Evolution Of Human Settlements In Jiangsu Province Since 2000

Worldwide,research on human settlements has become a hot topic since the publish of "The Global Human Settlements Report:World of Urbanization" by UNCHS(United Nations Centre for Human Settlements(habitat))in 1996.China had experienced a rapid urbanization and drastically increased human activities since 2000,which lead to profound impact on the development and change of human settlements.In consequence,the problems related to human settlements become more crucial,and extensive research has been devoted to exploring the evolution of human settlements in recent time.The study on the evolution of human settlements focuses on not only the analysis of the characteristics of human habitats across time,but also the evolution of spatial patterns.The rapid development of remote sensing and geographic information system overcomes the shortage of data source,research scale and research content of human settlements evolution and provides another solution to realize the evolution of natural and human environment and their interaction.Jiangsu Province that have witnessed a rapid rate of urbanization was taken as a case study.This dissertation focus on the spatiotemporal evolution characteristics of human settlements and its driving forces.The main objectives are:(?)to explore the evaluation of multi-scale human settlements quality since 2000 by using human settlements quality assessment index system and comprehensive model;(?)to analyze the evaluation of the spatiotemporal patterns of natural elements in human settlements;(?)to reveal the driving factors and mechanism of the spatiotemporal variations of the natural elements of human settlements.The main contents and conclusions of this dissertation are summarized as follows:(1)Constructing a system and comprehensive model for evaluating the evolution of human settlements since 2000.Firstly,using four-phase data(2000/2005/2010/2015),a quality evaluation index system of human settlements was established for the period 2000-2015 with an interval of five years by integrating natural elements(air quality,land surface temperature,water index and fractional vegetation coverage)and human elements(economic affluence,life happiness,social equity and road accessibility).Then,natural elements index,human elements index and comprehensive index model of human settlements were constructed by using the weights determined by projection pursuit.Finally,the spatiotemporal evolution of human settlements were analyzed at multiple scales(i.e.,grid,administrative division,and ecological zone).In addition,the relationship between population distribution and human settlements quality was assessed.The results showed that,natural environment in Jiangsu Province declined gradually from Jianghuai Plain to the north and south,which may be affected by distance from Huaihe River and Yangtze River.Meanwhile,from 2000 to 2015,the natural environment of human settlements in Jiangsu Province showed a decreasing trend with a faster decline rate.The human environment in the urban cores were obviously superior to other areas,and the higher-level administrative regions were better than the lower ones.Affected by the economic radiation effect of Shanghai,the human environment in South Jiangsu was better than that in North Jiangsu from 2005 to 2015.The human environment has shown a slight decline and then continued to rise since 2000,and the rate of increase was ranked as South Jiangsu>Middle Jiangsu>North Jiangsu.The spatial distribution pattern and time variation law of human settlements quality comprehensive index were consistent with the human elements index.Since 2000,the population of study region was mostly distributed in areas with high and medium human settlements quality.The proportion of population living in the high human settlements quality to the corresponding proportion of land area has first increased followed by a drop.It was indicated that the degree of coordination between population distribution and human settlements quality first declined and then increased,and the contradiction between people and land was relieved after becoming increasingly tense.(2)With the aid of time-series analysis,this section quantitatively uncovered the characteristics of spatiotemporal evolution of natural elements of human settlements in Jiangsu Province since 2000.By combining MODIS and PM2.5 data from 2000 to the current,the temporal change and spatial pattern characteristics(change trend,significance,stability and sustainability,etc.)of natural elements were investigated,including PM2.5,land surface temperature,water index and fractional vegetation coverage in Jiangsu Province since 2000.The results indicated that the annual average values of PM2.5 concentration and daytime land surface temperature(LST)in Jiangsu Province had shown a significant oscillating upward trend since 2000.In contrast to daytime LST,nighttime LST tended to be stable.As for water and vegetation cover,downward tendency with fluctuation were observed.The areas where PM2.5 was significantly rising were concentrated in the northernmost cities of Xuzhou and Lianyungang,while the areas where LST rises significantly during the daytime were mainly located in the central areas of cities and southern Jiangsu.The trend of nighttime LST and water index demonstrated the similar characteristics in the light of tendency,significance and stability of change.However,volatility of LST changes at night was more severe than that of water.The vegetation cover showed a spatial differentiation property that gradually became better from south to north.The area,which owns higher fluctuation in the change of vegetation coverage,was ranked as North Jiangsu>Middle Jiangsu>South Jiangsu.In the future,the changes of PM2.5 concentrations,daytime/nighttime surface temperature,water index and vegetation coverage in Jiangsu Province were all trending towards "unstably and sustainability".It was also proved that the natural habitat in Jiangsu Province would deteriorate slowdown in the future.(3)Based on the geographically weighted regression model(GWR)and geographically and temporally weighted regression model(GTWR),the driving forces and mechanism of the spatiotemporal variations of natural elements of human settlements has been identified.The bivariate correlation analysis method was used to select significant socio-economic and natural factors based on DEM data,statistical yearbook data and meteorological site data since 1999.Furthermore,the density,size,incremental,accumulative and hysteresis effects produced by abovementioned influencing factors were clarified.Finally,with the help of ordinary linear regression model,GWR model and GTWR model,we compared the fitting results,and revealed the spatiotemporal non-stationarity of human and natural factors.The results suggested that all socio-economic factors such as population growth,economic development,urban expansion,industrial structure,energy consumption,housing construction,roads and waste discharge and the natural factors were significant correlated with p<0.01.The difference lied in the positive and negative and the magnitude of the correlation coefficient.At the same time,the impact of all primary indicators on natural elements also had obvious hysteresis effects.In addition to building construction,road construction and energy consumption,the influence of other socio-economic factors on natural elements like PM2.5,land surface temperature and fractional vegetation coverage was ranked as "density effect>size effect>incremental effect".Otherwise,on water index was ranked as "size effect>incremental effect>density effect".The effects of natural factors on night LST,water index and fractional vegetation coverage were particularly significant,and the effects of natural factors(i.e.,vegetation,meteorology and topography)on night LST and water index were highly consistent.The optimal goodness of R2 of the GTWR model was higher than that of the OLR model and the GWR model,but there were differences in the optimal fitness between the three models for different response variables.PM2.5 concentrations and daytime LST showed significant space-time non-stationarity,which is suitable for modeling with GTWR model with time and space non-stationary.Night LST,water index and fractional vegetation coverage had some spatial non-stationarity,but time non-stationary was relatively weak.Therefore,night LST,water index and fractional vegetation coverage were more suitable for modeling and analysis with GWR model.