Study On The Effect Of The Landscape Pattern On The Thermal Environment In Chengdu And Its Urban Communities

With the development of our society and economy,the process of urbanization is accelerating,which has caused great changes in the surface morphology and landscape pattern in the urban.Those changes have had great influence on the surface thermal environment of the region.As the center and hub city of the Southwest,the level of urbanization of Chengdu has been improved in recent years,which has caused the urban thermal environment to be changed.Therefore,based on the first and the second circles area in Chengdu and the typical urban communities,the relationship between the urban landscape pattern and the thermal environment is discussed in this paper from two aspects of macro scale and micro scale.In the middle and long term development plan,it is expected to provide a scientific basis for the rational landscape planning of Chengdu and similar cities in future.1.The effect of the Landscape pattern on thermal environment in Chengdu(1)(1)There mainly exists artificial surface in the first circle area with large area and continuous distribution,which results in the phenomenon of high temperature discrete distribution in the first circle area.And there mainly exists cultivated land in the second circle area with large area and continuous distribution,which results in the phenomenon of the low temperature agglomeration distribution in the second circle area.(2)The temperature characteristic of the land cover types is: artificial surface > woodland(or cultivated land)> wetland.The cooling intensity characteristic is: wetland > woodland(or cultivated land).Therefore,the wetland is more conducive to the relief of the heat island effect.(2)The following conclusion can be drawn from the maximum correlation between the landscape pattern index and the temperature.With better connectivity,larger average patch area and smaller landscape fragmentation in the areas,the surface temperature is higher.The surface temperature is lower as landscape patch density is higher and patches are more crushing.The more complex the patch shape is and the more abundant patch types are,the lower the surface temperature is.And the surface temperature is lower if landscape's degree of dominance is lower.2.The effect of the Landscape pattern on thermal environment in urban communities(1)The following conclusion can be drawn from the relationship between landscape composition and temperature.The larger the area of the hard pavement and the proportion of the occupied area in urban communities is,the higher the temperature of the district is.Therefore,in urban communities planning,the area of hard pavement should be reduced as far as possible.(2)The following conclusion can be drawn from the relationship between landscape shape and temperature and the relationship between configuration and temperature.(1)If the distribution pattern of vegetation in the communities is characterized by strong dominance,good connectivity,high concentration and low fragmentation,it will be beneficial to decrease the temperature in the plot.(2)If the shape of the water body is complex,it is beneficial to the decrease of the temperature of urban communities.(3)If the distribution pattern of the building patch in the communities is characterized by small density,low fragmentation,high patch concentration and regular patch edge,it is conducive to the reduction of communities' temperature.(4)If the degree of dominance in hard pavement is weak,and the edge of the patch is regular,and the shape of hard pavement is complex,and the division degree of the hard pavement is high,and the patches' spatial distribution is concentrated and the connectivity of the patch is weak,it is in favor of reduction of communities' temperature.(5)When the components of vegetation,building and hard pavement in the urban communities are fixed,it is found that if vegetation patches' degree of segmentation is higher,and the vegetation patches' edge is more complex,and the pavement patches' degree of segmentation is higher,and pavement patches' shape is more complex,and the concentration of spatial distribution of building patches is higher,and building patches' density is smaller,and the building patches' shape is more regular,communities' temperature is lower.Therefore,in order to alleviate the urban heat island effect,in the planning of residential area,we can take the following measures.Reduce the area of pavement in the whole landscape.Hard pavement and vegetation should be interlaced and complex in shape.Buildings should have small density,concentrated distribution,and regular edge.