt a "decentralized and centralized crisscross" pattern of parkland layout. 2) For water bodies: the use of existing urban water system, establish urban ecological water network system. 3) For ecological corridor: ecological corridor should be ventilated and urban wind direction parallel to the wind direction parallel to with the green ribbon is more conducive to ventilation. Ecological Corridor in azimuth determining wind, the prevailing wind from the city should have a certain angle, so we can bypass airflow to both sides have reached a better intake purposes.