| 1. |
- Bodin, Theo, et al.
(författare)
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Survey context and question wording affects self reported annoyance due to road traffic noise: a comparison between two cross-sectional studies.
- 2012
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Ingår i: Environmental health : a global access science source. - 1476-069X. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: Surveys are a common way to measure annoyance due to road traffic noise, but the method has some draw-backs. Survey context, question wording and answer alternatives could affect participation and answers and could have implications when comparing studies and/or performing pooled analyses. The aim of this study was to investigate the difference in annoyance reporting due to road traffic noise in two types of surveys of which one was introduced broadly and the other with the clearly stated aim of investigating noise and health METHODS: Data was collected from two surveys carried out in the municipality of Malmo, southern Sweden in 2007 and 2008 (n = 2612 and n = 3810). The first survey stated an aim of investigating residential environmental exposure, especially noise and health. The second survey was a broad public health survey stating a broader aim. The two surveys had comparable questions regarding noise annoyance, although one used a 5-point scale and the other a 4-point scale. We used geographic information systems (GIS) to assess the average road and railway noise (LAeq,24h) at the participants' residential address. Logistic regression was used to calculate odds ratios for annoyance in relation to noise exposure. RESULTS: Annoyance at least once a week due to road traffic noise was significantly more prevalent in the survey investigating environment and health compared to the public health survey at levels >45 dB(A), but not at lower exposure levels. However no differences in annoyance were found when comparing the extreme alternatives "never" and "every day". In the study investigating environment and health, "Noise sensitive" persons were more likely to readily respond to the survey and were more annoyed by road traffic noise compared to the other participants in that survey. CONCLUSIONS: The differences in annoyance reporting between the two surveys were mainly due to different scales, suggesting that extreme alternatives are to prefer before dichotomization when comparing results between the two. Although some findings suggested that noise-sensitive individuals were more likely to respond to the survey investigating noise and health, we could not find convincing evidence that contextual differences affected either answers or participation.
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| 2. |
- Kristiansen, Jesper, et al.
(författare)
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Work stress, worries, and pain interact synergistically with modelled traffic noise on cross-sectional associations with self-reported sleep problems
- 2011
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Ingår i: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 1432-1246 .- 0340-0131. ; 84:2, s. 211-224
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Tidskriftsartikel (refereegranskat)abstract
- To examine the risk of sleep problems associated with work stress (job strain, job demands, and decision authority), worries and pain and to investigate the synergistic interaction between these factors and traffic noise. Sleep problems and predictor variables were assessed in a cross-sectional public health survey with 12,093 respondents. Traffic noise levels were assessed using modelled A-weighted energy equivalent traffic sound levels at the residence. The risk of sleep problems was modelled using multiple logistic regression analysis. With regard to sleep problems not attributed to any external source (general sleep problems), independent main effects were found for traffic noise (women), decision authority (women), job strain, job demands, suffering from pain or other afflictions, worries about losing the job, experiencing bullying at work, having troubles paying the bills, and having a sick, disabled, or old relative to take care of (women). Significant synergistic effects were found for traffic noise and experiencing bullying at work in women. With regard to sleep problems attributed to traffic noise, strong synergistic interactions were found between traffic noise and, respectively, job demands (men), having pain or other afflictions, taking care of a sick, old, or disabled relative, and having troubles paying the bills. Main effects were found for worries about losing the job, experiencing bullying at work, job strain (men), and decision authority (men). Synergistic interactions could potentially contribute with 10-20% of the sleep problems attributed to traffic noise in the population. Work stress, pain, and different worries were independently associated with general sleep problems and showed in general no synergistic interaction with traffic noise. In contrast, synergistic effects between traffic noise and psychological factors were found with regard to sleep problems attributed to traffic noise. The synergy may contribute significantly to sleep problems attributed to traffic noise in the population.
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| 3. |
- Stroh, Emilie, et al.
(författare)
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Measured and modeled personal and environmental NO2 exposure
- 2012
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Ingår i: Population Health Metrics. - : Springer Science and Business Media LLC. - 1478-7954. ; 10:10
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in Undetermined Background: Measured or modeled levels of outdoor air pollution are being used as proxies for individual exposure in a growing number of epidemiological studies. We studied the accuracy of such approaches, in comparison with measured individual levels, and also combined modeled levels for each subject's workplace with the levels at their residence to investigate the influence of living and working in different places on individual exposure levels. Methods: A GIS-based dispersion model and an emissions database were used to model concentrations of NO2 at the subject's residence. Modeled levels were then compared with measured levels of NO2. Personal exposure was also modeled based on levels of NO2 at the subject's residence in combination with levels of NO2 at their workplace during working hours. Results: There was a good agreement between measured facade levels and modeled residential NO2 levels (r(s) = 0.8, p > 0.001); however, the agreement between measured and modeled outdoor levels and measured personal exposure was poor with overestimations at low levels and underestimation at high levels (r(s) = 0.5, p > 0.001 and r(s) = 0.4, p > 0.001) even when compensating for workplace location (r(s) = 0.4, p > 0.001). Conclusion: Modeling residential levels of NO2 proved to be a useful method of estimating facade concentrations. However, the agreement between outdoor levels (both modeled and measured) and personal exposure was, although significant, rather poor even when compensating for workplace location. These results indicate that personal exposure cannot be fully approximated by outdoor levels and that differences in personal activity patterns or household characteristics should be carefully considered when conducting exposure studies. This is an important finding that may help to correct substantial bias in epidemiological studies.
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| 4. |
- Abdi, Hakim, et al.
(författare)
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The supply and demand of net primary production in the Sahel
- 2014
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 9:9, s. 11-094003
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Tidskriftsartikel (refereegranskat)abstract
- Net primary production (NPP) is the principal source of energy for ecosystems and, by extension, human populations that depend on them. The relationship between the supply and demand of NPP is important for the assessment of socio-ecological vulnerability. We present an analysis of the supply and demand of NPP in the Sahel using NPP estimates from the MODIS sensor and agri-environmental data from FAOSTAT. This synergistic approach allows for a spatially explicit estimation of human impact on ecosystems. We estimated the annual amount of NPP required to derive food, fuel and feed between 2000 and 2010 for 22 countries in sub-Saharan Africa. When comparing annual estimates of supply and demand of NPP, we found that demand increased from 0.44 PgC to 1.13 PgC, representing 19% and 41%, respectively, of available supply due to a 31% increase in the human population between 2000 and 2010. The demand for NPP has been increasing at an annual rate of 2.2% but NPP supply was near-constant with an inter-annual variability of approximately 1.7%. Overall, there were statistically significant (p < 0.05) increases in the NPP of cropland (+6.0%), woodland (+6.1%) and grassland/savanna (+9.4%), and a decrease in the NPP of forests (−0.7%). On the demand side, the largest increase was for food (20.4%) followed by feed (16.7%) and fuel (5.5%). The supply-demand balance of NPP is a potentially important tool from the standpoint of sustainable development, and as an indicator of stresses on the environment stemming from increased consumption of biomass.
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| 5. |
- Akkermans, T., et al.
(författare)
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Validation and comparison of two soil-vegetation-atmosphere transfer models for tropical Africa
- 2012
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Ingår i: Journal of Geophysical Research. - 2156-2202. ; 117, s. 02013-02013
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Tidskriftsartikel (refereegranskat)abstract
- This study aims to compare and validate two soil-vegetation-atmosphere-transfer (SVAT) schemes: TERRA-ML and the Community Land Model (CLM). Both SVAT schemes are run in standalone mode (decoupled from an atmospheric model) and forced with meteorological in-situ measurements obtained at several tropical African sites. Model performance is quantified by comparing simulated sensible and latent heat fluxes with eddy-covariance measurements. Our analysis indicates that the Community Land Model corresponds more closely to the micrometeorological observations, reflecting the advantages of the higher model complexity and physical realism. Deficiencies in TERRA-ML are addressed and its performance is improved: (1) adjusting input data (root depth) to region-specific values (tropical evergreen forest) resolves dry-season underestimation of evapotranspiration; (2) adjusting the leaf area index and albedo (depending on hard-coded model constants) resolves overestimations of both latent and sensible heat fluxes; and (3) an unrealistic flux partitioning caused by overestimated superficial water contents is reduced by adjusting the hydraulic conductivity parameterization. CLM is by default more versatile in its global application on different vegetation types and climates. On the other hand, with its lower degree of complexity, TERRA-ML is much less computationally demanding, which leads to faster calculation times in a coupled climate simulation.
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| 6. |
- Ardö, Jonas
(författare)
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A 10-year data set of basic meteorology and soil properties in central Sudan
- 2013
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Ingår i: Dataset Papers in Geosciences. - : Hindawi Limited. - 2314-5323. ; 2013, s. 29797-29797
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Tidskriftsartikel (refereegranskat)abstract
- Meteorological data and soil data have been collected at a site in the central Sudan from 2002 to 2012. The site is a sparse savanna in the semiarid region of Sudan. In addition to basic meteorological variables, soil properties (temperature, water content, and heat flux) and radiation (global radiation, net radiation, and photosynthetic active radiation) were measured. The dataset has a temporal resolution of 30 minutes and provides general data for calibration and validation of ecosystem models and remote-sensing-based assessments, and it is relevant for studies of ecosystem properties and processes.
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| 7. |
- Eklundh, Lars, et al.
(författare)
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High resolution mapping of vegetation dynamics from Sentinel-2
- 2012
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Ingår i: Proceedings of 1st Sentinel-2 Preparatory Symposium. - 0379-6566. - 9789290922711 ; 707 SP
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Konferensbidrag (refereegranskat)abstract
- The aim of this work is to develop and test a method for generation of information on vegetation dynamics from high-spatial resolution data, such as Sentinel-2. In order to accomplish this, Sentinel-2 data were simulated from existing SPOT HRG and HRVIR scenes over Sweden. We used TIMESAT, a well-tested computer package for generating smooth seasonal profiles and generation of seasonality parameters, like start and end, length, amplitude, integrated values, seasonal maximum, derivatives, etc. The processing works on a pixel-by-pixel basis and is resistant to clouds and noise. Data gaps are handled, and quality information can be included to increase the fidelity of the fits. The pilot study demonstrated that TIMESAT was successful in fitting smooth model functions to the data, and generating seasonality parameters for the test area at 10 × 10 m resolution. We conclude that TIMESAT will be useful for generating vegetation dynamics data from high-spatial resolution data such as Sentinel-2. The smooth seasonal profiles will be extremely useful for driving high-resolution biophysical vegetation models, and the seasonality parameters will be excellent for change detection, and for studying trends in vegetation productivity and seasonality.
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| 8. |
- El Tahir, Bashir Awad, et al.
(författare)
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Nutrient Balances as Indicators of Sustainability in acacia senegal Land use Systems in the Semi-arid Zone of North Kordofan, Sudan
- 2013
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Ingår i: Standard Scientific Research and Essays. - 2310-7502. ; 1:5, s. 93-112
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study were: (1) to assess nutrient flows and balances at land management systems and cropping seasons levels, and (2) to determine rate of nutrient depletion. The study was conducted in dry lands of Northern Kordofan, Sudan, at El Demokeya Forest Reserve (lat.13° 16′ ′′ ′N; long. 30° 29′ ′′ ′E, and alt. 560 m), over three cropping seasons (2002, 2003 and 2004). Flows and balances of organic carbon (OC), nitrogen (N), phosphorous (P) and potassium (K) in pure and intercropped sorghum, roselle and grasses with Acacia senegal at low- and high-tree density (LD 266 and HD 433 trees ha -1 , respectively) were investigated. Sources of nutrient inflows were organic matter (OM) from trees, gum Arabic, crop roots, atmospheric deposition, and N2fixation. Outflows were harvested products, crop residues, leaching, gaseous losses and wind erosion. Nutrient balances were positive in grass systems, but negative in pure sorghum and roselle. Large variations exist between inter cropped sorghum and roselle systems. Nutrient balances were positive during the poor cropping season (2002), while negative during the good season (2003). Nutrient depletion was severe for all studied nutrients in pure sorghum and roselle, but P depletion was remarkably more severe in roselle systems. For all systems, P availability is the major determinant of sustainability. The study demonstrated that OM was essential for positive nutrient balances. Hence, intercropping is considered as an appropriate option to enhance soil fertility. Ways for adjusting the negative balancesin the context of sustainability were suggested.
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| 9. |
- Garbulsky, Martin F., et al.
(författare)
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Patterns and controls of the variability of radiation use efficiency and primary productivity across terrestrial ecosystems
- 2010
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-8238 .- 1466-822X. ; 19:2, s. 253-267
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Tidskriftsartikel (refereegranskat)abstract
- Aim The controls of gross radiation use efficiency (RUE), the ratio between gross primary productivity (GPP) and the radiation intercepted by terrestrial vegetation, and its spatial and temporal variation are not yet fully understood. Our objectives were to analyse and synthesize the spatial variability of GPP and the spatial and temporal variability of RUE and its climatic controls for a wide range of vegetation types. Location A global range of sites from tundra to rain forest. Methods We analysed a global dataset on photosynthetic uptake and climatic variables from 35 eddy covariance (EC) flux sites spanning between 100 and 2200 mm mean annual rainfall and between -13 and 26 degrees C mean annual temperature. RUE was calculated from the data provided by EC flux sites and remote sensing (MODIS). Results Rainfall and actual evapotranspiration (AET) positively influenced the spatial variation of annual GPP, whereas temperature only influenced the GPP of forests. Annual and maximum RUE were also positively controlled primarily by annual rainfall. The main control parameters of the growth season variation of gross RUE varied for each ecosystem type. Overall, the ratio between actual and potential evapotranspiration and a surrogate for the energy balance explained a greater proportion of the seasonal variation of RUE than the vapour pressure deficit (VPD), AET and precipitation. Temperature was important for determining the intra-annual variability of the RUE at the coldest energy-limited sites. Main conclusions Our analysis supports the idea that the annual functioning of vegetation that is adapted to its local environment is more constrained by water availability than by temperature. The spatial variability of annual and maximum RUE can be largely explained by annual precipitation, more than by vegetation type. The intra-annual variation of RUE was mainly linked to the energy balance and water availability along the climatic gradient. Furthermore, we showed that intra-annual variation of gross RUE is only weakly influenced by VPD and temperature, contrary to what is frequently assumed. Our results provide a better understanding of the spatial and temporal controls of the RUE and thus could lead to a better estimation of ecosystem carbon fixation and better modelling.
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| 10. |
- Ghent, D., et al.
(författare)
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Assimilation of land surface temperature into the land surface model JULES with an ensemble Kalman filter
- 2010
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Ingår i: Journal of Geophysical Research: Atmospheres. - 2169-8996. ; 115:D19, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- Land surface models have uncertainties due to their approximation of physical processes and the heterogeneity of the land surface. These can be compounded when key variables are inadequately represented. Land surface temperature (LST) is critical as it forms an integral component in the surface energy budget, water stress evaluation, fuel moisture derivation, and soil moisture-climate feedbacks. A reduction in the uncertainty of surface energy fluxes, and moisture quantification, is assumed to be achievable by constraining simulations of LST with observation data. This technique is known as data assimilation and involves the adjustment of the model state at observation times with measurements of a predictable uncertainty. In this paper, the validity of LST simulations in a regionalized parameterization of the land surface model Joint UK Land Environment Simulator (JULES) for Africa is assessed by way of a multitemporal intercomparison study with the Moderate Resolution Imaging Spectroradiometer (MODIS), the Advanced Along Track Scanning Radiometer (AATSR), and the Spinning Enhanced Visible and Infrared Imager (SEVIRI) thermal products, with a two-thirds reduction in model bias found when soil properties are reparameterized. A data assimilation experiment of SEVIRI LST into the JULES model via an ensemble Kalman filter shows an improvement in the modeled LST, soil moisture, and latent and sensible heat fluxes. This paper presents the first investigation into reducing the uncertainty in modeling energy and water fluxes with the United Kingdom's most important land surface model, JULES, by means of data assimilation of LST.
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