Low‐lying coastlines are vulnerable to sea‐level rise and storm surge salinization, threatening the sustainability of coastal farmland. Most crops are intolerant of salinity, and minimization of saltwater intrusion is critical to crop preservation. Coastal wetlands provide numerous ecosystem services, including attenuation of storm surges. However, most research studying coastal protection by marshes neglects consideration of subsurface salinization. Here, we use two‐dimensional, variable‐density, coupled surface‐subsurface hydrological models to explore how coastal wetlands affect surface and subsurface salinization due to storm surges. We evaluate how marsh width, surge height, and upland slope impact the magnitude of saltwater intrusion and the effect of marsh migration into farmland on crop yield. Results suggest that along topographically low coastlines subject to storm surges, marsh migration into agricultural fields prolongs the use of fields landward of the marsh while also protecting groundwater quality. Under a storm surge height of 3.0 m above mean sea level or higher and terrestrial slope of 0.1%, marsh migration of 200 and 400 m protects agricultural yield landward of the marsh‐farmland interface compared to scenarios without migration, despite the loss of arable land. Economic calculations show that the maintained yields with 200 m of marsh migration may benefit farmers financially. However, yields are not maintained with migration widths over 400 m or surge height under 3.0 m above mean sea level. Results highlight the environmental and economic benefits of marsh migration and the need for more robust compensation programs for landowners incorporating coastal wetland development as a management strategy.

中文翻译：

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潮汐淹没对沿海农田土地沼泽迁移对洪水，咸水入侵和作物产量的影响

低洼的海岸线易受海平面上升和风暴潮盐碱化的影响，威胁着沿海农田的可持续性。大多数农作物不耐盐碱，因此尽量减少盐水入侵对农作物的保存至关重要。沿海湿地提供多种生态系统服务，包括减弱风暴潮。但是，大多数研究通过沼泽进行海岸保护的研究都忽略了对地下盐碱化的考虑。在这里，我们使用二维，变密度耦合的地表-地下水文模型来研究沿海湿地如何因风暴潮而影响地表和地下盐渍化。我们评估了沼泽宽度，浪涌高度和高地坡度如何影响盐水入侵的幅度以及沼泽向农田的迁移对农作物产量的影响。结果表明，在受到风暴潮影响的低地形海岸线上，沼泽向农田的迁移延长了对沼泽地土地的使用，同时还保护了地下水质量。在高于平均海平面或更高海拔3.0 m的风暴潮高度和0.1％的陆地坡度的情况下，尽管没有耕地，但200 m和400 m的沼泽迁移比没有迁移的情况保护了沼泽-农田交界处的农业单产。经济计算表明，沼泽移动200 m后保持的单产可能会给农民带来经济上的利益。但是，当迁移宽度超过400 m或浪涌高度高于平均海平面以下3.0 m时，将无法保持产量。