Projected sea-level rise will raise coastal water tables, resulting in groundwater hazards that threaten shallow infrastructure and coastal ecosystem resilience. Here we model a range of sea-level rise scenarios to assess the responses of water tables across the diverse topography and climates of the California coast. With 1 m of sea-level rise, areas flooded from below are predicted to expand ~50–130 m inland, and low-lying coastal communities such as those around San Francisco Bay are most at risk. Coastal topography is a controlling factor; long-term rising water tables will intercept low-elevation drainage features, allowing for groundwater discharge that damps the extent of shoaling in ~70% (68.9–82.2%) of California’s coastal water tables. Ignoring these topography-limited responses increases flooded-area forecasts by ~20% and substantially underestimates saltwater intrusion. All scenarios estimate that areas with shallow coastal water tables will shrink as they are inundated by overland flooding or are topographically limited from rising inland.

预计的海平面上升将提高沿海水位，导致地下水危害，威胁浅层基础设施和沿海生态系统的复原力。在这里，我们对一系列海平面上升情景进行了建模，以评估加利福尼亚沿海不同地形和气候下地下水位的响应。随着海平面上升1 m，预计从下方淹没的区域将向内陆扩展约50–130 m，低洼的沿海社区（如旧金山湾周围的社区）受到的威胁最大。沿海地形是一个控制因素；长期上升的地下水位将拦截低海拔的排水设施，从而使地下水排放减少了加利福尼亚沿海水位的70％（68.9–82.2％）的浅滩化程度。忽略这些地形受限的响应，会使洪水泛滥地区的预测增加约20％，并大大低估了盐水的入侵。所有方案都估计，沿海浅水区将因陆路洪水淹没或地形受内陆上升限制而缩小。