Adapting cities to sea level rise： A perspective from Chinese deltas

在最近的年里，在中国三角洲城市和邻近的区域里加强 waterlogging，盐水侵入，沼泽地损失，和生态系统降级产生了紧迫的需要创造被适合到合并海水平上升的两现在和将来的气候的一种城市的形式。然而，改编计划举起是慢的。因为城市的形式的模式以减少或加强它的影响的方法与吝啬的海水平上升(MSLR ) 交往，这是特别地不幸的。当前有二个主要障碍，在逮捕与设计从温暖的全球气候 geomorphologic MSLR 设计和海面升降的 MSLR 设计填写了的 MSLR 的参考计划的改编的实现是重要的，并且使全面风险成为对 MSLR 设计的评价。现在的评论在印射如下使这些城市适应 MSLR 设计的中国三角洲城市，然后一个观点上的 MSLR 设计和他们的风险评价途径显示出最近的进步六个方面。1 ) geomorphologic MSLR 设计被自然构造沉淀设计贡献，由人为的 geomorphologic 的 MSLR 设计变化。前者需要在一个全球框架被更新。后者由陆路被积累从地下的水弄空的沉淀，河床的侵蚀从归因于分水岭的构造的沉积供应衰落引起的水水平秋天建水坝，人工的沙挖掘，由包括陆地开垦设计工程的水水平加薪，深水路规定，并且新鲜的水水库。2 ) 由人为的 geomorphologic 控制 MSLR 设计变化。3 ) IPCC AR5 RCP MSLR 情形被期望在中国三角洲上被预测到本地海面升降的 MSLR 设计。4 )? MSLR 设计需要被匹配到一本本地举起资料。5 ) 与半分析的水动力学，河口隧道网络，系统动力学和改编点数字的地区性的河海的当模特儿的途径是观点。6 ) 计划到 MSLR 设计的改编要求对洪水的风险的一个全面风险评价，新鲜的水供应缺乏，沿海的侵蚀，沼泽地损失，中国三角洲城市和邻近的区域里的港口和水路的 siltation。

In recent years, intensifying waterlogging, salt water intrusion, wetland loss, and ecosystem degradation in Chinese delta cities and adjacent regions have generated the pressing need to create an urban form that is suited to both current and future climates incorporating sea level rise. However, adaptation planning uptake is slow. This is particularly unfortunate because patterns of urban form interact with mean sea level rise （MSLR） in ways that reduce or intensify its impact. There are currently two main barriers that are significant in arresting the implementation of adaptation planning with reference to the MSLR projections composed of geomorphologic MSLR projections and eustatic MSLR projections from global climate warming, and making a comprehensive risk assessment of MSLR projections. The present review shows recent progresses in mapping MSLR projections and their risk assessment approaches on Chinese delta cities, and then a perspective of adapting these cities to MSLR projections as following six aspects. 1） The geomorphologic MSLR projections are contributed by the natural tectonic subsidence projections and the MSLR projections by anthropogenic geomorphologic change. The former needs to be updated in a global framework. The latter is accumulated by land subsidence from underground water depletion, water level fall caused by the erosion of riverbeds from a sediment supply decline attributed to the construction of watershed dams, artificial sand excavation, water level raise by engineering projects including land reclamation, deep waterway regulation, and fresh water reservoirs. 2） Controlling MSLR projections by anthropogenic geomorphologic changes. 3） The IPCC AR5 RCPs MSLRs scenarios are expected to be projected to the local eustatic MSLR projections on the Chinese deltas. 4） The MSLR projections need to be matched to a local elevation datum. 5） Modeling approaches of regional river-sea numerical with semi- analytical hydrodynamics, estuarine channel network, system dynamics and adaptation points are perspective. 6） Adaptation planning to MSLR projections requires a comprehensive risk assessment of the risk of flood, fresh water supply shortage, coastal erosion, wetland loss, siltation of ports and waterway in Chinese delta cities and adjacent regions.