Measuring Urban Sustainability in Xi'an City through Ecological Security

Driven by unprecedented economic development, China has experienced a rapid urbanization for more than four decades. Such a record speed and scale of China’s urbanization has posed significant challenges to urban sustainability, which are especially critical for ecological fragile cities in Western China. Human well-being is the primary focus for urban sustainability, whereas ecological security reflects the degree of ecosystem integrity and health. The integrity and health of urban ecosystem are key to ensuring urban sustainability, which also provides a key nexus that links urban sustainability and ecological security. Therefore, the relationship between ecological security and urban sustainability can be deeply understood through urban ecosystem evaluation, and the key factors affecting urban sustainability can be found to provide a decision-making basis for promoting sustainable urban development. Xi'an, a central city in Western China, as an example, we have conducted a quantitative evaluation of the impact of ecological security on urban sustainability. An comprehensive assessment system based on “Driving Force-Pressure-State-Response’’ framework is established and the distribution of Ecological Security Index is analyzed by GIS software. In order to understand the degree of ecological security, we use the natural breaks method to classify the evaluation values. The assessment results show that the ecological security status of Xi'an is close to the safe status and the impact on Xi’an city sustainability is mainly high-density population, high-density water consumption, high per capita energy consumption, low vegetation coverage and low-density river corridor. The above research shows that the comprehensive assessment system we have established can help researchers and government agencies identify natural and artificial ecological security factors that threaten urban sustainability