A Study On The Spatial Variation Of Typical Ecological Indicators In Different Cities And Hinterland Of Temperate Zone In China

The city is the artificial environment of population,highly intensive industries which is reformed under human beings conquering the nature.With the rapid development of fast urbanization,city ecological environment problems have become increasingly prominent.Thus,the study of ecological relationship between city ecological environment and the surrounding hinterland becomes an important problem which depends on the nature,conforms to the nature and self-shaping for suitable survival.This paper studied the spatial distribution characteristics of city and hinterland regional ecological index in different climate region,depending on the change rule of China’s temperate climate longitude and selecting the typical cities which are in different dry and humid areas from the eastern part of China to the west(including Linyi City in wet area,Xuchang City in semi-humid area,Baiyin City in semi-arid area,Karamay City in arid area and Turpan City in semi-arid area)as research subjects.This study based on the Landsat 8 remote sensing image data in 2015.And semivariance analysis,gaussian fitting model and principal component analysis(PCA)are used in this study.In order to provide theoretical support for the city ecological construction practice in different climate zones,this paper will analyze the distribution characteristics of different city ecological index and summarize the distribution rule in different climatic region city and hinterland regional ecological indicators.The main conclusions include the following several aspects:(1)Based on Landsat8 remote sensing image,it can be found that the optimal scale of the ecological indexes is 240m × 240m,which explores the scale effect of ecological indexes(greenness,dryness,heat and wet)by using semi-variogram analysis method in Karamay city and lays the foundation for the scale optimization of urban ecological index.(2)In the 10km range from urban center to the edge,regarding the typical prefecture-level cities as objects and using the Gaussian fitting model and radiographic and concentric circles intersect sampling methods to explore the spatial distribution of regional urban ecological indexes,the study found:Firstly,in different cities,the distribution characteristics of green index and wet index show "U-shape" in the humid areas which change to the "inverse U-shape" in the arid areas.In addition,Turpan City depending on oasis shows "M-shape".The green index distribution characteristics in different cities are different.In Linyi City,the Gaussian fitting curve presents an insignificant "U-shape"(A<0,R2=0.45*),in Xuchang City,its fitting curve presents a significant "U-shape"(A<0,R2=0.80***).In Baiyin City,the Gaussian fitting curve shows an insignificant inverse "U-shape"(A>0,R2=0.27*).In Karamay,its fitted curve shows a significant inverse "U-shape"(A>0,R2=0.64**);In Turpan City,its fitting curve shows a significant "M-shape"(A>0,R2=0.6**).The distribution of the wet index in different cities is consistent with the green index.In Linyi City,the Gaussian fitting curve presents an insignificant "U-shaped"(A<0,R2=0.24*).In Xuchang City,the Gaussian fitting curve of WET index shows an insignificant "U-shaped"(A<0,R2=0.28*).In Baiyin City,the fitting curve presents a significant inverse "U-shape".In Karamay City,the fitting curve shows a significant inverse "U-shape "(A>0,R2=0.66**).In Turpan City,the fitting curve presents a"M-shape"(A>0,R2=0.61**).Secondly,in different cities,dryness and green index have opposite characteristics.The distribution characteristic of dryness index presents significant " inverse U shape" in the humid areas,which changes to " U shape" in the arid areas.In addition,Turpan City depending on oasis shows "M-shape".In different cities,dryness and green value have opposite characteristics.In Linyi City and Xuchang City,their Gaussian fitting curve present an insignificant inverse"U shape"(A>0,R2=0.21*);In Baiyin City,its fitting curve shows a significant inverse" U shape"(A>0,R2=0.34*),In Karamay City,its fitting curve shows a significant "U-shape"(A<0,R2=0.67**).In Turpan City,its fitting curve shows "W-shape"(A<0,R2=0.56*).Thirdly,the heat index in different cities is different.In Linyi City,the Gaussian fitting curve shows an insignificant inverse "U-shape"(A>0,R2=0.14*).In Xuchang City,the Gaussian fitting curve presents a significant inverse" U-shape"(A>0,R2=0.77**).· InBaiyin City,the fitting curve shows a significant "U-shape"(A<0,R2=0.84**).In Karamay City,the fitting curve shows a significant "U-shape"(A<0,R2=0.81*).In Turpan City,the fitting curve presents a "W shape"(A<0,R2=0.74**).Finally,the RSEI index distribution characteristic in different cities presents the "U-shape"in the humid areas which changes to the "inverse U-shape" in the arid areas.In addition,Turpan City depending on oasis shows "M-shape".The urban eco-environmental quality in different regions has significant difference.The spatial distributions of ecological index(RSEI)in different cities are different and present a hierarchical distribution.In Linyi City and Xuchang City,the fitting curve of RSEI shows "U" type(A<0).It can be seen that ecological environment effect produced by the farmland around the city is stronger than that in center of the city.In Baiyin City,the fitting curve of RSEI presents an insignificant "U" shape(A<0,R2=0.50**),which shows that ecological environment effect produced by the man-made construction is more stronger than that in urban periphery.In Karamay City,the fitting curve of RSEI index shows a significant "U" shape(A>0,R =0.79).Because of high investment in the ecological environment construction,the ecological environment effect produced by the man-made construction in the center of city is more significant than that in urban periphery.In Turpan City,the RSEI fitting curve shows a significant "M" shape(A>0?R2=0.62**),and the oasis shows obvious ecological effect.(4)According to the relationship between different urban regions and the surrounding areas,if the RSEI index fitting curve in urban regions and surrounding areas shows the"U-shape",these cities dominate with wedge type into the ecological construction.On the contrary,if the RSEI index fitting curve of urban regions and surrounding areas shows"inverse U-shape",these cities’ ecological construction should be dominated with layered protection of ecological construction.