Study On Spatiotemporal Evolution And Environmental Effects Of Landscape Pattern Based On Big Data

The change of the urban landscape pattern in the process of rapid urbanization has led to the irrational distribution of land resources,the deterioration of the thermal environment,the serious pollution of the air environment and the destruction of biodiversity.Thus,it seriously threatened the living environment and physical health of high-density urban population,affecting regional ecological security and sustainable development.Therefore,it is urgent to study the evolution of urban landscape pattern and its environmental effect.In this paper,we select Tianjin area as the research object,and use the methods of remote data,geographic information system and statistical analysis to study the change of landscape elements and the corresponding thermal environment and air environment.Firstly,the remote sensing images of 1992,1999,2006 and 2013 were interpreted,and the maximum likelihood method was used to divide the remote sensing images into urban construction land,green space,water and other land.The landscape index and the horizontal index were calculated by using the landscape index method and the moving window method.The spatial and temporal distribution of landscape elements was analyzed in the area of area/density,shape index,spread index and diversity index.The spatial distribution of the landscape scale,patch density and maximum patch index of the landscape elements were obtained by circular gradient analysis and eight direction gradient analyses.Based on the remote sensing images of 2006 and 2013,the CA-Markov model is used to predict the distribution pattern of landscape pattern in 2020,and the transfer matrix of landscape elements is analyzed.Secondly,the surface temperature of the remote sensing image is retrieved by the radiation transport equation method,and the thermal island landscape grade is divided,and the annual evolution characteristics and seasonal evolution characteristics of the heat island are analyzed.Six temperature profiles were established,and the correlation between temperature profile and landscape type was discussed.The correlation between annual temperature profile lines,seasonal temperature profile line and landscape pattern was obtained.The data of the corresponding point of the statistical temperature hatching and the remote sensing image were tested in SPSS,and the regression equation of LST and NDBI,NDVI and NDWI were obtained.By quantitative analysis of landscape type normalization index,heterogeneity index and other landscape pattern index and the relationship between the surface thermal environments,the quantitative coupling between the two laws.Select the typical park green space,analyze the relevant factors of its cooling effect,and get the cooling range,the temperature range and the parks.Thirdly,the temporal and spatial distributions of major pollutants such as NO₂,SO₂,PM₁₀ and PM_2.5 were retrieved by spatial interpolation and remote sensing inversion based on statistical data and remote sensing images.The qualitative and quantitative analysis of the socio-economic factors influencing the urban construction land is carried out,and the driving mechanism of the landscape pattern evolution is obtained by principal component analysis.Finally,according to the above study of the spatial and temporal evolution of urban landscape pattern and its environmental effect proposed to optimize the landscape pattern..