Reducing eutrophication risk of a reservoir by water replacement: a case study of the Qingcaosha reservoir in the Changjiang Estuary
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摘要: 城市淡水系统的富营养化风险是世界范围内普遍关注的问题。多种物理、生物和化学技术手段被应用到富营养化湖库的治理当中,以期抑制水体的富营养化程度和藻类生物量。经证实,在未有效降低营养盐来源的情况下,这些手段的效果有限。而在发展中国家,控制营养盐来源可能需要花费数十年的时间。本研究旨在分析某一高营养盐负荷的沿海水库的富营养化和藻类水华风险,以期确认通过水利调度来抑制水库富营养化状态的可行性。该案例水库为位于长江口的青草沙水库。该水库2009至2012年期间的库内五个点位的水质数据被用于进行案例分析。水质指标包括水温、透明度、溶解氧、总氮、总磷和浮游植物叶绿素a。该水库的建设期为2009年4月至2010年10月,期间水库未曾与长江口发生水体交换。该水库的试运营期为2010年10月至2011年1月,正式运营期为2011年1月至今。在运营期间,库内与长江口的水体交换逐步上升。综合营养状态指数(TLI)被用于评估该水库的营养状态变化情况,该指数是通过数个代表性水质指标计算得到。库区的TLI指数峰值在2009年夏季可达51,在2011年夏季可达55,超过TLI指数的富营养化阈值50。TLI的谷值32出现在2010年的夏季。水质观测期的其他时段的TLI指数均可保持在50以下。以上分析结果表明:水库在2009年和2011年夏季由于过量的营养盐负荷和藻类水华迅速恶化到富营养化状态。水库在2010年和2012年均未出现富营养化状态和藻类水华,这是由于2010年期间水库缺少营养盐输入,2012年期间水库调度充分地置换了库区水体。库区水质指标的时空变化均通过文中的观测资料和数据分析进行展示。经分析表明,通过潮汐涨落来充分置换库区水体的水库调度手段是一个极为经济有效的抑制高营养盐水体富营养化和藻类水华的工程手段。Abstract: Eutrophication of freshwater systems in cities is a major concern worldwide. Physical, biological and chemical methods have been used in eutrophic lakes and reservoirs to reduce their eutrophic state and algal biomass, but these approaches are not effective without a substantial reduction in nutrients input, which could take decades to achieve in the developing countries. This study aims to assess the risk of eutrophication and algal bloom in a coastal reservoir with high nutrient inputs to confirm the feasibility of inhibiting the reservoir's eutrophic state by hydrodynamic operations. A variety of water quality indexes (e.g., water temperature, secchi depth, dissolved oxygen, total nitrogen, total phosphorus, phytoplankton chlorophyll a) at five observed sites were investigated in the Qingcaosha reservoir, which located in the Changjiang Estuary, during the construction, trial and normal operation periods from 2009 to 2012. No water exchange happened during the construction from April 2009 to October 2010, and the water exchange increased during the trial from October 2010 to January 2011, and during normal operation period from January 2011. The comprehensive nutrition state index (TLI) calculated by several representative water quality indexes was adopted to evaluate the variation of the trophic state in the reservoir. The peak values of TLI reached 51 in the summer of 2009, and 55 in the summer of 2011, higher than the eutrophication threshold value 50. The lowest TLI, about 32, appeared in the summer of 2010. The values of TLI in other observation periods could keep under 50. The results showed that the reservoir could easily deteriorate into the eutrophic state because of excess nutrients and algal blooms in the summer of 2009 and 2011, while the eutrophication and algal blooms could be reduced by the lack of nutrients in 2010 or adequate water replacement in 2012. The temporal and spatial variations of water quality indexes were presented based on observation data and analysis. The adequate water replacement in the reservoir driven by tides was tested to be an efficient and economical method for controlling eutrophication and algae blooms in the water environment with high nutrient inputs.
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Key words:
- estuarine reservoir /
- eutrophic state /
- algal bloom /
- operation way
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Alongi D M. 2008. Mangrove forests:resilience, protection from tsunamis, and responses to global climate change. Estuarine, Coastal and Shelf Science, 76(1):1-13 Álvarez-Rogel J, del Carmen Tercero M, Isabel Arce M, et al. 2016. Nitrate removal and potential soil N2O emissions in eutrophic salt marshes with and without Phragmites australis. Geoderma, 282:49-58 Burgos L, Lehmann M, de Andrade H H R, et al. 2014. In vivo and in vitro genotoxicity assessment of 2-methylisoborneol, causal agent of earthy-musty taste and odor in water. Ecotoxicology and Environmental Safety, 100:282-286 Carmichael W W. 2001. Health effects of toxin-producing cyanobacteria:"the cyanoHABs". Human and Ecological Risk Assessment:An International Journal, 7(5):1393-1407 Chang P H, Isobe A, Kang K R, et al. 2014. Summer behavior of the Changjiang diluted water to the East/Japan Sea:a modeling study in 2003. Continental Shelf Research, 81(1):7-18 Chen Kaining, Bao Xianming, Shi Longxin, et al. 2006. Ecological restoration engineering in Lake Wuli, Lake Taihu:a large enclosure experiment. Journal of Lake Sciences, 18(2):139-149 Chen Feizhou, Song Xiaolan, Hu Yaohui, et al. 2009. Water quality improvement and phytoplankton response in the drinking water source in Meiliang Bay of Lake Taihu, China. Ecological Engineering, 35(11):1637-1645 Chen Yizhong, Lin Weiqing, Zhu Jianrong, et al. 2016. Numerical simulation of an algal bloom in Dianshan Lake. Chinese Journal of Oceanology and Limnology, 34(1):231-244 Edmondson W T. 1970. Phosphorus, nitrogen, and algae in Lake Washington after diversion of sewage. Science, 169(3946):690-691 Gao Xuelu, Song Jinming.. 2005. Phytoplankton distributions and their relationship with the environment in the Changjiang Estuary, China. Marine Pollution Bulletin, 50(3):327-335 Hu Weiping, Zhai Shujing, Zhu Zecong, et al. 2008. Impacts of the Yangtze River water transfer on the restoration of Lake Taihu. Ecological Engineering, 34(1):30-49 Huisman J, Matthijs H C P, Visser P M. 2005. Harmful Cyanobacteria. Dordrecht, the Netherlands:Springer-Verlag Jin Xiangcan. 1995. Chinese Lake Environment (in Chinese). Beijing:China Ocean Press Jin Xiangcan, Tu Qingying. 1990. The Standard Methods in Lakes Eutrophication Investigation (in Chinese). 2nd ed. Beijing:China Environmental Science Press Kang Yan, Zhang Jian, Xie Huijun, et al. 2017. Enhanced nutrient removal and mechanisms study in benthic fauna added surface-flow constructed wetlands:the role of Tubifex tubifex. Bioresource Technology, 224:157-165 Li Wenchao, Pan Jizheng, Chen Kaining, et al. 2005. Studies and demonstration engineering on ecological restoration technique in the Littoral Zone of Lake Dianchi:the target and feasibility. Journal of Lake Sciences, 17(4):317-321 Li Yiping, Tang Chunyan, Wang Chao, et al. 2013. Improved Yangtze River Diversions:are they helping to solve algal bloom problems in Lake Taihu, China?.. Ecological Engineering, 51:104-116 Ma Zhimei, Xie Ping, Chen Jun, et al. 2013. Microcystis blooms influencing volatile organic compounds concentrations in Lake Taihu. Fresenius Environmental Bulletin, 22(1):95-102 Nürnberg G K. 1996. Trophic state of clear and colored, soft-and hardwater lakes with special consideration of nutrients, anoxia, phytoplankton and fish. Lake and Reservoir Management, 12(4):432-447 Paerl H W, Fulton R S, Moisander P H, et al. 2001. Harmful freshwater algal blooms, with an emphasis on cyanobacteria. The Scientific World Journal, 1:76-113 Paerl H W, Xu Hai, Mccarthy M J, et al. 2011. Controlling harmful cyanobacterial blooms in a hyper-eutrophic lake (Lake Taihu, China):The need for a dual nutrient (N & P) management strategy. Water Research, 45(5):1973-1983 Pu Peimin, Wang Guoxiang, Li Zhengkui, et al. 2001. Degradation of healthy aqua-ecosystem and its remediation:theory, technology and application. Journal of Lake Sciences, 13(3):193-203 Pu Peimin, Yan Jingsong, Dou Hongshen, et al. 1993. An experimental study on the physio-ecological engineering for improving Taihu Lake water quality in water source area of Mashan drinking water plant. Journal of Lake Sciences, 5(2):171-180 Qin Boqiang, Li Wei, Zhu Guangwei, et al. 2015. Cyanobacterial bloom management through integrated monitoring and forecasting in large shallow eutrophic Lake Taihu (China). Journal of Hazardous Materials, 287:356-363 Qiu Cheng, Zhu Jianrong. 2013. Influence of seasonal runoff regulation by the Three Gorges Reservoir on saltwater intrusion in the Changjiang River Estuary. Continental Shelf Research, 71:16-26 Schindler D W. 2006. Recent advances in the understanding and management of eutrophication. Limnology and Oceanography, 51(1):356-363 Shen Zhiliang, Lu Jiaping, Liu Xingjun, et al. 1992. Distribution characteristics of the nutrients in the Changjiang River estuary and the effect of the Three Gorges Project on it. Studia Marina Sinica, 33:109-129 Song Lirong, Chen Wei, Peng Liang, et al. 2007. Distribution and bioaccumulation of microcystins in water columns:a systematic investigation into the environmental fate and the risks associated with microcystins in Meiliang Bay, Lake Taihu. Water Research, 41(13):2853-2864 Tu Qingying, Zhang Yongtai, Yang Xianzhi. 2004. Approaches to the ecological recovery engineering in Lake Shishahai, Beijing. Journal of Lake Sciences, 16(1):61-67 Ueno Y, Nagata S, Tsutsumi T, et al. 1996. Detection of microcystins, a blue-green algal hepatotoxin, in drinking water sampled in Haimen and Fusui, endemic areas of primary liver cancer in China, by highly sensitive immunoassay. Carcinogenesis, 17(6):1317-1321 Wei Fusheng. 2002. Water and Wastewater Monitoring and Analysis Method (in Chinese). 4th ed. Beijing:China Environmental Science Press Wu Hui, Zhu Jianrong, Chen Bingrui, et al. 2006. Quantitative relationship of runoff and tide to saltwater spilling over from the North Branch in the Changjiang Estuary:A numerical study. Estuarine, Coastal and Shelf Science, 69(1–2):125-132
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