Author(s): Peisheng Huang, Matthew Hipsey, Dylan Pritchard
Linked Author(s): Peisheng Huang
Keywords: Estuary, salt-wedge, residence time, stratification, climate change
Abstract: The impacts of changing hydrologic connectivity in the shallow Peel-Harvey Estuary, caused by an artificial channel and climate change, were assessed using a finite-volume hydrodynamic model. The results indicated that construction of the channel improved ocean flushing and reduced water residence time in the two main lagoons (by up to 54% in the Peel Inlet and 44% in the Harvey Estuary). As a consequence, the channel also introduced more saline water into the estuary, enhanced the extent of stratification during winter conditions when the estuary received significant freshwater inputs, and contributed to increased hyper-salinity in the dry summer months. The additional effect of climate change (from 2008�2058, considering the combined effect of reduced river flow and precipitation, sea level rise, and higher air temperature) was predicted to increase the water retention time only in the wet months by 24. 4 days in the Peel Inlet and 40. 8 days in the Harvey Estuary, whilst reducing the extent of stratification. Both the artificial channel and the climate change act to push the salt-wedge further upstream within the rivers, with implications for water quality and ecology. The results highlight the complication of the combined effects of changes in ocean, catchment and meteorological forcing on the estuarine hydrology, and the findings should be considered when setting monitoring strategies and nutrient load reduction targets
Year: 2017