Observation of the Dynamics and Horizontal Dispersion in a Shallow Intermittently Closed and Open Lake and Lagoon (ICOLL)

Water

Adrian McCallum¹  Helen Fairweather¹  Neda Mardani¹  Kabir Suara²  Richard Brown²  Chris Allan³  Roy Sidle⁴ 

[1] Environmental Engineering, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia;Environmental Fluid Mechanics Group, Queensland University of Technology, Brisbane, QLD 4000, Australia;Sunshine Coast Regional Council, Environmental Operations Infrastructure Services, Caloundra, QLD 4551, Australia;Sustainability Research Centre, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia;

关键词: mixing and transport;    estuary;    tide;    inland;    pollution;    liters;   

DOI  :  10.3390/w10060776

来源: DOAJ

【 摘 要 】

Among the 135 or more estuaries on the southeast Australian coastline, 45% are intermittently open. A number of others, which would normally have an intermittently open entrance, are kept permanently open to improve the flushing and water quality that are functions of the horizontal dispersion of the estuarine system. Field studies that investigate the dynamics and horizontal dispersion processes of open and closed states of Intermittenly Closed and Open Lakes and Lagoons (ICOLL) are conducted. Clusters of Lagrangian drifters were used to characterise the surface flow. Horizontal dispersion coefficients (K) under study varied significantly for different tidal phases; the mean ebb tide K (~4.7 ± 3.8 m2 s−1) is an order of magnitude higher than that of the flood tide. During the closed state, K values were up to two orders of magnitude lower than those observed in the open state. These results highlight the contribution of tidal dispersion to transport and mixing processes within an ICOLL. The results showed that tidal pumping effects and tidal-induced horizontal velocity gradients are responsible for the horizontal surface transport and dispersion occurring during the open inlet state. The horizontal surface dispersion processes identified at different inlets and environmental conditions within this site are valuable for managing transport of particles, freshwater mixing, larvae transport, waste, and pest control.

【 授权许可】

Unknown