Assessing urban flooding vulnerability with an emergy approach

Under the context of climate change adaption research, vulnerability assessment should take into consideration the interaction among natural processes, socio-economic conditions, and the mechanisms of response of the integrated ecological economic system. Pressure from urban development, land use and land cover change along the western coast of Taiwan not only has caused the loss of ecosystem services in pen-urban environments, but has also resulted in an increase in urban flooding vulnerability. This paper develops a framework, which incorporates the interaction among exposure, sensitivity, and adaptive capacity for assessing the vulnerability to flooding. To achieve this aim, this research interprets urban flooding vulnerability based on emergy concepts and develops emergy indices to assess the spatiality of urban flooding vulnerability in Taiwan's western coastal plain via GIS. Based on the results of the emergy evaluation of the three components of vulnerability and five emergy indices for urban flooding vulnerability, the areas with intense urbanization are characterized with high potential impact to flood. However, cities with higher potential impact do not necessarily lead to higher vulnerability for urban flooding because adaptive capacity can also mitigate the vulnerability of cities to extreme climate events. Using the framework developed by this research we show that the emergy concept can effectively provide a common measuring unit for evaluating exposure, sensitivity and adaptive capacity of urban flooding vulnerability. (C) 2015 Elsevier B.V. All rights reserved.