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Soerensen AL, Benskin JP, Faxneld S. Four Decades of Spatiotemporal Variability of Per- and Polyfluoroalkyl Substances (PFASs) in the Baltic Sea. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:10806-10816. [PMID: 38829301 PMCID: PMC11192033 DOI: 10.1021/acs.est.4c03031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 06/05/2024]
Abstract
Temporal and spatial variability of per- and polyfluoroalkyl substances (PFASs) in herring, cod, eelpout, and guillemot covering four decades and more than 1000 km in the Baltic Sea was investigated to evaluate the effect of PFAS regulations and residence times of PFASs. Overall, PFAS concentrations responded rapidly to recent regulations but with some notable basin- and homologue-specific variability. The well-ventilated Kattegat and Bothnian Bay showed a faster log-linear decrease for most PFASs than the Baltic Proper, which lacks a significant loss mechanism. PFOS and FOSA, for example, have decreased with 0-7% y-1 in the Baltic Proper and 6-16% y-1 in other basins. PFNA and partly PFOA are exceptions and continue to show stagnant or increasing concentrations. Further, we found that Bothnian Bay herring contained the highest concentrations of >C12 perfluoroalkyl carboxylic acids (PFCAs), likely from rivers with high loads of dissolved organic carbon. In the Kattegat, low PFAS concentrations, but a high FOSA fraction, could be due to influence from the North Sea inflow below the halocline and possibly a local source of FOSA and/or isomer-specific biotransformation. This study represents the most comprehensive spatial and temporal investigation of PFASs in Baltic wildlife while providing new insights into cycling of PFASs within the Baltic Sea ecosystem.
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Affiliation(s)
- Anne L. Soerensen
- Department
of Environmental Monitoring and Research, Swedish Museum of Natural History, 114 18 Stockholm, Sweden
| | - Jonathan P. Benskin
- Department
of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden
| | - Suzanne Faxneld
- Department
of Environmental Monitoring and Research, Swedish Museum of Natural History, 114 18 Stockholm, Sweden
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2
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Rautiainen N, Rantanen PL, Jalava M, Mikola A. Decreasing dietary nitrogen consumption improves wastewater treatment efficiency and carbon footprint. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2023; 87:1961-1968. [PMID: 37119166 DOI: 10.2166/wst.2023.094] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
This article aimed to connect protein consumption with the nitrogen load to wastewater treatment plants (WWTPs) in Finland. The influence of the changes in nitrogen consumption on the WWTP environmental footprint was estimated using process simulation. As the main result, a connection was found between nitrogen loads from food consumption and the incoming load to a WWTP. This was done by analysing protein consumption data from the Food and Agriculture Organization of the United Nations (FAO) and incoming nitrogen load data from the Finnish environmental institute, SYKE. The impact of nitrogen consumption was estimated using different diet scenarios. Decreasing dietary nitrogen consumption by 16-24% could decrease nitrous oxide emissions by 16-24% and aeration energy (AE) consumption by 6-11%. An increase in dietary nitrogen consumption of 6-42% could increase AE consumption by 2-14% when effluent requirements were met. When considering the environmental impact of this increased aeration, it corresponds to an increase of 2-16%. Furthermore, nitrous oxide emissions could rise by 6-42% This information can be valuable to WWTPs and even consumers for influencing incoming nitrogen loads.
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Affiliation(s)
- Nea Rautiainen
- Department of Built Environment, Aalto University, P.O. Box 15200, Aalto FI-00076, Finland E-mail:
| | - Pirjo-Liisa Rantanen
- Department of Built Environment, Aalto University, P.O. Box 15200, Aalto FI-00076, Finland E-mail: ; Helsinki Region Environmental Services HSY, P.O. Box 100, HSY FI-00066, Finland
| | - Mika Jalava
- Department of Built Environment, Aalto University, P.O. Box 15200, Aalto FI-00076, Finland E-mail:
| | - Anna Mikola
- Department of Built Environment, Aalto University, P.O. Box 15200, Aalto FI-00076, Finland E-mail:
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3
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Export of nutrients to the sea in a karstic basin in the west of Cuba. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-03679-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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4
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Carstensen J, Conley DJ, Almroth-Rosell E, Asmala E, Bonsdorff E, Fleming-Lehtinen V, Gustafsson BG, Gustafsson C, Heiskanen AS, Janas U, Norkko A, Slomp C, Villnäs A, Voss M, Zilius M. Factors regulating the coastal nutrient filter in the Baltic Sea. AMBIO 2020; 49:1194-1210. [PMID: 31707582 PMCID: PMC7128010 DOI: 10.1007/s13280-019-01282-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 05/30/2023]
Abstract
The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different biogeochemical processes altering nutrient and organic matter fluxes on the passage from land to sea. This review investigates the most important processes for removal of nutrients and organic matter, and the factors that regulate the efficiency of the coastal filter. Nitrogen removal through denitrification is high in lagoons receiving large inputs of nitrate and organic matter. Phosphorus burial is high in archipelagos with substantial sedimentation, but the stability of different burial forms varies across the Baltic Sea. Organic matter processes are tightly linked to the nitrogen and phosphorus cycles. Moreover, these processes are strongly modulated depending on composition of vegetation and fauna. Managing coastal ecosystems to improve the effectiveness of the coastal filter can reduce eutrophication in the open Baltic Sea.
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Affiliation(s)
- Jacob Carstensen
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Daniel J. Conley
- Department of Geology, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
| | | | - Eero Asmala
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
| | - Erik Bonsdorff
- Environmental and Marine Biology, Åbo Akademi University, BioCity, 20500 Turku, Finland
| | | | - Bo G. Gustafsson
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
- Stockholm University Baltic Sea Centre, 106 91 Stockholm, Sweden
| | - Camilla Gustafsson
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
| | | | - Urzsula Janas
- Department of Experimental Ecology of Marine Organisms, Institute of Oceanography, University of Gdańsk, al. Marsz. J. Pilsudskiego 46, 81-378 Gdynia, Poland
| | - Alf Norkko
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
| | - Caroline Slomp
- Department of Earth Sciences, Utrecht University, Princetonlaan 8A, 3584 CB Utrecht, The Netherlands
| | - Anna Villnäs
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
| | - Maren Voss
- Department of Biological Oceanography, Leibniz Institute of Baltic Sea Research, Seestr. 15, 18119 Rostock, Germany
| | - Mindaugas Zilius
- Marine Research Institute, Universiteto al. 17, 92294 Klaipeda, Lithuania
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5
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Sarris TS, Scott DM, Close ME, Humphries B, Moore C, Burbery LF, Rajanayaka C, Barkle G, Hadfield J. The effects of denitrification parameterization and potential benefits of spatially targeted regulation for the reduction of N-discharges from agriculture. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 247:299-312. [PMID: 31252229 DOI: 10.1016/j.jenvman.2019.06.074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 06/06/2019] [Accepted: 06/15/2019] [Indexed: 06/09/2023]
Abstract
Diffuse nitrate leaching from agricultural areas is a major environmental problem in many parts of the world. Understanding where in a catchment nitrate is removed is key for designing effective land use management strategies that protect water quality, while minimizing the impact on economic development. In this study we assess the effects of spatially targeted nitrate leaching regulation in a basin with limited knowledge of the complexity of chemical heterogeneity. Three alternative nitrate reactivity spatial parameterizations were incorporated in a catchment-scale flow and transport model and used to evaluate the effectiveness of four possible spatially targeted regulation options. Our findings confirm that denitrification parameterization cannot be numerically determined based on model inversion alone. Detailed field based characterization using physical and geochemical methods should be considered and incorporated in the numerical inversion scheme. We also demonstrate that there are potential benefits of implementing spatially targeted regulation compared to spatially uniform regulation. Focusing regulation in areas where nitrate residence time is short, such as riparian zones or areas with low natural N-reduction, results in greater reduction of N-discharges through groundwater. Significantly improved efficiencies can be expected when delineation of management zones considers the chemical heterogeneity and groundwater flow paths. These improved efficiencies are achieved by adopting management rules that regulate land use in discharge sensitive areas, where leaching changes contribute the most to the catchment nitrate discharges. In our case study, regulation in discharge sensitive zones was twice as efficient compared to other management options.
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Affiliation(s)
- Theo S Sarris
- Institute of Environmental Science and Research (ESR), Christchurch, New Zealand.
| | - David M Scott
- Institute of Environmental Science and Research (ESR), Christchurch, New Zealand
| | - Murray E Close
- Institute of Environmental Science and Research (ESR), Christchurch, New Zealand
| | - Bronwyn Humphries
- Institute of Environmental Science and Research (ESR), Christchurch, New Zealand
| | - Catherine Moore
- Institute of Environmental Science and Research (ESR), Christchurch, New Zealand; Now with GNS Science, Wellington, New Zealand
| | - Lee F Burbery
- Institute of Environmental Science and Research (ESR), Christchurch, New Zealand
| | - Channa Rajanayaka
- Aqualinc Research Ltd, Hamilton, New Zealand; Now with National Institute of Water and Atmospheric Research (NIWA), Christchurch, New Zealand
| | - Greg Barkle
- Aqualinc Research Ltd, Hamilton, New Zealand
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6
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Verrot L, Destouni G. Screening variability and change of soil moisture under wide-ranging climate conditions: Snow dynamics effects. AMBIO 2015; 44 Suppl 1:S6-S16. [PMID: 25576276 PMCID: PMC4289003 DOI: 10.1007/s13280-014-0583-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Soil moisture influences and is influenced by water, climate, and ecosystem conditions, affecting associated ecosystem services in the landscape. This paper couples snow storage-melting dynamics with an analytical modeling approach to screening basin-scale, long-term soil moisture variability and change in a changing climate. This coupling enables assessment of both spatial differences and temporal changes across a wide range of hydro-climatic conditions. Model application is exemplified for two major Swedish hydrological basins, Norrström and Piteälven. These are located along a steep temperature gradient and have experienced different hydro-climatic changes over the time period of study, 1950-2009. Spatially, average intra-annual variability of soil moisture differs considerably between the basins due to their temperature-related differences in snow dynamics. With regard to temporal change, the long-term average state and intra-annual variability of soil moisture have not changed much, while inter-annual variability has changed considerably in response to hydro-climatic changes experienced so far in each basin.
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Affiliation(s)
- Lucile Verrot
- Department of Physical Geography and Quaternary Geology, Stockholm University, 106 91 Stockholm, Sweden
| | - Georgia Destouni
- Department of Physical Geography and Quaternary Geology, Stockholm University, 106 91 Stockholm, Sweden
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7
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Hägg HE, Lyon SW, Wällstedt T, Mörth CM, Claremar B, Humborg C. Future nutrient load scenarios for the Baltic Sea due to climate and lifestyle changes. AMBIO 2014; 43:337-51. [PMID: 23765871 PMCID: PMC3946118 DOI: 10.1007/s13280-013-0416-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 02/13/2013] [Accepted: 05/23/2013] [Indexed: 05/22/2023]
Abstract
Dynamic model simulations of the future climate and projections of future lifestyles within the Baltic Sea Drainage Basin (BSDB) were considered in this study to estimate potential trends in future nutrient loads to the Baltic Sea. Total nitrogen and total phosphorus loads were estimated using a simple proxy based only on human population (to account for nutrient sources) and stream discharges (to account for nutrient transport). This population-discharge proxy provided a good estimate for nutrient loads across the seven sub-basins of the BSDB considered. All climate scenarios considered here produced increased nutrient loads to the Baltic Sea over the next 100 years. There was variation between the climate scenarios such that sub-basin and regional differences were seen in future nutrient runoff depending on the climate model and scenario considered. Regardless, the results of this study indicate that changes in lifestyle brought about through shifts in consumption and population potentially overshadow the climate effects on future nutrient runoff for the entire BSDB. Regionally, however, lifestyle changes appear relatively more important in the southern regions of the BSDB while climatic changes appear more important in the northern regions with regards to future increases in nutrient loads. From a whole-ecosystem management perspective of the BSDB, this implies that implementation of improved and targeted management practices can still bring about improved conditions in the Baltic Sea in the face of a warmer and wetter future climate.
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Affiliation(s)
- Hanna Eriksson Hägg
- />Baltic Nest Institute, Baltic Sea Centre, Stockholm University, Stockholm, Sweden
| | - Steve W. Lyon
- />Baltic Nest Institute, Baltic Sea Centre, Stockholm University, Stockholm, Sweden
- />Department of Physical Geography and Quaternary Geology, Stockholm University, Stockholm, Sweden
| | - Teresia Wällstedt
- />Department of Geological Sciences, Stockholm University, Stockholm, Sweden
| | - Carl-Magnus Mörth
- />Baltic Nest Institute, Baltic Sea Centre, Stockholm University, Stockholm, Sweden
- />Department of Geological Sciences, Stockholm University, Stockholm, Sweden
| | - Björn Claremar
- />Department of Earth Sciences, Uppsala University, Uppsala, Sweden
| | - Christoph Humborg
- />Baltic Nest Institute, Baltic Sea Centre, Stockholm University, Stockholm, Sweden
- />Applied Environmental Science, Stockholm University, Stockholm, Sweden
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8
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Arheimer B, Dahné J, Donnelly C. Climate change impact on riverine nutrient load and land-based remedial measures of the Baltic sea action plan. AMBIO 2012; 41:600-12. [PMID: 22926882 PMCID: PMC3428487 DOI: 10.1007/s13280-012-0323-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
To reduce eutrophication of the Baltic Sea, all nine surrounding countries have agreed upon reduction targets in the HELCOM Baltic Sea Action Plan (BSAP). Yet, monitoring sites and model concepts for decision support are few. To provide one more tool for analysis of water and nutrient fluxes in the Baltic Sea basin, the HYPE model has been applied to the region (called Balt-HYPE). It was used here for experimenting with land-based remedial measures and future climate projections to quantify the impacts of these on water and nutrient loads to the sea. The results suggest that there is a possibility to reach the BSAP nutrient reduction targets by 2100, and that climate change may both aggravate and help in some aspects. Uncertainties in the model results are large, mainly due to the spread of the climate model projections, but also due to the hydrological model.
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9
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Kepner WG, Ramsey MM, Brown ES, Jarchow ME, Dickinson KJM, Mark AF. Hydrologic futures: using scenario analysis to evaluate impacts of forecasted land use change on hydrologic services. Ecosphere 2012. [DOI: 10.1890/es11-00367.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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10
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Bouraoui F, Grizzetti B. Long term change of nutrient concentrations of rivers discharging in European seas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2011; 409:4899-916. [PMID: 21911245 DOI: 10.1016/j.scitotenv.2011.08.015] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 08/08/2011] [Accepted: 08/09/2011] [Indexed: 05/22/2023]
Abstract
Cases of severe eutrophication are still observed in European surface waters even though tough regulation has been in place since the beginning of the 1990s to control nutrient losses and inputs in the environment. The purpose of this paper is to evaluate the evolution since 1991 of the quality of the water entering European seas in terms of the concentration of major nutrients (nitrogen and phosphorus), and to analyze the effectiveness of implemented national/international measures and EU legislation in reducing water nutrient pollution. Despite the reduction in large portions of the European territory of agricultural nutrient applications and nutrient point source emissions, the impact on water quality is limited. It is shown using two large river basins that this lack of response for nitrogen, and nitrate in particular, between the reduction of the nitrogen surplus and the recovery of water quality is partly explained by the lag time due to transfer of nitrates in the unsaturated and saturated zones and storage in the soils and aquifers. In order to monitor efficiently the impact of policy implementation on water quality, the Nitrates Directive and the Urban Waste Water Treatment Directive in particular, it is recommended to use long term permanent monitoring stations to be able to separate the impact of climate variability from that of policy implementation. It is also recommended to investigate and develop harmonized methodologies for estimating the lag time in order to come up with realistic estimates of response time of water bodies due to the implementation of measures.
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Affiliation(s)
- Fayçal Bouraoui
- Joint Research Centre of the European Commission, Via Fermi 2749, Ispra (Va), 21027, Italy.
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11
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Eriksson Hägg H, Humborg C, Mörth CM, Medina MR, Wulff F. Scenario analysis on protein consumption and climate change effects on riverine N export to the Baltic Sea. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:2379-2385. [PMID: 20230019 DOI: 10.1021/es902632p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper evaluates possible future nitrogen loadings from 105 catchments surrounding the Baltic Sea. Multiple regressions are used to model total nitrogen (TN) flux as a function of specific runoff (Q), atmospheric nitrogen deposition, and primary emissions (PE) from humans and livestock. On average cattle contributed with 63%, humans with 20%, and pigs with 17% of the total nitrogen PE to land. Compared to the reference period (1992-1996) we then evaluated two types of scenarios for year 2070. i) An increased protein consumption scenario that led to 16% to 39% increased mean TN flux (kg per km(-2)). ii) Four climate scenarios addressing effects of changes in river discharge. These scenarios showed increased mean TN flux from the northern catchments draining into the Gulf of Bothnia (34%) and the Gulfs of Finland and Riga (14%), while the mean TN flux decreased (-27%) for catchments draining to the Baltic Proper. However, the net effect of the scenarios showed a possible increase in TN flux ranging from 3-72%. Overall an increased demand for animal protein will be instrumental for the Baltic Sea ecosystem and may be a major holdback to fulfill the environmental goals of the Baltic Sea Action Plan.
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Affiliation(s)
- Hanna Eriksson Hägg
- Department of Applied Environmental Science, Stockholm University, Stockholm, Sweden.
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12
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Yoshimura C, Zhou M, Kiem AS, Fukami K, Prasantha HHA, Ishidaira H, Takeuchi K. 2020s scenario analysis of nutrient load in the Mekong River Basin using a distributed hydrological model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2009; 407:5356-5366. [PMID: 19625073 DOI: 10.1016/j.scitotenv.2009.06.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 06/13/2009] [Accepted: 06/23/2009] [Indexed: 05/28/2023]
Abstract
A distributed hydrological model, YHyM, was integrated with the export coefficient concept and applied to simulate the nutrient load in the Mekong River Basin. In the validation period (1992-1999), Nash-Sutcliffe efficiency was 76.4% for discharge, 65.9% for total nitrogen, and 45.3% for total phosphorus at Khong Chiam. Using the model, scenario analysis was then performed for the 2020s taking into account major anthropogenic factors: climate change, population, land cover, fertilizer use, and industrial waste water. The results show that the load at Kompong Cham in 2020s is 6.3 x 10(4)tN a(-1) (+13.0% compared to 1990s) and 4.3 x 10(3)tP a(-1) (+24.7%). Overall, the noticeable nutrient sources are cropland in the middle region and urban load in the lower region. The installation of waste water treatment plants in urban areas possibly cut 60.6%N and 19.9%P of the estimated increase in the case without any treatment.
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Affiliation(s)
- Chihiro Yoshimura
- Department of Civil Engineering, Tokyo Institute of Technology, Tokyo 152-8552, Japan.
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13
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Wulff F, Savchuk OP, Sokolov A, Humborg C, Mörth CM. Management options and effects on a marine ecosystem: assessing the future of the Baltic. AMBIO 2007; 36:243-9. [PMID: 17520940 DOI: 10.1579/0044-7447(2007)36[243:moaeoa]2.0.co;2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We are using the coupled models in a decision support system, Nest, to evaluate the response of the marine ecosystem to changes in external loads through various management options. The models address all the seven major marine basins and the entire drainage basin of the Baltic Sea. A series of future scenarios have been developed, in close collaboration with the Helsinki Commission, to see the possible effects of improved wastewater treatment and manure handling, phosphorus-free detergents, and less intensive land use and live stocks. Improved wastewater treatment and the use of phosphorus-free detergents in the entire region would drastically decrease phosphorus loads and improve the marine environment, particularly the occurrence of cyanobacterial blooms. However, the Baltic Sea will remain eutrophic, and to reduce other effects, a substantial reduction of nitrogen emissions must be implemented. This can only be obtained in these scenarios by drastically changing land use. In a final scenario, we have turned 50% of all agricultural lands into grasslands, together with efficient wastewater treatments and a ban of phosphorus in detergents. This scenario will substantially reduce primary production and the extension of hypoxic bottoms, increase water transparency in the most eutrophied basins, and virtually eliminate extensive cyanobacterial blooms.
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Affiliation(s)
- Fredrik Wulff
- Department of Systems Ecology, Stockholm University, Sweden.
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