The Multi-functional Spatio-temporal Evolution Of Land Use In The Pan-Yangtze River Delta And Its Influencing Factors

With the diversity of human needs,the diversification of regional development goals and the appropriateness of land use,land could not only meet human production,but also provided living and ecological function.On the one hand,with the introduction of the Yangtze River Delta integrated development strategy,the demand for land had further increased,and the contradiction between people and land had become acute,so exerting multifunctional land use was helpful for relieving;on the other hand,41 cities in the Pan-Yangtze River Delta region were currently facing low land use efficiency and fierce competition in land functions.Clarifying the synergy/trade-off relationship of multi-functional land use was conducive to maximizing the benefits.In addition,the current multifunctional land use was a hot topic of research in the disciplines of land resource management and human geography.It aimed to sort out its conceptual connotation by integrating human-land relations,land use optimization theory,synergy,etc.,to establish evaluation index systems,and measured functional level,analysis of spatial and temporal evolution,identification of synergy/trade-off relationships,research of influencing factors,suggestion of countermeasures,etc.This study took Pan-Yangtze River Delta urban agglomeration as a case study,using human-land relationship theory,landscape ecology theory,dual economic structure theory,and optimal land use allocation theory as the theoretical basis,promoting urban green development and sustainable and healthy development,following the logical route of "elements measurement-spatial-temporal feature analysis-correlation analysis-influencing factors-optimization countermeasures",comprehensivly using target weighted average method,standard deviation ellipse,vertical and horizontal contrast,bivariate space autocorrelation,geographically weighted regression model,ridge regression and other methods to analyze the spatial-temporal evolution characteristics,internal correlation,and influencing factors of multifunctional land use in the region,and propose countermeasures for it.The main research contents and results of this article were as follows:Firstly,identified and classified multifunctional land use.Based on previous studies and taking into account the characteristics of the region,a evaluation index system use was constructed.The target average weighting method was used to evaluate the level of multifunctional land use in the Pan-Yangtze River Delta region from 2005 to 2015.Analytical methods and spatial econometric models characterized the spatial morphological characteristics,time-series evolution characteristics,and socio-economic gradient differences of search region.The research results showed that the production function was increasing from south to north,and the value was concentrated in the northwest.The trend line of living function had a distribution trend similar to that of production function,and the ecological function did not show strong regional differences.From 2005 to 2015,the overall production and living function of search region had generally risen,ecological function existed the spatial-temporal differences due to the transformation process of ecological pressure,ecological supply and ecological maintenance levels,not so,the regional spatial differentiation of change trends had become apparent;from 2005 to 2015,the production functions of the four types cities had been continuously strengthened.The overall observation showed that the proportional relationship between functions gradually balanceed,but there were still differences between different regions.The production-living-ecological function of developed regions had remained roughly ratio structure of 1: 1.03: 1.20,while the production-living-ecological function ratio in the less developed regions was about 1: 1.25: 1.59.Secondly,using spatial autocorrelation and geographically weighted regression models to study the synergy/trade-off relationship of multifunctional land use in the Pan-Yangtze River Delta,which revealed significant positive correlations that most of the indexes of urban production,living,and ecological function from 2005 to 2015,that was obvious spatial synergy,specifically: the interaction between production and living function was increasing,and the living function of the southern region had a stronger effect on the production function than the northern region.The interaction between production and ecological function had a negative intensification trend,and the area of negative correlation(trade-off relationship)between them had increased.The interaction between living and ecological function was weakened,and the negative effect between living and ecological function was obvious,closely related to the stage of social development,resource endowment,population distribution,etc.,in that good stage of social and economic development in the southeast region,the small gap between urban and rural areas such as basic service facilities and public basic services,so that the relationship was promoted in both directions,while the living function in the northwest region stressed the ecological function to a certain extent.Thirdly,The linear and ridge regression models were used to measure influencing factors of the spatial-temporal evolution of land use function.The research results showed that the ridge regression model could solve the problem of multi-collinearity among indicators,and had a good degree of fit to production function,living function and ecological function.Land reclamation index,industrial structure and urbanization rate would have a significant positive impact on the production function while average elevation and proportion of the built-up area would have a significant negative impact.Geographical location,industrial structure and per capita net income of farmers would have a significant positive impact on living function,and other factors would not have a significant impact.The mean elevation would have a significant positive impact on the ecological function while slope,land reclamation index and the employees proportion of scientific research,technical services and geological exploration industry would have a significant negative impact.Based on the results of the above research,a multifunctional land use promotion strategy in the Pan-Yangtze River Delta region was proposed.