Shoreline Change Transects 1983-2006

Shorelines are continuously moving in response to winds, waves, tides, sediment supply, changes in relative sea level, and human activities. Shoreline changes are generally not constant through time and frequently switch from negative (erosion) to positive (accretion) and vice versa. Cyclic and non-cyclic processes change the position of the shoreline over a variety of timescales, from the daily and seasonal effects of winds and waves, to changes in sea level over a century to thousands of years. The shoreline "rate of change" statistic thus reflects a cumulative summary of the processes that altered the shoreline for the time period analyzed.

海岸线始终处于动态变迁之中，其位移受风、波浪、潮汐、沉积物补给、相对海平面变化以及人类活动等多重因素共同驱动。海岸线的变化速率通常并非恒定不变，时常会在侵蚀（erosion）与淤积（accretion）两种状态间切换，反之亦然。周期性与非周期性过程会在不同时间尺度上改变海岸线位置，时间跨度涵盖风与波浪的日度、季节尺度影响，乃至百年至千年尺度的海平面变化。由此，海岸线“变化速率”这一统计量，实则为分析时段内所有驱动海岸线变迁的过程的累积性总结。