Effects Of Land Use Change On PM_2.5Concentration And Its Spatial Effects

With the rapid urbanization process in China,land use/cover and landscape pattern change dramatically.At the same time,various pollution emissions and environmental pollution problems have increasingly become the focus of research fields such as land science,resources and environment science.Among them,PM2 5 which is the main component of haze air pollution caused by LUCC,has become an important limiting factor to hinder the sustainable development of social economy and ecological environment in China.Based on ARCGIS.Geoda,SPSS,Fragstats,R language and other tools,this paper takes the core area of Yangtze River Delta,which has a high level of social economy and urbanization,but has a serious haze pollution,as the research area,and synthesizes the theories and methods of spatial analysis,landscape pattern analysis,correlation analysis,generalized additive model and spatial econometric model.Based on the recognition of spatial and temporal pattern change of land use and PM2 5 in the study area,analyze the correlation and non-linear response between land use structure and PM2.5,and explore the spatial effect of land use on PM2.5.The results are of great significance for further understanding the internal mechanism of the impact of land use change on PM2.5 concentration,guiding the joint prevention and control of regional air pollution,scientifically formulating regional land spatial planning,rationally allocating land resources,and realizing the sustainable development of regional economy and environment.The results show that:(1)The cultivated land,forest land and construction land are the dominant landscape in the study area.During the study period,the land use/cover change mainly manifested in the sharp expansion of construction land and the sharp decrease of cultivated land area.The fragmentation of the whole landscape area increased and landscape connectivity in the study decreased,the fragmentation of cultivated land and water increased,while the construction land decreased,which is related to the continuous development of cities in the study area.(2)The annual concentration of PM2 5 in 2000-2015 shows an overall upward trend;and decreases from northwest to southeast in the region,the pollution of PM2.5 in Jiangsu Province is more serious than that in the coastal cities of Eastern Zhejiang Province.(3)PM2.5 is significant negatively correlated with patch density and land shape index.Increasing the area of cultivated land,water area and construction land will lead to the aggravation of PM2.5 pollution,while forestland and grassland will inhibit the pollution of PM2.5.(4)There is a complex non-linear response between PM2.5 and the area of different land types.And There is an "environmental Kuznets curve" in construction land.Which means with the increase of construction land,the increasing trend of PM2.5 will slow down even decrease.(5)The spatial spillover effect of land use type change on PM2.5 is significant,and the indirect effect is more significant than the direct effect.Therefore,in the land space planning,we should reasonably control the city scale,change the extensive development mode;strictly protect the ecological space,increase the coverage scale of forestland,grassland and other vegetation,enrich the vegetation types;and attach great importance to the problem of cultivated land pollution.At the same time,we should attach importance to the management policy of PM2.5 regional joint defense and control,and break down the barrier of regional "administrative jurisdiction" appropriately.