CSIRO Ocean and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia.
CSIRO Ocean and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia.
Mar Pollut Bull. 2018 Oct;135:954-962. doi: 10.1016/j.marpolbul.2018.08.018. Epub 2018 Aug 17.
Numerical experiments using a 3D model of fine sediment transport in the Great Barrier Reef region indicate deposition of the bulk mass of catchment sediments from river plumes within a few tens of kilometres from river mouths. A very fine fraction of easily resuspended catchment sediment has a capacity to propagate over much greater distances reaching out into the mid-shelf and outer-shelf regions. The model suggests such particles, instrumental to the development of low density flocs in the marine environment, can play a critical role in altering optical properties of water masses over the shelf during wet years. The mid-term (4 year) impact of Great Barrier Reef catchments on the probability of suspended sediment concentration exceeding the ecologically significant trigger value of 2 mg/L is confined to inshore regions adjacent to river mouth locations.
数值实验表明，大堡礁地区细颗粒泥沙输运的三维模型中，大部分流域泥沙在距河口几十公里范围内发生沉积。而流域中很细的一部分易于再悬浮的泥沙颗粒，其传播距离更远，可以到达中陆架和外陆架区域。该模型表明，这些颗粒对于在海洋环境中形成低密度絮体至关重要，它们在湿润年份可能会对陆架区水体的光学性质产生重大影响。在大堡礁流域的中期（4 年）影响下，悬浮泥沙浓度超过 2mg/L 这一具有生态意义的触发值的概率仅限于紧邻河口的近岸区域。
