Resilience Assessment Of Coastal Urban Land-water System And Landscape Pattern Design

Coastal areas have experienced rapid urbanization and reclamation(land development)with increasing of impervious surface area,while experiencing considerable environmental degradation.The irreversible changes of landscape pattern may lead to a system's critical function loss and undesirable resilience transformation.The most significant affects were water quality deterioration and water shortage,which have adverse health impacts.With the purpose of understanding systematic resilience change of Urban Land-Water System,we used a quantitative approach to contextualize critical functionality of a complex system(impervious surface area,water quantity,and water quality)in terms of spatial-temporal resilience transformation across 15 years.The area had critical functionality loss of water quantity and increasing impervious surface area had significant influences on the nested and overlapping resilience change from 2005 to 2015.Especially,the central urban area and coastal zones experienced dramatic functionality loss in absorption phase of transformation,which caused degradation of the resilience of the interconnected systems.Based on the resilience assessment,we designed landscape patterns including key nodes such as Huairen ecological forest,critical sources and "hybrid corridor" such as Tongyu River and Ganyu shipping channel based on "Sink-Source" theory.This work revealed three key findings:(1)the integration of critical functionality loss and changing phases of resilience state provided a practical framework for resilience assessment;(2)hybrid corridors contributed to land-marine nexus and enhanced the connectivity of different ecological patches;(3)urban landscape pattern including critical elements like nodes,corridors and sources in Lianyungang were designed to solve the Urban Land-Water System related problems.Ultimately,adaptive management was conducted by integrating management of key variables and synergic multi-departments.This research provides a new perspective for specific resilience quantification combining with ecological resilience and engineering resilience as well as land-marine nexus,and provides an operational way for ecological planning.