This paper analyzes high-resolution lidar data to estimate sediment export to the Pennsylvania Lake Erie littoral zone from lakefront bluff retreat under relatively unique lake-level conditions: approximately a decade of average lake level transitioning into a mild transgression. Analysis identifies bluff-failure patterns important to coastal hazard planning, possible feeder-bluff conservation areas to preserve sediment supply, and data pertinent to sand management in the western Erie County littoral cell (WECLC) and at Presque Isle State Park in the next-downdrift cell.

Based on 2007–2015 bluff-face mapping, there were net losses of 318,250 m³ of total-sediment and 105,700 m³ of sand+ (sand-boulders) to the littoral zone. On an average annual basis, bluffs thus exported 39,800 m³ of total-sediment and 13,300 m³ of sand+ to the WECLC. Exports of sand+ by six HUC-12 watersheds ranged from ~0 to 4600 m³/yr, with ~ 30% supplied by Crooked Creek watershed bluffs that occupy only 18% of the coast. Sand+ export volumes reported here were ~65% lower than prior research covering different lake-level phases. Understanding sediment export during periods of average lake level is important because such lake-level phases occur in the record and will likely recur. Incorporating a decade-scale low sediment-supply scenario for sand management in the Presque Isle littoral cell would permit fine-tuning of estimates of sand nourishment needed to mitigate ongoing beach erosion. Uncertainty in bluff-face change can be minimized by expanding data-comparison windows; future tracking of sediment export from Pennsylvania bluffs may not need lidar surveys any more frequently than once every 10–15 years.

本文分析了高分辨率激光雷达数据，以估计在相对独特的湖面条件下从湖滨断崖撤退到宾夕法尼亚伊利湖沿岸带的沉积物输出：大约十年的平均湖面转变为轻度海侵。分析确定了对沿海灾害规划很重要的断崖模式、可能的馈线断崖保护区以保护沉积物供应，以及与伊利县西部沿海地区 (WECLC) 和下一个下流的普雷斯克岛州立公园的沙子管理相关的数据细胞。

根据 2007-2015 年断崖面测绘，总沉积物净损失 318,250 m ³和沙子+（沙砾）净损失105,700 m ³到沿岸带。因此，布拉夫斯每年平均向 WECLC出口 39,800 m ³的总沉积物和 13,300 m ³的沙子+。六个 HUC-12 流域的沙子出口范围从 ~0 到 4600 m ³/yr，其中约 30% 由仅占海岸 18% 的 Crooked Creek 流域断崖提供。此处报告的沙子+出口量比先前涵盖不同湖泊水位阶段的研究低约 65%。了解平均湖水位期间的沉积物输出很重要，因为此类湖水位阶段出现在记录中并且可能会再次发生。在 Presque Isle 沿岸单元中纳入一个十年规模的低沉积物供应情况进行沙子管理，将允许对减轻持续海滩侵蚀所需的沙子营养估计进行微调。可以通过扩大数据比较窗口来最小化虚张声势变化的不确定性；未来跟踪宾夕法尼亚悬崖出口的沉积物可能不需要比每 10 到 15 年更频繁地进行激光雷达调查。