Land Ecological Security In A Rapidly Urbanizing Area Based On Social-Economical-Spatial Indicator System

As a basic element of ecological environment,land has a very important impact on human survival and the sustainable development of social economy.Scientific evaluation of land ecological security can provide decision-making basis for territorial spatial planning and land resource management.Past research of land ecological security evaluation mainly based on the social and economic statistical index system,often ignore the land spatial pattern change influence on ecological security,and in the areas of rapid urbanization,because of the high strength and human activity disturbance,causing a drastic change of land use pattern in space and in turn affect the land ecological security pattern.In order to more comprehensively evaluate the evolution law of land ecological security,this study took Fengxian District of Shanghai as the study area,and based on the analysis of the status quo of land ecological security,constructed an evaluation index system including social economy and spatial pattern.This paper analyzes the dynamic evolution law of land ecological security in Fengxian District from 1998 to 2019 and the key factors affecting the security in different periods,and finally puts forward some policy suggestions to improve the land ecological security.The main conclusions are as follows:(1)The land use data analysis of Fengxian District shows that the land use of Fengxian District is in the development stage.The continuous decline of the sprawl index and the continuous decline of landscape fragmentation indicates that the human disturbance to the land is increasing,and the land use structure is gradually dispersed,indicating that the spatial fragmentation is serious and the land connectivity decreases significantly.Such land use change may affect the land ecological security and even the sustainable development of the whole land ecosystem to a certain extent.(2)Taking the period from 1998 to 2019 as a time series,the land ecological security in Fengxian District was evaluated during the past 22 years.The results showed that the land ecological security in Fengxian District experienced three stages of change.In the first stage,from 1998 to 2006,the comprehensive index of land ecological security gradually increased from sensitive level to good level.Solid waste discharge per unit area,urbanization level,pesticide usage per unit cultivated area,fertilizer usage per unit cultivated area,and population density were the factors contributing the most to the increase of land ecological security.In the second stage,the comprehensive index of land ecological security changed from good grade to critical grade in 2010.Solid waste discharge per unit area,landscape fragmentation degree,per capita cultivated land area,pesticide usage per unit cultivated land area,and population density were the factors that contributed the most to the decrease of land ecological security.In the third stage,from 2010 to 2019,the comprehensive index of land ecological security recovered from the critical level to the good level,and population density,per capita water resources,urbanization level,economic density and GDP growth rate were the factors that contributed the most to the increase of land ecological security.During the whole study period,the level of land ecological security showed an upward trend on the whole,gradually rising from "sensitive level" to "good level" and continuously developing to the level of safety,indicating that the land ecological security situation in Fengxian District was constantly improving.(3)In order to maintain and further improve the level of land ecological security in Fengxian District and realize regional sustainable development,the following suggestions are put forward: Can optimize the industrial structure of the development of low energy and low pollution industry,controlling the population quantity to achieve the harmonious development of the relationship between population and land,construction land control with chemical fertilizer use,improve the environmental protection into GDP ratio and forest land area covered,a reasonable formulation and strictly implement the measures such as land use planning and promote the district land ecological security of continuous improvement.In rapidly urbanized areas,the rapid conversion of land use has a profound impact on ecological security.Based on the evaluation framework of land ecological security,this study introduces the geographical space attribute index of land,namely: Landscape fragmentation,contagion index,the comprehensive evaluation to ecological security of land,in addition,in the determination of index weight,this research will be based on the analytic hierarchy process(ahp)weight of expert scoring results based on objective data analysis and information entropy weight method synthetically,not only overcome the subjectivity of analytic hierarchy process(ahp)rely on the expert scoring the shortage of the dominant,Also overcome the information entropy method to focus on the objective indicators and failed to reflect the subjective perception of insufficient,in combination with the space index and comprehensive index weight analysis,on the basis of this study can better reflect the rapid urbanization areas of land ecological security,for the land ecological security management policy provide scientific decision support.