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Hrund O. Andradottir
Faculty of Civil and Environmental Engineering, School of Engineering and Natural Sciences, University of Iceland, Hjardarhagi 2-6, 107 Reykjavík, Iceland

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Journal article
Published: 26 August 2021 in Sustainability
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Tire and road wear particles (TRWP) are a significant source of atmospheric particulate matter and microplastic loading to waterways. Road wear is exacerbated in cold climate by the widespread use of studded tires. The goal of this research was to assess the anthropogenic levers for suspendable road dust generation and climatic conditions governing the environmental fate of non-exhaust particles in a wet maritime winter climate. Sensitivity analyses were performed using the NORTRIP model for the Capital region of Reykjavík, Iceland (64.1° N). Precipitation frequency (secondarily atmospheric relative humidity) governed the partitioning between atmospheric and waterborne PM10 particles (55% and 45%, respectively). Precipitation intensity, however, increased proportionally most the drainage to waterways via stormwater collection systems, albeit it only represented 5% of the total mass of dust generated in winter. A drastic reduction in the use of studded tires, from 46% to 15% during peak season, would be required to alleviate the number of ambient air quality exceedances. In order to achieve multifaceted goals of a climate resilient, resource efficient city, the most important mitigation action is to reduce overall traffic volume. Reducing traffic speed may help speed environmental outcomes.

ACS Style

Brian Charles Barr; Hrund Ólöf Andradóttir; Throstur Thorsteinsson; Sigurður Erlingsson. Mitigation of Suspendable Road Dust in a Subpolar, Oceanic Climate. Sustainability 2021, 13, 9607 .

AMA Style

Brian Charles Barr, Hrund Ólöf Andradóttir, Throstur Thorsteinsson, Sigurður Erlingsson. Mitigation of Suspendable Road Dust in a Subpolar, Oceanic Climate. Sustainability. 2021; 13 (17):9607.

Chicago/Turabian Style

Brian Charles Barr; Hrund Ólöf Andradóttir; Throstur Thorsteinsson; Sigurður Erlingsson. 2021. "Mitigation of Suspendable Road Dust in a Subpolar, Oceanic Climate." Sustainability 13, no. 17: 9607.

Research article
Published: 30 June 2021 in Hydrological Processes
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Urban floods pose a societal and economical risk. This study evaluated the risk and hydro-meteorological conditions that cause pluvial flooding in coastal cities in a cold climate. Twenty years of insurance claims data and up to 97 years of meteorological data were analyzed for Reykjavík, Iceland (64.15°N; < 100 m above sea level). One third of the city's wastewater collection system is combined, and pipe grades vary from 0.5-10%. Results highlight semi-intensive rain (<7 mm/hr; ≤3-year return period) in conjunction with snow and frozen ground as the main cause for urban flood risk in a climate which undergoes frequent snow and frost cycles (avg. 13 and 19 per season, respectively). Floods in winter were more common, more severe and affected a greater number of neighborhoods than during summer. High runoff volumes together with debris remobilized with high winds challenged the capacity of wastewater systems regardless of their age or type (combined vs. separate). The two key determinants for the number of insurance claims were antecedent frost depth and total precipitation volume per event. Two pluvial regimes were particularly problematic: long duration (13-25 hours), late peaking rain on snow (RoS), where snowmelt enhanced the runoff intensity, elongated and connected independent rainfall into a singular, more voluminous (20-76 mm) event; shorter duration (7-9 hours), more intensive precipitation that evolved from snow to rain. Closely timed RoS and cooling were believed to trigger frost formation. Average seasonal snow depth and volume of rain and snowmelt during RoS events were found to be increasing due to climate change. More emphasis, therefore, needs to be placed on designing and operating urban drainage infrastructure with regard to RoS co-acting with frozen ground. Furthermore, more detailed, routine monitoring of snow and soil conditions is important to predict RoS flood events.

ACS Style

Andradóttir Hrundólöf; Anna Rut Arnardóttir; Tarek Zaqout. Rain on snow induced urban floods in cold maritime climate: Risk, indicators and trends. Hydrological Processes 2021, 1 .

AMA Style

Andradóttir Hrundólöf, Anna Rut Arnardóttir, Tarek Zaqout. Rain on snow induced urban floods in cold maritime climate: Risk, indicators and trends. Hydrological Processes. 2021; ():1.

Chicago/Turabian Style

Andradóttir Hrundólöf; Anna Rut Arnardóttir; Tarek Zaqout. 2021. "Rain on snow induced urban floods in cold maritime climate: Risk, indicators and trends." Hydrological Processes , no. : 1.

Journal article
Published: 09 March 2021 in Journal of Hydrology
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Sustainable urban drainage solutions (SuDS) are a diverse set of design options that mitigate floods and improve water quality. Grass swales are the sole component of SuDS that transports runoff over long distances to downstream recipients. A deeper understanding of the performance of grass swales in different winter conditions is important in order for cities to achieve a greater climate resiliency. The goal of this study was to assess the impacts of frequent rain-on-snow, and freeze–thaw cycles on the hydrologic performance of grass swales. A total of 63 field synthetic runoff experiments were performed in a 5.8 m long section of a grass swale in the Urriðaholt neighborhood, Gardabaer, Iceland over 18 months. A three-fold reduction in peak flow attenuation was observed in winter (avg. 13%) compared to summer (avg. 38%) for hydraulic loadings ranging between 19 and 131 cm/h. The reduction in the performance of the swale was primarily due to frost formation and secondarily due to snow. The frequent rainfall, snowmelt, and rain-on-snow events elevated the soil water content and rendered the swale media susceptible to frost formation. The formation of pore ice within the 5 cm soil horizon led to a considerable reduction in soil porosity, which negatively affected the infiltration capacity, and shortened runoff lag times. Snow affected the performance by concentrating the flow in narrow channels, which reduced the effective area of infiltration, but also led to longer lag times and stored a portion of the runoff water within its pack. Despite the deterioration in the swale’s efficiency in winter, infiltration was observed in all synthetic runoff experiments, indicating that frost was either porous/granular, or heterogeneous in nature. The swale served its purpose to moderately reduce runoff peaks and volumes, especially for small and medium events. This research highlights the importance of effectively draining infiltration-based systems in cold climates to avoid the adverse effects of low temperatures.

ACS Style

Tarek Zaqout; Hrund Ólöf Andradóttir. Hydrologic performance of grass swales in cold maritime climates: Impacts of frost, rain-on-snow and snow cover on flow and volume reduction. Journal of Hydrology 2021, 597, 126159 .

AMA Style

Tarek Zaqout, Hrund Ólöf Andradóttir. Hydrologic performance of grass swales in cold maritime climates: Impacts of frost, rain-on-snow and snow cover on flow and volume reduction. Journal of Hydrology. 2021; 597 ():126159.

Chicago/Turabian Style

Tarek Zaqout; Hrund Ólöf Andradóttir. 2021. "Hydrologic performance of grass swales in cold maritime climates: Impacts of frost, rain-on-snow and snow cover on flow and volume reduction." Journal of Hydrology 597, no. : 126159.

Journal article
Published: 13 August 2020 in Water Resources Research
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The effect of large‐amplitude isopycnal displacements, frequently observed in deep medium‐size arctic lakes during the ice‐free period, on the near‐ and far‐field fate of negatively buoyant river inflows is explored in this work. A three‐dimensional transport and hydrodynamic model of sub‐arctic Lake Lagarfljót was used to simulate the fate of river inflows during the summer stratification period. The intrusion dynamics are strongly affected by the amplitude and direction (downwelling/upwelling) of the isopycnal displacements induced by the wind near the river inlet. These displacements control the distance of travel of the river plume until reaching the layers with maximum density gradients (pycnocline) and, thus, the mixing ratio between the river plume and the lake water. Specifically, strong upwelling near the inlet causes the river to flow to the bottom as an underflow. Under downwelling, river plumes tend to form metalimnetic intrusions. The influence of the isopycnal displacements on the initial river fate can be parameterized using a time‐varying density Richardson number, which needs to be smoothed to account for the effects of unsteadiness. Large amplitude internal motions, of up to 70 m in Lake Lagarfljót, move deep underflows upwards to shallower basins where they could be readily incorporated into the surface mixed layer and rapidly flushed out of the lake. Metalimnetic currents associated with the V2H1 internal circulation can also accelerate riverine transport out of the lake.

ACS Style

C. L. Ramón; M. C. Priet‐Mahéo; F. J. Rueda; H. Andradóttir. Inflow Dynamics in Weakly Stratified Lakes Subject to Large Isopycnal Displacements. Water Resources Research 2020, 56, 1 .

AMA Style

C. L. Ramón, M. C. Priet‐Mahéo, F. J. Rueda, H. Andradóttir. Inflow Dynamics in Weakly Stratified Lakes Subject to Large Isopycnal Displacements. Water Resources Research. 2020; 56 (8):1.

Chicago/Turabian Style

C. L. Ramón; M. C. Priet‐Mahéo; F. J. Rueda; H. Andradóttir. 2020. "Inflow Dynamics in Weakly Stratified Lakes Subject to Large Isopycnal Displacements." Water Resources Research 56, no. 8: 1.

Journal article
Published: 21 July 2020 in Sustainability
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Many environmental problems stem from unsustainable human consumption. Accordingly, many studies have focused on the barriers to pro-environmental behavior. The inability or unwillingness to act is partially related to personal values as well as the psychological distance between individual actions and the resulting pollution, which is often perceived as abstract or intangible. In contrast, fireworks produce imminent, undeniable air pollution. The goal of this research was to advance the knowledge on the awareness-value-behavior gap by studying public fireworks consumption and the willingness to act against firework pollution. A nationally representative survey was conducted after the extremely polluting 2017/18 New Year’s Eve in Iceland (European hourly record in fine particulate matter: 3014 µg/m3). Our results demonstrate that, after controlling for the awareness of harmful pollution, hedonic motives predict the purchasing of fireworks and the opposition to mitigating action. Noticing public warnings regarding fireworks pollution did not significantly relate to the purchase behavior. The awareness of the harmful effects of firework pollution was, however, the largest predictor of the support for mitigating action. Despite reporting the pleasure derived from fireworks, 57% of the sample favored stricter governmental regulation, and 27% favored banning the public use of fireworks in order to “protect them from what they want”.

ACS Style

Ragna Benedikta Garðarsdóttir; Hrund Ólöf Andradóttir; Throstur Thorsteinsson. Protect Me from What I Want: Understanding Excessive Polluting Behavior and the Willingness to Act. Sustainability 2020, 12, 5867 .

AMA Style

Ragna Benedikta Garðarsdóttir, Hrund Ólöf Andradóttir, Throstur Thorsteinsson. Protect Me from What I Want: Understanding Excessive Polluting Behavior and the Willingness to Act. Sustainability. 2020; 12 (14):5867.

Chicago/Turabian Style

Ragna Benedikta Garðarsdóttir; Hrund Ólöf Andradóttir; Throstur Thorsteinsson. 2020. "Protect Me from What I Want: Understanding Excessive Polluting Behavior and the Willingness to Act." Sustainability 12, no. 14: 5867.

Journal article
Published: 02 July 2019 in Journal of Cleaner Production
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Extreme pollution associated with firework celebrations is recognized as an important health and environmental issue. Despite this knowledge, firework celebrations continue to be allowed in many countries around the world. This paper explores the physical and societal factors contributing to extreme recreational firework pollution, as well as stakeholders' perspectives on the resultant pollution and possible mitigation. Metropolitan Reykjavík (217 000 inhabitants) is taken as an example of an affluent, well informed community with a relatively recent history of fireworks displays. Largely non-regulated public access to fireworks has resulted in exceedance of the European air quality standard of PM10 (50 μg/m3), and hazardous hourly concentration (>500 μg/m3) every other year. In the second hour of New Year's Day (NYD) 2018, hourly particulate matter records, 4042 μg/m3 PM10 and 3014 μg/m3 PM2.5, were set in a residential, suburban area. Concentrations of potential toxic metals increased by a factor of 104 (Cu), 96 (Sr), 27 (Ba) during the celebrations compared to the preceding days. The reasons why these high pollution episodes continue to occur, based on stakeholders' interviews, are traced back to a series of societal and regulatory hurdles: (1) Conflicting interests at governmental, municipal and entrepreneurial levels because fireworks are an entertaining spectacle for locals and tourists and a major fundraiser for not-for-profit organizations (NPOs), and yet pose an unacceptable public burden in terms of air pollution. (2) The lawful public access to fireworks severely limits stakeholder involvement and air quality mitigation actions. (3) Implementation of fireworks policy is dispersed among multiple stakeholders. These factors promote stakeholder passiveness towards pollution mitigation: Continuing public awareness campaigns with the goal of slowly weaning the public off fireworks were favored over restricting public use to fireworks. Future opportunities lie in holistic policy making, using the United Nations Sustainable Development Goals as a roadmap; and in clarifying the risk of extreme particulate matter episodes, e.g. by accounting for the level of exceedances (concentration value divided by ambient air quality standard), and the nature of the particles (size, morphology, chemical composition) as defined in the relevant regulations.

ACS Style

Hrund O. Andradottir; Throstur Thorsteinsson. Repeated extreme particulate matter episodes due to fireworks in Iceland and stakeholders’ response. Journal of Cleaner Production 2019, 236, 117511 .

AMA Style

Hrund O. Andradottir, Throstur Thorsteinsson. Repeated extreme particulate matter episodes due to fireworks in Iceland and stakeholders’ response. Journal of Cleaner Production. 2019; 236 ():117511.

Chicago/Turabian Style

Hrund O. Andradottir; Throstur Thorsteinsson. 2019. "Repeated extreme particulate matter episodes due to fireworks in Iceland and stakeholders’ response." Journal of Cleaner Production 236, no. : 117511.

Article
Published: 24 September 2018 in Limnology and Oceanography
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The goal of the research was to identify the mixing features that distinguish wind forced, medium‐size fjord‐type lakes near the Arctic Circle from systems of similar geometry, but in a temperate climate. Experimental data and the results of 3D numerical hydrodynamic simulations were analyzed for Lake Lagarfljót (27 km long; 2 km wide; 110 m maximum depth; 65°N) during the 5‐month ice‐free period in 2009. The results showed that probably the most distinctive feature of arctic lakes is their low water column stability, one order of magnitude lower than that of mid‐latitude lakes, even in mid‐summer. The second characteristic is the high rate of energy imparted by wind in the Arctic, estimated as one order of magnitude larger than in a temperate climate. Frequent wind events with Lake and Wedderburn numbers below 1 occurred during the ice‐free period, leading to a strong shear at the base of the surface mixed‐layer and the upwelling of deep metalimnetic layers. As a result, nearly continuous density stratification developed in the shallowest 70 m of the water column, and longitudinal temperature gradients may therefore be very significant. On average, 15% of the wind forcing drove large‐scale internal motions. This energy was rapidly dissipated, partly as a result of stronger bottom velocities, nonlinear surges, and hydraulic jumps that repeatedly formed in the lake. The initial V1H1 setup rapidly evolved into spatially complex oscillatory modes, which, given the high latitude, are affected by the Earth's rotation, even in narrow basins.

ACS Style

M. C. Priet-Mahéo; C. L. Ramón; F. J. Rueda; H. Ó. Andradóttir. Mixing and internal dynamics of a medium-size and deep lake near the Arctic Circle. Limnology and Oceanography 2018, 64, 61 -80.

AMA Style

M. C. Priet-Mahéo, C. L. Ramón, F. J. Rueda, H. Ó. Andradóttir. Mixing and internal dynamics of a medium-size and deep lake near the Arctic Circle. Limnology and Oceanography. 2018; 64 (1):61-80.

Chicago/Turabian Style

M. C. Priet-Mahéo; C. L. Ramón; F. J. Rueda; H. Ó. Andradóttir. 2018. "Mixing and internal dynamics of a medium-size and deep lake near the Arctic Circle." Limnology and Oceanography 64, no. 1: 61-80.

Journal article
Published: 01 November 2017 in International Journal of Hygiene and Environmental Health
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Access to safe water is essential for public health and is one of the most important prerequisites for good living and safe food production. Many studies have shown that non-compliance with drinking water quality standards in small water supply systems is much higher than in large systems. Nevertheless, people served by small water supply systems have the right to the same level of health protection. Actions are therefore needed to improve the situation. The objective of the present study was to carry out a baseline analysis of the situation in the Nordic region and provide recommendations for governmental policy and actions. Data were gathered on number of water supplies, population served, compliance with regulations and waterborne disease outbreaks from various sources in the Nordic countries. The collected data showed that there are about 12500 regulated water supplies, 9400 of which serve fewer than 500 persons. The number of unregulated and poorly regulated supplies is unknown, but it can be roughly estimated that these serve 10% of the Nordic population on a permanent basis or 2.6 million people. However, this does not tell the whole story as many of the very small water supplies serve transient populations, summerhouse dwellers and tourist sites, with many more users. Non-compliance regarding microbes is much higher in the small supplies. The population weighted average fecal contamination incidence rate in the Nordic region is eleven times higher in the smaller supplies than in the large ones, 0.76% and 0.07%, respectively. Registered waterborne disease outbreaks were also more frequent in the small supplies than in the large ones.

ACS Style

Maria J. Gunnarsdottir; Kenneth M. Persson; Hrund O. Andradottir; Sigurdur M. Gardarsson. Status of small water supplies in the Nordic countries: Characteristics, water quality and challenges. International Journal of Hygiene and Environmental Health 2017, 220, 1309 -1317.

AMA Style

Maria J. Gunnarsdottir, Kenneth M. Persson, Hrund O. Andradottir, Sigurdur M. Gardarsson. Status of small water supplies in the Nordic countries: Characteristics, water quality and challenges. International Journal of Hygiene and Environmental Health. 2017; 220 (8):1309-1317.

Chicago/Turabian Style

Maria J. Gunnarsdottir; Kenneth M. Persson; Hrund O. Andradottir; Sigurdur M. Gardarsson. 2017. "Status of small water supplies in the Nordic countries: Characteristics, water quality and challenges." International Journal of Hygiene and Environmental Health 220, no. 8: 1309-1317.

Journal article
Published: 01 August 2017 in Journal of Environmental Engineering
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ACS Style

Hrund Ólöf Andradóttir. Impact of Wind on Stormwater Pond Particulate Removal. Journal of Environmental Engineering 2017, 143, 04017027 .

AMA Style

Hrund Ólöf Andradóttir. Impact of Wind on Stormwater Pond Particulate Removal. Journal of Environmental Engineering. 2017; 143 (8):04017027.

Chicago/Turabian Style

Hrund Ólöf Andradóttir. 2017. "Impact of Wind on Stormwater Pond Particulate Removal." Journal of Environmental Engineering 143, no. 8: 04017027.

Primary research paper
Published: 14 March 2017 in Hydrobiologia
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Once introduced into a new ecosystem, the benthic bivalve Corbicula fluminea (Asian clam) will spread rapidly through both active and passive transport. In Lake Tahoe, CA-NV, where C. fluminea was introduced in 2002, populations have been found to thrive at shallow depths, where individuals are reproductive, but also at deeper depths where the only possible mechanism of population growth is downslope recruitment. This study used a variety of field and laboratory measurements to parameterize a hydrodynamic drag force model to predict passive clam transport under varying flow conditions. Laboratory results for clam shells ranging from 5 to 20 mm in length under flow conditions from 10 to 25 cm s−1 were used to solve for drag and lift coefficients. Field results are presented during weak stratification (September 2010–March 2011) when cooler water temperatures acted as a potential stressor for buried individuals to rise to the surface and be subjected to flows from which they would otherwise be isolated. During episodic wind events throughout this time period, peak horizontal water velocities of 25 cm s−1 and peak vertical (downwards) water velocities of 4 cm s−1 were measured in which all size classes of adult C. fluminea were potentially transported. Using a fundamental hydrodynamic drag force model approach to predict passive transport, the results of this study can be extended to other bivalve species for a wide array of flow conditions.

ACS Style

A. L. Forrest; Hrund Andradóttir; T. J. Mathis; M. E. Wittmann; J. E. Reuter; S. G. Schladow. Passive transport of a benthic bivalve (Corbicula fluminea) in large lakes: implications for deepwater establishment of invasive species. Hydrobiologia 2017, 797, 87 -102.

AMA Style

A. L. Forrest, Hrund Andradóttir, T. J. Mathis, M. E. Wittmann, J. E. Reuter, S. G. Schladow. Passive transport of a benthic bivalve (Corbicula fluminea) in large lakes: implications for deepwater establishment of invasive species. Hydrobiologia. 2017; 797 (1):87-102.

Chicago/Turabian Style

A. L. Forrest; Hrund Andradóttir; T. J. Mathis; M. E. Wittmann; J. E. Reuter; S. G. Schladow. 2017. "Passive transport of a benthic bivalve (Corbicula fluminea) in large lakes: implications for deepwater establishment of invasive species." Hydrobiologia 797, no. 1: 87-102.

Journal article
Published: 01 October 2016 in Journal of Hydraulic Engineering
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A storm water pond’s effectiveness to treat particulate bound pollutants in urban runoff depends on its hydraulic behavior. Departures from the ideal plug flow, such as short-circuiting and mixing, pose hindrances to pond design. The goal of this study was to assess the importance of wind on storm water pond hydraulics. High resolution acoustic velocity measurements were conducted in a 0.3 ha, 2 m deep pond during dry weather. Results suggest that winds drive a turbulent, three-dimensional flow regime, including a lateral circulation and vertical exchange flows. A fully developed surface layer representing 1/3d of the water depth, with drift scaling as 0.004 on wind speed at 10 m above ground, was observed in the downwind section of the pond. Wind-induced vertical mixing, short-circuiting, and basin scale mixing were estimated to occur faster than the typical nominal residence time in storm water ponds. Wind is therefore an important hydraulic driver in small water systems, which may potentially reduce their treatment performance. Local landscaping may be used as a wind mitigation measure.

ACS Style

Hrund Ólöf Andradóttir; Marie-Léonie Mortamet. Impact of Wind on Storm-Water Pond Hydraulics. Journal of Hydraulic Engineering 2016, 142, 04016034 .

AMA Style

Hrund Ólöf Andradóttir, Marie-Léonie Mortamet. Impact of Wind on Storm-Water Pond Hydraulics. Journal of Hydraulic Engineering. 2016; 142 (10):04016034.

Chicago/Turabian Style

Hrund Ólöf Andradóttir; Marie-Léonie Mortamet. 2016. "Impact of Wind on Storm-Water Pond Hydraulics." Journal of Hydraulic Engineering 142, no. 10: 04016034.

Journal article
Published: 17 March 2015 in Water Science and Technology
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Short-duration precipitation bursts can cause substantial property damage and pose operational risks for wastewater managers. The objective of this study was to assess the present and possible future flood hazard in the combined sewer system in Reykjavik city centre. The catchment is characterised by two hills separated by a plain. A large portion of the pipes in the aging network are smaller than the current minimum diameter of 250 mm. Runoff and sewer flows were modelled using the MIKE URBAN software package incorporating both historical precipitation and synthetic storms derived from annual maximum rainfall data. Results suggest that 3% of public network manholes were vulnerable to flooding during an 11-year long rainfall sequence. A Chicago Design Storm (CDS) incorporating a 10-minute rainfall burst with a 5-year return period predicted twice as many flooded manholes at similar locations. A 20% increase in CDS intensity increased the number of flooded manholes and surface flood volume by 70% and 80%, respectively. The flood volume tripled if rainfall increase were combined with urban re-development, leading to a 20% increase in the runoff coefficient. Results highlight the need for reducing network vulnerabilities, which include decreased pipe diameters and low or drastically varying pipe grades.

ACS Style

Asta Osk Hlodversdottir; Brynjolfur Bjornsson; Hrund Olof Andradottir; Jonas Eliasson; Philippe Crochet. Assessment of flood hazard in a combined sewer system in Reykjavik city centre. Water Science and Technology 2015, 71, 1471 -1477.

AMA Style

Asta Osk Hlodversdottir, Brynjolfur Bjornsson, Hrund Olof Andradottir, Jonas Eliasson, Philippe Crochet. Assessment of flood hazard in a combined sewer system in Reykjavik city centre. Water Science and Technology. 2015; 71 (10):1471-1477.

Chicago/Turabian Style

Asta Osk Hlodversdottir; Brynjolfur Bjornsson; Hrund Olof Andradottir; Jonas Eliasson; Philippe Crochet. 2015. "Assessment of flood hazard in a combined sewer system in Reykjavik city centre." Water Science and Technology 71, no. 10: 1471-1477.

Journal article
Published: 01 March 2015 in Journal of Environmental Engineering
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ACS Style

Hrund Ólöf Andradóttir; Guðbjörg Esther G. Vollertsen. Temporal Variability of Heavy Metals in Suburban Road Runoff in a Rainy Cold Climate. Journal of Environmental Engineering 2015, 141, 04014068 .

AMA Style

Hrund Ólöf Andradóttir, Guðbjörg Esther G. Vollertsen. Temporal Variability of Heavy Metals in Suburban Road Runoff in a Rainy Cold Climate. Journal of Environmental Engineering. 2015; 141 (3):04014068.

Chicago/Turabian Style

Hrund Ólöf Andradóttir; Guðbjörg Esther G. Vollertsen. 2015. "Temporal Variability of Heavy Metals in Suburban Road Runoff in a Rainy Cold Climate." Journal of Environmental Engineering 141, no. 3: 04014068.

Journal article
Published: 21 July 2014 in Atmospheric Environment
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Hydrogen sulfide (H2S) emissions have been growing with the increasing utilization of geothermal resources. Atmospheric H2S concentration has been measured and studied but less is known about the natural sinks of the chemical. This study investigates the atmospheric depletion of H2S within a 35 km distance from two Icelandic power plants. The results showed that atmospheric oxidation by the OH radical was the largest sink in the area. The second largest sink was H2S uptake in surface water, in a neighboring lake, but it was, however, small compared to the reported difference of sulfur amount in the lake in- and outflow. Sulfur was found to accumulate in moss close to the power plants at a maximum rate of about 1500 mg S/kg moss per year and decreased exponentially from the source, being negligible at a distance of a few kilometers. Soil uptake was limited by diffusion of H2S into the porous media and was thus much smaller than the estimated soil uptake potential. Washout with precipitation was estimated to be the smallest sink due to the low H2S reactivity in the precipitation (pH = 5.6), compared to the surface water (pH ∼8). Depletion of H2S from the atmosphere in the study area was estimated to be about 1.2% of the 2012 power plants emissions of over 20,000 tons. Although the uncertainties in the depletion estimates were considerable, most of the H2S emitted from the power plants was strongly indicated to be transported out of the study area as H2S.

ACS Style

S. Olafsdottir; Sigurdur Gardarsson; H.O. Andradottir. Natural near field sinks of hydrogen sulfide from two geothermal power plants in Iceland. Atmospheric Environment 2014, 96, 236 -244.

AMA Style

S. Olafsdottir, Sigurdur Gardarsson, H.O. Andradottir. Natural near field sinks of hydrogen sulfide from two geothermal power plants in Iceland. Atmospheric Environment. 2014; 96 ():236-244.

Chicago/Turabian Style

S. Olafsdottir; Sigurdur Gardarsson; H.O. Andradottir. 2014. "Natural near field sinks of hydrogen sulfide from two geothermal power plants in Iceland." Atmospheric Environment 96, no. : 236-244.

Journal article
Published: 01 January 2014 in Atmospheric Environment
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ACS Style

S. Olafsdottir; Sigurdur Gardarsson; Hrund Andradóttir. Spatial distribution of hydrogen sulfide from two geothermal power plants in complex terrain. Atmospheric Environment 2014, 82, 60 -70.

AMA Style

S. Olafsdottir, Sigurdur Gardarsson, Hrund Andradóttir. Spatial distribution of hydrogen sulfide from two geothermal power plants in complex terrain. Atmospheric Environment. 2014; 82 ():60-70.

Chicago/Turabian Style

S. Olafsdottir; Sigurdur Gardarsson; Hrund Andradóttir. 2014. "Spatial distribution of hydrogen sulfide from two geothermal power plants in complex terrain." Atmospheric Environment 82, no. : 60-70.

Journal article
Published: 23 January 2013 in Water Policy
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This paper explores the fate and transport of microbial contamination in a cold climate and coarse aquifers. A confirmed norovirus outbreak in a small rural water supply in the late summer of 2004, which is estimated to have infected over 100 people, is used as a case study. A septic system, 80 m upstream of the water intake, is considered to have contaminated drinking water. Water samples tested were negative for coliform and strongly positive for norovirus. Modelling predicts that a 4.8-log10 removal was possible in the 8 m thick vadose zone, while only a 0.7-log10 and 2.7-log10 removal in the aquifer for viruses and Escherichia coli, respectively. The model results support that the 80 m setback distance was inadequate and roughly 900 m aquifer transport distance was needed to achieve 9-log10 viral removal. Sensitivity analysis showed that the most influential parameters on model transport removal rate are grain size diameter and groundwater velocity, temperature and acidity. The results demonstrate a need for systematic evaluation of septic systems in rural areas in lesser studied coarse strata at low temperatures, thereby strengthening data used for regulatory requirements for more confident determination on safe setback distances.

ACS Style

M. J. Gunnarsdottir; Sigurdur Gardarsson; Hrund Andradóttir. Microbial contamination in groundwater supply in a cold climate and coarse soil: case study of norovirus outbreak at Lake Mývatn, Iceland. Water Policy 2013, 44, 1114 -1128.

AMA Style

M. J. Gunnarsdottir, Sigurdur Gardarsson, Hrund Andradóttir. Microbial contamination in groundwater supply in a cold climate and coarse soil: case study of norovirus outbreak at Lake Mývatn, Iceland. Water Policy. 2013; 44 (6):1114-1128.

Chicago/Turabian Style

M. J. Gunnarsdottir; Sigurdur Gardarsson; Hrund Andradóttir. 2013. "Microbial contamination in groundwater supply in a cold climate and coarse soil: case study of norovirus outbreak at Lake Mývatn, Iceland." Water Policy 44, no. 6: 1114-1128.

Journal article
Published: 07 November 2012 in Water Resources Research
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[1] The average length of time land-borne compounds remain within an aquatic system is one of the key parameters controlling its biochemical processes. This study explores the magnitude and sources of daily, seasonal, and interannual variability of river water residence time in the Sau Reservoir, a prototypical example of a Mediterranean water supply. Daily estimates of residence time from 1998 to 2005 were obtained from a series of tracer experiments simulated with a one-dimensional physical model, based on actual observations and synthetic scenarios. Results highlight that multiple in situ factors, both natural and managed by humans, affect the residence time in reservoirs. Simulated residence times varied on average ∼30% on a daily basis, as a result of natural meteorological (17%) and river inflow temperature (11%) variability. The management of withdrawal depths largely controlled the seasonal variations: The practice of withdrawing water from the shallowest outlet, which was close to the intrusion level of summer inflows, promoted shorter residence times in summers than winters. Interannual variability was primarily associated with the natural variability of inflow volume (25%), and secondarily with surface meteorology (8%). Excessive withdrawals prior to and during long dry periods, however, drastically reduced the reservoir storage capacity and withdrawal options, leading to shorter residence times in dry years. The flushing time, calculated as the ratio of storage volume and flow rates, captured the trends in annual mean residence times reasonably well but not daily and seasonal residence times.

ACS Style

H. Ó. Andradóttir; F. J. Rueda; J. Armengol; Rafael Marcé. Characterization of residence time variability in a managed monomictic reservoir. Water Resources Research 2012, 48, 1 .

AMA Style

H. Ó. Andradóttir, F. J. Rueda, J. Armengol, Rafael Marcé. Characterization of residence time variability in a managed monomictic reservoir. Water Resources Research. 2012; 48 (11):1.

Chicago/Turabian Style

H. Ó. Andradóttir; F. J. Rueda; J. Armengol; Rafael Marcé. 2012. "Characterization of residence time variability in a managed monomictic reservoir." Water Resources Research 48, no. 11: 1.

Book chapter
Published: 01 January 2012 in Encyclopedia of Solid Earth Geophysics
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Iceland is a 103,000-km2 volcanic island situated on the Mid-Atlantic Ridge, just south of the Arctic Circle. Because of its geographical location, the country boasts both of glaciers and volcanos, earning itself the nickname “country of fire and ice.” Icelandic surface waters are classified based on their source. Sixty percent of the annual runoff is direct, the remainder is evenly divided between springwater and glacial meltwater (Bjornsson et al., 2008). Lakes cover 2.7% of the country’s surface area, ninety percent of which are smaller than 1 km2 (Adalsteinsson, 1987). Lake Thorisvatn is the largest lake (88 km2). Other largest and best known Icelandic lakes summarized in Table 1. Lake Thingvallavatn and Lagarfljot, both deep lakes, with a residence time of almost 1 year, and shallow. Lake Myvatn, with a residence time of approximately 1 month. Icelandic lakes have provided many important socioeconomic functions in the past and present. Considering the four la ...

ACS Style

Lars Bengtsson; Hrund Ó. Andradóttir; V. K. Dwivedi; Magnus Larson; Ulrich Lemmin. Icelandic Lakes, Physical Characteristics. Encyclopedia of Solid Earth Geophysics 2012, 362 -368.

AMA Style

Lars Bengtsson, Hrund Ó. Andradóttir, V. K. Dwivedi, Magnus Larson, Ulrich Lemmin. Icelandic Lakes, Physical Characteristics. Encyclopedia of Solid Earth Geophysics. 2012; ():362-368.

Chicago/Turabian Style

Lars Bengtsson; Hrund Ó. Andradóttir; V. K. Dwivedi; Magnus Larson; Ulrich Lemmin. 2012. "Icelandic Lakes, Physical Characteristics." Encyclopedia of Solid Earth Geophysics , no. : 362-368.

Journal article
Published: 03 September 2011 in Aquatic Sciences
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The fate of inflows into lakes has been extensively studied during summer stratification but has seen relatively little focus during the weak winter stratification, with or without ice-cover. Field observations are presented of groundwater inflow into a shallow bay of a subarctic lake. Atmospheric forcing of the bay during the study period was extremely variable and coincided with spring ice-cover break-up. Two dominant wind regimes were identified; (1) weak wind-forcing (wind speed −1 or land-fast ice-cover), and (2) strong wind-forcing (wind speed >5 m s−1 and open water). At a relatively constant temperature of ~3.3°C, the groundwater inflow was closer to the temperature of maximum density than the water in the main body of the lake, which during the observed winter stratification is ~1.2°C. During weak wind-forcing, the stratification within Silfra Bay approximated two-layers as this denser groundwater formed a negatively buoyant underflow. A calculated underflow entrainment rate of 2.8 × 10−3 agrees well with other underflow studies. During strong wind-forcing, the water column out to the mouth of the bay became weakly stratified as the underflow was entrained vertically by wind-stirring. Observed periods of mixing can be predicted to occur when turbulent kinetic energy (TKE) production by wind stirring integrated over the underflow hydraulic residence time in the bay exceeds the potential energy associated with the stratification. A decrease of ice cover, as observed in the studied subarctic lake over the last decade, will result in the underflow being more frequently exposed to the strong wind-forcing regime during winter, thereby altering the winter distribution of groundwater inflow within the lake.

ACS Style

Alexander L. Forrest; Hrund Andradóttir; Bernard E. Laval. Preconditioning of an underflow during ice-breakup in a subarctic lake. Aquatic Sciences 2011, 74, 361 -374.

AMA Style

Alexander L. Forrest, Hrund Andradóttir, Bernard E. Laval. Preconditioning of an underflow during ice-breakup in a subarctic lake. Aquatic Sciences. 2011; 74 (2):361-374.

Chicago/Turabian Style

Alexander L. Forrest; Hrund Andradóttir; Bernard E. Laval. 2011. "Preconditioning of an underflow during ice-breakup in a subarctic lake." Aquatic Sciences 74, no. 2: 361-374.

Journal article
Published: 01 December 2001 in Water Resources Research
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The flushing of littoral regions is governed by barotropic river flows, QR, and baroclinic exchange flows, ΔQ. This note presents field observations of two different flushing regimes in a shallow wetland that borders a lake. In spring, when river flows are high, the wetland circulation is river‐ or jet‐dominated, ΔQ/QR < 1, and the river short‐ circuits through the wetland in a much shorter time than the nominal residence time. During summer low flows, however, the wetland circulation is dominated by exchange flows, ΔQ/QR > 1, that vary both on diurnal and synoptic (10–20 days) timescales in response to differential heating and cooling between the wetland and lake and to wind. These exchange flows can enhance wetland flushing by a factor of 10 relative to river flushing. A one‐dimensional decoupled heat and flow model represents diurnal exchange flows in this system well and may be used to assess the importance of exchange flows in other systems.

ACS Style

Hrund Ó. Andradóttir; Heidi M. Nepf. Impact of exchange flows on wetland flushing. Water Resources Research 2001, 37, 3265 -3273.

AMA Style

Hrund Ó. Andradóttir, Heidi M. Nepf. Impact of exchange flows on wetland flushing. Water Resources Research. 2001; 37 (12):3265-3273.

Chicago/Turabian Style

Hrund Ó. Andradóttir; Heidi M. Nepf. 2001. "Impact of exchange flows on wetland flushing." Water Resources Research 37, no. 12: 3265-3273.