Papers by Oddbjørn Bruland
HIC 2018. 13th International Conference on Hydroinformatics, Sep 20, 2018
This paper deals with flood estimation in ungauged catchment using continuous rainfall-runoff mod... more This paper deals with flood estimation in ungauged catchment using continuous rainfall-runoff model. The rainfall-runoff model used in this study is developed based on the ENKI hydrological framework. In this study, flood estimation in ungauged catchment is based on transfer of parameter values from nearby station. The catchment used in this study to test the suitability of the ENKI system in flood estimation of ungauged catchment is the Gaula catchment located in Norway. This catchment has three main sub-catchments where flow records are available. The ENKI system is calibrated for each sub-catchment. In order to test its suitability in flood estimation, the average of the parameter set obtained from any of the two sub-catchments is used in the remaining sub-catchments. The performance of the ENKI system in flood estimation is evaluated in terms of the Nash-Sutcliffe (NSE) model efficiency index and the model ability to simulate the daily observed Annual Maximum Series (AMS). The result of this study shows that the ENKI framework has considerable potential in flood estimation in ungauged catchments.
Water
Due to the changing climate, flash floods have been increasing recently and are expected to furth... more Due to the changing climate, flash floods have been increasing recently and are expected to further increase in the future. Flash floods caused by heavy rainfall with snowmelt contribution due to sudden rises in temperature or rain-on-snow events have become common in autumn and winter in Norway. These events have caused widespread damage, closure of roads and bridges, and landslides, leading to evacuations in the affected areas. Hence, it is important to analyze such events. In this study, the rain-on-grid technique in the TELEMAC-2D hydrodynamic model was used for runoff modelling and routing using input of snowmelt, and precipitation partitioned on snow and rain was calculated via the hydrological model HBV. The results show the importance of including snowmelt for distributed runoff generation and how the rain-on-grid technique enables extracting flow hydrographs anywhere in the catchment. It is also possible to extract the flow velocities and water depth at each time step, reve...
Polar Research, Jun 1, 2002
ABSTRACT An energy balance based HBV model was calibrated to the run-off from Bayelva catchment i... more ABSTRACT An energy balance based HBV model was calibrated to the run-off from Bayelva catchment in western Spitsbergen, Svalbard. The model simulated the glacier mass balance, and the results were compared to observations at Austre Brøggerbreen for the period 1971-1997. Even though the model was optimized to observed run-off from a catchment in which the glaciers constitute 50% of the area, and not to the observation of glacier mass balance, the model was able to reconstruct the trends and values of the mass balance found through observations. On average the simulation gave a negative net balance of 696 mm. The observed average is 442 mm. The simulated winter accumulation was in average for the same period 9% lower and the summer ablation 17% higher than the observed. The years 1994-96 show deviations between simulated and observed winter accumulation up to 160%. This can probably be accounted for by extreme rainfall during the winter, leading to thick ice layers which make accurate observations difficult. The higher simulated summer ablation might indicate that the glaciers in the catchment as a whole have a larger negative mass balance than Austre Brøggerbreen. The simulations showed that the glacier mass-balance would be in equilibrium with a summer temperature 1.2°C lower than the average over the last decades or with a 100% increase in the winter (snow) precipitation. These are higher values than former estimates. A combined change of temperature and precipitation showed a synergic effect and thereby less extreme values.
Polar Research, Jan 6, 2002
Polar Research, Dec 1, 1999
In the near coastal regions of Dronning Maud Land, Antarctica, below-surface icemelt in blue-ice ... more In the near coastal regions of Dronning Maud Land, Antarctica, below-surface icemelt in blue-ice areas has been observed. The low scattering coefficients of the largegrained blue-ice allow penetration of solar radiation, thus providing an energy source below the ice surface. The sub-surface meltwater is significant enough to show up on remote-sensing imagery in the form of ice-covered lakes. Adjacent snow-accumulation areas have much higher scattering coefficients and consequently limit solar radiation penetration in these regions. These snow and ice surfaces are generally below freezing, and little surface melting occurs. To assess the response of these melt features to changes in atmospheric forcings such as cloudiness, air temperature, and snow accumulation, a physically-based model of the coupled atmosphere, radiation, snow, and blue-ice system has been developed. The model consists of a heat transfer equation with a spectrally-dependent solar-radiation source term. The penetration of radiation into the snow and blue-ice depends on the surface albedo, and the snow and blue-ice grain size and density. Model simulations show that ice melt occurring in this area is sensitive to potential variations in atmospheric forcing. Under certain conditions more traditional surface melting occurs and, under other conditions, the existing melt processes can be shut down completely. In light of the sensitivity of this system to variations in atmospheric forcing, and the ability to view melt-related features using remote sensing, a tool exists to efficiently monitor variations in Antarctic coastal climate.
Polar Research, Jan 6, 2002
CRC Press eBooks, Aug 27, 2020
Hydrology Research, Apr 1, 2002
No pan may be reproduced by any process without complete reference
Hydrology Research, Feb 1, 2001
No part may be reproduced by any process without complete reference
Antarctic Science, Mar 1, 2000
Surface patterns of alternating snow and blue-ice bands are found in the Jutulgryta area of Dronn... more Surface patterns of alternating snow and blue-ice bands are found in the Jutulgryta area of Dronning Maud Land, Antarctica. The snow-accumulation regions exist in the lee of blue-ice topographic ridges aligned perpendicular to winter winds. The snow bands are c. 500–2000 m wide and up to several kilometres long. In Jutulgryta, these features cover c. 5000 km2. These alternating snow and blue-ice bands are simulated using a snow transport and redistribution model, SnowTran-3D, that is driven with a winter cycle of observed daily screen-height air temperature, humidity, and wind speed and direction. The snow-transport model is coupled to a wind model that simulates wind flow over the relatively complex topography. Model results indicate that winter winds interact with the ice topographic features to produce alternating surface patterns of snow accumulation and erosion. In addition, model sensitivity simulations suggest that subtle topographic variations, on the order of 5m elevation change over a horizontal distance of 1 to 1.5 km, can lead to snow-accumulation variations that differ by a factor of six. This result is expected to have important consequences regarding the choice of sites for ice-coring efforts in Antarctica and elsewhere.
Hydrology Research, Jun 1, 2004
In Arctic regions snow cover has a major influence on the environment both in a hydrological and ... more In Arctic regions snow cover has a major influence on the environment both in a hydrological and ecological context. Due to strong winds and open terrain the snow is heavily redistributed and the snow depth is quite variable. This has a significant influence on the snow cover depletion and the duration of the melting season. In many ways these are important parameters in the climate change aspect. They influence the land surface albedo, the possibilities of greenhouse gas exchange and the length of the plant-growing season, the latter also being important for the arctic terrestrial fauna. The aim of this study is to test to what degree a numerical model is able to recreate an observed snow distribution in sites located in Svalbard and Norway. Snow depth frequency distribution, a snow depth rank order test and the location of snowdrifts and erosion areas were used as criteria for the model performance. SnowTran-3D is the model used in this study. In order to allow for occasions during the winter with milder climate and temperatures above freezing, a snow strengthening calculation was included in the model. The model result was compared to extensive observation datasets for each site and the sensitivity of the main model parameters to the model result was tested. For all three sites, the modelled snow depth frequency distribution was highly correlated to the observed distribution and the snowdrifts and erosion areas were located correspondingly by the model to those observed at the sites.
Journal of Glaciology, 1999
In theJutulgryta area of Dronning Maud Land, Antarctica, subsurface melting of the ice sheet has ... more In theJutulgryta area of Dronning Maud Land, Antarctica, subsurface melting of the ice sheet has been observed. The melting takes place during the summer months in blue-ice areas under conditions of below-freezing air and surface temperatures. Adjacent snow-covered regions, having the same meteorological and elimatic conditions, experience little or no subsurface melting. To help explain and understand the observed melt-rate differences in the blue-ice and snow-covered areas, a physically based numerical model of the coupled atmosphere, radiation, snow and blue-ice system has been developed. The model comprises a heat-transfer equation which ineludes a spectrally dependent solar-radiation source term. The penetration of radiation into the snow and blue ice depends on the solar-radiation spectrum, the surface albedo and the snow and blue-ice grain-sizes and densities. In addition, the model uses a complete surface energy balance to define the surface boundary conditions. It is run over the full annual cycle, simulating temperature profiles and melting and freezing quantities throughout the summer and winter seasons. The model is driven and validated using field observations collected during the Norwegian Antarctic Research Expedition (;...rARE)1996-97.The simulations suggest that the observed differences between subsurface snow and blue-ice melting can be eXplained largely by radiative and heat-transfer interactions resulting from differences in albedo, grain-size and density between the two mediums.
Research Square (Research Square), Apr 10, 2023
In recent years, the area of application of Virtual Reality (VR) has grown tremendously from the ... more In recent years, the area of application of Virtual Reality (VR) has grown tremendously from the entertainment industry to the military, to mental health, to hazard identi cation training, and to our daily lives. VR has been widely employed in hazard identi cation and prevention, safety training, evacuation, search and rescue, and damage identi cation of hazards. This paper investigates the application of VR for raising awareness about quick clay landslide hazard. Quick clay landslides are geological hazards that are often triggered suddenly, are di cult to forecast, and often result in disastrous consequences. Currently, hazard and risk maps are used to communicate quick clay landslide risk to the public. However, these maps are mostly expert speci c, and they may not appear convenient to communicate natural hazards such as quick clay landslides to the public. VR technology can be used to further enhance the communication of landslide risk to the public by developing simulations that can raise awareness about, among others, landslide initiation signs, preventive measures, safety training, and actions that can increase safety of individuals in a hazard event. To narrow this communication gap, we developed a tool, QuickAware, that can help in improving awareness of quick clay risk using a VR application. The development process of the tool started with a co design approach where stakeholder experts were brought to collaborate in setting up VR scenarios and de ning the VR environment contents. The contents were then conceptualized and translated into VR experience. The usability of the VR application was examined by conducting a survey with 16 participants. The results of the survey indicated that the tool has a promising value in improving awareness creation for quick clay landslide hazard.
Journal of Flood Risk Management, Apr 24, 2023
The frequency of extreme events is increasing as the consequences of climate change. In steep ter... more The frequency of extreme events is increasing as the consequences of climate change. In steep terrains, flash floods with high‐flow velocities induce erosion and sedimentation with potentially disastrous changes of flood path. Hence, the analysis of flash floods in steep terrains in terms of inundation area and flow‐velocity to identify critical points becomes more important. The output of a flood simulation with a traditional hydrologic model provides the flood hydrograph which must be combined with a hydraulic model for downstream consequences. In small and steep catchments, the inflow contribution from every section of the water course can be important to determine where critical conditions may arise. In this study, rain‐on‐grid technique in the hydraulic model Telemac‐2D is used to simulate flash‐flood peaks with spatially distributed precipitation as input in a small and steep catchment in western Norway. Seven events were simulated and sensitivity tests on parameters were conducted. A 200‐year design flood was simulated to show the potential consequences in the catchment. The results show that calibrated models can satisfactorily reproduce peak flows and produce relevant information about water velocities and inundation which decision makers can use for mitigation measures. The paper explores the benefits and limitations through a description of model construction, calibration, and test of sensitivities.
Hydrology Research, Apr 1, 2020
This study presents results of observations and analysis of the flood event in Utvik on 24 July 2... more This study presents results of observations and analysis of the flood event in Utvik on 24 July 2017. Observations during and after the event, hydraulic simulations and hydrological modelling along with meteorological observations, are used to estimate the peak discharge of the flood. Although both observations and hydraulic simulations of flood extremes are uncertain, even the most conservative assumptions lead to discharge estimates higher than 160 m 3 /s at culmination of the flood from the 25 km 2-large catchment. The most extreme assumptions indicate it may have been up to 400 m 3 /s, but there is also strong evidence for the discharge at culmination being between 200 and 250 m 3 /s. Observations disclosed that the majority of water came from about 50% of the catchment area giving unit discharges up to 18 to 22 m 3 /s,km 2. If the entire catchment contributed it would be from 9 to 11 m 3 /s,km 2. This is significantly higher than previously documented unit discharges in Norway and in the range of the highest observed peak unit discharges in southern Europe. The precipitation causing this event is estimated to be three to five times higher than a 200-year precipitation taken from the intensity-duration-frequency curves for the studied region.
Landslides
Immersive media technologies, such as virtual and augmented reality, have recently enabled a more... more Immersive media technologies, such as virtual and augmented reality, have recently enabled a more holistic way to comprehend natural hazards. In this work, we aim at visualizing the temporal and spatial evolution of a debris flow in a virtual reality environment. We develop a framework to integrate the output results obtained from a debris flow numerical model into virtual reality. To guide the framework, a real debris flow event, which happened in Hunnedalen (Norway) in 2016 and blocked a road network, is considered as a case study. The debris flow is back-calculated using a depth-averaged numerical model and the simulation results are imported into a dedicated game engine to construct a digital model of the debris flow event. The debris flow is visualized using a Head-Mounted Display. We therefore discuss a wide range of potential applications of virtual reality to manage and grasp landslide phenomena: training for rescue operations; improving decision-making; studying early warni...
Polar Research, 2002
Arctic snow cover is important to life on Earth from the microscale soil microarthropod populatio... more Arctic snow cover is important to life on Earth from the microscale soil microarthropod population, to reindeer at the local scale and even the global scale through its impact on the global climate. There is a consensus that global warming will be enhanced towards the Arctic. This will influence the hydrology and snow cover in these regions, which in turn will provide a feedback to climate. There is still a lack of knowledge regarding the impacts to polar hydrology and snow cover; the gaps are even larger with respect to feedback mechanisms.The objective of this study has been to improve the understanding and description of the dynamic processes of an Arctic snow cover. Here, the Arctic climate is studied from the first snow fall to the end of ablation in a series of nine publications grouped into three topics: "Snow Distribution", "Snowmelt and Energy Balance" and "Measurement Methods". The research is based on measurements and observations of climate,...
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Papers by Oddbjørn Bruland