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Kheiri G, Pabalan R, Duka MA, Azhikodan G, Yokoyama K. Factors contributing to the minimum water column stability and timing of the winter turnover in the Ogouchi reservoir. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121537. [PMID: 38944954 DOI: 10.1016/j.jenvman.2024.121537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 06/14/2024] [Accepted: 06/17/2024] [Indexed: 07/02/2024]
Abstract
Turnover in lakes and reservoirs causes circulation in the water column from the bottom to the surface when the water column stability becomes low. Previous studies commonly mentioned that turnover occurs when stratification indices become small, but the threshold is rarely discussed. While turnover phenomena have been extensively studied by evaluating changes in bottom dissolved oxygen (DO), the relationship between the disappearance of hypoxia and water temperature indices has not been determined. This study focused on the factors influencing the minimum thermal gradient (TG) and Schmidt Stability Index (SSI), and the timing of turnover events using DO as an indicator of mixing in the Ogouchi reservoir from 1992 to 2001. The results showed that the occurrence of minimum TG and SSI is mainly driven by inflow retention time and average maximum wind speed. Moreover, minimum air temperature and outflow retention time have few contributions to minimum SSI. It was found that 7 out of 10 years exhibited full winter turnover, while the remaining years showed incomplete mixing with persistent hypoxia at the reservoir bottom. This study identifies four cases based on onset thresholds of 0.0035 °C m-1 for TG and 30 J m-2 for SSI to explain turnover event: Case 1: an ideal state with stratification indices below the threshold, resulting in the disappearance of hypoxia; Case 2: indices above the threshold sustain hypoxia; Case 3: an irregular state where the indices exceed the threshold, yet hypoxia disappears; and Case 4: an unexpected persistence of hypoxia despite being below the threshold. The majority of the years (70 percent) were explained by thresholds. The multiple regression analysis indicated the importance of wind speed on the turnover event. Therefore, the effect of wind shear was analyzed for 30 percent of the years that cannot be explained by thresholds (cases 3 and 4). Case 3 shows turnover occurrence due to strong accumulated wind shear, despite exceeding thresholds. Conversely, Case 4 reveals weak wind shear preventing bottom water upwelling, even below thresholds. In conclusion, the precise TG and SSI thresholds for the onset of turnover event were determined using DO data. The thresholds explained the occurrence and non-occurrence of turnover event in most of the years and wind speed clarified unexplained cases by thresholds. The presented method successfully evaluated the timing of turnover and can be applicable elsewhere.
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Affiliation(s)
- Ghazaleh Kheiri
- Department of Civil and Environmental Engineering, Tokyo Metropolitan University, 1-1, Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan.
| | - Ronnel Pabalan
- Department of Civil and Environmental Engineering, Tokyo Metropolitan University, 1-1, Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan.
| | - Maurice A Duka
- Land and Water Resources Engineering Division, IABE, CEAT, University of the Philippines Los Baños, Laguna, 4031, Philippines.
| | - Gubash Azhikodan
- Department of Civil and Environmental Engineering, Tokyo Metropolitan University, 1-1, Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan.
| | - Katsuhide Yokoyama
- Department of Civil and Environmental Engineering, Tokyo Metropolitan University, 1-1, Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan.
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2
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Regev S, Carmel Y, Gal G. Assessing alternative lake management actions for climate change adaptation. AMBIO 2024:10.1007/s13280-024-02039-y. [PMID: 38874849 DOI: 10.1007/s13280-024-02039-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/30/2024] [Accepted: 05/16/2024] [Indexed: 06/15/2024]
Abstract
Lake management actions are required to protect lake ecosystems that are being threatened by climate change. Freshwater lakes in semiarid regions are of upmost importance to their region. Simulations of the subtropical Lake Kinneret project that rising temperatures will cause change to phytoplankton species composition, including increased cyanobacteria blooms, endangering lake ecosystem services. Using lake ecosystem models, we examined several management actions under climate change, including two alternatives of desalinated water introduction into the lake, hypolimnetic water withdrawal, watershed management changes and low versus high lake water level. To account for prediction uncertainty, we utilized an ensemble of two 1D hydrodynamic-biogeochemical lake models along with 500 realizations of meteorological conditions. Results suggest that supplying desalinated water for local use, thus releasing more natural waters through the Jordan River, increasing nutrient flow, may reduce cyanobacteria blooms, mitigating climate change effects. However, these results are accompanied by considerable uncertainty.
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Affiliation(s)
- Shajar Regev
- Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, 14950000, Migdal, Israel.
- Faculty of Civil and Environmental Engineering, The Technion-Israel Institute of Technology, 3200003, Haifa, Israel.
| | - Yohay Carmel
- Faculty of Civil and Environmental Engineering, The Technion-Israel Institute of Technology, 3200003, Haifa, Israel
| | - Gideon Gal
- Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, 14950000, Migdal, Israel
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3
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Olsson F, Mackay EB, Spears BM, Barker P, Jones ID. Interacting impacts of hydrological changes and air temperature warming on lake temperatures highlight the potential for adaptive management. AMBIO 2024:10.1007/s13280-024-02015-6. [PMID: 38795283 DOI: 10.1007/s13280-024-02015-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/10/2024] [Accepted: 03/21/2024] [Indexed: 05/27/2024]
Abstract
Globally, climate warming is increasing air temperatures and changing river flows, but few studies have explicitly considered the consequences for lake temperatures of these dual effects, or the potential to manage lake inflows to mitigate climate warming impacts. Using a one-dimensional model, we tested the sensitivity of lake temperatures to the separate and interacting effects of changes in air temperature and inflow on a small, short-residence time (annual average ≈ 20 days), temperate lake. Reducing inflow by 70% increased summer lake surface temperatures 1.0-1.2 °C and water column stability by 11-19%, equivalent to the effect of 1.2 °C air temperature warming. Conversely, similar increases in inflow could result in lake summer cooling, sufficient to mitigate 0.75 °C air temperature rise, increasing to more than 1.1 °C if inflow temperature does not rise. We discuss how altering lake inflow volume and temperature could be added to the suite of adaptation measures for lakes.
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Affiliation(s)
- Freya Olsson
- UK Centre for Ecology & Hydrology, Bailrigg, Lancaster, UK.
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, UK.
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.
| | | | - Bryan M Spears
- UK Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, UK
| | - Philip Barker
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, UK
| | - Ian D Jones
- Biological and Environmental Sciences, University of Stirling, Stirling, UK
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4
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Zhao S, Hermans M, Niemistö J, Jilbert T. Elevated internal phosphorus loading from shallow areas of eutrophic boreal lakes: Insights from porewater geochemistry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:167950. [PMID: 37865251 DOI: 10.1016/j.scitotenv.2023.167950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 10/03/2023] [Accepted: 10/18/2023] [Indexed: 10/23/2023]
Abstract
Internal phosphorus (P) loading is widely recognized as a major cause of lake eutrophication. One conventional paradigm states that the magnitude of internal loading through P diffusion is constrained by the presence of iron (Fe) oxides in surface sediments under oxic conditions near the sediment-water interface (SWI). However, biogeochemical P dynamics in Fe-rich sedimentary systems are still not fully understood, especially in eutrophic lakes where intensively coupled organic matter (OM) remineralization and reductive dissolution of Fe-bound P (Fe-P) exist concurrently. Here, we assess the diagenetic processes that govern sedimentary P cycling in two eutrophic Fe-rich lakes in southern Finland, Lake Hiidenvesi and Lake Kytäjärvi, using a combination of porewater and solid-phase analyses. Coupled reductive dissolution of Fe-P and OM remineralization controlled P regeneration in both lakes, with Fe-P acting as the dominant source for porewater P. Vivianite formation likely immobilized sedimentary P in the deepest basin of Hiidenvesi. Elevated P diffusion rates were observed at shallow sites under oxic bottom water conditions in summer in both lakes, stimulated by enhanced remineralization of both freshly- (mostly phytoplankton-origin) and earlier-deposited OM under elevated temperatures. Areas overlain by oxic bottom water contributed more benthic P fluxes to the water column compared to anoxic/hypoxic areas in both lakes during all sampling seasons. Our study suggests that in shallow eutrophic settings with high OM deposition and elevated temperatures, remineralization in upper sediments regenerates P efficiently enough to support a significant amount of P release to the water column even under sedimentary molar Fe/P ratios >20. We also discuss the implication of our findings for lake restoration strategies.
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Affiliation(s)
- Siqi Zhao
- Ecosystems and Environment Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, FI-00014 Helsinki, Finland; Environmental Geochemistry Group, Department of Geosciences and Geography, Faculty of Science, University of Helsinki, Gustaf Hällströmin katu 2, P.O. Box 64, FI-00014 Helsinki, Finland.
| | - Martijn Hermans
- Ecosystems and Environment Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, FI-00014 Helsinki, Finland; Environmental Geochemistry Group, Department of Geosciences and Geography, Faculty of Science, University of Helsinki, Gustaf Hällströmin katu 2, P.O. Box 64, FI-00014 Helsinki, Finland; Baltic Sea Centre, Stockholm University, Svante Arrhenius väg 20F, 114 18 Stockholm, Sweden
| | - Juha Niemistö
- Ecosystems and Environment Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, FI-00014 Helsinki, Finland; AFRY Finland Oy, Environment & Land Use Planning, P.O. Box 50, FI-01621 Vantaa, Finland
| | - Tom Jilbert
- Ecosystems and Environment Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, FI-00014 Helsinki, Finland; Environmental Geochemistry Group, Department of Geosciences and Geography, Faculty of Science, University of Helsinki, Gustaf Hällströmin katu 2, P.O. Box 64, FI-00014 Helsinki, Finland
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5
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Dai J, Sha H, Wu X, Wu S, Zhang Y, Wang F, Gao A, Xu J, Tian F, Zhu S, Ptak M. Pulses outweigh cumulative effects of water diversion from river to lake on lacustrine phytoplankton communities. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:3025-3039. [PMID: 36136253 DOI: 10.1007/s10653-022-01383-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 09/01/2022] [Indexed: 06/01/2023]
Abstract
Due to the allochthonous input of nutrients and species, the cumulative effects of water diversion on water-receiving lakes deserve attention. Taking the water diversion project from the Yangtze River to Lake Taihu (WDYT) as an example, we explored the temporal effects of WDYT on the phytoplankton community and physicochemical habitat of Lake Taihu in autumn and winter from 2013 to 2018. Although the short-term diversion significantly increased the risk of importing nutrients, the relatively high quality of the diversion water compared with other inflow rivers had improved the water quality of the water-receiving lake region. The seasonal water diversion significantly increased phytoplankton diversity and community network complexity and reshaped the lacustrine community to be diatom-dominated with their relative proportions of 24.1-64.9% during water diversion periods. The contributions of physicochemical habitat changes induced by water diversion to variations in phytoplankton communities were 24.0-28.0%. The differences in phytoplankton diversity, community composition and physicochemical habitat in the water-receiving lake region between the diversion and non-diversion years were more evident than those between the non-diversion years in the same season, when comparing the multivariate dispersion indices among them. However, the lacustrine phytoplankton community during non-diversion periods still has not been essentially altered after several years of diversion, so the pulse effects of short-term water diversion were more obvious than the long-term cumulative impacts. Better control of allochthonous nutrients, appropriate increase in inflow water, adhering to the long-term operation, should be effective to enhance ecological benefits of such water diversion projects.
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Affiliation(s)
- Jiangyu Dai
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Haifei Sha
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Xiufeng Wu
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China.
| | - Shiqiang Wu
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Yu Zhang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Fangfang Wang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Ang Gao
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Jiayi Xu
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Fuwei Tian
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Senlin Zhu
- College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Mariusz Ptak
- Department of Hydrology and Water Management, Adam Mickiewicz University, B. Krygowskiego 10, 61-680, Poznań, Poland
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6
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de Melo MC, Fernandes LFS, Pissarra TCT, Valera CA, da Costa AM, Pacheco FAL. The COP27 screened through the lens of global water security. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 873:162303. [PMID: 36805064 DOI: 10.1016/j.scitotenv.2023.162303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/29/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Water security is an expression of resilience. In the recent past, scientists and public organizations have built considerable work around this concept launched in 2013 by the United Nations as "the capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for sustaining livelihoods, human well-being, and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters, and for preserving ecosystems in a climate of peace and political stability". In the 27th Conference of the Parties (COP27), held in Sharm El-Sheikh (Egypt) in last November, water security was considered a priority in the climate agenda, especially in the adaption and loss and damage axes. This discussion paper represents the authors' opinion about how the conference coped with water security and what challenges remain to attend. As discussion paper, it had the purpose to stimulate further discussion in a broader scientific forum.
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Affiliation(s)
- Marília Carvalho de Melo
- Secretaria de Estado de Meio Ambiente e Desenvolvimento Sustentável, Cidade Administrativa do Estado de Minas Gerais, Rodovia João Paulo II, 4143, Bairro Serra Verde, Belo Horizonte, Minas Gerais, Brazil; Universidade Vale do Rio Verde (UNINCOR), Av. Castelo Branco, 82 - Chácara das Rosas, Três Corações, MG 37417-150, Brazil.
| | - Luís Filipe Sanches Fernandes
- Centro de Investigação e Tecnologias Agroambientais e Biológicas (CITAB), Universidade de Trás-os-Montes e Alto Douro (UTAD), Ap. 1013, 5001-801 Vila Real, Portugal.
| | - Teresa Cristina Tarlé Pissarra
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane, s/n, Jaboticabal, SP 14884-900, Brazil.
| | - Carlos Alberto Valera
- Coordenadoria Regional das Promotorias de Justiça do Meio Ambiente das Bacias dos Rios Paranaíba e Baixo Rio Grande, Rua Coronel Antônio Rios, 951, Uberaba, MG 38061-150, Brazil.
| | - Adriana Monteiro da Costa
- Universidade Federal de Minas Gerais, Avenida Antônio Carlos, 6620, Pampulha, Belo Horizonte, MG 31270-901, Brazil
| | - Fernando António Leal Pacheco
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane, s/n, Jaboticabal, SP 14884-900, Brazil; Centro de Química de Vila Real (CQVR), Universidade de Trás-os-Montes e Alto Douro (UTAD), Ap. 1013, 5001-801 Vila Real, Portugal.
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7
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Wang C. Regulating phytoplankton-available suspended particulate phosphorus (P) to control internal P pollution in lake: Conclusion from a short review. CHEMOSPHERE 2023; 331:138833. [PMID: 37137394 DOI: 10.1016/j.chemosphere.2023.138833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 04/20/2023] [Accepted: 04/30/2023] [Indexed: 05/05/2023]
Abstract
The necessity on controlling internal P pollution has been widely reported for lake restoration; thus far, cutting the migrations of soluble P from sediment to overlying water, especially under anoxic condition, is the main target of the internal P pollution control to achieve favorable ecological responses in lake. Here, according to the types of P directly available by phytoplankton, phytoplankton-available suspended particulate P (SPP) pollution, which mainly occurs under aerobic condition and due to sediment resuspension and soluble P adsorption by suspended particle, is found to be the other kind of internal P pollution. The SPP has long been a key index for environmental quality assessment, which could be indirectly reflected by the developed various methods for phytoplankton-available P pool analysis; also, the P has been demonstrated to be a major cause of phytoplankton breeding, typically in shallow lakes. Importantly, compared to the soluble P, SPP pollution clearly has more complicated loading pathways and P activation mechanisms and involves in different fractions of P, even part of which are with relatively high stability in sediment and suspended particle, leading to the potential control measures for the pollution being more complex. Considering the potential differences of internal P pollution among various lakes, this study is therefore calling for more research to focus on regulating phytoplankton-available SPP pollution. Recommendations are also offered to bridge knowledge gap of the regulation to design proper measures for lake restoration.
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Affiliation(s)
- Changhui Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
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8
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Huang Y, Fu M, Chen G, Zhang J, Xu P, Pan L, Zhang X, Chen X. Reducing the water residence time is inadequate to limit the algal proliferation in eutrophic lakes. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 330:117177. [PMID: 36603259 DOI: 10.1016/j.jenvman.2022.117177] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 12/24/2022] [Accepted: 12/28/2022] [Indexed: 06/17/2023]
Abstract
The eutrophication problem now threatens many lakes and reservoirs. To avoid the occurrence of algal blooms, some cities try to increase the flow rate or directly choose lakes or reservoirs with a short water residence time (WRT) as drinking water sources. However, up to now, whether such a strategy can achieve its goal is still unclear. In this study, a newly restored lake with a WRT of approximately 3 days was chosen to investigate algal growth potential as well as its responses to external nitrogen (N) and phosphorus (P) inputs. The results suggested that although the water quality of the lake could generally meet the environmental quality standards for surface water, dissolved inorganic nitrogen reached a high level with an average value of 1.58 mg/L. Meanwhile, a considerable increase in Chl-a concentration was observed across the flow direction. Especially, in July, Chl-a concentration at the site near the outlet was 8.1 times higher than that at the inlet, and cyanobacteria became the dominant species accounting for 83% of the total cell density. Nutrient enrichment experiments showed that algae could grow rapidly within 3 days with average specific growth rates (μ) of 0.36-0.42 d-1. The addition of N and P furtherly promoted the algal growth, and μ values of the treatments with P addition were the highest at 0.67-0.83 d-1. These results indicated that even if the WRT was reduced to 3 days, the risk of the occurrence of algal blooms still exists, and this undesirable trend would be enhanced by the short-term external nutrient input. Our findings indicated that the hydrodynamic control measures may not be entirely successful in protecting the drinking water source from algal blooms, especially when its influent has already been under eutrophication.
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Affiliation(s)
- Yingying Huang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, China.
| | - Min Fu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, China
| | - Guiqin Chen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, China
| | - Jieyun Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, China
| | - Ping Xu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, China
| | - Liping Pan
- Institute of Eco-Chongming, 3663N. Zhongshan Road, Shanghai, 200062, China
| | - Xiaohan Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, China
| | - Xuechu Chen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai, 200062, China; Institute of Eco-Chongming, 3663N. Zhongshan Road, Shanghai, 200062, China.
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9
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Zhang M, Wen S, Wu T, Wang S, Li X, Gong W, Wang H, Liu C, Zhong J. Patterns of internal nitrogen and phosphorus loadings in a cascade reservoir with a large water level gradient: Effects of reservoir operation and water depth. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 320:115884. [PMID: 35940015 DOI: 10.1016/j.jenvman.2022.115884] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 07/14/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Internal nutrient loadings pose a high risk of being an additional N and P source, exacerbating eutrophication and deteriorating water quality. In this study, we selected the Daheiting Reservoir (DHTR) in North China, with a pronounced water level gradient, to investigate internal N and P loadings, estimate N and P fluxes across the sediment‒water interface based on the pore water profiles, and reveal the potential effects of water discharge from an upstream reservoir and high-intensity cage aquaculture on the risks of internal N and P release. The results indicated that DHTR presented with severe internal nutrient loadings, and the N and P fluxes showed significant spatiotemporal variations. NH4+-N and soluble reactive phosphorus (SRP) fluxes were higher in deep areas (averages of 26.14 and 9.9 mgm-2d-1, respectively) than in shallow areas near inflows (averages of 5.0 and 1.24 mgm-2d-1, respectively). Unexpectedly, the estimated NH4+-N and SRP fluxes were the lowest in summer (averages of 3.94 and 0.33 mgm-2d-1, respectively), which may have been influenced by seasonal thermal stratification and copious discharge from the hypolimnion of the upstream reservoir (Panjiakou Reservoir). Comparison of annual internal and external N and P loadings revealed that water discharge from the upstream Panjiakou Reservoir was the dominant source of N and P to the reservoir, contributing up to 83.6% of N input and 55.4% of P input. The internal P loading also contributed to water eutrophication to a great extent, accounting for 34.7% of the total P input. Our results highlight the impact of upstream reservoir discharge operation on downstream reservoir water quality and the importance of controlling the internal nutrient loading in cascade reservoirs, and further provide theoretical and practical foundations for the development of policies and strategies to conserve reservoir ecosystems.
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Affiliation(s)
- Min Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Shuailong Wen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Tao Wu
- Tianjin Hydraulic Research Institute, Tianjin, 300061, PR China
| | - Shaoming Wang
- Bureau of Luanhe Diversion Project, Haihe Water Conservancy Commission, Ministry of Water Resources, Qianxi, 064309, PR China
| | - Xin Li
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China
| | - Wanqing Gong
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Hongwei Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Cheng Liu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China
| | - Jicheng Zhong
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China.
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10
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Olsson F, Mackay EB, Moore T, Barker P, Davies S, Hall R, Spears B, Wilkinson J, Jones ID. Annual water residence time effects on thermal structure: A potential lake restoration measure? JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 314:115082. [PMID: 35468434 DOI: 10.1016/j.jenvman.2022.115082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
Innovative methods to combat internal loading issues in eutrophic lakes are urgently needed to speed recovery and restore systems within legislative deadlines. In stratifying lakes, internal phosphorus loading is particularly problematic during the summer stratified period when anoxia persists in the hypolimnion, promoting phosphorus release from the sediment. A novel method to inhibit stratification by reducing residence times is proposed as a way of controlling the length of the hypolimnetic anoxic period, thus reducing the loading of nutrients from the sediments into the water column. However, residence time effects on stratification length in natural lakes are not well understood. We used a systematic modelling approach to investigate the viability of changes to annual water residence time in affecting lake stratification and thermal dynamics in Elterwater, a small stratifying eutrophic lake in the northwest of England. We found that reducing annual water residence times shortened and weakened summer stratification. Based on finer-scale dynamics of lake heat fluxes and water column stability we propose seasonal or sub-seasonal management of water residence time is needed for the method to be most effective at reducing stratification as a means of controlling internal nutrient loading.
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Affiliation(s)
- Freya Olsson
- UK Centre for Ecology & Hydrology, Bailrigg, Lancaster, UK; Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, UK.
| | | | - Tadhg Moore
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Phil Barker
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, UK
| | - Sian Davies
- Environment Agency, Red Kite House, Howbery Park, Wallingford, UK
| | - Ruth Hall
- Natural England, Worcester County Hall, Spetchley Road, Worcester, UK
| | - Bryan Spears
- UK Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, UK
| | - Jayne Wilkinson
- South Cumbria Rivers Trust, The Refinery, The Clock Tower Business Centre, Low Wood, Ulverston, Cumbria, UK
| | - Ian D Jones
- Biological and Environmental Sciences, University of Stirling, Stirling, UK
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