Regional and structural effects of North Sea oil in Norway     

Kjell Stenstadvold 《GeoJournal》1980,1(1):71-93

The discovery of oil in the North Sea has had an important impact on Norway. The article presents the development of the oil policy. Of particular interest is the heavy involvement in Norway in products as mobile rigs, supply ships and concrete platforms. The distribution of the oil activities in Norway as related to locational factors is discribed, with examples of the local impacts of oil activities. Of particular concern are the regional effects. Norway will be a high cost country and low-wage industries (e.g. textiles, furniture) may be squeezed. Industrial decay areas like in Britain and Europe are feared. Also some main problems and decisions such as the landing of Statfjord oil by pipeline are considered. The original version received valuable criticism from Prof. J. Chr. Hansen, Bergen, and Dr. W. Tietze, Wolfsburg, Germany. The author would be grateful for further comments from the readers.  相似文献   

Is trophic state or regional location the strongest determinant for Chl-a/TP relationships in lakes?     

Knut L. Seip  Erik Jeppesen  Jens Petter Jensen  Bj?rn Faafeng 《Aquatic Sciences - Research Across Boundaries》2000,62(3):195-204

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News and notes: Environmental change and human health in countries of Africa, the Caribbean and the Pacific     

Gordon McGranahan  Simon Lewin  Taryn Fransen  Caroline Hunt  Marianne Kjellén  Jules Pretty  Carolyn Stephens  Ivar Virgin 《Global Change & Human Health》2000,1(1):9-9

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Synergistic effects of water repellency and macropore flow on the hydraulic conductivity of a burned forest soil,south‐east Australia     

Petter Nyman  Gary Sheridan  Patrick N. J. Lane 《水文研究》2010,24(20):2871-2887

Research shows that water repellency is a key hydraulic property that results in reduced infiltration rates in burned soils. However, more work is required in order to link the hydrological behaviour of water repellent soils to observed runoff responses at the plot and hillslope scale. This study used 5 M ethanol and water in disc infiltrometers to quantify the role of macropore flow and water repellency on spatial and temporal infiltration patterns in a burned soil at plot (<10 m²) scale in a wet eucalypt forest in south‐east Australia. In the first summer and winter after wildfire, an average of 70% and 60%, respectively, of the plot area was water repellent and did not contribute to infiltration. Macropores (r > 0·5 mm), comprising just 5·5% of the soil volume, contributed to 70% and 95%, respectively, of the field‐saturated and ponded hydraulic conductivity (K_p). Because flow occurred almost entirely via macropores in non‐repellent areas, this meant that less than 2·5% of the soil surface effectively contributed to infiltration. The hydraulic conductivity increased by a factor of up to 2·5 as the hydraulic head increased from 0 to 5 mm. Due to the synergistic effect of macropore flow and water repellency, the coefficient of variation (CV) in K_p was three times higher in the water‐repellent soil (CV = 175%) than under the simulated non‐repellent conditions (CV = 66%). The high spatial variability in K_p would act to reduce the effective infiltration rate during runoff generation at plot scale. Ponding, which tend to increase with increasing scale, activates flow through macropores and would raise the effective infiltration rates at larger scales. Field experiments designed to provide representative measurements of infiltration after fire in these systems must therefore consider both the inherent variability in hydraulic conductivity and the variability in infiltration caused by interactions between surface runoff and hydraulic conductivity. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Solving complex fisheries management problems: What the EU can learn from the Nordic experiences of reduction of discards     

Jahn Petter Johnsen  Søren Eliasen 《Marine Policy》2011

A crucial issue for the new EU common fisheries policy is how to solve the discard problem. Through a study of the institutional set up and the arrangements for solving the discard problem in Denmark, the Faroe Islands, Iceland and Norway, the article identifies the discard problem as related to both natural, other material and to cultural conditions. Hence, solving the discard problem requires not only technical and regulatory instruments, but also arenas and structures that allow and facilitate processes of cultural change.  相似文献   

Secondary production in a Laminaria hyperborea kelp forest and variation according to wave exposure     

Kjell M. Norderhaug  Hartvig Christie 《Estuarine, Coastal and Shelf Science》2011

The secondary production of mobile invertebrate fauna in the Laminaria hyperborea (Gunn.) Foslie kelp forest increases with wave exposure level. This faunal group has a key function in transferring kelp carbon to higher levels in the food web. By using a size-frequency method the calculated production was 68 (±18) g D.W. m⁻² yr⁻¹ (±S.E.) at low, 250 (±57) at medium and 308 (±64) at high exposure levels. The calculations included 30 macrofauna species, which accounted for 96% of the specimens registered, with Gastropods, amphipods and bivalves being the most abundant taxa. The calculated secondary production is high, but comparable to that previously reported from other macrophyte systems and was 3%, 8% and 8% of the total primary production at low, medium and high exposure levels, respectively. Our results indicate that large quantities of Laminaria kelp are exported from the system, although the production of sessile animals was not taken into account. The most important factor in determining faunal densities and secondary production was probably habitat size but at low exposure levels the percentage of egg-carrying crustacean females and juveniles were lower than at medium and high exposure levels, thereby indicating lower fitness for animals at low exposure stations.  相似文献   

Is climate change a driver of armed conflict?     

Ole Magnus Theisen  Nils Petter Gleditsch  Halvard Buhaug 《Climatic change》2013,117(3):613-625

The world is generally becoming less violent, but the debate on climate change raises the specter of a new source of instability and conflict. In this field, the policy debate is running well ahead of its academic foundation—and sometimes even contrary to the best evidence. Although comparative research on security implications of climate change is rapidly expanding, major gaps in knowledge still exist. Taken together, extant studies provide mostly inconclusive insights, with contradictory or weak demonstrated effects of climate variability and change on armed conflict. This article reviews the empirical literature on short-term climate/environmental change and intrastate conflict, with special attention to possible insecurity consequences of precipitation and temperature anomalies and weather-related natural disasters. Based on this assessment, it outlines priorities for future research in this area.  相似文献   

Variations in temperature and extent of Atlantic Water in the northern North Atlantic during the Holocene     

Morten Hald  Carin Andersson  Hanne Ebbesen  Eystein Jansen  Dorthe Klitgaard-Kristensen  Bjrg Risebrobakken  Gaute R. Salomonsen  Michael Sarnthein  Hans Petter Sejrup  Richard J. Telford 《Quaternary Science Reviews》2007,26(25-28):3423-3440

We compare six high-resolution Holocene, sediment cores along a S–N transect on the Norwegian–Svalbard continental margin from ca 60°N to 77.4°N, northern North Atlantic. Planktonic foraminifera in the cores were investigated to show the changes in upper surface and subsurface water mass distribution and properties, including summer sea-surface temperatures (SST). The cores are located below the axis of the Norwegian Current and the West Spitsbergen Current, which today transport warm Atlantic Water to the Arctic. Sediment accumulation rates are generally high at all the core sites, allowing for a temporal resolution of 10–10² years. SST is reconstructed using different types of transfer functions, resulting in very similar SST trends, with deviations of no more than ±1.0/1.5 °C. A transfer function based on the maximum likelihood statistical approach is found to be most relevant. The reconstruction documents an abrupt change in planktonic foraminiferal faunal composition and an associated warming at the Younger Dryas–Preboreal transition. The earliest part of the Holocene was characterized by large temperature variability, including the Preboreal Oscillations and the 8.2 k event. In general, the early Holocene was characterized by SSTs similar to those of today in the south and warmer than today in the north, and a smaller S–N temperature gradient (0.23 °C/°N) compared to the present temperature gradient (0.46 °C/°N). The southern proxy records (60–69°N) were more strongly influenced by slightly cooler subsurface water probably due to the seasonality of the orbital forcing and increased stratification due to freshening. The northern records (72–77.4°N) display a millennial-scale change associated with reduced insolation and a gradual weakening of the North Atlantic thermohaline circulation (THC). The observed northwards amplification of the early Holocene warming is comparable to the pattern of recent global warming and future climate modelling, which predicts greater warming at higher latitudes. The overall trend during mid and late Holocene was a cooling in the north, stable or weak warming in the south, and a maximum S–N SST gradient of ca 0.7 °C/°N at 5000 cal. years BP. Superimposed on this trend were several abrupt temperature shifts. Four of these shifts, dated to 9000–8000, 5500–3000 and 1000 and 400 cal. years BP, appear to be global, as they correlate with periods of global climate change. In general, there is a good correlation between the northern North Atlantic temperature records and climate records from Norway and Svalbard.  相似文献   

Scientists' warning on extreme wildfire risks to water supply     

François-Nicolas Robinne  Dennis W. Hallema  Kevin D. Bladon  Mike D. Flannigan  Gabrielle Boisramé  Christian M. Bréthaut  Stefan H. Doerr  Giuliano Di Baldassarre  Louise A. Gallagher  Amanda K. Hohner  Stuart J. Khan  Alicia M. Kinoshita  Rua Mordecai  João Pedro Nunes  Petter Nyman  Cristina Santín  Gary Sheridan  Cathelijne R. Stoof  Matthew P. Thompson  James M. Waddington  Yu Wei 《水文研究》2021,35(5):e14086

2020 is the year of wildfire records. California experienced its three largest fires early in its fire season. The Pantanal, the largest wetland on the planet, burned over 20% of its surface. More than 18 million hectares of forest and bushland burned during the 2019–2020 fire season in Australia, killing 33 people, destroying nearly 2500 homes, and endangering many endemic species. The direct cost of damages is being counted in dozens of billion dollars, but the indirect costs on water-related ecosystem services and benefits could be equally expensive, with impacts lasting for decades. In Australia, the extreme precipitation (“200 mm day −1 in several location”) that interrupted the catastrophic wildfire season triggered a series of watershed effects from headwaters to areas downstream. The increased runoff and erosion from burned areas disrupted water supplies in several locations. These post-fire watershed hazards via source water contamination, flash floods, and mudslides can represent substantial, systemic long-term risks to drinking water production, aquatic life, and socio-economic activity. Scenarios similar to the recent event in Australia are now predicted to unfold in the Western USA. This is a new reality that societies will have to live with as uncharted fire activity, water crises, and widespread human footprint collide all-around of the world. Therefore, we advocate for a more proactive approach to wildfire-watershed risk governance in an effort to advance and protect water security. We also argue that there is no easy solution to reducing this risk and that investments in both green (i.e., natural) and grey (i.e., built) infrastructure will be necessary. Further, we propose strategies to combine modern data analytics with existing tools for use by water and land managers worldwide to leverage several decades worth of data and knowledge on post-fire hydrology.  相似文献   

Using Multiple Grids in Markov Mesh Facies Modeling     

Odd Kolbjørnsen  Marita Stien  Heidi Kjønsberg  Bjørn Fjellvoll  Petter Abrahamsen 《Mathematical Geosciences》2014,46(2):205-225

A multigrid Markov mesh model for geological facies is formulated by defining a hierarchy of nested grids and defining a Markov mesh model for each of these grids. The facies probabilities in the Markov mesh models are formulated as generalized linear models that combine functions of the grid values in a sequential neighborhood. The parameters in the generalized linear model for each grid are estimated from the training image. During simulation, the coarse patterns are first laid out, and by simulating increasingly finer grids we are able to recreate patterns at different scales. The method is applied to several tests cases and results are compared to the training image and the results of a commercially available snesim algorithm. In each test case, simulation results are compared qualitatively by visual inspection, and quantitatively by using volume fractions, and an upscaled permeability tensor. When compared to the training image, the method produces results that only have a few percent deviation from the values of the training image. When compared with the snesim algorithm the results in general have the same quality. The largest computational cost in the multigrid Markov mesh is the estimation of model parameters from the training image. This is of comparable CPU time to that of creating one snesim realization. The simulation of one realization is typically ten times faster than the estimation.  相似文献