| With the development of economy and society and the aggravation of human activities,the severe situation of environmental pollution and ecosystem degradation in Guangzhou has been brought about,which has greatly threatened the normal metabolism function and coordinated development of urban ecosystem.It is of great significance for monitoring and sustainable development of urban ecological environment to evaluate and measure urban ecosystem health reasonably.Therefore,based on GIS and RS technology,combined with "pressure state response" model(PSR)and analytic hierarchy process(AHP),this study established the urban ecosystem health evaluation index system of Guangzhou.Through the ecological integration method of time,space,quantity and order and the spatial quantitative analysis of geography,this paper quantitatively measures the population interference,land reclamation rate,ecological flexibility and other indicators of Guangzhou in2002-2017,obtains the spatial distribution characteristics and evolution rules of each evaluation index and its comprehensive urban ecosystem health,And explore the urban ecosystem health response strategy under the multi factor coupling mechanism.The main conclusions are as follows:(1)The weight values of each factor were determined by AHP: population disturbance(0.1825),population density(0.0797),land reclamation rate(0.0348),NDVI index(0.1461),landscape diversity index(0.0910),average patch index(0.0370),evenness index(0.0370),ecological elasticity(0.2286),landscape fragmentation(0.052)2),forest land coverage(0.0913),per capita GDP(0.0198).(2)By using range transformation,density analysis,moving window method,comprehensive evaluation model and other calculation methods,the spatial distribution characteristics and evolution rules of health grade of each factor in Guangzhou during 2002-2017 are quantitatively measured.The main conclusions are as follows:(1)The evaluation degree of urban ecosystem health stress in Guangzhou is good,showing the spatial differentiation of the middle > the South > the north;from2002 to 2017,the overall proportion of level 4 and level 5 areas increased by 12.58%,the overall proportion of level 3 areas increased by 3.53%,and the overall proportion of level 1 and level 2 areas decreased by 15.98%,indicating that the pressure intensity of Guangzhou city is increasing.(2)The evaluation level of urban ecosystem health in Guangzhou is poor,and the health status in the northern region is better than that in the central and southern regions.During the 15 years from 2002 to 2017,the overall proportion of level 4 and level 5 areas increased by 14.62%,the overall proportion of level 3 areas decreased by5.03%,and the overall proportion of level 1 and level 2 areas decreased by 9.6%,indicating that the state of Guangzhou city presents a trend of degradation.(3)The evaluation of urban ecosystem health response in Guangzhou is poor as a whole,and the response intensity shows the spatial differentiation of North >middle > other areas;the overall proportion of the level 4 and level 5 areas increased by 2.45%,the overall proportion of the level 3 areas increased by 4.80%,and the overall proportion of the level 1 and level 2 areas decreased by 7.25%,indicating that the response level of Guangzhou city has been weakened year by year.(4)In the past 15 years,50.36% of the areas in which the comprehensive assessment of urban ecosystem health in Guangzhou is at or above the level 3,overall ecosystem health is in a sustainable state;from the perspective of spatial distribution,there are obvious differences in spatial distribution,and the health status of the northern region is generally better than that of the central and southern regions;from the perspective of the trend of health level change,the overall proportion of the level4 and level 5 areas increased by 11.53%,the overall proportion of the level 3 areas decreased by 3.17%,and the overall proportion of the level 1 and level 2 areas decreased by 8.37,which indicates that the comprehensive urban ecosystem health of Guangzhou city has been deteriorating year by year.(3)Based on the difference analysis and District Statistics,the changes of urban ecosystem health in Guangzhou and its districts from 2002 to 2017 were monitored.The main conclusions are as follows(1)In recent 15 years,the proportion of urban ecosystem health changes in Guangzhou was flat > worsening > improving,accounting for 60.57%,30.73% and8.70% respectively,indicating that the overall urban ecosystem health level in Guangzhou was in a maintainable state.(2)In the past 15 years,Conghua District,Huadu District,Baiyun District,Huangpu District,Panyu District and Nansha District have suffered more deterioration in urban ecosystem health;Tianhe District,Haizhu District,Yuexiu District and Liwan District have maintained more balance;Zengcheng District,Baiyun District,Tianhe District and Panyu District have witnessed more improvement;From the internal changes of each area,it is found that there are more areas of deterioration of urban ecosystem health in Nansha District and Huangpu District,which indicates that the deterioration of these two areas is serious in recent years.(4)Based on the monitoring results,this paper puts forward the corresponding strategies for different levels of urban ecosystem health changes,in order to better achieve the sustainable development of urban health for Guangzhou. |
PDF Full Text Request