Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2026
Abstract
Pedotransfer functions (PTFs) are widely used as an efficient alternative for estimating soil hydraulic properties. However, insufficient understanding of how specific input data characteristics drive PTF prediction performance, coupled with challenges in assessing PTF transferability beyond their development datasets, limit their robustness and broad application. Here, we employed the hierarchical Rosetta3 as the development dataset and evaluated its PTF performance using two independent application datasets (National Cooperative Soil Survey (NCSS) and HYBRAS-V2), comprising over 51,900 samples. To further investigate the effect of the input similarity on PTF performance, the Chamfer Distance (CD) was used to quantify the similarity between the development and application datasets. The extensive NCSS database allowed us to stratify the application dataset by soil temperature regimes, texture classes, and depths for a detailed performance evaluation. Results showed that incorporating additional inputs (e.g., bulk density, field capacity, and wilting point) moderately reduces the correlations between these newly added inputs and the estimation residuals, and that higher residual-input correlations are associated with inferior PTF performance. Furthermore, a lower CD (better resemblance of development and application dataset) leads to better PTF performance. However, increasing input complexity using the hierarchical Rosetta3 models mitigates this effect of resemblance, enhancing robustness across diverse soil and environmental conditions. These findings highlight the importance of analyzing residual-input correlations and suggest that quantifying input-data similarity between PTF development and application datasets can serve as a practical approach to assess the transferability of PTFs.
Abstract
ABSTRACT This study evaluated the SWAT+ model in a Norwegian catchment with mixed forest-agriculture land use, tile drainage, and multiple lakes, and examined the added value of incorporating soft data as process-based constraints during calibration. The primary aim was to test whether such constraints improve hydrological consistency in addition to statistical fit. A stepwise methodology was applied, including parameter initialization, model verification, water balance soft calibration, and constraint-based hard calibration. We showed how each stage incrementally improved model performance. Three hydrological constraints were defined to represent water balance components (runoff coefficient), streamflow signatures (baseflow index), and expert knowledge of catchment behavior (tile flow ratio). Constraint-based calibration achieved slightly lower efficiency scores (NSE = 0.61, KGE = 0.72) than unconstrained calibration (NSE = 0.65, KGE = 0.77), reflecting the trade-off between optimizing performance metrics and ensuring realistic hydrological processes. The baseflow index was the most influential constraint, eliminating about 77% of non-behavioral simulations when assessed individually. The results also highlight the importance of lake initialization and the need for multiple performance metrics when tuning lake release parameters. Overall, integrating process-based knowledge strengthened internal consistency and increased confidence that SWAT+ performs well for the right reasons.
2025
Abstract
This paper addresses water governance in the context of dissolved organic matter emissions into water bodies and cultural eutrophication. Through a comparative interdisciplinary analysis of cases from Norway, the Czech Republic, and China, it seeks to identify core principals of effective water governance and suggest strategies for achieving good ecological and chemical status of raw water. The analysis presents each case by exploring natural and societal processes, emphasising the interdependence between society and nature, and applying a theoretical framework. In this way, the paper contributes to the broader field of water governance studies. The central conclusion is that raw water quality results from “muddling through” processes involving stakeholders with diverse and sometimes conflicting interests. Building the capabilities to manage such contingencies is essential for successful governance. Four critical dimensions are identified as key to this capability: (i) robust environmental knowledge and literacy; (ii) stronger representation of non-human interest; (iii) regulatory measures and economic incentives to enhance raw water quality; and (iv) integrated multi-level governance combining top-down and bottom-up approaches. Strengthening these dimensions can also help mitigate the structural economic pressure driving the exploitation of “cheap nature”.
Authors
Tibor Zsigmond Csilla Farkas Andor Bódi Zsófia Bakacsi Eszter Tóth Márton Dencső Ágota HorelAbstract
The aim of the present study was to investigate stream turbidity and water chemical parameters under varying environmental conditions. We analyzed a three-year-long (2021-2023) daily and bi-weekly dataset collected at six points (P1-P6) along a small stream. We measured stream water turbidity (FNU), total dissolved inorganic nitrogen (TDIN) content, water pH, and specific conductivity (SPC). Meteorological data were collected at the catchment outlet. Daily data showed a moderate positive correlation between FNU and precipitation (r=0.42, p <0.001), while weak negative connections were observed between SPC and FNU values (r=-0.14, p =0.011, n=349). The FNU values at the groundwater spring-fed sampling point (P3) were significantly different from the other sampling points on most parameters ( p <0.05). The results of the cluster analysis revealed three main clusters based on daily turbidity data. These groups of daily precipitation totals were i) below 4.8 mm, ii) averaging 6.3 mm, and iii) averaging 23.7 mm. The clusters were most significantly separated along precipitation and FNU values. Turbidity values were strongly correlated with precipitation events for two days, after which stream water quality returned to baseline. Stream water quality was not significantly influenced by soil management or antecedent moisture content but rather by water origin (i.e., precipitation, groundwater).
Authors
Hannu Marttila Joy Bhattacharjee Katrin Bieger Brian Kronvang Mikołaj Piniewski Svajunas Plunge Ignacy Kardel Marek Giełczewski Csilla Farkas Moritz Shore Mojtaba Shafiei Arturs Veinbergs Ieva Siksnane Kaspars Abramenko Ainis Lagzdins Kristina Mårtensson Sara Sandström Katarina KyllmarAbstract
This document describes comparison of SWAT+ model with national/regional hydrogeochemical models as well as graphs and maps of the most relevant outputs documenting the model performance and comparison. Case and demonstration study-specific model descriptions and inputs are in the report as appendices.
Abstract
No abstract has been registered
Abstract
Reducing diffuse nutrient losses to water bodies remains a major problem in the agricultural areas of the Nordic countries. The transition towards a bioeconomy and ongoing climate change raise questions on the future of water quality and freshwater ecosystems and what kind of adaptation strategies could be implemented to maintain both food and environmental safety. The objective of our study was to evaluate the effectiveness of Natural Soil Water Retention Measures (NSWRMs) under current and future climate conditions in retaining water, soil particles and nutrients within the landscape. The hydro-biochemical model SWAT+ was implemented in the Krakstad catchment in southern Norway using the novel approach developed within the EU H2020 project OPTAIN. This approach enables an improved spatial representation of NSWRMs in the landscape. Available discharge and water quality monitoring data were used as reference data for model calibration. The effectiveness of reduced tillage, grassed waterways, sedimentation ponds established in the forested areas and buffers on water retention and nutrient loads was evaluated. Our simulation results indicate that conservation tillage, which maintains stubble on the soil surface during winter, has the strongest impact on reducing soil and nutrient losses towards surface water bodies. Grassed waterways, established in existing erosion prone gullies, could also significantly contribute to water and nutrient retention within the landscape. The implemented NSWRMs did not appear to increase the soil moisture content in early spring even under future climate conditions, which is an important aspect for ensuring soil trafficability and the timing of sowing spring cereals
Abstract
Fresh water quality problems in Norway are largely caused by high phosphorus (P) inputs from the catchments. The need for measures in the agricultural landscape, such as constructed wetlands (CWs), are needed and the importance of the measures will most probably increase due to the consequences of climate changes. In agricultural areas in South-Eastern Norway, several hundred small vertical flow CWs were established in the streams during the last two decades, to reduce downstream losses of sediments (SS) and nutrients. The focus of the CWs has been on reducing losses of P and SS, due to the naturally P-rich clay soils of marine origin in lowland areas. Whereas our study included 11 CWs altogether, we here present the data from the CW with the most intensive monitoring, i.e., the Skuterud CW, around 20 years after it was constructed. The catchment’s total area was 450 ha with 61% agricultural land. The CW occupies 0.05% of the catchment area. The methods included analyses of waterflow-proportional water composite samples, water grab samples, sensor monitoring (turbidity), bed sediments, and biological quality elements (invertebrates and benthic algae). Analyses of three years of composite samples showed a retention of 47 % for SS, 41 % for total phosphorus (TP), 4.2 % for total nitrogen (TN), 0.8 % for ortho-phosphate, and a negative retention for nitrate (i.e., nitrate leaching). Monitoring by turbidity sensors (correlations to SS and TP; R2 = 0,7802) during a 5 - month period showed that retention during episodes of elevated water discharges was 26 % for SS and 11 % for TP. Grab sampling gave more confusing results. It was revealed by the sensor monitoring that to assess the retention in CWs by grab sampling at the in- and outlet can be misleading, even if the sampling is done at the same time. The reason is the rapid variation in concentrations. Bed sediments have been removed from the CW several times since it was established, and in total approx. 1140 tons of SS and approx. 1090 kg of particle bound P. However, it is difficult to assess the total amount of retention, as we did not know the extent of leaching of nutrients from the bed sediments over the years. The analysis of invertebrates and benthic algae revealed that the ecological condition was better at the inlet and worse at the outlet (similar for five CWs). The reason is probably that the oxygen levels and substrate conditions are better at the inlet, where the running creek enters, whereas the outlet would have still-standing waters with lower oxygen contents and a clayey substrate. Moreover, this can be due to the method used, as the outlet area had fewer stones where the benthic algae could grow. Hence, it would be better to sample biology a bit more downstream, but that is often not practical, as the CWs often have their outlet into another stream or directly into a drainage system. In summary therefore, our recommendation is to use composite sampling and/or sensor monitoring (combined with grab sampling for correlation purposes), to assess the retention capacity of a CW. However, for cost-effective assessment of the effect of sediments and particle bound nutrients, bed sediments are recommended.
Abstract
Fertilizers and pesticides contribute to the pollution of water resources. The areas along streams are affected by climate change as stream bank failures often occur following floods or during prolonged rainfalls. In addition to BMP (best management practices) on the fields, grassed cover buffer zones are one of the most common measures for improving water quality in Norway’s agricultural catchments. Increased focus on buffer zones is important in a future climate perspective, both for food production, natural diversity and water quality. The efficiency of vegetation cover is composed of a variety of factors; therefore, effectives of these measures are to a large degree site specific. Recently, increased attention is given to the buffer zones efficiency, depending on both conditions in the catchments and the design of the buffer zones itself. However, most research is focusing in investigating the effect of buffer zones looking mostly at the surface runoff. According to our knowledge there is no previous research investigating the efficiency of the buffer zones with flower mixture. We focus on these types of vegetation as they also stimulate increased biodiversity. Moreover, previous investigations show that more than 50% of simulated runoff infiltrates into buffer zones with grass and bushes, while within buffer zones with trees there all the water infiltrates into the soil. Herein we show the results of 3 years monitoring surface runoff from buffer zones with different types of plant cover (grass and flower mixture). The idea was to monitor real live surface runoff from the field with autumn tillage (as “worst case scenario”). The results show significant differences, especially in the runoff quality. The visual differences are confirmed by water quality analysis.
Authors
Martyn Futter Emma Lannergård Katrin Bieger Csilla Farkas Jens Fölster Pia Geranmayeh Anastasija Isidorova Brien Kronvang Dominika Krzeminska Katarina Kyllman Ainis Lagzdins Anu Lähteenmäki-Uutela Hannu Marttila Michael Peacock Katri Rankinen Eva Skarbøvik Anne Lyche Solheim Pasi Valkama Joachim AudetAbstract
Society increasingly expects that food will be produced in a sustainable, climate-smart manner. Nature based solutions (NBS), including ponds and constructed wetlands are widely promoted by researchers as a class of measures promoting healthy agricultural landscapes. However, a range of trade-offs associated with NBS influence practitioner’s decisions about their implementation and use. Making the right decisions about NBS requires, amongst other things, access to data from environmental monitoring programmes. The value of monitoring programmes depends on how well the data they collect and curate can be used to support decision-making. Here, we present a conceptual framework for assessing the value of monitoring programmes based on the relevance of the data they collect to decision maker needs, their overall running costs and their levels of uncertainty in characterizing the state of the environment. We demonstrate how our proposed framework can be used to assess the value of a range of monitoring programmes for quantifying trade-offs between nutrient load reduction and climate impacts from artificial wetlands in agricultural landscapes.