基于系统动力学的城市洪涝韧性仿真研究——以南京市为例

Simulation of Urban Flood Resilience Based on A System Dynamic Model:A Case Study in Nanjing

城市是一个开放的、复杂的巨系统,洪涝灾害对该系统中的自然、基础设施、社会经济等要素产生直接或间接影响,理清洪涝灾害与城市系统的交互关系,并评估预测其应对洪涝灾害的韧性能力,有助于韧性城市的规划建设。通过分析洪涝灾害与城市系统要素间的反馈关系,构建了城市洪涝韧性仿真模型,并以南京市为例,设定了现状延续型、经济优先型、规划发展型、韧性发展型4种发展情景,模拟在4种情景下2009~2025年南京市洪涝韧性的动态变化。结果表明:(1)构建的城市洪涝韧性仿真模型能够反映洪涝灾害与城市系统要素间的交互关系,用于预测城市洪涝韧性变化;(2)城市系统中建成区绿化覆盖面积、雨水管网设计标准对城市洪涝韧性影响显著;(3)根据现有城市发展规划,南京市洪涝韧性将不断提升,且优于现状延续发展情景,但与世界典型韧性城市还有一定差距,建议南京市从城市绿化、雨水管网设计标准、经济结构、人口素质等方面提升其洪涝韧性能力。研究结果可为南京市及其它城市韧性城市发展规划制定提供理论与科学依据。

The city is an open and complex giant system.Flood disaster has direct or indirect impact on the natural,infrastructural,social and economic factors in the system.It is important to clarify the interactive relationships among the flood disaster and the urban system elements,and to evaluate and predict urban flood resilience,which contribute to the planning and construction of resilient cities.In this study,the simulation model of urban flood resilience was developed by analyzing the feedback relationships among flood disaster and urban system elements.Nanjing city was taken as an example.Four development scenarios were set to simulate the dynamic changes of flood resilience of Nanjing from 2009 to 2025.The results show that:(1)the urban flood resilience simulation model can reflect the interaction relationships among flood disaster and urban system elements,which can be used to predict urban flood resilience;(2)the greening coverage area of built-up areas and the design standard of rainwater pipe network in the urban system have significant influences on the urban flood resilience;(3)according to the existing urban development plan,the flood resilience in Nanjing will be continuously improved,which will be better than the continuous development scenario.However,there is still a certain gap with the typical resilient cities around world.Further improvements on urban greening,rainwater pipe network design standards,economic structure,and population quality should be taken to boost the flood resilience in Nanjing.The results of this study can provide theoretical and scientific support for the resilient urban development planning of Nanjing city and other cities.