Research On The Relationship Between Park Landscape And Urban Thermal Environment In Wuhan Based On Deep Learning Machine Classification

The change of urban landscape pattern is one of the important manifestations of human activities shaping the urban surface morphology,and urban landscape heterogeneity is an important source of spatial difference in the urban thermal environment pattern.As an important part of the urban landscape ecosystem,the park landscape not only provides leisure and entertainment places for urban residents,but also the vegetation and water bodies in the park can regulate the urban climate and even effect the urban ecosystem service function.Therefore,it is important to explore the influence of urban parks and their internal landscape structures with vegetation and water bodies on urban thermal environment effects,which are important for urban park planning and site selection,landscape structure design and urban ecosystem service value.Based on the Landsat-8 OLI remote sensing image in July 2016,the image-based temperature inversion(IB)algorithm is used to invert the surface temperature of the main urban area of Wuhan.Secondly,the multi-scale segmentation algorithm is used to calculate the high score 2 remote sensing image of the study area.Based on the GoogleNet network model,the park landscape classification model is constructed by means of migration learning method,and the automatic classification and extraction of the park landscape in the study area is realized.Finally,from the three aspects of landscape composition,plaque morphology and spatial layout,the combination of qualitative and quantitative analysis reveals the impact of the park and its internal landscape pattern on its surrounding thermal environment.The main conclusions are as follows:(1)There are obvious spatial differences in the surface temperature distribution pattern in the main urban area of Wuhan.The high temperature areas are mainly concentrated in the vicinity of the urban core areas such as Jiang'an District,Jianghan District and Qingshan District,which are mainly constructed for construction,while the low temperature areas are mainly concentrated.It is distributed in the southeast of Hongshan District and the main urban area with water bodies and green vegetation.At the same time,over the Yangtze River,Hanjiang River and large lakes,a clear "cold island" gathering area has been formed.(2)From the perspective of the internal landscape composition of urban parks,there are significant differences in the thermal environment effects of different types of landscapes.The average surface temperature of the impermeable layers in the park is the highest,reaching 36.19?.While the average temperature of forest,grassland and water bodies relatively low,both below 30?.The average temperature of the water body is the lowest,only 27.57?.This shows that the park vegetation and water bodies can alleviate the heat island effect inside the city to some extent.(3)There is a strong correlation between the average temperature inside the park and the size of the park landscape type.There is a significant negative correlation between the size of forest land,grassland and water body and the average temperature of the park.There is a significant positive correlation between the size of the impervious layer and the average temperature of the park.That is,within a certain threshold range,the larger the area of forest grassland and water body in the park,the smaller the area of the impervious layer,the lower the average temperature of the park,and the higher the average temperature inside the park.It can be seen that the low-temperature accumulation area is easy to form in the forest,grassland and water body inside the park,and the high-temperature accumulation area is easy to form on the surface of the non-permeable layer.(4)Within a certain buffer zone from the outer boundary of the park,the internal landscape of the park can regulate the surrounding thermal environment.By establishing a relationship model between the average temperature in the park buffer zone and the distance between the buffer zone and the park boundary,the closer the outer boundary of the park is,the lower the ambient temperature of the park is.The lower the ambient temperature of the park when the distance increases to a certain threshold.It has also gradually stabilized.There are also significant differences in the range of influence and temperature drop of the park due to the difference in area and internal landscape heterogeneity.Among them,Yuehu Park has the widest range of influence on the surrounding environment and the largest temperature drop,which is 1106.25 m and 4.80?,respectively.And Qingshan Park has the smallest cooling range,with a size of 287.5 m.Wangjiadun Park has the smallest cooling rate of 1.50?.(5)There is a certain correlation between the impact range and cooling range of the park on the surrounding environment and the landscape structure and plaque morphology inside the park.The range of impact and cooling of the park showed a significant positive correlation with the area of forest and grassland in the park and the degree of forest and grassland landscape,but a significant negative correlation with the area of the impervious layer and the degree of landscape agglomeration.That is,the larger the area of forest grassland and water body inside the park,the wider the influence on the cooling of the surrounding environment.At the same time,the more complex the grassland patches in the park,the smaller the area of the impervious layer and the more scattered the patches,the greater the impact of the park on the surrounding environment and the extent of cooling.The existing research based on the relationship between urban park landscape and urban thermal environment is mainly qualitative analysis,and quantitative monitoring and analysis of the relationship between park landscape structure and its surrounding thermal environment from the perspective of landscape ecology is still rare.Make up for this type of gap.The results of this thesis can provide decision-making and reference for urban park planning and site selection,landscape planning and design of the park,and effective mitigation of the heat island effect within the city.