Research On The Optimization Method Of Plant Layout Of Waterfront Site Based On Microclimate Effect

Global climate change has gradually become an important challenge for urban development.As a key ecological control factor,park waterfront space plays a significant role in climate optimization and improvement of human settlements.As the core elements of the landscape,plants play a key role in the creation of the park’s waterfront space.Therefore,scientifically discussing the optimization method of plant layout in waterfront sites from the perspective of microclimate can effectively improve the climate environment and improve the human comfort of active people.This study takes waterfront sites in hot summer and cold winter regions as the research object,starting from the horizontal structure of plants,using ENVI-met software to quantify the relationship between boundary enclosure form,tree planting method,tree coverage rate,shrub coverage rate and summer microclimate.The relationship between the four factors was simulated by using the orthogonal experimental design method to analyze the contribution of each factor to the comfort of the site in summer and winter,to obtain a suitable plant layout plan,and to propose a plant layout optimization method for different spaces.The purpose of this paper is to explore the optimization method of plant layout under the influence of these four factors,and to provide more ideas for improving the microclimate of waterfront sites in hot summer and cold winter regions.First,research the theoretical basis,summarize the research progress of waterfront microclimate and plant microclimate at home and abroad,and sort out the development history of microclimate related theories and comfort indicators,and understand the operation process of ENVI-met software.Secondly,conduct field research on the waterfront site of Xuanwu Lake Park in Nanjing,summarize common features and establish an ideal model.After that,three typical sites were selected for meteorological observation at the observation points,and through the analysis of the data at each observation point,the adjustment effect of different plant factors on Microclimate was preliminarily demonstrated.In order to verify the accuracy and applicability of the ENVI-met software,site one was taken as an example to compare the temperature and humidity differences between the measured and simulated measurement points,and the root mean square error RMSE and correlation analysis R~2 were used for verification analysis.After that,based on the ideal model,the ENVI-met software was used to carry out factor quantitative simulation.First,starting from the horizontal structure of plants,discuss the relationship between the boundary enclosure forms under different forms of the site,arbor planting methods,and the arbor coverage rate,shrub coverage rate and summer microclimate at different levels,and quantitatively analyze the relationship between each factor and Relationships between microclimates.Second,use the orthogonal experimental design method to combine the four factors and conduct simulation experiments.Through the calculation and analysis of range and variance,the order of primary and secondary influence and contribution of four factors on comfort in summer and winter are obtained.Third,according to the function and time of use,considering the weight of different times,and adopting the weighted average method,the optimal combination of plant layout under summer,winter and comprehensive seasons is screened out.Fourth,starting from the nature of space use,optimize the program of activity space and rest space,and refine the corresponding optimization method of space plant layout.Finally,the obtained plant layout optimization method was applied to the waterfront site renovation of Xuanwu Lake Park in Nanjing,and the feasibility of the conclusion was judged by comparing the changes in comfort before and after optimization.The results showed that the summer average PET of the optimized site decreased by 1.29°C,and the average winter PET increased by 0.43°C.The comfort in both seasons was improved,which proved that the plant layout optimization method was more feasible.