Per Stålnacke

Director of Research

(+47) 932 02 520
per.stalnacke@nibio.no

Place
Ås H7

Visiting address
Høgskoleveien 7, 1433 Ås

Abstract

The determination of environmentally minimum water level in lakes is essential for the protection of their ecosystems. The assessment of minimum water level depends on a number of biotic and abiotic factors of the lake ecosystem; however, in many cases these factors are not easy to collect and assess in their entirety. At the same time, the lakes in many cases consist an important water reserve to meet the requirements arising from economic activities, e.g. industry, agriculture. In this paper, the morphological features in four lakes – Vegoritida, Petron, Cheimaditida and Zazari – of Northern Greece are analysed in order to assess their environmentally minimum water level. The morphological analysis is based on the relationship of the lake surface area and volume with the water level. An optimization method is applied taking into account that the biodiversity is favoured as the surface area covered by the lake is increased and the human water requirements are satisfied to the greatest possible extent by the available water volume of the lake. The environmentally minimum water level determined by the morphological analysis in the four lakes is compared with the minimum water level based on the analysis of the requirements of fish fauna and macrophytes.

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Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2016 have been estimated in accordance with the OSPAR Commission’s principles. Nutrients, metals and organic pollutants have been monitored in rivers; discharges from point sources have been estimated from industry, sewage treatment plants and fish farming; and nutrient inputs from diffuse sources have been modelled. Trends in riverine inputs have been analysed, and threshold concentration levels investigated.

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Abstract

The statistical model MESAW (Matrix Equations for Source Apportionment on Watershed) was used to estimate the diffuse unit-area source emission coefficients of nitrogen in Estonian rivers. The input data included monitored riverine loads, point sources and land use categories from a total of 50 rivers/catchment areas. Two independent studies were conducted: the estimation of emission coefficients for the whole of Estonia and for a smaller study area near Tallinn. The results from both cases showed that drained peat soils were the highest diffuse source contributor in unit-area loads. The results show that the unit-area loads from drained peat soils were up to 2.3 times higher than from arable land. Moreover, a comparison of emission coefficients for the whole of Estonia and for the Tallinn catchment area indicated that coefficients can vary significantly between sources and single years. Additional detailed studies and monitoring are needed to support these conclusions.

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Abstract

A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts- Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons’ stakeholders, complemented by scientic knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations.

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Abstract

Agricultural management practices are among the major drivers of agricultural nitrogen (N) loss. Legislation and management incentives for measures to mitigate N loss should eventually be carried out at the individual farm level. Consequently, an appropriate scale to simulate N loss from a scientific perspective should be at the farm scale. A data set of more than 4000 agricultural fields with combinations of climate, soils and agricultural management which overall describes the variations found in the Baltic Sea drainage basin was constructed. The soil–vegetation–atmosphere model Daisy (Hansen et al. 2012) was used to simulate N loss from the root zone of all agricultural fields in the data set. From the data set of Daisy simulations, we identified the most important drivers for N loss by multiple regression statistics and developed a statistical N loss model. By applying this model to a basin-wide data set on climate, soils and agricultural management at a 10 × 10 km scale, we were able to calculate root-zone N losses from the entire Baltic Sea drainage basin and identify N loss hot spots in a consistent way and at a level of detail not hitherto seen for this area. Further, the root-zone N loss model was coupled to estimates of nitrogen retention in catchments separated into retention in groundwater and retention in surface waters allowing calculation of the coastal N loading.

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Abstract

A statistical model MESAW was used to estimate the diffuse emission coefficients of nitrogen in Estonia. This includes analysis of data on loads, point sources, land use types etc. Two studies were conducted to determine the emission coefficients for the whole Estonia and for a smaller study area near Tallinn. Investigations showed that in addition to arable lands, drained peat soils can be a significant source of nitrogen. In fact, our results show that the unit-area loads from drained peat soils may be 1.5 to 2.3 times higher than from arable lands. Additional detailed investigations and measurements are needed to support these conclusions. Comparison of emission coefficients for the whole Estonia and of the Tallinn catchment area indicated that the coefficients can vary significantly between sources and single years. Therefore it is suggested that the sources of nitrogen loads should be defined in a catchment area level rather than a country level.

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Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2015 have been estimated in accordance with the OSPAR Commission’s principles. Nutrients, metals and organic pollutants have been monitored in rivers; discharges from point sources have been estimated from industry, sewage treatment plants and fish farming; and nutrient inputs from diffuse sources have been modelled. Trends in riverine inputs have been analyzed, and threshold concentration levels investigated.

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Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2014 have been estimated in accordance with the OSPAR Commission’s principles. Nutrients, metals and organic pollutants have been monitored in rivers; discharges from point sources have been estimated from industry, sewage treatment plants and fish farming; and nutrient inputs from diffuse sources have been modelled. Trends in riverine inputs have been analysed, and threshold concentration levels investigated.

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Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2012 have been estimated in accordance with the requirements of the OSPAR Commission. Water discharges in 2012 were lower than in 2011, but higher than the 30-year normal. This caused a small but overall decrease in inputs since 2011, with an exception of zinc, which increased in the overall loads due to an increase in River Glomma. The reason is presently unknown. Analyses of data since 1990 from nine main rivers in the program revealed downward trends both for nutrients and metals, with an exception of upwards trends for ammonium in one river. Fish farming continued to be a major source of nutrients, with an increase of about 15 % of phosphorus and nitrogen loads since last year. Inputs of PCBs and the pesticide lindane were, as in previous years, insignificant

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Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2013 have been estimated in accordance with the requirements of the OSPAR Commission. Nutrients, metals and organic pollutants have been monitored in rivers; discharges from point sources have been estimated from industry, sewage treatment plants and fish farming; and nutrient inputs from diffuse sources have been modelled. Trends in riverine inputs have been analysed. Concentrations above given threshold levels have been detected for both metals and organic pollutants in some rivers.

Abstract

VIDEO: Issues such as contamination from surrounding agriculture, increased tourism and climate change all pose a threat to Europe’s many lagoons - vulnerable ecosystems in densely populated areas. Scientists are now going new ways to secure better lagoon management in future.

Abstract

In Norway, water quality of small streams draining agricultural catchments has been monitored since 1993 by the Agricultural and Environmental Monitoring Program. This article attempted to examine the concentration levels, temporal dynamics and long-term trends (1993–2009 and 1996–2009) of Al, Fe, Cu, Mn and Zn in streams draining the catchment areas of Skuterud (4.5 km2) and Mørdre (6.8 km2), located in south-east Norway. In the Mørdre stream, Al, Fe, Cu, Mn and Zn all showed statistically significant downward trends (p<0.05), whilst in the Skuterud stream only Al and Fe showed statistically downward significance (p<0.05). The general declining trends of metal concentrations are most likely associated with reduction of acid rain deposition in southern Norway. In spite of this declining trends, over the 14–17 years of monitoring mean monthly concentrations of total Al (2.0–3.2 mg L−1), Fe (1.3–2.5 mg L−1) and Cu (8.9–26.1 µg L−1) in Skuterud and Mørdre streams, respectively exceeded the limits of the Norwegian Water Framework Directives, whereas the concentrations of Mn (22.3–40.8 µg L−1) and Zn (13.1–99.4 µg L−1) fell within the range of desired limits. Of the total water samples analysed from Skuterud (n=370) and Mørdre streams (n=255), nearly 80–84%, 70–87% and 79–96% were above the desired limits for Al (0.2 mg L−1), Fe (0.3 mg L−1) and Cu (3 µg L−1), respectively. In 2011, water analysis from drainage of forest soils (in Skuterud catchment) measured total Al: 0.42–0.79 mg L−1 and total Fe: 0.84–1.0 mg L−1 which were two to three folds greater than the desired limits. In general, weak correlations between runoff and concentrations of the metals in the streams were noted. Future research should focus on identifying the sources of Al, Fe and Cu and management interventions of elevated metal inputs to Skuterud and Mørdre streams.

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Abstract

Access to sufficient quantities of water of acceptable quality is a basic need for human beings and a pre-requisite to sustain and develop human welfare. In cases of limited availability, the allocation of water between different sectors can result in conflicts of interests. In this study, a modified version of the Building Block Methodology (BBM) was demonstrated for allocation of waters between different sectors. The methodology is a workshop-based tool for assessing water allocation between competing sectors that requires extensive stakeholder involvement. The tool was demonstrated for allocation of water in the Sri Ram Sagar water reservoir in the Godavari Basin, Andhra Pradesh, India. In this multipurpose reservoir, water is used for irrigation, drinking water supply and hydropower production. Possible water allocation regimes were developed under present hydrological conditions (normal and dry years) and under future climate change, characterized by more rain in the rainy season, more frequent droughts in the dry season and accelerated siltation of the reservoir, thus reducing the storage capacity. The feedback from the stakeholders (mainly water managers representing the various sectors) showed that the modified version of the BBM was a practical and useful tool in water allocation, which means that it may be a viable tool for application also elsewhere.

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Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2011 have been estimated in accordance with the requirements of the OSPAR Commission. Due to high water discharges in 2011, the riverine inputs of both nutrients and metals were greater than 2010. Analyses of data since 1990 from nine main rivers in the program revealed downward trends both for nutrients and metals, with an exception of upwards trends for nitrogen in one river. Fish farming continued to be a major source of nutrients and copper to coastal waters. Inputs of PCBs and the pesticide lindane were, as in previous years, insignificant.