School of Engineering and Built Environment, Griffith University, Gold Coast Campus, QLD, 4215, Australia.
School of Engineering and Built Environment, Griffith University, Gold Coast Campus, QLD, 4215, Australia.
J Environ Manage. 2020 Sep 1;269:110796. doi: 10.1016/j.jenvman.2020.110796. Epub 2020 May 25.
The Logan-Albert estuary in southeast Queensland, Australia, has high biodiversity and supports multiple economic and recreational services. Elevated nutrient and sediment loads have been a longstanding management issue for the estuary. We investigated the spatial and seasonal patterns of nutrients and turbidity along the Logan-Albert estuary and assessed the effects of a recently constructed upstream dam. Nutrient concentrations and turbidity levels were analysed using 15 years of monitoring data from 19 water quality sites throughout the estuary. We hypothesised that the construction of Wyaralong Dam would act as a nutrient and sediment sink which may have positive effects on downstream water quality. Long-term trends of water quality constituents were evaluated using a non-parametric seasonal Mann-Kendall test and the effect of upstream impoundment was assessed with a Before-After Control-Impact (BACI) test. Nutrient concentrations and turbidity levels declined significantly with time in the upper Logan estuary and, to a lesser extent, in the lower Albert estuary. The general improvement of water quality in the upper Logan estuary was attributed to construction of the Wyaralong Dam. Significant decreases in concentrations of total phosphorus (TP) and oxidised nitrogen (NO-N) along the lower Albert were principally attributed to wetter conditions over the 15-year dataset, which diluted point-source loads from a nearby wastewater treatment plant (WWTP). Our results show that estuarine water quality changes can be highly dynamic with interactions amongst climate and management practices that necessitate long-term monitoring programs with good spatial coverage.
澳大利亚昆士兰州东南部的洛根-艾伯特河口生物多样性丰富，支持多种经济和娱乐服务。高营养和泥沙负荷一直是该河口的长期管理问题。我们调查了洛根-艾伯特河口的营养物质和浊度的空间和季节性模式，并评估了最近建造的上游水坝的影响。使用 15 年来在河口 19 个水质监测点的监测数据，分析了营养物浓度和浊度水平。我们假设 Wyaralong 水坝的建造将成为营养物和泥沙的汇，这可能对下游水质产生积极影响。使用非参数季节性 Mann-Kendall 检验评估水质成分的长期趋势，并使用 Before-After Control-Impact (BACI) 检验评估上游蓄水的影响。营养物浓度和浊度随时间在上游洛根河口显著下降，在下游艾伯特河口的下降程度较小。由于 Wyaralong 水坝的建设，上游洛根河口的水质总体得到改善。由于近 15 年的数据集湿润条件下，下游艾伯特河的总磷（TP）和氧化氮（NO-N）浓度显著下降，从而稀释了附近污水处理厂（WWTP）的点源负荷。我们的研究结果表明，由于气候和管理实践之间的相互作用，河口水质变化可能具有高度动态性，需要进行长期监测计划，以确保良好的空间覆盖范围。
