Kataoka Tomoya, Hinata Hirofumi
Coastal Zone Systems Division, Coastal, Marine and Disaster Prevention Department, National Institute for Land and Infrastructure Management, 3-1-1 Nagase, Yokosuka, Kanagawa 239-0826, Japan.
Department of Civil and Environmental Engineering, Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
Mar Pollut Bull. 2015 Feb 15;91(1):73-81. doi: 10.1016/j.marpolbul.2014.12.026. Epub 2015 Jan 7.
We established a method for evaluating beach cleanup effects (BCEs) based on a linear system analysis, and investigated factors determining BCEs. Here we focus on two BCEs: decreasing the total mass of toxic metals that could leach into a beach from marine plastics and preventing the fragmentation of marine plastics on the beach. Both BCEs depend strongly on the average residence time of marine plastics on the beach (τ(r)) and the period of temporal variability of the input flux of marine plastics (T). Cleanups on the beach where τ(r) is longer than T are more effective than those where τ(r) is shorter than T. In addition, both BCEs are the highest near the time when the remnants of plastics reach the local maximum (peak time). Therefore, it is crucial to understand the following three factors for effective cleanups: the average residence time, the plastic input period and the peak time.
我们基于线性系统分析建立了一种评估海滩清理效果（BCEs）的方法，并研究了决定BCEs的因素。在此，我们关注两种BCEs：减少可能从海洋塑料中沥滤到海滩的有毒金属的总质量，以及防止海滩上的海洋塑料破碎。这两种BCEs都强烈依赖于海洋塑料在海滩上的平均停留时间（τ(r)）和海洋塑料输入通量的时间变化周期（T）。在τ(r)长于T的海滩上进行清理比在τ(r)短于T的海滩上更有效。此外，两种BCEs在塑料残余量达到局部最大值的时间附近（峰值时间）最高。因此，对于有效的清理来说，了解以下三个因素至关重要：平均停留时间、塑料输入周期和峰值时间。
