Norwegian Water

Abstract. Landslides in glacial and periglacial environments are increasingly affected by climate change, with rapid failures reported in high mountain regions and the Arctic. The complex mechanisms behind these events are often poorly understood due to a lack of dense in situ data. We investigate two slow-moving landslides in Arctic Norway (70° N), the Jettan and Gámanjunni landslides, located about 10 km apart, with Jettan below and Gámanjunni above the permafrost boundary. Using over a decade of multi-physics observations, including geodetic, borehole, seismic, and hydrological data, we examine surface and subsurface deformation. Both landslides display similar seasonal surface velocity patterns, with peaks in spring and autumn, likely influenced by pore-water infiltration. At Jettan, twelve years of inclinometer data in boreholes reveal a transition from steady state to seasonal deformation in two shear zones. Since 2020, spring accelerations have intensified in years coinciding with deeper snowpacks and associated melt. These observations, together with statistical modeling, suggest that the shear-band interface is becoming increasingly localized and sensitive to pore-water pressure. Conversely, autumn acceleration is not seen in localized shear zones but manifests as distributed volumetric deformation. Seismic velocity variations within the landslide body also exhibit seasonal patterns that correspond with GNSS velocity, interpreted as changes in landslide rigidity due to water infiltration. This integrated analysis of surface and subsurface data offers new insights into the evolving deformation of Arctic landslides, emphasizing the influence of hydrological forcings on both seasonal and long-term deformation processes.

Abstract The sealing behaviour of labyrinth seals plays a crucial role in minimizing leakage losses by preventing unwanted flow between high-pressure and low-pressure regions and hence, enhancing the efficiency of Francis turbines. Stepped labyrinth seals are mostly common in high-head Francis turbines. Leakage loss and, consequently, the sealing behavior of stepped seals are significantly influenced by geometrical parameters such as cavity numbers, length, depth, distance between the cavities and shape of the cavity. Most of the studies regarding the design of stepped labyrinth seals deal with the steam turbines. Therefore, in the case of Francis turbines, it is now necessary to get deep insights into the impacts of various geometrical factors on the stepped seals. The three-dimensional band side stepped labyrinth seals consisting of different cavity or step dimensions, clearance gap and distance between the cavities for the numerical study were built in CAD software. The meshing and the simulations were carried out in the Ansys workbench. The leakage losses for every numerical model were investigated in the study. The numerical results showed that 0.1 mm clearance gaps, 5 cavity numbers, 4.5 mm cavity depth and optimal 4 mm cavity length have a significant reduction in the leakage losses for the band side stepped labyrinth seals. Similarly, the results also conveyed that, there is a minimal control of leakages with the increase in distance between the cavities in comparison to the cavity length. This research work provides valuable insights for designing stepped labyrinth seals to enhance the operational efficiency and reliability of Francis turbines.

Freshwater aquaculture plays an important role in the global aquaculture industry. The success of freshwater aquaculture relies on the integration of bio-ecological remediation technologies to ensure its sustainable development. This paper systematically reviews the global literatures on bio-ecological remediation of freshwater aquaculture environments from 1990 to 2021, and discusses in detail the research progress and status quo in this field using both bibliometric analysis and content analysis. Our results indicate that the number of publications per year has increased year by year, with a particularly rapid increase after 2015. Institutions and researchers from China and the USA publish the greatest number of papers and contribute the most to this field. By analyzing the research progress in this field, we also find that the protection and restoration of freshwater aquaculture environments has received attention since as early as 1990, such as the application of constructed wetlands and recirculating aquaculture systems. Recently, researchers have increasingly focused on the use of microbial communities in remediation. Furthermore, vanRijn, J's papers are of great value to the research in this field. In content analysis, the application of primary technologies, including plant selection, aquatic animals, microorganisms, and biological filtration and purification equipment, as well as ecological engineering technologies with combinations of various types of organisms, is described to improve the effectiveness and efficiency of remediation. The performance, advantages, disadvantages, or limitations and prospects of these technology applications are analyzed in detail. By comparison, ecological engineering is shown to be the best remediation technology, being most comprehensive, and well-established. Taken together, this paper composes and summarizes existing work in this field, and provides guidance for future research on the improvement of existing technologies and the development of new technologies, with the aim of enhancing remediation capability, improving ecological sustainability and ensuring economic viability.

Bioretention facilities with different inflow concentrations, growing media and plants were examined to determine whether the soil in these facilities was polluted with heavy metals and whether runoff had obvious toxic effects on plants. Using Beijing soil background value as the standard, the soils were evaluated by bioaccumulation index and single factor index. The results show that stormwater runoff containing Cu caused slight pollution in soils, and stormwater runoff containing Zn and Pb was not polluted. Nemerow comprehensive index evaluation revealed that the heavy metals content in the facilities containing vermiculite (a yellow or brown mineral found as an alteration product of mica and other minerals, used for insulation or as a moisture-retentive medium for growing plants) and perlite (a form of obsidian characterized by spherulites formed by cracking of the volcanic glass during cooling, used as insulation or in plant growth media) were higher than the standard. High influent concentration caused significantly higher heavy metals content in plants. While Pb accumulation in the two studied plants was the highest, Cu and Zn accumulation, which are essential for plant growth, was relatively low. The contents of the three heavy metals in the studied plants also exceeded their corresponding critical values.

Oil spill clean-up measures using in situ burning can potentially result in seafloor contamination affecting benthic organisms. To mimic realistic exposure and measure effects, ovigerous Northern shrimp were continuously exposed for two weeks to the water-soluble fraction of oil coated on gravel followed by two weeks in clean seawater. North Sea crude oil (NSC) and field generated in situ burn residue (ISBR) of NSC were used (Low: 3 g/kg gravel, Medium: 6 g/kg gravel and High: 12 g/kg gravel). The concentrations of polyaromatic hydrocarbons (PAHs) in the water resulting from NSC were higher compared to ISBR. No mortality was observed in any treatment and overall moderate sublethal effects were found, mostly after exposure to NSC. Feeding was temporarily reduced at higher concentrations of NSC. PAH levels in hepatopancreas tissue were significantly elevated following exposure and still significantly higher at the end of the experiment in NSCHigh and ISBRHigh compared to control. Mild inflammatory response reactions and tissue ultrastructural alterations in gill tissue were observed in both treatments. Signs of necrosis occurred in ISBRHigh. No change in shrimp locomotory activity was noted from NSC exposure. However, ISBR exposure increased activity temporarily. Larvae exposed as pleopod-attached embryos showed significant delay in development from stage I to stage II after exposure to NSCHigh. Based on this study, oil-contaminated seafloor resulting from in situ burning clean-up actions does not appear to cause serious effects on bottom-living shrimp.

Good practice and standards set strict requirements for optimization and continuous improvement of physical asset management. The new international standard for asset management provides a framework for asset intensive industries to develop and implement sound asset management systems. Unlike the largest and most global industries, there are very few, if any, providers of services in the water sector that have developed and implemented a full set of best practices, in compliance with specifications created by the standard. Oslo Water and Sewerage Works (Oslo VAV) has worked systematically to evolve its asset management system by standardizing work processes and operating procedures in its Business Process Management System, implementing good practice in infrastructure asset management, and by improved management and control of the private contractor that operates the wastewater treatment plant's processes and activities. This paper provides insight into Oslo VAV's asset management system, assessment of current practice vs. best practice for complying with the standard and high priority areas for improvement.

SummaryThe prevention of hydrocarbon (HC) leaks is of great importance because they are the most critical precursor events that may lead to major accidents, such as in the case of Piper Alpha. The number of HC leaks on offshore production installations on the Norwegian continental shelf (NCS) peaked just after the year 2000, with more than 40 leaks per year of an initial rate greater than 0.1 kg/s. The Norwegian Oil and Gas Association (Norwegian Oil and Gas) conducted a reduction project from 2003 to 2008, which resulted in only 10 HC leaks greater than 0.1 kg/s in 2007. The number of leaks increased in the years after 2007, and there were 15, on average, in the period 2008–2010, without any significant increase in the number of installations. Norwegian Oil and Gas started a new project early in 2011 to reduce the number of HC leaks yet further. The initiative will be completed at the end of 2013, but has already started to show promising results. A study undertaken as part of the project concluded that more than 50% of the leaks are associated with the failure of operational barriers during human intervention into the process systems. Human and organizational factors predominate with respect to circumstances and root causes. This paper presents the HC-leak-reduction project, the rationale behind it, and its main activities, which aim to reflect the operational challenges. The activities tie in closely with the results of the analysis of the leaks during the period 2008 through 2011. The single operational barrier that has failed most commonly is the verification of critical activities. The paper also discusses the risk-reduction principles in a barrier context, with an emphasis on operational barriers, as well as some of the challenges faced in the project.

This chapter contains sections titled: Introduction Precision VBD -Comparative Studies TBD -Comparative Study Method Development in ASTM - VBD Method Development in ISO -VBD Discussion Authors' Background in Standard Development