Modes of berm and beachface recovery following storm reset: observations using a continuously scanning lidar

Following the rapid and destructive impacts of storm erosion, beach recovery is a key natural process of restoration, returning eroded sediment to the subaerial beach and rebuilding coastal morphology. While the effects of storm erosion have commonly been investigated, detailed studies into post-storm recovery are currently lacking. This study investigates wave-driven recovery processes of the berm and beachface on a microtidal, swash-aligned sandy beach. Following complete removal of the berm by a significant storm event, the entire 76-day rebuilding of a swash berm is analysed at the timescale of every semi-diurnal tidal cycle, utilising high resolution (5 Hz) swash and subaerial beach profile measurements from a continuously scanning fixed lidar. Tide-by-tide rates of subaerial volume change during berm recovery were most frequently observed between 1 - 2 m3/m/day, including losses and gains on the order of several m3/m/day, substantially larger in magnitude than the more gradual rat...

风暴侵蚀（storm erosion）具有快速且极具破坏性的影响，海滩恢复（beach recovery）作为关键的自然修复过程，能将侵蚀流失的沉积物输送回潮上带海滩（subaerial beach）并重构海岸地貌形态（coastal morphology）。尽管风暴侵蚀的影响已被广泛探究，但针对风暴后恢复（post-storm recovery）过程的详细研究目前仍显不足。本研究聚焦于微潮（microtidal）、冲流平行（swash-aligned）砂质海滩的滩肩（berm）与滩面（beachface），对其由波浪驱动的恢复过程（wave-driven recovery processes）展开探究。在一次强风暴事件彻底清除滩肩后，研究以半日潮周期（semi-diurnal tidal cycle）为时间分辨率，解析了冲流滩肩长达76天的完整重建过程——借助连续扫描固定式激光雷达（continuously scanning fixed lidar）获取的高分辨率（5 Hz）冲流（swash）数据及潮上带海滩剖面（subaerial beach profile）测量数据。滩肩恢复期间，逐潮计算的潮上带体积变化率（tide-by-tide rates of subaerial volume change）多数介于1-2立方米/米/日之间，其中不乏数立方米/米/日量级的增减波动，其量级远大于更为平缓的……