Study On The Evolution Of Landscape Pattern And Its Thermal Environmental Effects In Yiling District,Yichang City

Along with the rapid urbanisation process in China,a large number of artificial impermeable surfaces have replaced natural surfaces such as green areas and water bodies,and urban land use patterns have also changed drastically,leading to an increase in urban surface temperature and thermal environmental effects,which directly affect human production and social stability.Based on this,this study uses the Yiling District of Yichang City as the target area for research.Using 3S technology and field surveys,we quantitatively analyse the land use patterns and thermal environmental effects in Yiling District over the past 20 years,reveal the correlation between different land use types and the thermal environment,and propose relevant strategies to mitigate the thermal environmental effects in the study area.The results of the study are of great significance for optimising the land use layout,mitigating the thermal environmental effects and improving the regional ecological environment in Yiling District,Yichang City.The main research results are as follows:(1)The dynamic changes in the landscape pattern of Yiling District of Yichang City over the past 20 years are significant.Between 2002 and 2020,the main land types in Yiling District of Yichang City are all woodlands and the overall ecological environment is good.By 2020,the proportion of forested land in the study area is 76.32%,the proportion of built-up land increased from 2.76% in 2002 to 7.69% in 2020,and the area of cultivated land decreases from 18.32% in2002 to 13.46% in 2020.During the urbanisation process in Yiling District,Yichang City,the area of construction land has increased rapidly and a large amount of forest land has shifted to construction land;construction land and water tends to form an aggregated and stable pattern,while arable land tends to form a dispersed pattern.(2)The change in land use has resulted in a significant thermal environmental effect.In the past 20 years,the average surface temperature in Yiling District has been increasing year by year,and the thermal environment effect is obvious.The high temperature and very high temperature areas are mainly located in Xiaoxita Town,the central city of Yiling District,with an overall northwest-southeast distribution and the centre of gravity shifting to the north.(3)The characteristics of the thermal environment effect vary greatly among different land use types.The surface temperatures of different land use types in Yiling District,Yichang,in descending order,are: construction land > cropland > grassland > forest land > water area >unused land.The temperature of construction land and cropland is often higher than the average surface temperature,while the temperature of forest land and water bodies is often lower than the average surface temperature.The increase in water bodies and woodlands has a significant cooling effect on the study area,while the increase in built-up land has a significant warming effect.(4)Reasonable urban expansion patterns,scientific land use layout and an increase in the area of ecological land types will help to mitigate the effects of the thermal environment.Yiling District can learn from the "satellite" urban expansion model of metropolitan cities,retain as much green space as possible in urban centres,optimise the spatial pattern of urban and rural green space,actively promote the construction of rooftop gardens and three-dimensional greening,increase the proportion of ecological land types,accelerate the construction of urban and rural forests,retain more natural water bodies,and at the same time continuously increase the concentration of woodland and water bodies.and water bodies can not only improve the thermal environmental effect of the area,but also continuously enhance the human living environment.Faced with the dual pressures of global urbanisation and climate warming,this study further deepens the understanding of regional thermal environment research through the study of the evolution of landscape patterns and their thermal environmental effects in Yiling District,Yichang City.The research results can be applied to urban and rural planning and landscape design to mitigate thermal environment hazards in urban and rural areas,promote ecological health and lead healthy development of human living environment.