19 research outputs found

    Effects of urban morphology on traffic noise: A parameter study including indirect noise exposure and estimated health impact

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    Noise exposure has been calculated and analysed for 31 different urban morphologies in an urban setting. For five of the urban morphologies also vegetation surfaces on facades and roofs were studied. Facade exposures were analysed for both smaller (single-sided) flats and larger (floor-through) flats, considering the direct exposure from the roads as well as the indirect exposure at noise-shielded positions like inner yards. Also, grid map area exposures at ground level were calculated and analysed for both sidewalk and yard areas. The facade exposure levels, using indicators Lden and Lnight, were used to estimate annoyance and sleep disturbance as well as disease burden in terms of DALY (Disability-Adjusted Life Years) per person. In all urban morphology cases, single-sided flats showed overall better performance (i.e. lower DALY) than larger, floor-through flats; however, the inclusion of a bonus for additional facade elements having a lower noise exposure gave the large flats a similar or better predicted overall performance compared with the small flats. Among the building types studied, for small flats and constant building density, the use of perimeter blocks with closed inner yards, slightly open yards and U-shaped buildings showed results of relatively better overall performance compared with I-shaped, L-shaped and point buildings. When the yards grow in size, the performance of closed inner yards dropped. As general trends, perimeter blocks were shown to perform better than morphologies with less enclosed yards and densification with constant traffic flow was shown to result in improved performance. However, building types with slightly open yards may provide an attractive compromise solution due to its relatively good noise shielding at the same time as enabling solutions to air pollution and corner-flat layouts. In addition, complementing the perimeter blocks with towers was shown to enable improvement. Furthermore, traffic concentration by locating all local traffic to a single road was shown to be beneficial, increasingly so by widening the road. Predicted effects of vegetation surfaces on facades and roofs showed significant overall improvement, where closed inner yards benefit from vegetated roofs. The area exposure results showed that when the building blocks are successively less enclosed the levels are reduced on the sidewalks and increased in the yards. Also, the benefit of facade vegetation is shown for the area exposures

    Quality and representability of mobile measurements for local climatological research

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    Temperature recordings from a moving vehicle are frequently used in microclimatological research. This work aims at investigating three aspects of the quality and the representability of mobile-recorded temperature data: the displacement of air near the car's front; the inertia of the sensors which hinders the accurate recording of fast fluctuations, and how good temperature profiles obtained above a road correspond to temperature profiles of areas adjacent to the road. 72 Air parcels undergo a slight vertical deflection close to the car's front compared to their undisturbed level farther away from the car. Sonic anemometer measurements while the car is at rest were done to estimate the displacement of air parcels at the car's front. The results indicate small total vertical deflection at sensor position. The time behaviour of two different thermocouples was estimated using spectral analysis. At low frequencies the effect of the sensors' time constant is negligible, but inereases above 0.01 Hz. The spectra are corrected for the influenee of the time constant and compared with a spectrum of a simultaneously obtained sonic anemometer measurement. The differenees are small at the lowest frequencies but increase with inereasing frequencies. Measurements on foot along transects perpendicular to a road were done to estimate the representability of mobile-collected temperature data and the influence of the road. The measurements carried out during autumn showed no substantial influence caused by the road. There may be, however, marked differences in the near-ground temperature distribution on both sides of the road. The ground's influence diminishes with increasing sensor height

    The Lund instrumental record of air pressure 1780-1997

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    A multi-state weather generator for daily precipitation for the Torne River basin, northern Sweden/western Finland

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    This paper describes a new weather generator – the 10-state empirical model – that combines a 10-state, first-order Markov chain with a non-parametric precipitation amounts model. Using a doubly-stochastic transition-matrix results in a weather generator for which the overall precipitation distribution (including both wet and dry days) and the temporal-correlation can be modified independently for climate change studies. This paper assesses the ability of the 10-state empirical model to simulate daily area-average precipitation in the Torne River catchment in northern Sweden/western Finland in the context of 3 other models: a 10-state model with a parametric (Gamma) amounts model, a wet/dry chain with the empirical amounts model, and a wet/dry chain with the parametric amounts model. The ability to accurately simulate the distribution of multi-day precipitation in the catchment is the primary consideration. Results showed that the 10-state empirical model represented accumulated 2- to 14-day precipitation most realistically. Further, the distribution of precipitation on wet days in the catchment is related to the placement of a wet day within a wet-spell, and the 10-state models represented this realistically, while the wet/dry models did not. Although all four models accurately reproduced the annual and monthly averages in the training data, all models underestimated inter-annual and inter-seasonal variance. Even so, the 10-state empirical model performed best. We conclude that the multi-state model is a promising candidate for hydrological applications, as it simulates multi-day precipitation well, but that further development is required to improve the simulation of interannual variation

    Characterizing and visualizing spatio-temporal patterns in hourly precipitation records

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    We develop new techniques to summarize and visualize spatial patterns of coincidence in weather events such as more or less heavy precipitation at a network of meteorological stations. The cosine similarity measure, which has a simple probabilistic interpretation for vectors of binary data, is generalized to characterize spatial dependencies of events that may reach different stations with a variable time lag. More specifically, we reduce such patterns into three parameters (dominant time lag, maximum cross-similarity, and window-maximum similarity) that can easily be computed for each pair of stations in a network. Furthermore, we visualize such threeparameter summaries by using colour-coded maps of dependencies to a given reference station and distance-decay plots for the entire network. Applications to hourly precipitation data from a network of 93 stations in Sweden illustrate how this method can be used to explore spatial patterns in the temporal synchrony of precipitation events.funding agencies|Swedish Research Council (VR)||Gothenburg Atmospheric Science Centre (GAC)||FORMAS|2007-1048-8700*51|</p

    Assessment of agrarian reform in Latvia (1920-1937) in historiography

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    Bakalaura darba “Latvijas agrārās reformas (1920.-1937.g.) atspoguļojums historiogrāfijā” mērķis ir apkopot agrāras reformas uzstādījumu un rezultātu izvērtējumu galvenās tendences historiogrāfijā. Darbs veidots, ievērojot hronoloģiskos un lokālos atskaites punktus, sākot ar reformas uzsākšanu un beidzot ar mūsdienām, atsevišķas nodaļas veltot starpkaru perioda, emigrācijas, padomju un mūsdienu latviešu autoru darbiem. Darbā tika secināts, ka agrārās reformas vērtējums ir izkliedēts dažādu virzienu pētījumos, kā arī, vispamatīgāk agrārās reformas vērtējums ir saistīts ar tautsaimniecības vēsturei veltītiem pētījumiem. Darba procesā arī atklājās jauna, līdz šim nepētīta agrārās reformas šķautne - urbānais agrārās reformas aspekts - pilsētu un agrārās reformas attiecību jautājums.The aim of the Bachelor thesis "Assessment of agrarian reform in Latvia (1920-1937) in Historiography" is to summarize the evaluation of results of agrarian reform, and the major trends in historiography. This work is created on the chronological and local reference points, starting with the launch of agrarian reform and ending with the present day, devoting a separate chapters on the interwar period, emigration, the Soviet and contemporary Latvian authors. In the study was concluded that the assessment of agrarian reform is divided into different directions, as well as studies. Mainly assessment of agrarian reform is related to research in national economic history. Work process also revealed a new facet of the agrarian reform - the urban aspect of the agrarian reform

    Effect of urban morphology and greening on noise and air pollution - case studies including disease burden estimates

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    Exposure of both noise and air pollution due to road traffic in urban environments has been calculated and evaluated for multiple cases. A model study in an urban setting used 31 cases of building morphologies and traffic concentration. An evaluating second set was based on a real case of an arterial road transformed into a boulevard. Besides the effect of building morphology, the effects of driving speed, electric vehicles and urban greening were studied. The levels of noise exposure (Lden and Lnight at housing fa\ue7ades) and air pollution (NO2 and PM10 at sidewalks and yards) were calculated as input to estimating the health impact using DALY (Disability-Adjusted Life Years). Concluding from the results, the best solution from a noise perspective is closed blocks with green roofs, while the best solution concerning air quality is point buildings or closed blocks with added high towers. Urban greening was shown to improve the noise situation in general whereas air quality varied due to the interaction between wind speed, dispersion, and filtering effect of leaves. Urban planning guidelines were formulated, including also suggestions of traffic concentration by locating all local traffic to a single widened road as well as transitioning to electric vehicles in combination with reduced vehicle speed
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