از مهندسی به تکامل، یک رویکرد کلی در شناسایی قابلیت انعطاف پذیری طراحی شهری تا سیل From engineering to evolutionary, an overarching approach in identifying the resilience of urban design to flood

1. Introduction ”Floods are acts of God, but flood losses are largely an act of man.” (Gilbert White, 1945) Natural disasters including flooding, earthquakes and extreme weather events have escalated in recent years and increasingly capture attention on a global scale. Resilient urban design has become an essential theme for cities to withstand disasters, yet cities and their infrastructure are becoming vulnerable and more threatened; and flood protection measurements are yet to adapt their approach to the principles of resilience found in the natural world. Conventional structures of flood protection are increasingly questioned among academics, decision makers and communities, and new approaches are urgently needed at local and regional scales. In this sense, Hall et al. (1997) affirmed that explicit assessment of risks has in the past tended to be limited to the appraisal of major decisions to invest in flood defence infrastructure. This paper highlights the potential role of using ecological principles in urban design to mitigate flood consequences. It identifies the minimum acceptable level of functionality from which urban systems can bounce back/forth or forward from a flood disaster to a state of equilibrium. In order to realize this objective, an exploration of the nature of resilience pivotal dimension will be identified. This is going to be envisioned in connection with the characteristics of urban design. The theoretical basis of urban design main commodity will be examined due to realize the essential functionality required during and after flood event. From epistemological perspective, and in the light of the escalating environmental inevitability, solution for the problem within urban design discipline can be realized into two interrelated urban levels: 1-Urban Innovation: responsive change achieved by advancing the technical properties of manmade objects and materials over the ground and the geotechnical aspects of the ground itself to account for a more adaptive performance in times of flooding. 2-Urban Regeneration: which relies on the urban design capacities to invest in inherent resilience and develop a flood-responsive physical urban form. The paper is shedding the light on the second level, identifying the resilient value of urban design in correspondence with the relevant resilience perspective. Although the field of urban design is very well established and clearly addressed, and the resilience line of thinking witnessed a considerable theorizing throughout the last decade, yet, potentials of association between urban design and resilience are awaiting realization. The author is not claiming to address the full nexus between resilience thinking and urban design, rather an initial effort to specify where the urban design as a discipline systemically meets the resilience thinking and on which resilience perspective. Though, the study offers quantifiable approaches in applying selective ecological-built resilience scenarios.