Identification of slushflow situations from regional weather models

Slushflows are known phenomena that cause significant problems for settlements and infrastructure in Norway. Even though single events in the same location are rather rare compared to avalanches, slushflows do occur annually on a national scale. Both intensive snowmelt events as well as high amounts of rain on the snow cover can cause slushflows during the whole winter season. In recent years eight fatalities and widespread problems for infrastructure in Norway have increased the focus on slushflows. Early warning criteria based on readily available meteorological, hydrological and snow data need to be identified to allow a nationwide monitoring of potentially critical situations and corresponding locations that might lead to slushflow events. Earlier work focused on input data from meteorological stations. These stations are often located at sea level and give little information on the meteorological conditions in the release and drainage areas in the mountains. During the last decade, regional weather models have been developed that deliver weather prognosis every hour with up to 4 km grid resolution. In Norway, observed precipitation and temperature are interpolated to a one-kilometre grid and used to model snow conditions and snowmelt. This study aims at analysing the available data to identify critical meteorological elements and their thresholds for the release of slushflows. Examples from recent years will be studied also taking into account the development of the snow cover prior to the slushflow events. The results indicate that the available data has a promising ability to identify critical situations on a regional level

Physically-based landslide assessment for railway infrastructure

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RV 362 Bitu bru, Vinje kommune Telemark, Pilotprosjekt erosjonssikring

Rapporten inngår i en serie rapporter fra FoU-prosjektet ’Klima og transport’, etatsprosjekt 2007-2010. Hensikten med prosjektet er å forbedre rutiner og regelverk for planlegging, prosjektering, bygging, drift og vedlikehold av vegnettet som svar på endrede klimaforhold. Delprosjekt 3 Flom og erosjon, som denne rapporten er en del av, gjennomgår prosjekterings- og vedlikeholdstiltak for å tilpasse til klimabildet. Dette gjelder både for dimensjonering av vegen, drenerings- og erosjonssikringstiltak og kriterier for valg av konstruksjonsløsninger. Rapporten beskriver sikringstiltak mot erosjon ved landkarfundamentene for Bitu bru. Den gjennomgår hydrologien i vassdraget med beregning av vannhastighet etc, fram til dimensjonering av steinstørrelse for erosjonssikring med blokkstein

Hydro-Mechanical Effects of Several Riparian Vegetation Combinations on the Streambank Stability — A Benchmark Case in Southeastern Norway

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Coastal inundation multi-hazard analysis for a construction site in Malaysia

-Establishment of new manufacturing sites in high-technology industries requires considerable investments. These investments need to be safeguarded against the impacts of natural hazards. The March 2011 Tohoku earthquake and tsunami highlighted the tremendous impacts of cascading hazards and emphasised the importance of hazard and risk assessment in the early stages of site selection. A screening study of coastal inundation due to multiple hazards was performed for a potential manufacturing plant at the Batu Kawan Industrial Park in Penang state, Malaysia. The analysis accounted for river floods, rainfall and flash floods, cyclones, tides, storm surges, sea-level rise, and tsunamis. Natural hazards not related to inundation, such as earthquakes and volcanoes, were also briefly evaluated. Where relevant data were available, the hazards were assessed quantitatively. Otherwise, they were assessed qualitatively. The effects of climate changes were discussed for temperature and rainfall and for sea-level rise. The proposed development site elevation of 2.60 m LSD (Land Survey Data Level; 30 cm above mean sea level) will probably be reached by both the 100-year flood and the 100-year combined tide and storm surge. With a well-engineered drainage system the flooding risk is low, but in this low-lying area coincidence with a storm surge or high tide will aggravate the flooding situation. Sea-level rise over the next 100 years for the region is assumed to be less than 0.55 m. The relative levels for the other hazards were found to be lower. There is obviously significant uncertainty associated with the estimated hazard at the return periods considered for design. A further comparison of the various hazard levels is not meaningful without considering also the consequences (i.e. the risk)

Coastal inundation multi-hazard analysis for a construction site in Malaysia

Postojećim metodama za proračun složenih uzemljivačkih sustava izračunata je raspodjela potencijala za zadane modele uzemljivača. Izračunata raspodjela potencijala bila je temelj za istraživanje mogućnosti razvoja metodologije za rješavanje inverznog problema u strujnom polju uzemljivača. Ostvaren je središnji cilj istraživanja; razvijena je metodologija za rekonstrukciju strukture uzemljivača iz izračunate raspodjele potencijala na površini tla. Dobiveni rezultati uspoređeni su sa zadanim strukturama uzemljivača te je napravljena analiza osjetljivosti metodologije rekonstrukcije. Utvrđena je osjetljivost rezultata inverznog postupka na brojne utjecajne parametre i situacije koje se mogu dogoditi prilikom mjerenja na stvarnom uzemljivaču. Za primjenu razvijene metodologije na izmjerenu raspodjelu potencijala, ustanovljeni su postupci za regularizaciju rješenja inverznog problema u cilju smanjenja osjetljivosti na brojne mjerne nesigurnosti i druge utjecajne parametre. Problem neizmjernih vrijednosti potencijala u određenim mjernim točkama riješen je razvijenim ekstrapolacijskim i interpolacijskim postupcima koji su integralni dio metodologije rekonstrukcije. Mjerenju na stvarnom uzemljivačkom sustavu prethodio je razvoj složenog računalnog mjernog sustava u koji su ugrađena potrebna znanja za automatiziranu sustavnu provedbu mjernog postupka. Korištenjem razvijenog mjernog sustava za mjerenje na stvarnom uzemljivačkom sustavu u visokonaponskom postrojenju dokazana je primjenjivost razvijene metodologije.In accordance with the recent methods for large grounding system calculations, surface potential distributions for the user-defined grounding grid models were calculated. By using the calculated distributions, a methodology for inverse problem solving in current field of a grounding system was researched. The main scope of the thesis is justified; the methodology for grounding grid reconstruction from the calculated earth surface potential distribution is developed. The results gained by the reconstruction methodology were compared with the predefined models. The sensitivity analysis was performed in order to simulate the real conditions in exploatation. It was found that the solution of the inverse problem is extremely sensitive to various measuring uncertainties in real measurement situations. In order to increase the accuracy of the reconstruction, regularization procedures were developed and implemented to stabilize the solution of the inverse problem. The interpolation and extrapolation procedures were embedded in reconstruction methodology for solving the missing – data problem. Complex computerized measurement system is developed in order to assure systematic earth surface potential measurements with automated measuring procedures and documenting. The usability of both developed reconstruction methodology as well as of the developed measurement system was approved by performing the on-site earth surface potential measurements on the real grounding system