Numerical Simulation Of "Cold Island Effect" Of Concave Green Space In Hot-summer And Cold-winter Zone

The urban population increase leads to the expansion of building area,increased artificial heat source,slow air circulation and other negative effects,which are known as the UHI(Urban Heat Island effect).In order to reduce these adverse impacts on the human settlement environment,low-impact development has become an important technical means of urban construction.Among them,concave green space is more mature and common because of low construction cost and simple application of engineering measures.However,there are relatively few quantitative studies on the impact of the built environment of concave green space on the urban microclimate,and there is also a lack of parameter design standards and optimization strategies.Therefore,based on the typical summer climate conditions in Hefei,this study uses ENVI-met software to explore and analyze the components of the investigation and simulation,simulation and optimization scheme.Firstly,the field measurement of the concave green space was carried out,the atmospheric physical environment data around the sample site was collected,and the measured results were quantitatively analyzed.This paper explores the "cold island effect" of concave-down green space from four aspects: climate conditions,underlying surface materials,plant collocation and other factors,and puts forward the representative influencing factors,for example,soil type,soil moisture content,plant variety and plant coverage rate.Then the numerical simulation software was used to establish the optimization scheme model,and the experimental comparison group was formed by adjusting the influence factor parameters to evaluate and analyze the influence mechanism of the four influence factors on the microclimate effect.This research method is beneficial to compare and optimize the construction scheme of the concave green space from the perspective of practice.At the same time,by comparing the difference between the measured data and the simulated data,this study proposes that the weak variation of the local climate in the software will be multiplied in the real environment.This also shows that the software is more sensitive when calculating different modules,and the simulation results are more targeted and practical.Finally,based on the analysis,the following concave green space to improve the micro climate effect and feasibility of construction as the goal,the concave green space design are summarized in the practice of changing the parameters of the above four factors influence on its UCI(Urban Cold Island effect),and put forward the concave green space play a UCI optimization strategy and measures,for the next concave green space construction for reference.