GIS based measurement and regulatory zoning of urban ecological vulnerability

Abstract

Urban ecological vulnerability is measured on the basis of ecological sensitivity and resilience based on the concept analysis of vulnerability. GIS-based multicriteria decision analysis (GIS-MCDA) methods are used, supported by the spatial analysis tools of GIS, to define different levels of vulnerability for areas of the urban ecology. These areas are further classified into different types of regulatory zones. Taking the city of Hefei in China as the empirical research site, this study uses GIS-MCDA, including the index system, index weights and overlay rules, to measure the degree of its ecological vulnerability on the GIS platform. There are eight indices in the system. Raking and analytical hierarchy process (AHP) methods are used to calculate index weights according to the characteristics of the index system. The integrated overlay rule, including selection of the maximum value, and weighted linear combination (WLC) are applied as the overlay rules. In this way, five types of vulnerability areas have been classified as follows: very low vulnerability, low vulnerability, medium vulnerability, high vulnerability and very high vulnerability. They can be further grouped into three types of regulatory zone of ecological green line, ecological grey line and ecological red line. The study demonstrates that ecological green line areas are the largest (53.61% of the total study area) and can be intensively developed; ecological grey line areas (19.59% of the total area) can serve as the ecological buffer zone, and ecological red line areas (26.80%) cannot be developed and must be protected. The results indicate that ecological green line areas may provide sufficient room for future urban development in Hefei city. Finally, the respective regulatory countermeasures are put forward. This research provides a scientific basis for decision-making around urban ecological protection, construction and sustainable development. It also provides theoretical method references for future research into urban ecological vulnerability, including the introduction of GIS-MCDA methods into the field of urban ecological vulnerability, which expands the application for these techniques.