Fant 9887 publikasjoner. Viser side 322 av 396:
2020
Social-Environmental Analysis for the Management of Coastal Lagoons in North Africa
This study provides an overview of 11 lagoons in North Africa, from the Atlantic to the Eastern Mediterranean. Lagoons are complex, transitional, coastal zones providing valuable ecosystem services that contribute to the welfare of the human population. The main economic sectors in the lagoons included fishing, shellfish harvesting, and salt and sand extraction, as well as maritime transport. Economic sectors in the areas around the lagoons and in the watershed included agriculture, tourism, recreation, industrial, and urban development. Changes were also identified in land use from reclamation, changes in hydrology, changes in sedimentology from damming, inlet modifications, and coastal engineering. The human activities in and around the lagoons exert multiple pressures on these ecosystems and result in changes in the environment, affecting salinity, dissolved oxygen, and erosion; changes in the ecology, such as loss of biodiversity; and changes in the delivery of valuable ecosystem services. Loss of ecosystem services such as coastal protection and seafood affect human populations that live around the lagoons and depend on them for their livelihood. Adaptive management frameworks for social–ecological systems provide options that support decision makers with science-based knowledge to deliver sustainable development for ecosystems. The framework used to support the decision makers for environmental management of these 11 lagoons is Drivers–Activities–Pressures–State Change–Impact (on Welfare)–Responses (as Measures).
Frontiers Media S.A.
2020
Costs and benefits of implementing an Environmental Speed Limit in a Nordic city
We present a comprehensive study on the impacts and associated changes in costs resulting from the implementation of Environmental Speed Limits (ESLs), as a measure to reduce PM10 and associated health effects. We present detailed modelled emissions (i.e., CO2, NOx, PM2.5 and PM10), concentration levels (i.e., PM2.5 and PM10) and population exposure to PM2.5 and PM10 under three scenarios of ESL implementation for the Metropolitan Area of Oslo. We find that whilst emissions of NOx and CO2 do not seem to show significant changes with ESL implementation, PM10 emissions are reduced by 6–12% and annual concentration levels are reduced up to 8%, with a subsequent reduction in population exposure. The modelled data is used to carry out a detailed analysis to quantify the changes in private and social costs for the roads in Oslo where ESL are implemented today. This involves assessments related to human health, climate, fuel consumption, time losses and the incidence of traffic accidents. For a scenario using actual speed data from ESL implementation, our study shows a net benefit associated with the implementation of ESLs, whilst for a theoretical scenario with strict speed limit compliance we find a net increase in costs. This is largely due to variation in costs due to time losses between the scenarios, although uncertainties are high.
Elsevier
2020
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2020
Kartlegging av NO2-konsentrasjoner i luft ved E16 Arna – Vågsbotn ble utført av NILU på oppdrag fra Statens vegvesen.
Målingene ble utført med passive prøvetakere ved 10 steder i området Gaupås-Kalsås-Blinde. Prosjektet ble gjennomført
vinteren 2020 (28. januar – 24. mars) i et område som er utsatt for inversjonsforhold i vintermånedene.
Vinteren 2019-2020 viste seg til å bli en mild vinter, inversjonsforhold ble ikke registrert. NO2-konsentrasjonen var høyest den første uken målingene pågikk og ble gradvis lavere i påfølgende uker. De siste 2 ukene var påvirket av mindre trafikk som en følge av pandemitiltak. Middelkonsentrasjonen ved det mest forurensede målestedet over hele måleperioden var 22,9 μg/m3. Sammenligning av resultatene fra måleområdet med observasjoner fra målestasjoner i Bergen viste at NO2-konsentrasjonen rett ved E16 var på samme nivå som ved veinære stasjoner i Bergen.
NILU
2020
Equinor Mongstad. Spredningsberegninger av utslipp til luft.
NILU har vurdert spredning av utslipp til luft fra Mongstad raffineri. Bakgrunnen er krav fra Miljødirektoratet i forbindelse med ny virksomhetstillatelse. Fokus i studien er på NOx, SOx og støv/partikler. Timemiddelkonsentrasjoner er beregnet ved hjelp av modellen CONCX. Regionale beregninger av konsentrasjoner og avsetning er utført med WRF-EMEP modellsystem. CONCX-beregningene viser at maksimalt beregnet timemiddel er langt lavere enn norske grenseverdier. WRF-EMEP-beregningene viser lave maksimumsverdier av NOx/NO2, SO2 og svevestøv/PM10 i nærområdet til Mongstad raffineri. Alle beregnede maksimumsverdier er lavere enn norske grenseverdier. Av utslippene fra Mongstad avsettes 12 % av nitrogen, 17 % av svovel og 18 % av PM10 innenfor det innerste gridet (105 x 105 km2). Som et tillegg er det gjort vurderinger av de prioriterte stoffene bly, kvikksølv, krom, PCB7, kadmium og arsen. Bidraget fra Mongstad raffineri er lite.
NILU
2020
2020
Atmospheric turbulence and in particular its effect on tracer dispersion may be measured by cameras sensitive to the absorption of ultraviolet (UV) sunlight by sulfur dioxide (SO2), a gas that can be considered a passive tracer over short transport distances. We present a method to simulate UV camera measurements of SO2 with a 3D Monte Carlo radiative transfer model which takes input from a large eddy simulation (LES) of a SO2 plume released from a point source. From the simulated images the apparent absorbance and various plume density statistics (centre-line position, meandering, absolute and relative dispersion, and skewness) were calculated. These were compared with corresponding quantities obtained directly from the LES. Mean differences of centre-line position, absolute and relative dispersions, and skewness between the simulated images and the LES were generally found to be smaller than or about the voxel resolution of the LES. Furthermore, sensitivity studies were made to quantify how changes in solar azimuth and zenith angles, aerosol loading (background and in plume), and surface albedo impact the UV camera image plume statistics. Changing the values of these parameters within realistic limits has negligible effects on the centre-line position, meandering, absolute and relative dispersions, and skewness of the SO2 plume. Thus, we demonstrate that UV camera images of SO2 plumes may be used to derive plume statistics of relevance for the study of atmospheric turbulent dispersion.
2020
2020
2020
2020
Survey of emissions of volatile organic chemicals from handheld toys for children above 3 years
NILU has, on behalf of the Norwegian Environment Agency, performed a screening study to identify volatile organic chemicals (VOCs) emitted from handheld toys for children. The goal was to identify individual VOCs emitted from toys at room temperature and to evaluate what impact the toys may have on the composition and concentrations of VOCs in indoor air. 12-30 individual VOCs were identified in each toy and 65-143 individual VOCs were detected with a concentration higher than 1 µg/m3. VOCs emitted at high concentrations and/or with hazardous properties were cyclohexanone, aromatic VOCs (xylenes, toluene, ethylbenzene), cyclic siloxanes and 2,2,4-Trimethyl-1,3-pentanediol diisobutyrate (TXIB). A regulated hydrochlorofluorocarbon (HCFC-141 b) was also detected from 5 toys. The toys with high concentrations of cyclohexanone and cyclic siloxanes affected the composition and concentrations of VOCs in indoor air.
NILU
2020