Browsing by Subject "218 Environmental engineering"

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  • Koppelmäki, Kari; Eerola, Markus; Albov, Sophia; Kivelä, Jukka; Helenius, Juha; Winquist, Erika; Virkkunen, Elina (2016)
    COMREC Studies in Environment and Development
    What could be a functioning food system model for a food secure and sustainable world. This project studies a pilot case - 'Palopuro Agroecological Symbiosis' (Palopuro AS) - for restructuring the food system in Palopuro village in the Finnish countryside. The project challenges the present linear, globalizing food chain and suggests a global network of localized cyclical systems. A local food cycle highlights reconnection of farmers and consumers, minimizes nutrient loss, and relies on local (bio)energy. This project investigates the cultural, social, political, ecological, and spatial changes in Finnish agricultural landscapes as a result of implementation of an ecological symbiosis . We use the term ‘agro-ecological symbiosis’ to describe the cooperation between producers, processors, other businesses, and consumers in an effort to build an integrated food system.
  • Baltrenaite, Edita; Baltrenas, Pranas; Bhatnagar, Amit; Vilppo, Teemu; Selenius, Mikko; Koistinen, Arto; Dahl, Mari; Penttinen, Olli-Pekka (2017)
    The environmental legislation and strict enforcement of environmental regulations are the tools effectively used for developing the market of materials for environmental protection technologies. Sustain ability criteria shift environmental engineering systems to more sustainable-material-based technologies. For carbon-based medium materials in biofiltration, this trend results in attempts to use biochar for biofiltration purposes. The paper presents the analysis of biochar properties based on the main criteria for biofiltration medium integrating the environmental quality properties of biochar, following the European Biochar Certificate guidelines. Three types of biochar produced from feedstock of highly popular and abundant types of waste are analysed. A multi component approach was applied to summarize the results. The lignocellulosic type of biochar was found to be more competitive for use as a biofiltration medium than the types of biochar with high ash or lignin content. (C) 2016 Elsevier Ltd. All rights reserved.
  • Haghighi, Ali Torabi; Ashraf, Faisal Bin; Riml, Joakim; Koskela, Jarkko; Kløve, Bjørn; Marttila, Hannu (Elsevier, 2019)
    Applied Energy 255 (2019), 113905
    With increasing power production from renewable energy sources, sub-daily variations in energy demand need to be balanced. Today, hydropower is commonly used as balancing power. In this study, we quantified the impact of capacity constraints, in terms of reservoir volume and hydropower capacity, on the potential to comply with instant energy demand. To evaluate the impact, we developed two new metrics, power market impact and system efficiency ratio, which are based on two threshold flow regimes derived from natural flow as lower threshold release and regulated flow (based on hourly energy prices) as upper threshold release. The operation support model comprises 96 different regulation scenarios based on varying combinations of hydropower and reservoir capacities. For each scenario, an hourly water balance was simulated, to obtain the highest complying with upper threshold release based on actual energy demand. We tested the framework on the Kemijoki river with defined thresholds based on the natural flow regime (tributary river Ounasjoki) and the hourly energy price in Finland in 2017, and estimated the impact of regulation on hourly flow regime at the Taivalkoski hydropower station. The annual flow regime impact in 2013, 2014 and 2015 was estimated to be 74%, 84% and 61%, respectively, while the monthly impact varied from 27% to 100%. Our framework for evaluating interactions between the power market and sub-daily regulation practices is a useful novel tool for sustainable river management and can be easily applied to different rivers and regions and evaluated for different timescales.
  • Venäläinen, Salla; Hartikainen, Helka Helinä (2017)
    Utilisation of sodium (Na+) containing alkali in the neutralisation of acidic industrial process waters rich in sulphate (SO4 2−) produces effluents high in sodium sulphate (Na2SO4) reluctant to precipitate. Discharge of the saline effluents leads to permanent chemical stratification of the recipient freshwater systems, which prevents their annual overturn and the subsequent oxygen supply to hypolimnion. Novel and sustainable technologies are desperately needed to prevent the hazardous environmental impacts of saline effluents. We investigated the ability of anionic nanofibrillated cellulose (NFC) gels of three different consistencies to recover solubilised Na+ and SO4 2− from authentic circumneutral mining water onto a solid phase. The water was treated with the NFC gels in three sequential batches at three sorbent-to-solution ratios. NFC-induced changes in the ion concentrations were determined to calculate the Na+ and SO4 2− retention capacity and purification efficiency of the NFC gels. All NFC gels efficiently and coincidentally removed Na+ and SO4 2− from the mining water. We concluded that Na+ ions electrostatically adsorbed onto the deprotonated carboxyl groups of the anionic NFC and attracted SO4 2− ions which also acted as bridging anions between the neighbouring nanofibrils. Decrease in the consistency of the NFC gel enhanced accessibility of the sorption sites and, consequently, promoted the ion retention. A high sorbent-to-solution ratio favoured the intermolecular interactions within the NFC gels, thus decreasing the number of available sorption sites. A high ionic strength of the effluent favoured the ion retention, indicating that anionic NFC is particularly suitable for the treatment of highly saline solutions. The best purification result was obtained at a moderate sorbent-to-solution ratio with a dilute NFC gel. This lowers the demand for the cellulose raw material and the treatment expenses. We conclude that anionic NFC, made of renewable materials, may serve as an efficient and sustainable purification agent for removal and recycling of highly soluble Na+ and SO4 2−from industrial effluents
  • Marbouti, Marjan; Antropov, Oleg; Eriksson, Patrick; Praks, Jaan; Arabzadeh, Vahid; Rinne, Eero; Leppäranta, Matti (IEEE, 2018)
    IEEE International Symposium on Geoscience and Remote Sensing IGARSS
    In this study, bistatic interferometric Synthetic Aperture Radar (InSAR) data acquired by the TanDEM-X mission were used for automated classification of sea ice over the Baltic Sea, in the Bothnic Bay. A scene acquired in March of 2012 was used in the study. Backscatter-intensity, coherence-magnitude and InSAR-phase, as well as their different combinations, were used as informative features in several classification approaches. In order to achieve the best discrimination between open water and several sea ice types (new ice, thin smooth ice, close ice, very close ice, ridged ice, heavily ridged ice and ship-track), Random Forests (RF) and Maximum likelihood (ML) classifiers were employed. The best overall accuracies were achieved using combination of backscatter-intensity & InSAR-phase and backscatter-intensity & coherence-magnitude, and were 76.86% and 75.81% with RF and ML classifiers, respectively. Overall, the combination of backscatter-intensity & InSAR-phase with RF classifier was suggested due to the highest overall accuracy (OA) and smaller computing time in comparison to ML. In contrast to several earlier studies, we were able to discriminate water and the thin smooth ice.
  • Niemi, Tero; Kokkonen, Teemu; Sillanpää, Nora; Setälä, Heikki; Koivusalo, Harri (2019)
    Constructing hydrological models for large urban areas is time consuming and laborious due to the requirements for high-resolution data and fine model detail. An open-source algorithm using adaptive subcatchments is proposed to automate Storm Water Management Model (SWMM) construction. The algorithm merges areas with homogeneous land cover and a common outlet into larger subcatchments, while retaining small-scale details where land cover or topography is more heterogeneous. The method was tested on an 85-ha urban catchment in Helsinki, Finland. A model with adaptive subcatchments reproduced the observed discharge at the catchment outlet with high model-performance indices emphasizing the strength of the proposed method. Computation times of the adaptive model were substantially lower than those of a corresponding model with uniformly sized high-resolution subcatchments. Given that high-resolution land cover and topography data are available, the proposed algorithm provides an advanced method for implementing SWMM models automatically even for large urban catchments without a substantial manual workload. Simultaneously, the high-resolution land cover details of the catchments can be maintained where they matter the most. (c) 2019 American Society of Civil Engineers.
  • White, Joanne C.; Saarinen, Ninni; Kankare, Ville; Wulder, Michael A.; Hermosilla, Txomin; Coops, Nicholas C.; Pickell, Paul D.; Holopainen, Markus; Hyyppä, Juha; Vastaranta, Mikko (2018)
    Landsat time series (LTS) enable the characterization of forest recovery post-disturbance over large areas; however, there is a gap in our current knowledge concerning the linkage between spectral measures of recovery derived from LTS and actual manifestations of forest structure in regenerating stands. Airborne laser scanning (ALS) data provide useful measures of forest structure that can be used to corroborate spectral measures of forest recovery. The objective of this study was to evaluate the utility of a spectral index of recovery based on the Normalized Burn Ratio (NBR): the years to recovery, or Y2R metric, as an indicator of the return of forest vegetation following forest harvest (clearcutting). The Y2R metric has previously been defined as the number of years required for a pixel to return to 80% of its pre-disturbance NBR (NBRpre) value. In this study, the Composite2Change (C2C) algorithm was used to generate a time series of gap-free, cloud-free Landsat surface reflectance composites (1985–2012), associated change metrics, and a spatially-explicit dataset of detected changes for an actively managed forest area in southern Finland (5.3 Mha). The overall accuracy of change detection, determined using independent validation data, was 89%. Areas of forest harvesting in 1991 were then used to evaluate the Y2R metric. Four alternative recovery scenarios were evaluated, representing variations in the spectral threshold used to define Y2R: 60%, 80%, and 100% of NBRpre, and a critical value of z (i.e. the year in which the pixel's NBR value is no longer significantly different from NBRpre). The Y2R for each scenario were classified into five groups: recovery within 17 years, and not recovered. Measures of forest structure (canopy height and cover) were obtained from ALS data. Benchmarks for height (>5 m) and canopy cover (>10%) were applied to each recovery scenario, and the percentage of pixels that attained both of these benchmarks for each recovery group, was determined for each Y2R scenario. Our results indicated that the Y2R metric using the 80% threshold provided the most realistic assessment of forest recovery: all pixels considered in our analysis were spectrally recovered within the analysis period, with 88.88% of recovered pixels attaining the benchmarks for both cover and height. Moreover, false positives (pixels that had recovered spectrally, but not structurally) and false negatives (pixels that had recovered structurally, but not spectrally) were minimized with the 80% threshold. This research demonstrates the efficacy of LTS-derived assessments of recovery, which can be spatially exhaustive and retrospective, providing important baseline data for forest monitoring.
  • Marttila, H.; Tammela, S.; Mustonen, K.-R.; Louhi, P.; Muotka, Timo; Mykrä, Heikki; Klove, B. (IWA Publishing, 2019)
    Hydrology Research 1 June 2019; 50 (3): 878–885
    We conducted a series of tracer test experiments in 12 outdoor semi-natural flumes to assess the effects of variable flow conditions and sand addition on hyporheic zone conditions in gravel beds, mimicking conditions in headwater streams under sediment pressure. Two tracer methods were applied in each experiment: 2–5 tracer-pulse tests were conducted in all flumes and pulses were monitored at three distances downstream of the flume inlet (0 m, 5 m and 10 m, at bed surface), and in pipes installed into the gravel bed at 5 m and 10 m distances. The tracer breakthrough curves (total of 120 tracer injections) were then analysed with a one-dimensional solute transport model (OTIS) and compared with data from the gravel pipes in point-dilution pulse tests. Sand addition had a strong negative effect on horizontal fluxes (qh), whereas the fraction of the median travel time due to transient storage (F200) was determined more by flow conditions. These results suggest that even small additions of sand can modify the hyporheic zone exchange in gravel beds, thus making headwater streams with low sediment transport capacity particularly vulnerable to sediments transported into the stream from catchment land use activities.
  • Tossavainen, Marika; Nykänen, Anne; Valkonen, Kalle Santeri; Ojala, Anne; Silja, Kostia; Romantschuk, Martin (2017)
    Growth and fatty acid production of microalga Selenastrum sp. with associated bacteria was studied in lab-scale experiments in three composting leachate liquids. Nutrient reduction in cultures was measured at different initial substrate strengths. A small, pilot-scale photobioreactor (PBR) was used to verify labscale results. Similar growth conditions supported growth of both Selenastrum and bacteria. CO2 feed enhanced the production of biomass and lipids in PBR (2.4 g L-1 and 17% DW) compared to lab-scale (0.1-1.6 g L-1 and 4.0-6.5% DW) experiments. Also prolonged cultivation time increased lipid content in PBR. At both scales, NH4-N with an initial concentration of ca. 40 mg L-1 was completely removed from the biowaste leachate. In lab-scale, maximal COD reduction was over 2000 mg L-1, indicating mixotrophic growth of Selenastrum. Co-cultures are efficient in composting leachate liquid treatment, and conversion of waste to biomass is a promising approach to improve the bioeconomy of composting plants. (C) 2017 The Authors. Published by Elsevier Ltd.
  • Bhattacharjee, Joy; Marttila, Hannu; Haghighi, Ali Torabi; Saarimaa, Miia; Tolvanen, Anne; Lepistö, Ahti; Futter, Martyn N.; Kløve, Bjørn (American Society of Civil Engineers, 2021)
    Journal of Irrigation and Drainage Engineering, 147(4), 04021006
    Spatiotemporal information on historical peatland drainage is needed to relate past land use to observed changes in catchment hydrology. Comprehensive knowledge of historical development of peatland management is largely unknown at the catchment scale. Aerial photos and light detection and ranging (LIDAR) data enlarge the possibilities for identifying past peatland drainage patterns. Here, our objectives are (1) to develop techniques for semiautomatically mapping the location of ditch networks in peat-dominated catchments using aerial photos and LIDAR data, and (2) to generate time series of drainage networks. Our approaches provide open-access techniques to systematically map ditches in peat-dominated catchments through time. We focused on the algorithm in such a way that we can identify the ditch networks from raw aerial images and LIDAR data based on the modification of multiple filters and number of threshold values. Such data are needed to relate spatiotemporal drainage patterns to observed changes in many northern rivers. We demonstrate our approach using data from the Simojoki River catchment (3,160  km2) in northern Finland. The catchment is dominated by forests and peatlands that were almost all drained after 1960. For two representative locations in cultivated peatland (downstream) and peatland forest (upstream) areas of the catchment; we found total ditch length density (km/km2), estimated from aerial images and LIDAR data based on our proposed algorithm, to have varied from 2% to 50% compared with the monitored ditch length available from the National Land survey of Finland (NLSF) in 2018. A different pattern of source variation in ditch network density was observed for whole-catchment estimates and for the available drained-peatland database from Natural Resources Institute Finland (LUKE). Despite such differences, no significant differences were found using the nonparametric Mann-Whitney U test with a 0.05 significance level based on the samples of pixel-identified ditches between (1) aerial images and NLSF vector files and (2) LIDAR data and NLSF vector files.
  • Väänänen, Kristiina; Abel, Sebastian; Oksanen, Tähti; Nybom, Inna; Leppänen, Matti T.; Asikainen, Harri; Rasilainen, Maj; Karjalainen, Anna K.; Akkanen, Jarkko (Elsevier, 2019)
    Science of The Total Environment 662 (2019), 88-98
    There are several methods for studying metal-contaminated freshwater sediments, but more information is needed on which methods to include in ecological risk assessment. In this study, we compliment the traditional Sediment Quality Triad (SQT) approach – including information on chemistry, toxicity and ecological status – with studies on metal bioavailability and metal body residues in local organisms. We studied four mining-affected boreal lakes in Finland by conducting chemical analyses of sediment and water, toxicity tests (L. variegatus, V. fischeri, C. riparius, L. stagnalis), and analysis of benthic organism community structure. In addition, we studied the relationships between metal loading, toxicity, metal bioavailability, and metal body residues in the field-collected biota. Chemistry and benthic organism community structures show adverse effects in those lakes, where the metal concentrations are the highest. However, toxicity was connected to low sediment pH during the experiment, rather than to high metal concentrations. Toxicity was observed in 4 out of 6 toxicity tests including growth test with L. variegatus, bulk sediment test with V. fischeri, and the L. stagnalis toxicity test. The C. riparius test did not show toxicity. Metal body residues in biota were not high enough to induce adverse effects (0.1–4.1 mg Cu/kg fw, 0.01–0.3 mg Ni/kg fw, 2.9–26.7 mg Zn/kg fw and 0.01–0.7 mg As/kg fw). Chemical analyses, metal bioavailability assessment and benthic community structures survey revealed adverse effects in the sediments, where metal concentrations are highest (Lake SJ and Lake KS). Standard toxicity tests were not suitable for studying acid, sulfide-rich sediments and, therefore, benthic structure study and chemical analyses are believed to give more reliable results of the ecological status of these sediments.
  • Laakso, Senja; Heiskanen, Eva (ENERGISE project, 2017)
  • Arriga, Nicola; Rannik, Ullar; Aubinet, Marc; Carrara, Arnaud; Vesala, Timo; Papale, Dario (2017)
    Footprint models, which simulate source area for scalar fluxes, are fundamental tools for a correct interpretation of micromoeteorological flux measurements and ecosystem exchange inferred from such data. Over the last two decades models of varying complexity have been developed, but all of them suffer from a significant lack of experimental validation. In this study two different experimental tests have been conducted with the aim of offering validation: a manipulation of the vegetation cover and an artificial tracer emission. In the first case the extension of the flux source has been changed progressively by successive cuts of vegetation, while in the second case by varying the distance of a tracer emission line respect to the measurement point. Results have been used to validate two analytical and a numerical footprint models. The experimental data show a good agreement with footprint models and indicate a limited extension of the flux source area, with approximately 75% of the sources confined within a range of 10-20 times the effective measurement height, i.e. the measurement height above the zero plane displacement. Another interesting result was the strong dependence on the surface roughness of both experimental estimates and numerical simulations of footprint. The effect of surface roughness on experimental results and models outputs was comparable to the effect of atmospheric stability. This indicates that surface roughness and turbulence conditions may play a significant role in source area location, in particular above inhomogeneous surfaces with change in roughness, as in the case of the manipulation experiment. Consequently a careful site specific quantification of these parameters seems to be fundamental to obtain realistic footprint estimates and significantly improve eddy covariance flux interpretation at complex sites.
  • Honkavaara, Eija; Hakala, Teemu; Nevalainen, Olli; Viljanen, Niko; Rosnell, Tomi; Khoramshahi, Ehsan; Näsi, Roope; Oliveira, R.; Tommaselli, Antonio (2016)
  • Kutuniva, Johanna; Mäkinen, Jari; Kauppila, Tommi; Karppinen, Anssi; Hellsten, Seppo; Luukkonen, Tero; Lassi, Ulla (Elsevier, 2019)
    Journal of Environmental Chemical Engineering 7, 1 (2019), 102852
    Metal(loid) contamination in sediments is a widespread environmental issue. Sediments act normally as metal(loid) sinks, but if chemical conditions (such as pH or redox potential) change, they can become sources of secondary pollution. Consequently, various strategies for both in and ex situ remediation of contaminated sediments have been developed. One promising method is active capping, which involves the injection of adsorbents as a layer on the sediment surface or the mixing of adsorbents within the sediment. Adsorbents decrease the bioavailability of metal(loid)s. In the present work, the suitability of alkali-activated blast-furnace-slag, metakaolin geopolymer, and exfoliated vermiculite were evaluated for in situ stabilization of two metal(loid)-contaminated lake sediments through laboratory-scale experiments. The results indicated that adsorbent amendments had metal(loid)-specific performance: alkali-activated blast-furnace slag was suitable for Al, Cu, Fe, and Ni; metakaolin geopolymer for Cu, Cr (total), and Fe; and vermiculite for Al and Zn. None of the materials could stabilize Ba, Sr, or Ti. Furthermore, the amendments performed differently in two different lake sediments, implying that the effectiveness of the amendments needs to be confirmed on a case-by-case basis.
  • Wang, Qingkai; Li, Zhijun; Lu, Peng; Cao, Xiaowei; Leppäranta, Matti (2018)
    The kinetic coefficient of friction μk was measured for sea ice, stainless steel, and coated steel sliding on a natural sea ice cover. The effects of normal stress (3.10–8.11 kPa), ice columnar grain orientation (vertical and parallel to the sliding direction), sliding velocity (0.02–2.97 m·s–1), and contact material were investigated. Air temperature was higher than −5.0 °C for the test duration. The results showed a decline of μk with increasing normal stress with μk independent of ice grain orientation. The μk of different materials varied, partly due to distinct surface roughnesses, but all cases showed a similar increasing trend with increasing velocity because of the viscous resistance of melt-water film. The velocity dependence of μk was quantified using the rate- and state- dependent model, and μk was found to increase logarithmically with increasing velocity. In addition, μk obtained at higher air temperatures was greater than at lower temperatures. The stick-slip phenomenon was observed at a relatively high velocity compared with previous studies, which was partly due to the low-stiffness device used in the field. Based on the experimental data, the calculation of physical models can be compared.
  • Cabling, Ludwig Paul B.; Kobayashi, Yumi; Davies, Evan G. R.; Ashbolt, Nicholas J.; Liu, Yang (2020)
    Municipal sewage contains significant embedded resources in the form of chemical and thermal energy. Recent developments in sustainable technology have pushed for the integration of resource recovery from household wastewater to achieve net zero energy consumption and carbon-neutral communities. Sewage heat recovery and fit-for-purpose water reuse are options to optimize the resource recovery potential of municipal wastewater. This study presents a comparative life cycle assessment (LCA) focused on global warming potential (GWP), eutrophication potential (EUP), and human health carcinogenic potential (HHCP) of an integrated sewage heat recovery and water reuse system for a hypothetical community of 30,000 people. Conventional space and water heating components generally demonstrated the highest GWP contribution between the different system components evaluated. Sewage-heat-recovery-based district heating offered better environmental performance overall. Lower impact contributions were demonstrated by scenarios with a membrane bioreactor (MBR) and chlorination prior to water reuse applications compared to scenarios that use more traditional water and wastewater treatment technologies and discharge. The LCA findings show that integrating MBR wastewater treatment and water reuse into a district heating schema could provide additional environmental savings at a community scale.
  • Kuoppamäki, Kirsi; Setälä, Heikki; Hagner, Marleena (2021)
  • Pirjola, Liisa; Kuuluvainen, Heino; Timonen, Hilkka; Saarikoski, Sanna; Teinilä, Kimmo; Salo, Laura; Datta, Arindam; Simonen, Pauli; Karjalainen, Panu; Kulmala, Kari; Rönkkö, Topi (2019)
    The use of fossil fuels in traffic is a significant source of air pollutants and greenhouse gases in rapidly growing and densely populated cities. Diesel exhaust emissions including particle number concentration and size distribution along with the particles’ chemical composition and NOx were investigated from a Euro 4 passenger car with a comprehensive set of high time-resolution instruments. The emissions were compared with three fuel standards – European diesel (EN590), Indian diesel (BS IV) and Finnish renewable diesel (Neste MY) – over the New European Driving Cycle (NEDC) and the Worldwide harmonized Light vehicles Test Cycle (WLTC). Fuel properties and driving conditions strongly affected exhaust emissions. The exhaust particulate mass emissions for all fuels consisted of BC (81–88%) with some contribution from organics (11–18%) and sulfate (0–3%). As aromatic-free fuel, the MY diesel produced around 20% lower black carbon (BC) emissions compared to the EN590 and 29–40% lower compared to the BS IV. High volatile nanoparticle concentrations at high WLTC speed conditions were observed with the BS IV and EN590 diesel, but not with the sulfur-free MY diesel. These nanoparticles were linked to sulfur-driven nucleation of new particles in cooling dilution of the exhaust. For all the fuels non-volatile nanoparticles in sub-10 nm particle sizes were observed during engine braking, and they were most likely formed from lubricant-oil-originated compounds. With all the fuels, the measured particulate and NOx emissions were significantly higher during the WLTC cycle compared to the NEDC cycle. This study demonstrated that renewable diesel fuels enable mitigations of particulate and climate-warming BC emissions of traffic, and will simultaneously help tackle urban air quality problems.
  • Vanhatalo, Jarno; Huuhtanen, Juri; Bergström, Martin; Helle, Inari; Mäkinen, Jussi Antti-Eerikki; Kujala, Pentti (2021)
    Ships operating in ice-infested Arctic waters are exposed to a range of ship-ice interaction related hazards. One of the most dangerous of these is the possibility of a ship becoming beset in ice, meaning that a ship is surrounded by ice preventing it from maneuvering under its own power. Such a besetting event may not only result in severe operational disruption, but also expose a ship to severe ice loading or cause it to drift towards shallow water. This may cause significant structural damage to a ship and potentially jeopardize its safety. To support safe and sustainable Arctic shipping operations, this article presents a probabilistic approach to assess the probability of a ship becoming beset in ice. To this end, the proposed approach combines different types of data, including Automatic Identification System (AIS) data, satellite ice data, as well as data on real-life ship besetting events. Based on this data, using a hierarchical Bayesian model, the proposed approach calculates the probability of a besetting event as a function of the Polar Ship Category of a ship, sea area, and the distance travelled in the prevailing ice concentration. The utility of the proposed approach, e.g. in supporting spatiotemporal risk assessments of Arctic shipping activities as well as Arctic voyage planning, is demonstrated through a case study in which the approach is applied to ships operating in the Northern Sea Route (NSR) area. The outcomes of the case study indicate that the probability of besetting is strongly dependent on the Polar Ship Category of a ship and that the probability increases significantly with higher ice concentrations. The sea area, on the other hand, does not appear to significantly affect the probability of besetting.