The Research On Construction And Planning Of Multi-scale Ventilation Corridors In Zhengzhou

Urban wind environment,as an important field in urban climate research,is closely related to a series of environmental problems such as high temperature waves and air pollution in cities.In recent years,some large cities at home and abroad have carried out field research and planning applications on ventilation corridors in order to solve the problem of urban ventilation.This article taked Zhengzhou as an example,based on meteorological data,satellite remote sensing data and basic geographic information data,to perform numerical simulation and research on the wind environment at the two scales of the city and urban areas.By using meteorology combined with GIS technology and RS technology,this paper discussed the construction and planning methods of multi-scale urban ventilation corridors,and provided a reference for the planning and construction.of Zhengzhou.The study of the city-scale ventilation corridors used the WRF/UCM model to simulate and analyze the local circulation of the city,and then combined with the prevailing wind directions in the region to build city ventilation corridors.Urban-scale ventilation corridors studies used Digital Surface Model combined with building distribution data to calculate some parameters such as ground roughness,and then comprehensively constructed urban-scale ventilation corridors based on the LCP model.Finally,the urban design method was used to propose a control strategy for ventilation corridor planning.The article realized interdisciplinary communication and integration by applying the knowledge of disciplines such as meteorology and geographic information system to the actual construction of human settlement environment The main results are as follows:(1)Based on conventional station meteorological observation data and Landsat8 remote sensing data,this paper drew various thematic maps such as wind rose maps and urban heat islands,and specifically analyzed the characteristics of wind and heat environment in Zhengzhou.The results showed that:?From 1971 to 2019,the annual average temperature of Zhengzhou fluctuated from 13.5? to 16.8?,and it was generally characterized by "slow increase rate and large fluctuations";The average annual wind speed in the city decreased by about 44%in the period of forty-nine years,and the decline was more obvious.The urban wind environment was affected by the urban construction situation,resulting in different prevailing wind directions in the four seasons.?The spatial distribution of the surface temperature in the urban center was significantly different.The high-temperature area was mainly concentrated in the old urban area(Erqi District,Guancheng District and the west of Jinshui District),and the strong heat island area and medium heat island area were distributed in a flaky shape.The non-thermal island area and the cold island area were mainly distributed in the new urban area(the east of Jinshui District)and Huiji District with low population density.(2)The construction of the ventilation corridor was mainly based on the fine simulation of urban natural wind and the study of the underlying ventilation potential,which was carried out on scales.The study of city-scale ventilation corridors was based on the WRF/UCM model,which simulated the characteristics of the local wind environment in Zhengzhou during a specific period of time,and analyzed that cities were mainly affected by monsoon and valley winds.By combining the simulation results with the prevailing wind direction characteristics of the city,this article comprehensively constructed city-scale ventilation corridors:four primary ventilation corridors and four secondary ventilation corridors.(3)Based on the morphological model of building density and building height,the study of urban-scale ventilation corridors analyzed the distribution characteristics of urban surface roughness that was highest in the southwest,followed by the north,and the lowest in the northeast.The potential ventilation corridors based on the LCP model tended to areas with low roughness,such as rivers,farmland,green space squares,and roads.The next step was to combine the result with various other influencing factors to construct urban-scale ventilation corridors:five primary ventilation corridors and three secondary ventilation corridors.The feasibility of constructing urban-scale ventilation corridors was verified by field experiments.