Successful reduction of diffuse nitrogen emissions at catchment scale: example from the pilot River Odense, Denmark

2016 ◽  
Vol 73 (11) ◽  
pp. 2583-2589 ◽  
Author(s):  
J. Windolf ◽  
H. Tornbjerg ◽  
C. C. Hoffmann ◽  
J. R. Poulsen ◽  
G. Blicher-Mathiesen ◽  
...  
Keyword(s):  
Wetland Restoration ◽  
Coastal Waters ◽  
Point Sources ◽  
Downward Trend ◽  
Mitigation Measures ◽  
N Leaching ◽  
Catchment Scale ◽  
Nitrogen Emissions ◽  
Successful Reduction ◽  
Gauging Station

Land-based total nitrogen (N) loadings to Danish coastal waters have been markedly reduced since 2000. This has been achieved by general measures reducing discharges from all point sources and N leaching from farmed land supplemented with more local and targeted mitigation measures such as restoration of wetlands to increase the catchment-specific N retention. In the catchment of River Odense, restoration of wetlands has been extensive. Thus, in the major gauged catchment (485 km2) eleven wetlands (860 ha) have been restored since 2000. A comparison of data on N concentrations and loss from a gauging station in the River Odense with data from a control catchment (772 km2), in which a significantly less intensive wetland restoration programme has been undertaken, showed an excess downward trend in N, amounting to 124 t N yr−1, which can be ascribed to the intensive wetland restoration programme carried out in the River Odense catchment. In total, the N load in the River Odense has been reduced by 377 t N yr−1 (39%) since 2000. The observed downward trend is supported by monitoring data from two wetlands restored in 2001 and 2004 in the River Odense catchment.

scholarly journals Characterising phosphorus transfers in rural catchments using a continuous bank-side analyser

2007 ◽  
Vol 11 (1) ◽  
pp. 372-381 ◽  
Author(s):  
P. Jordan ◽  
A. Arnscheidt ◽  
H. McGrogan ◽  
S. McCormick
Keyword(s):  
Point Sources ◽  
Mitigation Measures ◽  
Data Series ◽  
Storm Events ◽  
Catchment Scale ◽  
Concentration Data ◽  
Monitoring Technology ◽  
Transfer Event ◽  
Discharge Data ◽  
Total Period

Abstract. A six-month series of high-resolution synchronous stream discharge and total phosphorus (TP) concentration data is presented from a 5 km2 agricultural catchment in the Lough Neagh basin, Northern Ireland. The data are hourly averages of 10-minute measurements using a new bankside, automatic, continuous monitoring technology. Three TP transfer "event-types" occur in this catchment: (1) chronic, storm independent transfers; (2) acute, storm dependent transfers; (3) acute, storm independent transfers. Event-type 2 transferred over 90% of the total 279 kg TP load in 39% of the total period; it corresponded to diffuse transfers from agricultural soils. Event-types 1 and 3, however, maintained the river in a highly eutrophic state between storm events and were characteristic of point source pollution, despite there being no major industrial or municipal point sources. Managing P transfers at the catchment scale requires a robust monitoring technology to differentiate between dynamic, multiple sources and associated event types and so enable a reliable assessment of the performance of mitigation measures, monitored at catchment outlets. The synchronous and continuous TP and discharge data series generated in this study demonstrate how this is possible.

Documenting success stories of management of phosphorus emissions at catchment scale: an example from the pilot river Odense, Denmark

2016 ◽  
Vol 74 (9) ◽  
pp. 2097-2104 ◽  
Author(s):  
B. Kronvang ◽  
H. Tornbjerg ◽  
C. C. Hoffmann ◽  
J. R. Poulsen ◽  
J. Windolf
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Water Quality Monitoring ◽  
Downward Trend ◽  
Mitigation Measures ◽  
Catchment Scale ◽  
Balance Study ◽  
Success Stories ◽  
Significant Downward Trend ◽  
Mass Balance Study

Documentation of the effects of different mitigation measures adopted at different scales to reduce phosphorus (P) loadings to surface waters is needed to help catchment managers select the best management practices. Water quality monitoring data from the outlets of two paired catchments (the river Odense catchment versus a neighbouring control catchment) on the island of Funen, Denmark, showed significantly different trends in annual flow-weighted P concentrations during the period 2000–2013. A significant downward trend in flow-weighted particulate P (PP) concentrations (0.051 mg P L−1) and loss (0.155 kg P ha−1) was detected for the river Odense catchment, whereas a similar trend did not emerge in the control catchment. The observed differences in PP reductions may be due to wetlands acting as P sinks since wetland restoration activities have been much more comprehensive in the river Odense catchment (1.8 ha wetlands km−2) than in the control catchment (0.5 ha wetland km−2). The excess downward trend in total P and PP in the river Odense catchment (5,600 kg P and 3,700 kg P) is corroborated by extrapolating the results from a mass-balance study and 10 years of in situ measurements of P storage (3,700 kg P and 15,000 kg P).

Groundwater protection and diffuse nitrogen emissions to surface waters – which catchment areas have to be considered?

2007 ◽  
Vol 7 (3) ◽  
pp. 103-110
Author(s):  
C. Schilling ◽  
M. Zessner ◽  
A.P. Blaschke ◽  
D. Gutknecht ◽  
H. Kroiss
Keyword(s):  
Surface Water ◽  
Total Nitrogen ◽  
Surface Waters ◽  
Flow Path ◽  
Emission Model ◽  
Catchment Scale ◽  
Danube Basin ◽  
Nitrogen Emissions ◽  
Nitrogen Levels ◽  
Catchment Areas

Two Austrian case study regions within the Danube basin have been selected for detailed investigations of groundwater and surface water quality at the catchment scale. Water balance calculations have been performed using the conceptual continuous time SWAT 2000 model to characterise catchment hydrology and to identify individual runoff components contributing to river discharge. Nitrogen emission calculations have been performed using the empirical emission model MONERIS to relate individual runoff components to specific nitrogen emissions and for the quantification of total nitrogen emissions to surface waters. Calculated total nitrogen emissions to surface waters using the MONERIS model were significantly influenced by hydrological conditions. For both catchments the groundwater could be identified as major emission pathway of nitrogen emissions to the surface waters. Since most of the nitrogen is emitted by groundwater to the surface water, denitrification in groundwater is of considerable importance reducing nitrogen levels in groundwater along the flow path towards the surface water. An approach was adopted for the grid-oriented estimation of diffuse nitrogen emissions based on calculated groundwater residence time distributions. Denitrification in groundwater was considered using a half life time approach. It could be shown that more than 90% of the total diffuse nitrogen emissions were contributed by areas with low groundwater residence times and short distances to the surface water. Thus, managing diffuse nitrogen emissions the location of catchment areas has to be considered as well as hydrological and hydrogeological conditions, which significantly influence denitrification in the groundwater and reduce nitrogen levels in groundwater on the flow path towards the surface water.

scholarly journals A cost-effectiveness analysis of water security and water quality: impacts of climate and land-use change on the River Thames system

2013 ◽  
Vol 371 (2002) ◽  
pp. 20120413 ◽  
Author(s):  
P. G. Whitehead ◽  
J. Crossman ◽  
B. B. Balana ◽  
M. N. Futter ◽  
S. Comber ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Cost Effectiveness ◽  
Land Use Change ◽  
Algal Blooms ◽  
Economic Benefits ◽  
Point Sources ◽  
Mitigation Measures ◽  
Mitigation And Adaptation ◽  
River Thames

The catchment of the River Thames, the principal river system in southern England, provides the main water supply for London but is highly vulnerable to changes in climate, land use and population. The river is eutrophic with significant algal blooms with phosphorus assumed to be the primary chemical indicator of ecosystem health. In the Thames Basin, phosphorus is available from point sources such as wastewater treatment plants and from diffuse sources such as agriculture. In order to predict vulnerability to future change, the integrated catchments model for phosphorus (INCA-P) has been applied to the river basin and used to assess the cost-effectiveness of a range of mitigation and adaptation strategies. It is shown that scenarios of future climate and land-use change will exacerbate the water quality problems, but a range of mitigation measures can improve the situation. A cost-effectiveness study has been undertaken to compare the economic benefits of each mitigation measure and to assess the phosphorus reductions achieved. The most effective strategy is to reduce fertilizer use by 20% together with the treatment of effluent to a high standard. Such measures will reduce the instream phosphorus concentrations to close to the EU Water Framework Directive target for the Thames.

scholarly journals Nitrogen Risk Assessment Model for Scotland: II. Hydrological transport and model testing

2004 ◽  
Vol 8 (2) ◽  
pp. 205-219 ◽  
Author(s):  
S. M. Dunn ◽  
A. Lilly ◽  
J. DeGroote ◽  
A. J. A. Vinten
Keyword(s):  
Risk Assessment ◽  
Transport Model ◽  
Meteorological Data ◽  
Preceding Paper ◽  
Assessment Model ◽  
Balance Model ◽  
N Leaching ◽  
Risk Assessment Model ◽  
National Scale ◽  
Catchment Scale

Abstract. The amount and concentration of N in catchment runoff is strongly controlled by a number of hydrological influences, such as leaching rates and the rate of transport of N from the land to surface water bodies. This paper describes how the principal hydrological controls at a catchment scale have been represented within the Nitrogen Risk Assessment Model for Scotland (NIRAMS); it demonstrates their influence through application of the model to eight Scottish catchments, contrasting in terms of their land use, climate and topography. Calculation of N leaching rates, described in the preceding paper (Dunn et al., 2004), is based on soil water content determined by application of a weekly water balance model. This model uses national scale datasets and has been developed and applied to the whole of Scotland using five years of historical meteorological data. A catchment scale transport model, constructed from a 50m digital elevation model, routes flows of N through the sub-surface and groundwater to the stream system. The results of the simulations carried out for eight different catchments demonstrate that the NIRAMS model is capable of predicting time-series of weekly stream flows and N concentrations, to an acceptable degree of accuracy. The model provides an appropriate framework for risk assessment applications requiring predictions in ungauged catchments and at a national scale. Analysis of the model behaviour shows that streamwater N concentrations are controlled both by the rate of supply of N from leaching as well as the rate of transport of N from the land to the water. Keywords: nitrogen, diffuse pollution, hydrology, model, transport, catchment

scholarly journals Nitrogen Risk Assessment Model for Scotland: I. Nitrogen leaching

2004 ◽  
Vol 8 (2) ◽  
pp. 191-204 ◽  
Author(s):  
S. M. Dunn ◽  
A. J. A. Vinten ◽  
A. Lilly ◽  
J. DeGroote ◽  
M. A. Sutton ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Land Use ◽  
Policy Development ◽  
Agricultural Land ◽  
Growing Season ◽  
Assessment Model ◽  
N Leaching ◽  
Risk Assessment Model ◽  
Catchment Scale ◽  
Residual N

Abstract. The Nitrogen Risk Assessment Model for Scotland (NIRAMS) has been developed for prediction of streamwater N concentrations draining from agricultural land in Scotland. The objective of the model is to predict N concentrations for ungauged catchments, to fill gaps in monitoring data and to provide guidance in relation to policy development. The model uses nationally available data sets of land use, soils, topography and meteorology and has been developed within a Geographic Information System (GIS). The model includes modules to calculate N inputs to the land, residual N remaining at the end of the growing season, weekly time-series of leached N and transport of N at the catchment scale. This paper presents the methodology for calculating N balances for different land uses and for predicting the time sequence of N leaching after the end of the growing season. Maps are presented of calculated residual N and N leaching for the whole of Scotland and the spatial variability in N leaching is discussed. The results demonstrate the high variability in N leaching across Scotland. The simulations suggest that, in the areas with greatest residual N, the losses of N are not directly proportional to the amount of residual N, because of their coincidence with lower rainfall. In the companion paper, the hydrological controls on N transport within NIRAMS are described, and results of the full model testing are presented. Keywords: nitrogen, diffuse pollution, agriculture, leaching, land use, model, national, catchment

Distribution of Mercury in the Sediments and Fishes of the Lagoon of Aveiro, Portugal

1986 ◽  
Vol 18 (4-5) ◽  
pp. 141-148 ◽  
Author(s):  
M. F. Lucas ◽  
M. T. Caldeira ◽  
A. Hall ◽  
A. C. Duarte ◽  
C. Lima
Keyword(s):  
Coastal Waters ◽  
Total Mercury ◽  
Feeding Habits ◽  
Sediment Concentration ◽  
Point Sources ◽  
The Other ◽  
Ecological Niches ◽  
Ongoing Work ◽  
Superficial Sediments ◽  
Significant Point

Dry and wet sieving were compared on their suitability for the size fractionation of bottom sediment samples, collected from a brackish water, coastal lagoon, prior to flameless atomic absorption analysis of the sediment concentration of total mercury. The work aimed at identifying the most important point sources of mercury to the lagoon waters and at assessing the distribution, throughout the ecosystem, of the mercury discharged. The results reported in this paper refer to the lagoon sediments and fishes. Ongoing work is extending the survey to the other inland ecological niches and to the coastal waters and sediments. A chlor-alkali plant proved to be the most important source of mercury but its contribution has not yet been disentangled from those originating at a pyrite roasting facility and a PVC factory operating in the same industrial park. Sewage discharges from the bankside communities are the other significant point sources of Hg. Concentrations of Hg in the superficial sediments ranged from 850 mgkg−1, near the chlor-alkali sewer outlet, to 0.05 mgkg−1 in the intertidal sands of the coastal beaches. Sewage-affected sediments have concentrations of Hg in the range of 1 to 2 mgkg−1. The concentrations observed in the water samples and superficial sediments suggest that some of the Hg historically discharged into the lagoon may have been exported to the Atlantic Ocean coastal waters. Bioaccumulation of Hg in fish tissues shows the usual dependence on species, territoriality, feeding habits and size. Concentrations as high as 25 mgkg−1 fresh weight have been observed but the average values do not exceed the EEC quality objective of 0.3 mgkg−1 (EEC, 1982).

Valuation of nitrogen retention as an ecosystem service on a catchment scale

2013 ◽  
Vol 45 (3) ◽  
pp. 411-424 ◽  
Author(s):  
Katri Rankinen ◽  
Kirsti Granlund ◽  
Randall Etheridge ◽  
Pentti Seuri
Keyword(s):  
Ecosystem Service ◽  
Nutrient Recycling ◽  
Nitrogen Retention ◽  
Animal Husbandry ◽  
N Leaching ◽  
Management Scenarios ◽  
Catchment Scale ◽  
Artificial Wetlands ◽  
Protection Measures ◽  
Policy Proposal

An ecosystem service approach was used to study the water purification service exemplified by impacts of land management scenarios. Nitrogen retention was calculated in two agricultural catchments by the dynamic Integrated Nutrients in Catchments (INCA)-N model. The monetary valuation was based on purification efficiency of artificial wetlands. The set of scenarios were based on existing agricultural water protection measures, and greening of the Common Agricultural Policy proposal. Scenarios were: wintertime crop cover on fields, increase in area of set aside land, decrease in nitrogen fertilization, crop diversification and nutrient recycling in organic farming. Nitrogen retention provided more value in the Yläneenjoki catchment where the main production line was animal husbandry. In the slowly flowing river Lepsämänjoki, the N retention was more effective than in the fast flowing river Yläneenjoki. When comparing measures some proved to have no value or even a negative value. Set aside had a high positive value when calculated per area, but on a catchment scale the value remained low because of the small area of implementation. Nutrient recycling and winter time vegetation cover were the scenarios that reduced N leaching from fields close to targets set in current political decisions. None of the scenarios increased greenhouse gas emissions.

scholarly journals The harbour porpoise (Phocoena phocoena) in the North Atlantic: Variability in habitat use, trophic ecology and contaminant exposure

2003 ◽  
Vol 5 ◽  
pp. 223 ◽  
Author(s):  
Arne Bjørge
Keyword(s):  
Habitat Use ◽  
North Atlantic ◽  
Coastal Waters ◽  
Trophic Ecology ◽  
Point Sources ◽  
Phocoena Phocoena ◽  
Cetacean Species ◽  
Contaminant Exposure ◽  
The North ◽  
Management Plans

Harbour porpoises inhabit coastal waters, in habitats that are characterized by high diversity and complexity in terms of their bathymetry, substrate, fish communities and point sources of contaminants. The complexity in these habitats influences both the habitat use and feeding ecology of porpoises. Congregations of porpoises feeding primarily on one species are observed in some areas and seasons, while wide movements and diets composed of several species are observed in other areas. Due to these observations, this paper suggests that caution is needed when extrapolatingknowledge from one area to another with regard to porpoise habitat use, exposure to contaminants, and interactions with fisheries. Management plans should be site specific and based on local knowledge incorporating porpoise population structure, habitat use, and multiple environmental factors in order to ensure appropriate conservation of this abundant but still vulnerable small cetacean species.

scholarly journals Seismic hazard assessment of eastern Nepal using 1934 and 1988 earthquakes

2011 ◽  
Vol 42 ◽  
pp. 85-93
Author(s):  
Deepak Chamlagain ◽  
Ganesh Kumar Bhattarai ◽  
Sudhir Rajaure
Keyword(s):  
Seismic Hazard ◽  
Urban Areas ◽  
Local Level ◽  
Large Population ◽  
Point Sources ◽  
Population Pressure ◽  
Mitigation Measures ◽  
Engineering Structures ◽  
Earthquake Disaster ◽  
Nepal Earthquake

The Himalayan arc is widely considered as one of the hot spots in terms of earthquake disaster. Nepal, which is centrally located in the Himalayan region, has witnessed many medium to large earthquakes in the past, e.g., 1934 Bihar-Nepal earthquake, 19 88 Udayapur earthquake. Because of lack of income resources in rural area, considerable number of population has already migrated to the major urban areas of the country and the trend is still continued. With such population pressure and also economic constrains, major part of population is residing in weak and non-engineered structures of the unplanned urban areas. Consequently, it has put large population at high risk of earthquake disaster. It is, therefore, necessary to assess the seismic hazard so that proper mitigation measures may be adopted for the safeguard of the population, property and infrastructures under risk. In this contribution, preliminary Probabilistic Seismic Hazard Analysis (PSHA) for eastern Nepal is carried out taking two point sources, i.e. 19 3 4 Bihar -Ne pal and 1988 Udayapur earthquakes. For Bihar-Nepal earthquake Peak Ground Acceleration (PGA) of 100 gal is computed for southeastern Nepal and exceeds as much as 350 gal near the epicenter. The 1988 Udayapur earthquake having smaller magnitude than 1934 Bihar Nepal earthquake has given maximum 300 gal of PGA. The computed intensities for both earthquakes almost correspond with the observed values. The study, for the first time, provides strong ground motion data at local level and may be useful in designing engineering structures, upgradation of building code and most importantly to formulate policy for earthquake risk management in eastern Nepal.

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