Linking Climate Change to Urban Water Infrastructure Design and Management: An Integrated Conceptual Modeling Framework for Multi-scale Simulation of Extreme Rainfall Processes

加拿大在城市水基础设施（例如，暴雨排水和洪水管理系统）方面进行了大量投资。每天，加拿大人依靠这些系统来保护生命、财产和自然水环境。这些基础设施降低了城市的脆弱性，但同时也可能使它们更容易受到极端气候的影响，因为它们没有考虑到超过设计标准时可能发生的情况。此外，最近关于加拿大气候变化的评估报告表明，未来时期极端风暴的发生和强度极有可能显著增加。因此，研究开发创新方法来限制和适应气候变化对城市水基础设施的影响是至关重要的，因为涉及大量投资。然而，人们普遍认识到，处理气候变化对城市地区影响的主要困难是“如何准确地估计由全球/区域气候模型预测的城市流域尺度上的水文过程的变化，因为这些模型不包含影响和适应研究所需的有关高时空分辨率的降雨控制过程的充分描述。”这就需要对气候模式模拟进行某种形式的降尺度处理，从粗糙的（20-300公里）空间分辨率降至更精细的空间网格，如果要评估当地水文过程的变化，甚至需要对点数值进行降尺度处理。此外，评估气候变化对城市降雨过程影响所需的时间尺度通常小于一天。因此，本研究的总体目标是建立“综合气候-城市水文过程建模框架”，以准确建立给定地点的大尺度气候预估与极端水文变量之间的联系。该框架的发展将为理解气候变化导致的主要城市水文过程（降雨、温度和径流）的可能变化提供重要工具，从而为城市水系统开发更具成本效益的设计程序和更准确的脆弱性评估方法。因此，预计本研究的结果将增强我们对气候变率及其在城市地区的影响的理解，将为高质量的影响评估研究提供改进的工具和方法，并最终将帮助决策者制定适当的适应战略和强有力的缓解政策，以更有效地管理我们的城市水系统。我们在这一研究领域的开创性研究工作目前被提名为NSERC Donna Strickland自然科学和工程研究的社会影响奖，以表彰为加拿大社会，环境和经济带来特殊利益的杰出研究贡献。

Canada has significant investments in urban water infrastructures (e.g., storm drainage and flood management systems). Every day, Canadians rely on these systems to protect lives, property, and natural water environment. These infrastructures have reduced the vulnerability of the cities, but at the same time could make them more vulnerable to climate extremes, due to the lack of consideration of what might occur when the design criteria are exceeded. Furthermore, recent assessment reports on climate change for Canada have indicated a very strong likelihood of a significant increase in the occurrence and intensity of extreme storms for future periods. Consequently, research on developing innovative approaches for limiting and adapting climate change impacts on urban water infrastructures is highly critical due to substantial investments involved. However, it has been widely recognized that the main difficulty in dealing with climate change impacts for urban areas is "how to estimate accurately the changes in the hydrologic processes at the urban basin scale projected by global/regional climate models because these models do not contain an adequate description of the rainfall governing processes at relevant high temporal and spatial resolutions as required by the impact and adaptation studies." This necessitates some form of downscaling of the climate model simulations from a coarse (20-300 km) spatial resolution down to much finer spatial grids, and even point values if changes in local hydrologic processes are to be assessed. In addition, the required time scales for assessing the climate change impacts on the urban rainfall processes are usually less than one day. Therefore, the overall objective of this study is to develop "an integrated climate-urban hydrologic processes modeling framework" to establish accurately the linkages between coarse-scale climate projections and extreme hydrologic variables at a given location. The development of this framework will provide an essential tool for understanding the possible changes in key urban hydrologic processes (rainfall, temperature, and runoff) due to climate change to develop more cost-effective design procedures and more accurate vulnerability assessment methods for urban water systems. It is therefore expected that results of this research will enhance our understanding of climate variability and their effects in urban regions, will provide improved tools and methods for high-quality impact assessment studies, and ultimately will help policy-makers in developing appropriate adaptive strategies and robust mitigating policies for more effective management of our urban water systems. Our pioneering research work in this research area is currently being nominated for the NSERC Donna Strickland Prize for Societal Impact of Natural Sciences and Engineering Research to recognize the outstanding research contribution that has led to exceptional benefits for Canadian society, environment, and economy.