Spatial And Temporal Characteristics Of Urban Vulnerability In Gansu Province

China is in an important stage of urbanization acceleration and transformation.Cities are facing more and more risks,showing great vulnerability.Urban vulnerability theory is urgently needed to guide urban management and development in order to reduce urban risks and achieve sustainable urban development.Gansu Province,as the golden section of the Silk Road,plays an important role in regional development.Although the urbanization rate of Gansu Province has increased rapidly in recent years,the quality of urbanization is low and the vulnerability is relatively high.Therefore,to study the comprehensive vulnerability of cities in Gansu Province,we can formulate targeted countermeasures to reduce urban vulnerability.According to the concept of urban vulnerability and the actual situation of cities in Gansu Province,this paper constructs an evaluation index system of comprehensive vulnerability of cities,analyses the spatial and temporal characteristics of comprehensive vulnerability as well as the vulnerability of resources,ecological environment,economic and social subsystems of cities in Gansu Province.The conclusions are as follows:(1)The comprehensive vulnerability of cities in Gansu Province has been decreasing.The average annual decline rate was 15.05%.The vulnerability status has developed along the direction of crisis-alert-general-good-excellent.Each subsystem also showed a downward trend,in which the decline rate of ecological environmental subsystem was the highest,and the decline rate of social subsystem was the lowest.In 2007,the urban vulnerability of Gansu Province was the socio-economic dominant vulnerability,and it had been transformed into the social dominant vulnerability in 2016.(2)From 2007 to 2016,the comprehensive vulnerability status of Lanzhou City,Tianshui City,Pingliang City,Qingyang City,Longnan City and Gannan State all have developed along the direction of crisis-alert-general-good.The comprehensive vulnerability status of Jinchang City,Baiyin City,Zhangye City,Jiuquan City,Dingxi City and Linxia Prefecture all have developed along the direction of alert-general-good.The comprehensive vulnerability state of Jiayuguan City has evolved along the direction of alert-general-alert-general-good.Wuwei City's comprehensive vulnerability state has developed along the direction of alertgeneral-good-excellent.(3)From 2007 to 2016,the urban vulnerability types of Baiyin City,Tianshui City,Wuwei City and Jiuquan City all have transformed from economic-led to social-led.The urban vulnerability types of Qingyang City and Linxia Prefecture have been the social-led.The urban vulnerability types of Lanzhou City has changed from economic-led to eco-environment-led.The urban vulnerability types of Jiayuguan has changed from social and economic-led to economic-led.The urban vulnerability types of Jinchang has changed from social,eco-environment and economic-led to social-led.Pingliang City changed from economic-led to social and economic-led.The urban vulnerability types of Dingxi City has changed from economic-led to eco-environment-led.The urban vulnerability types of Longnan has changed from social-led to resource and eco-environment-led.The urban vulnerability types of Gannan has changed from social-led to economic-led.(4)In terms of space,from 2007 to 2016 the average comprehensive vulnerability index of Longnan City was the highest and the index of Jiuquan City was the lowest.Longnan City has the highest vulnerability index of resource subsystem and Jiuquan City has the lowest one.Longnan City has the highest vulnerability index of eco-environmental subsystem and Jinchang City has the lowest one.Jiayuguan City has the highest vulnerability index of economic subsystem and Tianshui City has the lowest one.Longnan City has the highest vulnerability index of social subsystem and Tianshui City has the lowest one.Finally,based on the study of temporal and spatial characteristics of urban vulnerability in Gansu Province,according to the dominant vulnerability types of cities in 2016,targeted countermeasures and suggestions are given to reduce urban vulnerability.