Internal positive feedback promotes water quality improvement for a recovering hyper-eutrophic lake: A three-dimensional nutrient flux tracking model
Internal positive feedback promotes water quality improvement for a recovering hyper-eutrophic lake: A three-dimensional nutrient flux tracking model
复制标题
内部正反馈促进恢复中的富营养化湖泊水质改善：三维养分通量跟踪模型
DOI：
10.1016/j.scitotenv.2021.145505
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发表时间：
2021-02-12
影响因子：
9.8
通讯作者：
Wang, Hailing
中科院分区：
文献类型：
--
作者：
Ji, Ningning;Zou, Rui;Wang, Hailing
湖泊营养盐的动态是由外部和内部营养盐通量的综合作用决定的。然而，营养盐通量和水质变化的反馈回路仍然是一个悬而未决的问题。基于环境流体动力学（Environmental Fluid Dynamics Code）模型，建立了一种综合的三维通量跟踪方法，定量研究了滇池（中国三大富营养化湖泊之一）外部和内部过程的长期动态变化，并探讨了2012-2018年水质改善的潜在原因。确定了营养盐通量对水质的长期趋势和相对影响。结果表明，入流通量是最大的输入源，2003 - 2012年下降了50%，2012 - 2018年保持稳定。第二大输入源是底栖释放，表现出显着的年际减少。藻类沉降是最大的去除过程，在2012年至2018年期间下降了45%。综合分析表明，在2012年之前，外部负荷减少后，内部通量的正反馈促进了2012-2018年期间的水质改善。考虑到营养盐通量反馈机制的时间尺度较长，减少外部负荷仍是富营养化湖泊修复过程中实现水质长期良性循环的重中之重。(C)2021爱思唯尔有限公司版权所有。
Nutrient dynamics in lakes are determined by the combined effects of external and internal nutrient fluxes. However, the feedback loop of nutrient fluxes and water quality changes is still an open question. An integrated three-dimensional flux tracking approach based on the Environmental Fluid Dynamics Code model was established to quantify the long-term dynamic changes in external and internal processes in Lake Dianchi (one of the three most hyper-eutrophic lakes in China), and to explore the potential causes of water quality improvement during 2012-2018. The long-term trends and relative influences of nutrient fluxes on water quality were identified. The results showed that the inflow flux was the largest input source and declined by 50% between 2003 and 2012, which was followed by a stable trend from 2012 to 2018. The second largest input source was benthic release, which exhibited a significant interannual reduction. Algae sedimentation was the largest removal process, and declined by 45% between 2012 and 2018. An integrated analysis demonstrated that, following an external loading reduction prior to 2012, the positive feedback of internal fluxes promoted water quality improvement during 2012-2018. Considering the long timescale of the nutrient-flux feedback mechanism, reducing external loading is still the top priority for a long-term virtuous cycle of water quality in the process of eutrophic lake restoration. (C) 2021 Elsevier B.V. All rights reserved.