Beaches are natural capital stocks that provide value through localized storm protection, recreational amenities, and ecosystem services at regional and global scales. In response to increased storm risks and sea-level rise, coastal communities invest in shoreline stabilization by rebuilding eroding sections of the coast through periodic re-nourishment. While conceptual models of the coastal-economic system provide a capital-theoretic framework to study beach management, empirical analysis of the drivers of beach nourishment policy is limited. Using data from 21 coastal towns in North Carolina, we examine the geophysical and economic factors that reflect coastal vulnerability and influence the frequency of beach nourishment investments. We find that beach towns with access to periodically replenishable sand deposits from inlets and river channels nourish more frequently. Beaches that rely on offshore sand reserves are nourished less frequently. Our results provide new insights into the heterogeneous risks that local communities face with higher costs, limited sand reserves and the growing nourishment demand driven by climate change and increased vulnerability.

中文翻译：

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疏浚沙滩：海滩营养的经济和地球物理驱动力

海滩是自然资本存量，通过区域和全球范围内的局部风暴保护、娱乐设施和生态系统服务提供价值。为应对风暴风险增加和海平面上升，沿海社区通过定期再营养重建海岸侵蚀部分来投资稳定海岸线。虽然沿海经济系统的概念模型提供了研究海滩管理的资本理论框架，但对海滩营养政策驱动因素的实证分析是有限的。使用来自北卡罗来纳州 21 个沿海城镇的数据，我们研究了反映沿海脆弱性并影响海滩营养投资频率的地球物理和经济因素。我们发现可以从入口和河道获得定期补充的沙子沉积物的海滩城镇更频繁地滋养。依赖近海沙子储备的海滩较少得到滋养。我们的研究结果为当地社区面临的各种风险提供了新的见解，这些风险包括更高的成本、有限的沙子储备以及气候变化和脆弱性增加导致的营养需求不断增长。