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  • 1. Askebjer, P
    et al.
    Johansson, Sverker
    Högskolan för lärande och kommunikation, Högskolan i Jönköping, HLK, Ämnesforskning.
    On the Age vs Depth and Optical Clarity of Deep Ice at the South Pole1995In: Journal of Glaciology, no 41, p. p 445-Article in journal (Refereed)
  • 2. Askebjer, P
    et al.
    Johansson, Sverker
    Högskolan för lärande och kommunikation, Högskolan i Jönköping, HLK, Ämnesforskning.
    Optical properties of the South Pole ice at depths between 0.8 and 1 km1995In: Science, no 267, p. 1147-1150Article in journal (Other academic)
  • 3.
    Beland Lindahl, Karin
    et al.
    Luleå universitet.
    Westholm, Erik
    Dalarna University, School of Technology and Business Studies, Human Geography.
    Transdisciplinarity in practice: aims, collaboration and integration in a Swedish research programme2014In: Journal of Integrative Environmental Sciences, ISSN 1943-815X, E-ISSN 1943-8168, Vol. 11, no 3-4, p. 155-171Article in journal (Refereed)
    Abstract [en]

    This article discusses the practice of crossdisciplinarity in the context of future-oriented sustainability studies. Much research into crossdisciplinarity has concentrated on programmatic and epistemological questions. In this study, we focus on research practice and efforts to realize transdisciplinary aims across a research programme. We use the Swedish Future Forests programme as a case study and explore its aims, forms of collaboration and level of conceptual integration. The study demonstrates that efficient integration requires organizational settings able to support the development of a common conceptual framework. To achieve this, the aims and forms of collaboration and the means of integration ought to be consistent. Far-reaching integration and short-term instrumental objectives may be difficult to combine because integration requires intellectual space, specific boundary settings and time. Short-term instrumental objectives may also hamper open and reflexive discussion of alternative pathways to sustainability and of how participating actors shape the research process. These insights may help researchers and participating actors to design research programmes that enable a realization of their transdisciplinary ambitions.

  • 4.
    Berglund, Mikael
    Dalarna University, School of Education and Humanities, Geography.
    Early Holocene in Gästrikland, east central Sweden: shore displacement and pattern of isostatic recovery2012In: Boreas, ISSN 0300-9483, E-ISSN 1502-3885, Vol. 41, no 2, p. 263-276Article in journal (Refereed)
    Abstract [en]

    In Gästrikland in central Sweden, deglaciation took place c. 11 000 cal. a BP. In the present study the shore displacement during the earliest ice-free period is investigated by the 14C dating of sediment from isolated lake basins. The shore displacement in Gästrikland includes an initial phase (∼500 years) of rapid regression, followed by a slowing of the relative sea level (RSL) fall to a rate similar to that of the remaining Holocene c. 9250 cal. a BP. The Ancylus Lake stage of the Baltic Sea belongs to the analysed interval. The RSL curve and glacial unloading history are used to separate and quantify elements of isostatic uplift. The postglacial uplift is ∼260 m, of which ∼45 m forms a rapid initial rise, which can be treated as qualitatively separate from the later, slower rise. There is considerable glacial unloading just prior to the deglaciation, but calculations suggest that only a small part of this relates directly to the rapid early Holocene rebound: most unloading is transferred either to uplift immediately prior to the deglaciation or to subsequent Holocene or future uplift. The isostatic rise in Gästrikland occurring between the end of the Younger Dryas stadial and the deglaciation, c. 11 500–11 000 cal. a BP, is estimated to be 100–110 m. Observations and estimations are incompatible with a Weichselian maximum ice thickness much smaller that 3000 m. The lack of glacial unloading during the Younger Dryas has a measurable impact on the Holocene isostatic rebound in Gästrikland, reducing it by an estimated 20–25 m.

  • 5.
    Berglund, Mikael
    Dalarna University, School of Education and Humanities, Geography.
    Holocene shore displacement and chronology in Ångermanland, eastern Sweden, the Scandinavian glacio-isostatic uplift centre2004In: Boreas, ISSN 0300-9483, E-ISSN 1502-3885, Vol. 33, p. 48-60Article in journal (Refereed)
    Abstract [en]

    The shore displacement during the Holocene in southeastern Ångermanland, Sweden, has been investigated by means of radiocarbon-dating of isolation intervals in sediment cores from a total of nine new basins. Results from earlier investigations have been used in complement. There is a forced regression in the area from c. 9300 BP (c. 10500 cal. yr BP) until c. 8000 BP (c. 9000 cal. yr BP), on averagec. 8 m/100 years, after which there is a gradually slowing regression of c. 2.5–1.0 m/100 years up to the present time. The most rapid regression occurs during the later phase of the Ancylus Lake stage, 9500–9000 cal. yr BP. There is no evidence of halts in the regression. Crustal uplift in the area since deglaciation is c. 310 m. The deglaciation of southeastern Ångermanland took place c. 9300 BP (c. 10500 cal. yr BP); this is c. 900 years earlier than the age given by clay varve dating. The shore displacement curve provides a means of estimating the difference between the clay varve time scale and calibrated radiocarbon dates, by comparison with varve-dated altitudes of alluvial deltas of the River Ångermanalven. From c. 2500 to c. 8000 cal. BP there is a deficit in clay varves of some 300 years; further back in time this discrepancy increases significantly. The main explanation for the discrepancy is most likely lacking varves in the time-span 8500–10200 cal. yr BP, located along the upper reaches of River Ångermanalven below the highest shore level.

  • 6.
    Berglund, Mikael
    Dalarna University, School of Education and Humanities, Geography.
    Litorina Sea shore displacement and pollen analytical indications of forest succession during the Mid-Holocene in Gästrikland, east central Sweden2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, p. 213-226Article in journal (Refereed)
    Abstract [en]

    This paper deals with the mid-Holocene shore level history and vegetation development in Gästrikland, east-central Sweden. This is investigated using sediment and microfossil records and 14C datings. The time span covered is c. 8000–5000 cal yr BP. Vegetation history during this time includes an increase in Tilia pollen 6500–6300 cal yr BP and a decrease in Ulmus and Corylusc. 5500 cal yr BP. The former change coincides with a sharp drop in relative sea level (RSL) of some 5 m; this RSL drop can be correlated to the regression from the L3 transgression of the Litorina Sea, identified in other areas around the Baltic Sea. The possible connections between RSL and climate (in particular changes on a maritime-continental continuum), as indicated by new pollen data and other records, are investigated. The new material shows, in comparison to other pollen records from southern and central Scandinavia, unusually high percentages of Tilia,Ulmus and Corylus pollen, but less Quercus. The change in pollen spectra around 5500 cal yr BP can be correlated to the northern European “elm decline”. A regional cooling is recorded in widespread data for this time, but observations suggest that other factors must be considered here, including disease and change in the physical landscape due to the ongoing land uplift.

  • 7.
    Berglund, Mikael
    Dalarna University, School of Education, Health and Social Studies, Geography.
    The highest postglacial shore levels and glacio-isostatic uplift pattern in northern Sweden2012In: Geografiska Annaler. Series A, Physical Geography, ISSN 0435-3676, E-ISSN 1468-0459, Vol. 94, no 3, p. 321-337Article in journal (Refereed)
    Abstract [en]

    The detailed clay varve chronology and an extensive knowledge of the highest postglacial shore level elevation (HS) in northern Sweden, along the Bothnian western coast, provides opportunities for determining the pattern of isostatic rise and centre of uplift from the early Holocene. The shore level of c. 10 100 cal yr bp (10 ka) for this area is determined by subtracting, from the metachronous HS elevations, the fall in relative sea level between local deglaciation time and the chosen reference time. The area of highest uplift since 10 ka is situated somewhat north of the location with the world-record HS (Skuleberget in Angermanland), but south of the area with most rapid current rise. Wave erosion marks in the studied area are seen to be more consistent indicators of HS than glaciofluvial delta levels. The gradients of shore marks at 10 ka are generally small within the investigation area. The regional 10 ka shore level pattern shows considerable irregularity compared to the current uplift. Central Sweden and western Finland show 10 ka gradients that indicate isostatic response to late (1310 ka bp) glacial unloading. Indications of a secondary uplift centre west of the present investigation area are reported in previous work; this also suggests rapid isostatic response to unloading. Finally, the possibility of identifying errors in the varve-dated deglaciation chronology via the 10 ka shore level pattern is illustrated.

  • 8.
    Berglund, Mikael
    Dalarna University, School of Education and Humanities, Geography.
    The Holocene shore displacement of Gästrikland, eastern Sweden: a contribution to the knowledge of Scandinavian glacio-isostatic uplift2005In: Journal of Quaternary Science, ISSN 0267-8179, Vol. 20, no 6, p. 519-531Article in journal (Refereed)
  • 9.
    Berglund, Mikael
    Dalarna University, School of Education and Humanities, Geography.
    Time-transgressive early Holocene vegetational succession following shore displacement: a case study from central Sweden2008In: Boreas, ISSN 0300-9483, E-ISSN 1502-3885, Vol. 37, no 1, p. 87-101Article in journal (Refereed)
    Abstract [en]

    Deglaciation took place in eastern Jämtland and Ångermanland in central Sweden c. 10 500–10 200 cal. yr BP. In the present study, vegetation development and shore displacement during the earliest ice-free period are investigated by 14C dating of sediment from six isolated lake basins and by pollen analysis. A brief but distinct peak in Hippophaë occurs in all pollen diagrams coincident with basin isolation, followed by up to 500 years (varying locally) by an Alnus rise. The Alnus curve does not display a synchronous rise in the area. Its expansion below the highest shore level is time-transgressive and controlled mainly by the timing of basin isolation. The relationship between regional Alnus expansion and changes in hydrology and climate is discussed. The pollen diagrams show Pinus predominance with Corylus to the east (more coastal areas) and Betula predominance (though less pronounced) to the west during the period 10 200–9000 cal. yr BP. However, comparisons between sites suggest marked variability in the forest development. Shore displacement in easternmost Jämtland c. 10 300–9000 cal. yr BP is equal to or slightly more rapid than that of SE Ångermanland, contrary to the present pattern of isostatic recovery. A rapid shore level regression c. 10 300–10 000 cal. yr BP may be related to drainage of the Ancylus Lake.

  • 10.
    Berglund, Mikael
    et al.
    Dalarna University, School of Education, Health and Social Studies, Geography.
    Dahlström, Niklas
    Post-glacial fault scarps in Jämtland, central Sweden2015In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 137, no 4, p. 339-343Article in journal (Refereed)
    Abstract [en]

    Analysis of a light detection and ranging-derived digital elevation model has revealed previously unknown fault scarps in central Jämtland, Sweden. These are interpreted to have been formed by earthquakes at the time of deglaciation, c. 10 ka BP, in an area with current low-magnitude seismicity. The dating is based upon morphology and comparison with similar features at other locations in Sweden but not supported by independent dating. Observed scarps are 0.4–6 km long, 2–8 m high, trending SSW–NNE to WSW–ENE, the northern and western sides uplifted. The dimensions of the scarps suggest an approximate moment magnitude M 7 of the strongest corresponding earthquakes.

  • 11.
    Carling, Kenneth
    et al.
    Dalarna University, School of Technology and Business Studies, Statistics.
    Han, Mengjie
    Dalarna University, School of Technology and Business Studies, Statistics.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Information Systems. Dalarna University, School of Technology and Business Studies, Human Geography.
    Meng, Xiangli
    Dalarna University, School of Technology and Business Studies, Statistics.
    Rudholm, Niklas
    Dalarna University, School of Technology and Business Studies, Economics.
    Measuring transport related CO2 emissions induced by online and brick-and-mortar retailing2015In: Transportation Research Part D: Transport and Environment, ISSN 1361-9209, E-ISSN 1879-2340, Vol. 40, p. 28-42Article in journal (Refereed)
    Abstract [en]

    We develop a method for empirically measuring the difference in transport related carbon footprint between traditional and online retailing (“e-tailing”) from entry point to a geographical area to consumer residence. The method only requires data on the locations of brick-and-mortar stores, online delivery points, and residences of the region’s population, and on the goods transportation networks in the studied region. Such data are readily available in most countries. The method has been evaluated using data from the Dalecarlia region in Sweden, and is shown to be robust to all assumptions made. In our empirical example, the results indicate that the average distance from consumer residence to a brick-and-mortar retailer is 48.54 km in the studied region, while the average distance to an online delivery point is 6.7 km. The results also indicate that e-tailing increases the average distance traveled from the regional entry point to the delivery point from 47.15 km for a brick-and-mortar store to 122.75 km for the online delivery points. However, as professional carriers transport the products in bulk to stores or online delivery points, which is more efficient than consumers’ transporting the products to their residences, the results indicate that consumers switching from traditional to e-tailing on average reduce their transport CO2 footprints by 84% when buying standard consumer electronics products. 

  • 12.
    Carling, Kenneth
    et al.
    Dalarna University, School of Technology and Business Studies, Statistics.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Information Systems.
    Meng, Xiangli
    Dalarna University, School of Technology and Business Studies, Statistics.
    Rudholm, Niklas
    Dalarna University, School of Technology and Business Studies, Economics.
    The effects of taxing truck distance on CO2 emissions from transports in retailing2015Report (Other academic)
    Abstract [en]

    To finance transportation infrastructure and to address social and environmental negative externalities of road transports, several countries have recently introduced or consider a distance based tax on trucks. In the competitive retail market such tax can be expected to lower the demand and thereby reduce CO2 emissions of road transports. However, as we show in this paper, such tax might also slow down the transition towards e-tailing. Considering that previous research indicates that a consumer switching from brick-and-mortar shopping to e-tailing reduces her CO2 emissions substantially, the direction and magnitude of the environmental net effect of the tax is unclear. In this paper, we assess the net effect in a Swedish regional retail market where the tax not yet is in place. We predict the net effect on CO2 emissions to be positive, but off-set by about 50% because of a slower transition to e-tailing.

    Download full text (pdf)
    fulltext
  • 13.
    Carling, Kenneth
    et al.
    Dalarna University, School of Technology and Business Studies, Statistics.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Human Geography.
    Rudholm, Niklas
    Dalarna University, School of Technology and Business Studies, Economics.
    Optimal retail location and CO2 emissions2012Report (Other academic)
    Abstract [en]

    In this paper, the p-median model is used to find the location of retail stores that minimizes CO2 emissions from consumer travel. The optimal location is then compared with the existing retail location,and the excess CO2 emissions compared with the optimal solution is calculated. The results show that by using the environmentally optimal location, CO2 emissions from consumer travel could be reduced by approximately 25percent. 

    Download full text (pdf)
    fulltext
  • 14.
    Carling, Kenneth
    et al.
    Dalarna University, School of Technology and Business Studies, Statistics.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Human Geography.
    Rudholm, Niklas
    Dalarna University, School of Technology and Business Studies, Economics.
    Optimal retail location and CO2-emissions2013In: Applied Economics Letters, ISSN 1350-4851, E-ISSN 1466-4291, Vol. 20, no 14, p. 1357-1361Article in journal (Refereed)
    Abstract [en]

    In this paper, the p-median model is used to find the location of retail stores that minimizes CO2-emissions from consumer travel. The optimal location is then compared with the existing retail location,and the excess CO2-emissions compared with the optimal solution is calculated. The results show that by using the environmentally optimal location, CO2-emissions from consumer travel could be reduced by approximately 25 per cent.

  • 15. Chang, Li
    et al.
    Chong, Wen Tong
    Wang, Xinru
    Pei, Fei
    Zhang, Xingxing
    Dalarna University, School of Information and Engineering, Energy Technology.
    Wang, Tongzhao
    Wang, Chunqing
    Pan, Song
    Recent progress in research on PM2.5 in subways.2021In: Environmental Science: Processes & Impacts, ISSN 2050-7887, E-ISSN 2050-7895, Vol. 23, no 5, p. 642-663Article in journal (Refereed)
    Abstract [en]

    Nowadays, PM2.5 concentrations greatly influence indoor air quality in subways and threaten passenger and staff health because PM2.5 not only contains heavy metal elements, but can also carry toxic and harmful substances due to its small size and large specific surface area. Exploring the physicochemical and distribution characteristics of PM2.5 in subways is necessary to limit its concentration and remove it. At present, there are numerous studies on PM2.5 in subways around the world, yet, there is no comprehensive and well-organized review available on this topic. This paper reviews the nearly twenty years of research and over 130 published studies on PM2.5 in subway stations, including aspects such as concentration levels and their influencing factors, physicochemical properties, sources, impacts on health, and mitigation measures. Although many determinants of station PM2.5 concentration have been reported in current studies, e.g., the season, outdoor environment, and station depth, their relative influence is uncertain. The sources of subway PM2.5 include those from the exterior (e.g., road traffic and fuel oil) and the interior (e.g., steel wheels and rails and metallic brake pads), but the proportion of these sources is also unknown. Control strategies of PM mainly include adequate ventilation and filtration, but these measures are often inefficient in removing PM2.5. The impacts of PM2.5 from subways on human health are still poorly understood. Further research should focus on long-term data collection, influencing factors, the mechanism of health impacts, and PM2.5 standards or regulations.

  • 16.
    Craven, Anna
    Uppsala universitet, Institutionen för geovetenskaper.
    Electromobility in Sweden: Facilitating market conditions to encourage consumer uptake of electric vehicles2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Download full text (pdf)
    FULLTEXT01
  • 17.
    Dalvik, Linn
    Dalarna University, School of Education, Health and Social Studies, Geography.
    STUDIE AV SKIFTESREFORMER I DELAR AV ÖSTERGÖTLAND: In-och utflyttande befolkning och industriutveckling i samband med Laga skifte2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Linköpings kommun har karaktäriserats som både en religös stad och rådsstad mellan 1200-talet och 1900-talet. En stad som genomgick många stora förändringar mellan dessa årtal. Skiftesreformerna kom till Linköping 1770 och staden skiftades mest mellan 1900-1910. Under 1800-talets första del ägde en mycket hastig tillväxt rum i Norrköpings fabriksväsende, särskilt klädesproduktionen och mellan åren 1805 och 1855 ökade antalet fabriksarbetare från ca 800 till över 3 200, skiftesreformerna kom innan denna tillväxt. Redan 1764 och den period som skiftades mest var 1860-1870. Motala är en hamn- och industristad vid Vättern och Göta kanal och var en av Östergötlands viktigaste platser för kvarndrift och hade omfattande anläggningar. Skiftesreformerna kom till Motala 1748 och det skedde flest laga skifte mellan 1850-1860. Syftet med denna uppsats var att testa hypotesen, som är vanlig i samband med forskning om laga skiftets genomförande, om huruvida laga skiften påverkade eller påverkades av befolkningens in-och ut flyttande i socknarna som skiftena genomfördes i. En annan hypotes som testades var ifall växande industrier hade någon inverkan på genomförandet av laga skifte. Resultatet blev att dessa hypoteser motbevisades i de socknar som undersökts i uppsatsen.

  • 18.
    Fagerström, Arne
    et al.
    Högskolan i Gävle, Företagsekonomi.
    Cunningham, GaryHögskolan i Gävle, Företagsekonomi.
    A good life for all: Essays on sustainability celebrating 60 years of making life better2017Collection (editor) (Other academic)
    Abstract [en]

    For a better world now and in the future

    For a world that sustains itself for genereations to come, the University of Gävle is an ambitious and development-oriented organization with a focus on sustainability now and in the future. Under the leadership of Dr. Maj-Britt Johansson, the University is creating a sustainable community. This book commemorates her efforts in hounour of her 60th birthday.

    The ten essays here show the wide variety of sustainability activities under her leadership, not limited to ecological issues, includning science, social work, building design and contruction, and World Hertiage sites, along with a variety of other cutting-edge topics.

    Download (pdf)
    SUMMARY01
  • 19. Farsari, Ioanna
    et al.
    Chrysoulakis, Nektarios
    Kmarianakis, Yiannis
    Diamantakis, Manolis
    Prastacos, Poulicos
    Combining satellite and socioeconomic data for Land Use Models estimation2004Conference paper (Refereed)
    Abstract [en]

    Land use is an important explanatory variable in urban growth models, which explore the way various factors (e.g. geographic, economic, demographic etc.) interact to simulate growth dynamics. A serious and recurring problem for modelling urban systems has been the lack of spatially detailed data. Remote sensing and Geographical Information Systems have the potential to support such models, by providing data and analytical tools for the study of urban environments. High spatial resolution sensors such as the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) allow the estimation of land covers using either supervised or unsupervised classification techniques. Moreover, the accuracy of the classification can be improved by incorporating ancillary data in the classification scheme. In this study, spatial data from various sources are combined to develop statistical models relating land use to population density, distance from the center of the city, a land use mix index and monetary land values. The work emphasizes spatial relationships between various geographic, land-use, and demographic variables characterizing fine zones across and around regions. It derives and combines land use data for the Heraklion (Greece) region from ASTER images, cartographic maps and Greek National Statistical Service census of population data. The statistical techniques applied for explaining the variability of land use are ordinary and logistic regression. Land use mix appears to be a significant predictive factor whereas the explanatory power of population increases as the grid cell categorization with respect to land use becomes finer.

  • 20. Grånäs, Karin
    et al.
    Berglund, Mikael
    Dalarna University, School of Education, Health and Social Studies, Geography.
    Beskrivning till jordarterna i Mjällåns dalgång - från Stavre till Graningesjön2016Report (Other academic)
  • 21.
    Gál, Csilla V
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    A városi tér szerkezete és hatása a mikroklímára [Urban space and structure and its effect on the urban microclimate]2017In: 43. Meteorológiai Tudományos Napok. 2017. November 23-24. Mikro- és mezoskálájú légköri folyamatok modellezése. Az előadások összefoglalói. / [ed] István Geresdi, Ferenc Ács, Balázs Szintai, and Tamás Weidinger, Budapest, Hungary, 2017Conference paper (Refereed)
    Abstract [hu]

    A városok sajátos éghajlata, a városklíma, a természetes környezethez képest módosult éghajlattal jellemezhető. A klímaparaméterek városi módosulásának hátterében a beépített felszínek megváltozott energiaháztartása áll. Míg a városok éghajlata markánsan elkülönül a környező természetes területek éghajlatától, a városokon belül is jelentős klimatikus különbségek alakulnak ki. Ezen különbségek kialakulására alapvető hatással van a beépítettség foka, valamint a zöld területek részaránya. A városokon belüli éghajlati különbségek tanulmányozása mérések és numerikus szimulációk révén lehetséges. Utóbbiak segítségével széleskörűen tanulmányozható a beépítettség, a városokra jellemző mesterséges anyagok, valamint a városon belül alkalmazott zöld- és kék infrastruktúra elemeinek hatása a kialakuló mikro- és lokális éghajlatra, illetve mindezek hatása a lakosok komfortérzetére. Eme ismeretanyagra alapozva megfogalmazhatók olyan várostervezési irányelvek, melyekkel az éghajlatváltozással kombinálódó városklíma negatív hatásai mérsékelhetőek, s a városlakók számára klimatikus szempontból élhetőbb környezet teremthető.Tanulmányomban Budapest jellemző városi beépítési formáit, s a köztük lévő mikroklimatikus különbségeket vizsgálom numerikus szimulációk útján, különös tekintettel a nyári hőterhelés mérséklésére irányuló várostervezési beavatkozások eredményességére az egyes beépítési formák esetén. Az egyik ilyen beavatkozás az épülethomlokzatok albedójának növelése nagyobb sugárzás-visszaverő képességű anyagok, illetve festékek alkalmazása révén. Egy másik jellemző beavatkozás a zöldterületek részarányának növelése, melyet tanulmányomban a lombkorona borítás értékének változtatásával vizsgálok. A különféle beépítési formák, homlokzat albedók és korona borítottság értékek komplex hatásának feltárására az ENVI-met szimulációs software-t alkalmaztam. Az eredmények alapján elmondható, hogy a megnövekedett albedó következtében a napsugárzásnak kitett homlokzatok hőmérséklete – s ez által az épületek hőterhelése is – csökken. A visszavert sugárzási hányad megnövekedése azonban az épületek között sugárzás többletként jelenik meg, mely többlet a nem módosított albedójú felületek (utak, terek) nagyobb sugárzási terheléséhez és ezáltal a városi határréteg felmelegedéséhez vezet. Ezzel ellentétben, a korona borítottság növelése a városi határrétegben a rövidhullámú sugárzás és a léghőmérséklet csökkenését eredményezi. Mivel ezen tényezők hatása a lakosok komfortérzetét és az épületeket érő hőterhelést is előnyösen befolyásolja, a közterületek fásítása a nyári hőterhelés mérséklésére irányuló várostervezési beavatkozás egyik hatásos eszköze lehet.

  • 22. Gál, Csilla V
    Experiencing Urban Climate in the Nation's Capital2015Conference paper (Other (popular science, discussion, etc.))
  • 23.
    Gál, Csilla V
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Mean radiant temperature modeling, A comparative model evaluation2018Conference paper (Refereed)
    Abstract [en]

    As a result of the changing climate with trends of rising temperatures and increasing extreme heat events, urban planners and city officials have recently taken a great interest in improving the climate of cities and maintaining comfortable outdoor conditions in spite of these trends.In order to meet the demand for this special knowledge and to deliver scientific assistance, several numerical models have emerged with an aim to assess the microclimate of cities and their influence on human thermal comfort over the course of the past decade. While these tools differ both in the human thermal comfort indices they deliver and in their numerical modeling approach, they all rely on the calculation of mean radiant temperature—the driving parameter of outdoor human thermal comfort. While the assessment of models lags behind the perpetual software updates and releases, the documentation of many such models is also lacking or insufficient. In addition, a great deal of existing validation studies assess clear cut situations where the site is either sunlit or in shade, whereas conditions in the urban environment are generally more complex. Given both the growing importance the outdoor thermal environment of cities and the role played by these tools, reporting on their performance is of high importance.The aim of this study is to assess the ability of several recently emerged or updated microclimate models to reproduce mean radiant temperature (Tmrt) in a complex urban setting. The evaluation is made against field data obtained by integral radiation measurements. Results indicate that most microclimate models underestimate Tmrt both at sunlit locations and at night, whereas in shade Tmrt is generally overestimated. These errors are related to the surface temperature parametrization, the isotropic sky assumption, simplifications in the reflected shortwave radiation calculation and the incorrect representation of a standing person.

  • 24. Gál, Csilla V
    Microclimate assessment of urban block typologies, a simulation approach2012Conference paper (Other academic)
    Abstract [en]

    Urban environments are characterized by a diversity of microclimates. To manage this complexity, assessments generally involve a certain kind of simplification: either an areal constriction (e.g. the analysis of distinct urban squares), or a spatial reduction (e.g. the reliance on the urban canyon model). This paper approaches the task at the scale of the urban block. In the analysis of metropolitan urban block typologies, the study adopts Probáld's concept of microclimate assemblages. With the presented approach, the research aims to compliment existing urban microclimate assessments. Utilizing the numerical modelENVI‐met, this paper focuses on the effect of building configurations.

  • 25.
    Gál, Csilla V
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Modeling mean radiant temperature in outdoor spaces: A comparative numerical simulation and validation study2018Conference paper (Refereed)
    Abstract [en]

    Cities are increasingly under pressure to address the challenges of climate change. One of the most pressing and unifying issue in this respect is the maintenance of comfortable outdoor conditions despite rising air temperatures and increasing extreme heat events. As a means to inform urban planner and city officials, the assessment of outdoor thermal comfort conditions—either via numerical modeling or field measurements—have gained popularity over the past decade. While measurements can deliver highly accurate data, they are expensive and time-consuming endeavors that can only inform us about the conditions in an existing environment on a specific day and time of the year. In contrast, numerical modeling allows us to evaluate alternative urban design scenarios as well as to grasp the spatial and temporal variability of outdoor human thermal comfort conditions.

    Given the advantages of numerical modeling and the increasing computational power of personal computers, several tools have emerged with an aim to assess the microclimate and human thermal comfort impacts of urban planning and design decisions. While these tools differ both in the human thermal comfort indices they deliver and in their numerical modeling approach, they all rely on the calculation of mean radiant temperature, in one way or another. Mean radiant temperature (Tmrt), the driving parameter of human thermal comfort in outdoor spaces, requires the modeling of both short- and long waver radiation fluxes. While different calculation methods exist to deriving this parameter, most models also introduce some kind of numerical simplification to increase computational speed. The multitude of numerical approaches in deriving Tmrt, coupled with the high spatial and temporal variability of this parameter, can result in a range of values delivered by these tools. Given both the growing importance of improving the outdoor thermal environment of cities and the role these tools play in it, reporting on their performance is of high importance.

    The aim of this study is to assess popular microclimate models in their ability to reproduce the complex radiative environment of cities, as indicated by Tmrt, and to inform to the research and design community about their performance, compared to integral radiation measurement derived filed data. While the documentation of some numerical simulation tools is lacking or incomplete, this paper will nevertheless attempt to shed lights on the reasons behind the disparities in the derived Tmrt values. Initial results indicate that most microclimate models have a tendency to underestimate nighttime Tmrt together with daytime values when the location is exposed to the sun. In contrast, when the locations become shaded, Tmrt values are generally overestimated. In general, these errors indicate issues with surface temperature parametrization and point to the greatest challenge of the numerical simulation community.

  • 26. Gál, Csilla V
    Revisiting the urban block in the light of climate change: A case study of Budapest2014Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Since the beginning of the twentieth century, the urban block configuration of free-standing buildings has been deemed superior to other built forms, as it provided the necessities of modern healthy living: sunlight and fresh air. In light of climate change, the dissertation aims to reevaluate these long held beliefs and to reintroduce microclimate as an urban design consideration. The study takes four metropolitan block typologies of Budapest as cases to clarify the microclimate influence of key urban design parameters by means of a numerical simulation study. The effects of built form, orientation, vegetation and facade properties are evaluated for a typical summer day. The cases are assessed on the basis of diurnal potential air and mean radiant temperatures within the urban canopy layer. Numerical modeling is performed by ENVI-met and analysis is conducted with MATLAB. The findings indicate that built form and vegetation are key factors governing the microclimate. During the day, intraurban cool island develops between dense configurations and in tree-shaded urban canopies. Orientation is decisive in configurations with large open spaces, where east-west alignment corresponds with peak radiant and air temperatures. Apart from albedo, facade properties have little effect on the microclimate. The rise of air temperature with facade albedo is the outcome of canopy floor heating, resulting from the increased ratio of reflected shortwave radiation. A short-term field experiment was conducted in Budapest to complement the numerical simulation study and to evaluate ENVI-met. The measurement campaign utilized six air temperature and humidity loggers. Additionally, wind speed, air temperature and humidity were recorded at the pedestrian level during an anticyclonic period. In courtyards, thermal stratification developed by day with cool island intensities up to 7 C. In the case of open configurations, neither cool island, nor stratification was observed. The comparison of measured and predicted air temperatures revealed the strengths and weaknesses of the numerical model. In general, predicted temperatures had a decreased diurnal range with maximum values systematically underestimated. ENVI-met also failed to reproduce the thermal stratification in courtyards. Despite these shortcomings, the predicted trends and the relative microclimate differences between the configurations agreed with observations reasonably well.

  • 27.
    Gál, Csilla V
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    The effectiveness of shade trees for urban heat mitigation, a comparative numerical simulation study2016Conference paper (Other academic)
    Abstract [en]

    As a result of climate change, many regions are projected to see increases in air temperatures and extreme heat events over the coming decades. Since these trends are expected to exacerbate existing conditions in cites, urban heat mitigation will be one of the key challenges of the twenty-first century. A frequently advocated means of mitigating urban heat is through shade trees. Through the reduction of air and radiative temperatures trees not only improve outdoor human thermal comfort, but also reduce the cooling loads of buildings. This paper investigates the impact of different canopy cover ratios and tree layouts on the urban microclimate. The numerical simulation study utilizes four characteristic dense urban configurations from Budapest (Hungary) to assess the influences of these factors on the effectiveness of shade trees in mitigating urban heat. The study applies ENVI-met for microclimate simulation and MATLAB for the analysis and visualization of the results. Microclimate conditions within the urban canopy layer are examined on the basis of diurnal air and mean radiant temperatures. Preliminary results indicate that the effectiveness of shade trees is the function of the urban configurations' initial thermal performance. Since microclimate improvements by way of trees are primarily achieved through shading, greatest reduction in radiative temperatures is achieved in configurations with large open spaces. In the case of air temperature, increasing the canopy cover increases the added benefit of temperature reduction—indicating that reduced turbulence can in certain cases be beneficial.

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  • 28. Gál, Csilla V
    The impact of built form on the urban microclimate at the scale of city blocks2014Conference paper (Other academic)
    Abstract [en]

    Following the first oil crisis, Philip Steadman concluded that as a result of the twentieth-century developments in architecture "the means for environmental control within and around buildings, which was formerly achieved through effects of mutual shading, enclosure and wind protection, [were] lost" (Steadman 1975). Nevertheless, subsequent building regulations further strengthened the already prevailing design emphasis on single buildings by introducing energy measures that largely disregarded the effects of the surrounding environment [of the local climate]. While in countries with mild to moderate climates wintertime energy conservation became the primary preoccupation, climate model projections indicate rising temperatures and prolonged heat waves in these parts of the world. As a consequence, architects and planners increasingly find themselves ill equipped to address the challenges of climate change.The aim of this paper is to assess the microclimate performance of built form at the scale of city blocks. The study takes four metropolitan urban block typologies from Budapest as models. The purpose of this analysis is to obtain basic understanding regarding the interaction between built forms and microclimates in general, and to gain knowledge regarding the microclimatic behavior of these existing typologies in particular. The understanding of the performance of these forms is necessary both for developing climate- sensitive design principles and for proposing effective climate mitigation strategies.The comparative numerical simulation study utilizes ENVI-met and MATLAB. The models are compared on the basis of diurnal air temperature, mean radiant temperature and Predicted Mean Vote cycles. The analysis found mean radiant temperature a good indicator of the built form's influence on the canopy layer thermal environment. It is sensitive to directionalities in the model and signals problematic periods and places with high surface and air temperatures. Consequently, mean radian temperature that governs outdoor thermal comfort on warm and hot days is also useful to analyzing and understanding the effects of mutual shading.

  • 29. Gál, Csilla V
    The influence of built form and vegetation on the canopy layer microclimate within urban blocks2014In: Acta Climatologica et Chorologica, ISSN 1587-5903, Vol. 47-48, p. 43-52Article in journal (Refereed)
    Abstract [en]

    A numerical simulation study was conducted to reveal the effects of built form on the canopy layer microclimate at the scale of city blocks and to evaluate the role of vegetation in modifying these environments. The study took four metropolitan urban block typologies from Budapest as models and compared their microclimate dynamics with and without vegetation. Microclimate modeling was performed by ENVI-met (Bruse 2011), while MATLAB was utilized for the data analysis. The findings indicate that built form and vegetation are key factors governing the canopy layer microclimate. Their influence is primarily exerted through shading and enclosure.

  • 30. Gál, Csilla V
    The influence of built form on the microclimate within urban blocks2014Conference paper (Other academic)
    Abstract [en]

    Urban morphology, that is the characteristic size, shape, orientation and distribution of buildings, plays a significant role in affecting the climate within cities. However, despite computational advances over the past decades, simulation studies investigating the effect of built form on the microclimate generally adopt either the array of cubes or the urban canyon model. What these models leave out are the microclimatic conditions within urban blocks and other complex environments that also constitute spaces of human activity. While the recently developed local climate zone (LCZ) classification system also took urban morphology to delineate ten urban categories, it also conceptualized built form as a cluster of free-standing buildings and therefore failed to account for semi-enclosed spaces. The aim of this study is to assess the effect of built form on the microclimate at the scale of the urban block. Taking the built environment of Budapest as a starting point, the study compares the microclimatic performance of four historic metropolitan urban block typologies. The comparative numerical study focuses on the influence of built form and orientation, and employes both a three- dimensional microclimate model (ENVI-met) and a high-level language for numerical computation and visualization (MATLAB). The presentation will compare the diurnal-cycles of air temperature, mean radiant temperature and Predicted Mean Vote of the four urban block configurations. The insights of this study could facilitate the development of targeted climate change adaptation strategies.

  • 31. Gál, Csilla V
    The influence of facade properties on the canopy layer microclimate within city blocks2014Conference paper (Other academic)
    Abstract [en]

    The application of high albedo surfaces and 'cool' materials — characterized by high solar reflectance and emissivity — are often advocated as a means to mitigate the urban heat island (UHI), to decrease indoor temperatures and consequently to reduce cooling loads in warm weather. The frequently described mechanism that links higher surface albedos with lower outdoor temperatures emphasizes the role of decreased surface temperatures in the process. Admittedly, the high albedo approach to UHI mitigation is primarily recommended for roofs, which, compared to roads and facades, have less obstructed sky views. During the day, the higher sky view factor of roofs prevents the trapping of radiation within the urban texture, and ensures a better radiative cooling by night. Nevertheless, the high albedo approach and the application of `cool materials' are increasingly recommended for both urban roads (Akbari, Pomerantz, and Taha 2001; Alchapar, Correa, and Cantón 2014; Santamouris et al. 2012; Santamouris, Synnefa, and Karlessi 2011; Synnefa et al. 2011; Zinzi, Carnielo, and Fasano 2012) and facades (Bougiatioti et al. 2009; Doya, Bozonnet, and Allard 2012; Synnefa, Santamouris, and Apostolakis 2007). The goal of this study is to investigate the role of facade surface properties on the canopy layer microclimate in a dense urban context.

  • 32. Gál, Csilla V
    The influence of shade trees on the canopy layer microclimate within urban blocks: a numerical simulation study2015Conference paper (Other academic)
    Abstract [en]

    Over the coming decades, many locatons are predicted to see warmer temperatures and more frequent extreme heat events as a result of climate change. Rising temperatures, coupled with the urban heat island effect, are expected to exacerbate existng conditons in cites. As a consequence, heat mitgaton in urban areas is antcipated be one of the key challenges of the twenty-first century. A frequently advocated means of mitgatng the urban heat island is through shade trees. Through the reducton of air and radiatve temperatures, they also improve the outdoor human thermal comfort and reduce building cooling loads. Utlizing four Hungarian metropolitan block typologies as cases, a numerical simulaton study is carried out to assess the impact of shade trees on the microclimate within urban blocks. The study applied ENVI-met for microclimate simulaton and MATLAB for the analysis and visualizaton of the results. Microclimate conditons within the blocks---with and without trees---are examined on the basis of diurnal air and mean radiant temperatures. Findings indicate that microclimate improvement by way of trees are primarily achieved through shading. The greatest reducton in daytme air and radiatve temperatures is achieved in configuratons with large open spaces, suggestng that effectve heat mitgaton strategies should also consider the interference between the shading of trees and buildings.

  • 33. Gál, Csilla V
    Urban design and building regulation changes in the transformation of the urban block: A design analysis though the lens of urban climatology in Budapest2011In: City Weathers: Meteorology and Urban Design 1950-2010 / [ed] Michael Hebbert, Vladimir Jankovic and Brian Webb, 2011Conference paper (Refereed)
    Abstract [en]

    Hungary witnessed limited climatic considerations in the practice of architecture and urban planning in the past. The omission of urban climate related issues was — and still is — essentially the outcome of the prevailing technocratic approach. This negligence, coupled with the growth in motor vehicle ownership, changing building design and air-conditioning practices, contributed to the the deterioration of the urban atmospheric environment over the last decades. The efforts to improve dwelling conditions over previous centuries, culminated in several waves of urban design and planning reforms. The outcome of these changing forces was the evolution of the Budapest urban block. During the twentieth century, its development followed the line described by Ernst May (‘from the block to the slab'), only to surpass it with hybrid forms in the twenty-first. This paper, focusing on the transformation of the Budapest urban block, sets forth to provide a historic cross section from the period of the city’s late industrialization to present day. The analysis of this process is facilitated though the identification and use of urban block typologies: each representing distinct urban design and regulatory paradigms. By reviewing the main forces that influenced the emergence of different urban block typologies, and subsequently, presenting an analysis of the resultant configurations, the author aims at introducing climatic considerations into urban design. Downtown urban blocks are at the center of this study, as they represent the most crucial section of the city. These blocks are not only exposed to the highest intensities of the urban heat island effect, but are also facing drear consequences due to the lack of urban green spaces. Because the study aims at addressing urban living and urban environmental concerns, the analysis is focused on existing metropolitan housing models. The first part of the paper presents the evolution of aesthetic, hygienic, structural and other concerns that contributed to the development of Budapest urban block, as well as, identifies the four developed typologies. The second part of the paper presents an analysis by juxtaposing the main regulatory principles and the resultant typologies, in an attempt to pinpoint measures that both effects micro-climate, as well as, are within the control of urban planning, design or architecture. The aim of this analysis is to bring forth the readily available regulatory measures that could become climate- sensitive design guidelines in the future. The outcome of this paper aims to inform policy makers, urban planners, architects and other building professionals regarding the necessity of the inclusion of climate- sensitive design principles into our current design and regulatory practices. In order to extend our understating of this subject -- regarding the casual relationship between urban design parameters and the resultant microclimates --, the author argues for further microclimatic investigations. These subsequent studies will clarify and support the emerging climate-sensitive urban design guidelines, which in turn could ameliorate the existing microclimatic conditions.

  • 34. Gál, Csilla V
    Urban greening and cool surfaces: the effectiveness of climate change adaptation strategies within the context of Budapest2015Conference paper (Other academic)
    Abstract [en]

    Regional climate projections for Central and Eastern Europe indicate a rise in summertime temperatures along with an increase in the frequency of warm temperature extremes by the end of the next century. In the case of Hungary, models indicate a 1.7–2.6°C rise in summer temperatures in the near future, and a 3.5–6.0°C increase is projected for the end of the twenty-first century—based on the A1B scenario. Besides rising temperatures, long term projections also signal a 20–40% decrease in summer precipitation in Hungary. In Budapest, the existing urban heat island (UHI) intensity of 4–8°C is expected to make these already adverse projections worse. Since the combined influences of these phenomena will be most pronounced in the densely built and populated areas of the city, identifying effective UHI mitigation and climate change (CC) adaptation strategies for these ares is of primary importance. This paper investigates the impact of cool roofs and pavements along with the influence of different canopy cover ratios on the urban canopy layer (UCL) climate for a summer day, and assesses their impact on human thermal comfort under projected climate conditions at the pedestrian level. The goal is to evaluate the effectiveness of these popular CC adaptation actions and to contribute to the development of a systematic framework for the assessment of UHI mitigation strategies. The study took four dense urban configurations from Budapest—characteristic to most Central European cities—to examine the effectiveness of these approaches. The numerical simulation study utilizes ENVI-met and MATLAB. Preliminary results indicate that the performance of CC adaptation strategies is the function of the configurations' initial thermal performance. Consequently, the starting point of any adaptation proposals should be the evaluation of the initial thermal behavior of the selected focus area, followed by the selection of appropriate strategies—based on both the shortcomings of the initial local or microclimate, and the available opportunities for improvements. This study is a first attempt to quantify key CC adaptation strategies for Budapest. The results of this research will provide feedback to local authorities on the effectiveness of the assessed approaches and foster the articulation of more precise and economic CC adaptation actions and measures.

  • 35.
    Gál, Csilla V
    Dalarna University, School of Information and Engineering, Construction.
    Urban weather generation: the intercomparison of three emerging models2021Conference paper (Refereed)
    Abstract [en]

    Cities modify the background climate through the surface-atmosphere interaction. This modification is function of urban design features, such as the configuration of buildings and the amount of vegetation. Compared to the undisturbed climate of the region, the climate of cities is characterized by higher temperature and lower wind speed. This modification is especially pronounce in dense urban areas. The climate modification of cities is not static, but varies in space and time. The spatial variations are governed by land use and built form differences, as well as by the presence or absence of green and blue infrastructures. Due to the spatial complexity of cities and the general lack of urban weather station networks in most places, the amount of available urban weather data is limited. As a consequence, planners, engineers and public health professionals can only approximate the climate impact of built environments in their respective fields.

    Over the past years, several numerical simulation models have emerged that are able to model the influence of built areas on the atmosphere at the local scale and thus, deliver urban weather data for an area of interest. The aim of this study is to assess the performance of three numerical models with an ability to predict site-specific urban air temperature. The evaluated models are the Urban Weather Generator (UWG), the Vertical City Weather Generator (VCWG) and the Surface Urban Energy and Water Balance Scheme (SUEWS). Although the models differ in their scopes, modeling approaches and applications, they all derive the urban weather data from rural observations considering the land use and built form characteristics of the site.

    The models are evaluated against air temperature measurements from the dense, 13th District of Budapest (Hungary). The field measurement utilized simple air temperature and relative humidity loggers placed in non-aspirated solar radiation screens at four shaded sites. The two week measurement period encompassed a five-day-long anticyclonic period with clear sky and low wind speed. Preliminary results indicate a good general agreement between modeled and observed values with root mean square error below or at 2ºC and index of agreement between 0.92-0.96. During the anticyclonic period most models slightly overestimate the daily maximum and underestimated the daily minimum urban air temperature.

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  • 36.
    Gál, Csilla V
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Gulyás, Ágnes
    Kántor, Noémi
    Heat mitigation with shade trees: the role of landscape design and tree parameters in ameliorating summertime heat stress in a Central-European square2017Conference paper (Refereed)
    Abstract [en]

    Climate change projections for Central Europe indicate a significant rise in summertime temperatures and an increase in the frequency and severity of extreme heat events. Combined with the peculiar climate of cities—characterized by the Urban Heat Island effect and reduced ventilation due to high building density—climate change is expected to have more pronounced effects in urban environments. Shade trees are demonstrated to be one of the most effective means to mitigate heat stress in cities. However, very few studies have evaluated systematically the impact of different landscape design and tree parameters (e.g. the species selection or the spatial distribution) on the heat mitigation effectiveness of shade trees. This study aims to assess the role of vegetation transmissivity, canopy size and tree distribution in a medium-sized Central-European square. The rectangular Bartók Square, located in the inner city of Szeged (Hungary), was selected as a study area. The numerical simulations were carried out with the radiation model SOLWEIG (v.2015a). The necessary meteorological data, collected on clear and warm summer day, was obtained from a nearby weather station run by the Hungarian Weather Service. The default model was built on the basis of available GIS data and utilized tree related parameters from detailed field measurements (tree location, canopy size and shape, etc.). Crown transmissivity data originated from a preliminary, long-term radiation measurement survey covering the vegetation period. Alternative scenarios were constructed with the following characteristics:1) keeping the original tree layout of the square, the initial tree crown transmissivity of 0.0678 was changed to small (0.0243) and high (0.1328) values;2) keeping the original canopy volume, two additional scenarios were introduced with evenly distributed trees of different crown sizes: that of several small trees and of fewer large ones;3) keeping the original canopy volume and using the same number and size of trees, we assessed the role of tree distribution by introducing a scenario were the trees were arranged along the bounding facades of the square—this scenario was compared to the evenly distributed configuration. In order to evaluate the impact of vegetation, all scenarios are reported in reference to a theoretical, nonvegetated square. Since several studies revealed that mean radiant temperature (Tmrt) plays a key role in summertime heat stress in the European context, this parameter was selected as performance indicator. Tmrt combines the heat effect of all short-and long-wave radiation fluxes reaching the human body. Our results indicate that when shade is provided for the facades only, the nighttime Tmrt surplus nearly disappears. However, while horizontal long-wave radiation fluxes have a greater impact on human thermal comfort due to the different absorption coefficients of the human body (0.7 vs. 0.95 for short and long-wave radiation, respectively), providing shade for the facades only is not a successful daytime heat mitigation strategy in open urban places. Comparing the influence of vegetation transmissivity revealed that low transmissivity species were able to reduce Tmrt by only 2C on average during the day. According to our case study, when transmissivity and canopy volume is kept constant, considerable mean radiant temperature reduction can be achieved by evenly distributed mature trees.

  • 37.
    Gál, Csilla V
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Kántor, Noémi
    Modeling mean radiant temperature in outdoor spaces: A comparative numerical simulation and validation study2020In: Urban Climate, E-ISSN 2212-0955, Vol. 32, article id 100571Article in journal (Refereed)
    Abstract [en]

    The parameter governing outdoor human thermal comfort (HTC) on warm, clear-sky days is radiation. Its effect on HTC is accounted for by mean radiant temperature (Tmrt). While Tmrt differences owing to different measurement methods are well established, the impact of different computational approaches have not been systematically evaluated. This study assesses the performance of three microclimate models in their ability to estimate Tmrt values in complex urban environments. The evaluated models are RayMan Pro, SOLWEIG and ENVI-met. The model evaluation encompasses both the comparison of modeled Tmrt values with those derived from observations and model intercomparisons with analyses extending to several radiation terms and parameters that comprise or explain the resultant Tmrt. Results indicate that the models systematically underestimate nighttime Tmrt. SOLWEIG and ENVI-met tend to overestimate Tmrt during prolonged periods of shade and underestimate when the sites are sunlit. RayMan underestimates Tmrt values during most part of the day. The largest Tmrt errors occur at low sun elevations in all three models, mainly as a result of underestimated longwave emitted and shortwave reflected radiation fluxes by the adjacent facades. These errors indicate room for improvement with regards to surface temperature estimation and shortwave reflected radiation calculations in the models.

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  • 38.
    Gál, Csilla V
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Nice A., Kerry
    Monash University.
    Mean radiant temperature modeling outdoors: A comparison of three approaches2020Conference paper (Refereed)
    Abstract [en]

    As a result of both urbanization and climate change, the thermal environment of cities is deteriorating steadily. Thus, urban planner and city officials are increasingly under the pressure maintain livable environments in cities. The quickest and most economic means to assessing the performance of various urban heat mitigation strategies is via numerical modeling. Owing to these advantages, the approach gained popularity over the past decade, as well as resulted in the proliferation of microclimate models. The driving parameter of outdoor human thermal comfort is radiation, which is accounted for via mean radiant temperature (Tmrt). While this parameter is at the center of most outdoor thermal comfort indices, it is also rather challenging to measure and calculate. Along with the recent emergence of microclimate models, the ways of calculating outdoor Tmrt also multiplied. However, beyond individual model validations, very few studies have attempted to compare the performance of different models. Thus, the aim of this paper is to assess the performance of three microclimate models in estimating Tmrt in the urban environment. The reviewed models are VTUF-3D, the Grasshopper add-ons of Rhinoceros 3D and the latest ENVI-met version utilizing the Indexed View Sphere (IVS) algorithm. The adopted spatial resolution in each model were not identical. In the case of ENVI-met and VTUF-3D, 3 and 5 meter resolutions were used, respectively. The Grasshopper add-on was set to calculate surface temperatures at 6 m resolution and view factors (along with Tmrt) for a denser, 3-meter spatial grid. The model assessment utilized data from a 26-hours-long integral radiation measurement, conducted in Szeged (Hungary). The observations were undertaken along the four bounding facades of Bartók Square during a clear summer day in 2016. According to the preliminary results, ENVI-met performs the best when the observation sites are exposed to direct solar radiation. However, it underestimates Tmrt values by up to 10 ºC when the sites are in shade and during night. In general, both VTUF-3D and the Grasshopper add-on underestimate Tmrt values considerably during sunlit conditions (exceeding 20 ºC at times), but reproduce radiative conditions well at night (with errors remaining below 4 ºC). One reason for the above errors is the way Tmrt is calculate by these models. While Tmrt calculations differ in each model, at the core of their adopted approaches is a Tmrt estimation developed for indoor environments---which was later adopted to outdoors. One of the lingering simplification is the assumption of a seated posture and/or the conceptualization of the human body as a sphere. The other transferred simplification is the assumption of small temperature differences between the surrounding surfaces. These assumptions not only diminish the impact of horizontal fluxes, but also depict a less diverse radiative environment.

  • 39.
    Hansson, Jonas
    Dalarna University, School of Education and Humanities, Geography.
    Från våtmark till våtmark i Ängelholms kommun: Fallstudie kring två våtmarker2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Huvudsyftet med denna uppsats är redogöra hur två våtmarker i Ängelholms kommun har kommit till och dess nytta för miljön. För att kunna besvara denna fråga har jag noga studerat beslutsgången, gjort fältstudier, talat med markägare tagit del av opublicerat material och studerat äldre och nya kartor över de båda våtmarkerna, båda belägna i trakten av Höja, ungefär fem kilometer sydost om Ängelholm, och även gjort fältstudier.

    Utöver detta har jag visat hur Ängelholms och Åstorps kommun arbetar för att främja anläggningen av våtmarker. Båda intresserar sig för att minska övergödningen och med våtmarker så åstadkommer de detta. Utöver vattenrenare så är våtmarker också av intresse rent utbildningsmässigt och bra för att få en heterogen landskapsbild.

    Slutsatser

    • Det är skillnad på storleken av våtmarker i nordvästra Skåne gentemot i Danmark. Detta beror på att Danmark tidigare var indelade i amt som hade hand om vattenfrågor och kunde genomdriva våtmarksanläggningar i större utsträckning.
    • Våtmarkerna i Skörpinge och Höja fungerar båda som naturliga reningsverk av närsalter. Våtmarken i Skörpinge bör vara mer effektiv när det gäller rening av närsalter då denna har större antal hektar avrinningsområde i förhållandet till våtmarksareal. Till detta skapar våtmarkerna en biologisk mångfald,
    • Våtmarken i Höja visade sig vara väldigt effektiv, 43,4%, när det gällde rening av kväve. Men siffrorna är troligen missvisande i och med att det gjorde för få stickprov under för kort tidsrymd. Andra studier visar en reningseffektivitet på mellan 2 – 20 %.
    • Det som skiljer våtmarkerna åt är dels formen och utförandet och dels antalet markägare. Våtmarken i Höja ägs av bara en markägare medan den andra ägs av fyra. Till detta krävdes det ett godkännande från Miljödomstolen för att våtmarken i Skörpinge skulle få anläggas. Båda våtmarkerna tog lika lång tid att anlägga, ungefär två år. Hur lång tid det tar att anlägga en våtmark kan bero på om markägare vill ha bidrag eller inte och i så fall från vilket myndighet. Så det kan säkerligen ta kortare tid att anlägga en våtmark.
    • För att följa upp nyttan av våtmarkerna i Höja och Skörpinge bör det göras fler stickprov under längre tid och med dessa avgöra hur effektiva våtmarkerna egentligen är. Till detta bör det göras en inventering av flora och fauna för att undersöka den biologiska mångfalden.

     

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  • 40.
    Henning, Annette
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Ambiguous Artefacts: Solar Collectors in Swedish Contexts. On Processes of Cultural Modification2000Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This is a book about solar collectors and the place of these artefacts in a political energy debate that has aroused strong feelings in Sweden during the last twenty-five years. It is a book about the hopes for a less polluted earth, which solar collectors have come to symbolise, and a book about the ways in which problems in utilising solar energy are culturally perceived. One main aims of this study has been to find out more about the conflicting perceptions of solar collectors as 'saviours of the world' and simultaneously as uninteresting or less credible artefacts that 'may come in the future'. Another main purpose of the study has been to describe and explain those cultural processes of modification that are taking place around solar collectors in active attempts to integrate these into established cultural structures.

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  • 41.
    Henning, Annette
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Klimatsmart villavärme?: Solvärme, nya byggregler och möjligheten att förändra2010Book (Other academic)
    Abstract [sv]

    Är vi på väg mot klimatsmartare, resurssnålare och flexiblare uppvärmning av nybyggda småhus? Denna fråga ställer sig fem forskare vid Centrum för solenergiforskning SERC. En socialantropolog, en statsvetare och tre energiteknikforskare beskriver här tillsammans dagsläget, samt pekar på möjligheter och svårigheter med att åstadkomma en förändring i denna riktning. Den senaste revideringen av Boverkets byggregler uppmärksammas särskilt, liksom möjligheten att utnyttja solfångare och ackumulatortank för att reducera mängden inköpt primärenergi samtidigt som man bevarar de boendes valfrihet.

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  • 42.
    Henning, Annette
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Temporal landscapes for the public good: negotiating solar collectors among ancient remains2008In: Social & cultural geography (Print), ISSN 1464-9365, E-ISSN 1470-1197, Vol. 9, no 1, p. 27-40Article in journal (Refereed)
    Abstract [en]

    This article concerns the contested siting of a solar collector field in Torsång, Sweden, a designated area of national heritage. The contest is described as a 'planning drama' and a locally articulated controversy between two national policies and priorities: national heritage versus sustainable development. Two professional groups are at the centre of this drama: antiquarians at the county administrative board, and a group of employees at the municipally owned utility company. The article focuses in particular on the clash of two knowledge systems; how these are expressed, clarified and elaborated on when being confronted with one another in this specific situation. Temporal, horizontal and vertical scales a re used to analyse the material. Contrary to what has previously been assumed to be the case for modern Western societies, the contested landscapes are shown to depend for their realization or destruction, not only on temporal and horizontal dimensions, but also on a vertical dimension including artefacts above and below the surface. The struggle to find a solution that everyone could agree on was not merely a matter of making two conflicting ways of perceiving this land come to terms. It was, in fact, an attempt to force two incommensurable landscapes into the same piece of land.

  • 43.
    Henning, Annette
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    The illusion of economic objectivity: linking local risks of credibility loss to global risks of climate change2008In: Journal of Risk Research, ISSN 1366-9877, E-ISSN 1466-4461, Vol. 11, no 1-2, p. 223-235Article in journal (Refereed)
    Abstract [en]

    This article analyses economic thinking as a conceptual construct and discusses the link it provides between local risks of losing credibility and global risks of resource depletion and climate change. Due to the high-ranking value given to economic thinking in many Swedish contexts, economic arguments are perfect ways to win an argument or negotiation, to prevent risks of loosing credibility, or to discredit others. As illlustrated in this article, legitimacy-creating acts of communication tend to precede or follow upon a decision to install a solar heating system. An immediate and massive use of solar energy for heating purposes would mitigate the risks of global warming and depletion of energy resources. Unfortunately however, the conspicuous use of economic arguments accompanying solar heating installations tend to be interpreted by policy-makers as a preference for economic motives rather than a sign of questioned consumption. The illusion that economy is an objective entity rising above all other social issues seems to be confirmed, and political measures based on economic thinking can continue to block adequate steps towards the mitigation of climate changing emissions. The cultural representation of economic sovereignty is continuously reproduced through communication. It is a circle, a vicious circle if you like.

  • 44.
    Jia, Tao
    et al.
    Wuhan University.
    Carling, Kenneth
    Dalarna University, School of Technology and Business Studies, Statistics.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Human Geography.
    Trips and their CO2 emissions induced by a shopping center2013Report (Other academic)
    Abstract [en]

    Most previous studies have focused on entire trips in a geographic region, while a few of them addressed trips induced by a city landmark. Therefore paper explores trips and their CO2 emissions induced by a shopping center from a time-space perspective and their usage in relocation planning. This is conducted by the means of a case study in the city of Borlänge in mid-Sweden where trips to the city’s largest shopping mall in its center are examined. We use GPS tracking data of car trips that end and start at the shopping center. Thereafter, (1) we analyze the traffic emission patterns from a time-space perspective where temporal patterns reveal an hourly-based traffic emission dynamics and where spatial patterns uncover a heterogeneous distribution of traffic emissions in spatial areas and individual street segments. Further, (2) this study reports that most of the observed trips follow an optimal route in terms of CO2 emissions. In this respect, (3) we evaluate how well placed the current shopping center is through a comparison with two competing locations. We conclude that the two suggested locations, which are close to the current shopping center, do not show a significant improvement in term of CO2 emissions.

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  • 45.
    Jia, Tao
    et al.
    School of Remote Sensing and Information Engineering, Wuhan University.
    Carling, Kenneth
    Dalarna University, School of Technology and Business Studies, Statistics.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Human Geography.
    Trips and their CO2 emissions to and from a shopping center2013In: Journal of Transport Geography, ISSN 0966-6923, E-ISSN 1873-1236, Vol. 33, p. 135-145Article in journal (Refereed)
    Abstract [en]

    Previous studies have focused on entire trips within a geographical region, while only a few have examined trips to and from a city landmark. This paper examines trips (and their CO2 emissions) to and from a shopping center from a time-space perspective, and it further considers how this information can be used in relocation planning. It is a case study in the Borlänge city in mid-Sweden where trips to the city’s largest shopping mall are scrutinized. We use GPS tracking data of car trips starting and ending at the shopping center. Firstly, we analyze the traffic emission patterns from a time-space perspective where the temporal patterns reveal hourly-based traffic emission dynamics. The spatial analysis uncovers a heterogeneous distribution of areal traffic emissions as well as of single street segments. Secondly, we find the observed trips mostly agree with an optimal route in terms of CO2 emissions. Drawing on this finding, we thirdly evaluate the location of the current shopping center by comparing it to two competing locations. We conclude that the two competing locations, being in the vicinity of the current one, would induce an insignificant improvement in terms of CO2 emissions.

  • 46.
    Johansson, Björn
    Dalarna University, School of Education, Health and Social Studies, Geography.
    Bruten Katrineholmsbygd: Järnvägens effekter på ett landskap2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den här uppsatsen har syftat till att undersöka vilka landskapsomdanande effekter stambanornas anläggande fick på det omgivande landskapet i undersökningsområdet under järnvägens första halvsekel, ca 1860-1910. Undersökningsområdet har varit trakten kring Katrineholm. Sedan har effekterna analyserats utifrån ett landskapsperspektiv.Min metod för landskapsanalys baseras på kulturgeografen Ulf Sporrongs tankebanor. Han föreslår hur man i olika steg kan analysera ett landskap. Jag har modifierat det en aning. Så här har jag gjort:1. Redogjort för de naturgivna förutsättningarna.2. Tittat närmare på landskapets humanhistoria och sett hur människan har tagit landskapet i anspråk genom bosättning, kommunikationer och ytanvändning för areell produktion.3. Sett hur kulturlandskapet förändrades sedan järnvägen byggts, under ett halvsekel. Här har kommunikationer, bebyggelse, produktion samt det sociala och kulturella livet behandlats.4. Samordnat de ovanstående delområdena till en landskaplig helhet.Jag har också tagit fasta på landskapsarkitekten Mattias Qviströms betoning på aktörer, transportteknik och landskapets otidsenlighet. På så sätt har ett järnvägspåverkat landskap växt fram. Viktiga slutsatser: Banans sträckning var rak, med relativt försiktiga ingrepp i landskapet i förhållande till järnvägens inneboende egenskaper och undersökningsområdets topografi. Banvallen blev ett dominant inslag i landskapsbilden, vilket förstärktes i de fall banvallen bildade ägogräns vid laga skifte. Bygget av stambanorna innebar en ny transportteknik som radikalt förändrade grundförutsättningarna för undersökningsområdets lokalsamhälle. Den längre landsvägstrafiken gällande gods- och persontrafik fick övermäktig konkurrens. Till en början byggdes tre stationshus med tillhörande anrättningar, samt banvaktsstugor. Två stationssamhällen blev nya sockencentra. Till slut växte fem stationssamhällen upp, vid vilka nya arbetstillfällen kunde erbjudas. Transportmöjligheterna utökades enormt, samtidigt som transporternas tidsåtgång minskades lika dramatiskt. Rummet upplevdes ha krympt. Nya fysiska resurser kunde göras tillgängliga och exploateras. Järn-, skog-, tegel-, och mejerinäringarna upplevde ett uppsving. De kunde förädla lokala produkter och avyttra dem på nya marknader. Befolkningstillväxten under 1800-talet var i undersökningsområdet 259 %, jämfört med 100 % i övriga landet. Samhället Katrineholm stod för en stor del av denna tillväxt, medan socknen Östra Vingåker som var utan station hade svag tillväxt under perioden. Den sociala strukturen förändrades i grunden. Andelen bönder minskade kraftigt. En ny fattigdomsorganisation infördes.

  • 47.
    Johansson, Sverker
    Högskolan för lärande och kommunikation, Högskolan i Jönköping, HLK, Ämnesforskning.
    Oil seepage would have drained offshore reservoirs in 20,000 years2005In: The Counter-Creationism handbook, Westport: Greenwood Publishing , 2005Chapter in book (Other (popular science, discussion, etc.))
  • 48.
    Johansson, Sverker
    Högskolan i Jönköping, Högskolan för lärande och kommunikation.
    Seriös kristen geologi: Recension av The Bible, Rocks and Time: Geological Evidence for the Age of the Earth av Davis A. Young & Ralph F. Stearley2009In: Folkvett, ISSN 0283-0795, no 1, p. 57-61Article, book review (Other (popular science, discussion, etc.))
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  • 49.
    Johansson, Sverker
    Högskolan för lärande och kommunikation, Högskolan i Jönköping, HLK, Ämnesforskning.
    The Faint Young Sun1999Report (Other (popular science, discussion, etc.))
  • 50.
    Karlsson, Johan
    Dalarna University, School of Education, Health and Social Studies, Geography.
    Anpassningar till klimatförändringar i Rwanda: En fältstudie som avser att undersöka vilka anpassningar småskaliga jordbrukare i Rwanda gör för att möta de rådande klimatförändringarna2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Rwanda är ett litet land i Östafrika som ungefär är lika stort som Dalarna. Det bor 11,1 miljoner människor i landet. 81% av dessa 11 miljoner människor livnär sig på jordbruk.

    Syftet med studien är att undersöka hur småskaliga jordbrukarhushåll i Rwanda anpassar sig till rådande klimatförändringar.

    Utifrån syftet utformades fyra stycken frågeställningar:

    - Vilka begränsningar har jordbrukarna att anpassa sitt jordbruk till de rådande klimatförändringarna?

    - Vilka metoder och åtgärder använder jordbrukarna för att anpassa sig till klimatförändringarna?

    - Hur skulle jordbrukarna vilja utveckla sitt jordbruk för att möta rådande klimatförändringar?

    - Vilken hjälp och vägledning får jordbrukarna för att kunna anpassa sitt jordbruk?

    De metoder som användes i studien var intervjuer och kartläggning av tolv stycken jordbruk. Kartläggningen gjordes av jordbrukarnas jordbruksmark och intervjuerna gjordes med den jordbrukare vars gård vi besökte.

    Studiens resultat visar att den vanligaste anpassningsåtgärden som har gjorts för att möta klimatförändringarna är att plantera träd. Övriga anpassningar som gjorts är att byta planteringsperiod på grödorna och även byta grödor till mindre vätskekrävande grödor visar resultatet. Vidare visar resultatet att den vanligaste anpassningsåtgärden som jordbrukarna vill göra är att installera konstbevattning på gården. Den främsta begränsningen som jordbrukarna upplevde vid anpassningen av sitt jordbruk var bristen på ekonomiska resurser. Flera jordbrukare berättade att på grund av bristen av pengar kunde de inte göra de investeringar de vill på gården. Jordbrukarna i studien menar att mest vägledning kommer från Vi-skogen, elva av de tolv jordbrukarna berättar att de får hjälp därifrån. En handfull jordbrukare berättar att de är medlemmar i ett kooperativ där de får hjälp och vägledning.

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