Secchi Disc data measured during a high rainfall event in Port Jackson, 20 August 2007

The Sydney Harbour catchment area includes a number of different river systems which drain into the Port Jackson estuary. During high rainfall events the catchment areas behave differently to deliver contaminants into the Port Jackson estuary. Under conditions of high rainfall contaminants are delivered to areas very quickly as freshwater slides over the top of the denser more saline waters of the estuary. Secchi Disc samples were taken along the Port Jackson estuary over four days to determine the behaviour of the freshwater plume as it travels in a layer of freshwater to be flushed or flocculate out at some point in the estuary.

悉尼港集水流域（Sydney Harbour catchment area）包含多条汇入杰克逊港河口（Port Jackson estuary）的不同河流水系。强降雨事件期间，该集水流域的污染物输送行为会呈现出显著差异。在强降雨条件下，淡水会以表层流的形式漂浮于河口密度更高、盐度更大的水体之上，快速将污染物输送至相关区域。本研究沿杰克逊港河口开展了为期四天的赛克盘（Secchi Disc）采样工作，旨在探明淡水羽流（freshwater plume）以淡水层形式运移时的行为特征，及其在河口内特定区域被冲刷或发生絮凝沉降的过程。