Research On The Characteristics And Relationship Between Surface Landscape Pattern And Thermal Environment Change In New Urban Areas

With the accelerating process of global urbanization,the contradiction between the ecological environment problems caused by the change of landscape pattern and the urban development is increasing,among which the deterioration of regional thermal environment is one of the most serious problems.Urban new area is the hot spot of current urban construction,and also the main area of urban spatial growth and surface landscape change.In-depth study of the temporal and spatial evolution law of urban new area surface landscape pattern and thermal environment,explore the quantitative relationship between the two,and find out the changes of urban new area surface landscape pattern and its thermal environment effect,which can provide reference for urban new area and urban management and planning,and provide reference for urban new area and urban planning To deal with the relationship between urban development and ecological construction provides scientific basis.Taking Xixian New District as an example,based on the historical high-resolution image of Google Earth in 1995,2005 and 2015 and Landsat series remote sensing data,visual interpretation method and Qin Zhihao's single window algorithm are adopted to obtain the surface landscape type and surface temperature data respectively.Through area statistics,dynamic degree analysis,transfer matrix,landscape index,thermal center of gravity transfer model,CA Markov based By means of V-model thermal environment simulation,thermal effect evaluation index,moving window and correlation analysis,the temporal and spatial characteristics of surface landscape and thermal environment in Xixian new area are studied,and the quantitative relationship between surface landscape pattern and thermal environment is studied.The following conclusions are obtained:(1)During 1995-2015,the surface landscape of Xixian New District changed dramatically,among which the period of 2005-2015 was the most dramatic,its comprehensive dynamic degree was 0.47%,0.17%higher than the previous study period.The area of all kinds of construction land continues to grow,with the growth rate of logistics and storage land>commercial service facilities land>industrial land>public management and public service land>Road and transportation facilities land>residential land.There are differences in the changes of surface landscape in the five major areas:Fengdong new town develops most rapidly,and the differences of landscape types in different areas are small and high in complexity;the proportion of land for roads and transportation facilities in airport new town is prominent,and the proportion of residential land is decreasing gradually;the forest land in Jinghe and Qinhan new town is increasing as a whole,and the proportion of industrial land in the two new towns is prominent;the public management and public service in Fengxi new town The proportion of land use is prominent and growing rapidly.With the construction and development of Xixian New District,the landscape of non construction land has been transferred to all kinds of construction land,of which cultivated land is an important source.From the perspective of landscape pattern change:the growth of various construction land makes the original dominant landscape of the region be continuously divided,landscape fragmentation and structural complexity increase,and the distribution of landscape types tends to be balanced.(2)From 1995 to 2015,the regional thermal environment of Xixian New District changed significantly.As a whole,the total area of the higher temperature and high temperature areas increases gradually,which indicates that the regional thermal environment effect is continuously strengthened,and its spatial form is distributed from point to line to cluster in patches and areas,and the expansion is most obvious in the surrounding areas of Fengdong new city and Xianyang International Airport.There are differences in the changes of thermal environment among the five regions,among which the thermal effect of Jinghe and Qinhan new town is slightly alleviated,that of airport and Fengxi new town is slightly enhanced,and that of Fengdong new town is the most significant.In 2015,the area around the water area that was originally in a relatively high temperature and high temperature area was significantly reduced or even turned into a low temperature area,which is also an important reason for the mitigation of the thermal effect of Jinghe and Qinhan new city.In the analysis of the surface temperature profile,it can be clearly seen that the effect of water area low value in 2015 is more obvious than that in the first two periods.In 2015,the center of gravity of the low-temperature thermal landscape changed greatly due to the thermal effect mitigation in the surrounding areas of the water area,which was obviously moved northward;the center of gravity of the low-temperature and normal temperature moved northward as a whole;the center of gravity of the high-temperature,high-temperature and high-temperature thermal landscape was consistent with the center of gravity of the construction land,which was moving southward and westward year by year,reflecting the urbanization It is an important driving factor for the enhancement of regional thermal effect.In the whole research period,the contribution rate of high-temperature thermal center transfer of the five major divisions is in the order of Fengdong new town,airport new town,Qinhan new town,Fengxi new town and Jinghe new town.From 1995 to 2015,the fragmentation degree of thermal landscape in the new area increased,the complexity of structural composition increased,the distribution tended to be balanced,and the degree of agglomeration weakened;however,with the current development trend to 2025,the degree of agglomeration within each thermal patch will increase,the shape and structure tend to be simplified,the dominance and area of higher temperature and high temperature patches will increase significantly,and the thermal effect will be strengthened.(3)The thermal environment effects of different landscape types are obviously different.During 1995-2005,the bare land,sparse forest land and sparse grassland along the Jinghe River and Weihe River were distributed more.In addition,the heavy industrial land adjacent to Weihe River Power Plant and non-ferrous metal factory made the surface temperature of forest land,grassland,water area and unused land higher.With the increase of water ecological management in the new area,the thermal effect in the surrounding areas of the water area is obviously alleviated.By 2015,the average surface temperature of all kinds of non construction land is lower than that of construction land.The complexity and heterogeneity of the surface landscape type increase with the thermal power level,the proportion of all kinds of construction land in the high-temperature area increases gradually,the construction land gradually replaces the non construction land landscape,and the thermal effect is also strengthened.The contribution degree of thermal effect of cultivated land and the weight index of regional thermal unit are the highest,but the weight index of thermal unit is lower.In 2015,the contribution degree of heat effect,the weight of heat unit and the single weight index of regional heat decreased significantly.The contribution degree of thermal effect and the weight index of regional thermal unit of all kinds of construction land increase gradually,showing the rule of residential land>Road and transportation facilities land>industrial land>commercial service facilities land>public management and public service land>Logistics and storage land.In addition to residential land,Public Management land and public service land,the thermal unit weight index shows a decreasing trend,while the other construction land shows an increasing trend,especially the logistics and storage land.(4)Four indexes of area,shape,density and aggregation were selected to analyze the relationship between the landscape pattern index and the surface temperature in 2015.It was found that the correlation between the area index and the surface temperature was the strongest,and the interpretation rate of the surface temperature was the highest.With the increase of surface temperature,the fragmentation degree of all kinds of non construction land increases,the shape becomes more complex,and the dominance and aggregation degree decrease.Except that the complexity of the shape of the land for roads and transportation facilities increases with the increase of the surface temperature,the shape of other construction land types tends to be simplified with the increase of the surface temperature,the degree of fragmentation decreases,and the degree of dominance,connectivity and aggregation increases.The correlation between landscape pattern index and surface temperature is the highest in non construction land,and the lowest in grassland except unused land.In the construction land,the landscape pattern indexes of commercial service facilities land,logistics storage land and industrial land have a strong correlation with the surface temperature as a whole;the aggregation index factors of residential land have a high correlation with the surface temperature;the landscape pattern indexes of public management and public service land have a weak correlation with the surface temperature as a whole.