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Hydrodynamic implications of large offshore mussel farms 总被引：2，自引：0，他引：2
Plew D.R. Stevens C.L. Spigel R.H. Hartstein N.D. 《Oceanic Engineering, IEEE Journal of》2005,30(1):95-108
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David R. Plew John R. Zeldis Ude Shankar Alexander H. Elliott 《Estuaries and Coasts》2018,41(6):1643-1659
A tool based on simple dilution models is developed to predict potential nutrient concentrations and flushing times for New Zealand estuaries. Potential nutrient concentrations are the concentrations that would occur in the absence of nutrient uptake or losses through biogeochemical processes, and so represent the pressure on a system due to nutrient loading. The dilution modelling approach gives a single time- and space-averaged concentration as a function of flow and nutrient input, with the capability to include seasonal nutrient and flow differences. This tool is intended to be used to identify estuaries likely to be highly sensitive to current nutrient loads based on their physical attributes, or to quickly compare the effects of different land-use scenarios on estuaries. The dilution modelling approach is applied both to a case study of a single New Zealand estuary, and used in a New Zealand-wide assessment of 415 estuaries. For the NZ-wide assessment, annual nutrient loads to each estuary were obtained from a GIS-based land-use model. Comparison with measured data shows that the predicted potential nitrate concentrations are significantly correlated with, but higher than, measured nitrate values from water quality sampling time series. This is consistent with expectations given that the measured concentrations include the effects of nitrogen uptake and loss. The estuary dilution modelling approach is currently incorporated into the GIS-land use model, and is also available as a web-app for assessing eutrophication susceptibility of New Zealand estuaries. 相似文献
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ABSTRACT National-scale analyses of land cover effects on water quality can aid in directing environmental policy. We compiled a coastal water quality database for New Zealand comprising 320 estuarine and coastal sites with records between 2013 and 2018. Previous literature had shown strong effects of agricultural and urban land cover on the quality of New Zealand’s rivers, so we examined their effects on estuaries, while controlling for marine dilution and freshwater flushing. Sites with greater freshwater influence had higher nutrient and faecal indicator bacteria concentrations, and turbidity, indicating that open coast and estuarine water quality is reduced predominantly via flows from the land. Nitrate, ammonium, total and dissolved reactive phosphorus, and water column chlorophyll-a concentrations were greater in estuaries with higher urban land cover and total phosphorus concentrations were greater with higher agricultural land cover. There was a marginally significant increase in turbidity as agricultural land cover increased. This is the first national-scale compilation and analysis of New Zealand coastal water quality data, and the first national analysis of land cover effects on water quality in New Zealand estuaries. 相似文献
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Development of closures and parameterizations for subgrid scale effects is a significant and longstanding problem in the numerical
simulation of environmental flows. The model described herein uses a rigorous approach for developing double-averaged governing
equations — first a traditional Reynolds averaging to derive the Reynolds averaged Navier-Stokes equation (RANS), then a volume
average to derive a set of double-averaged equations (DANS). An existing finite element flow model is then modified to accommodate
these equations. This process gives rise to several new terms that require closures, as well as a new equation for free surface
elevation. This paper is directed toward model development and uses several existing closure schemes as test cases. 相似文献
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