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An analytically based numerical method for computing view factors in real urban environments

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Abstract

A view factor is an important morphological parameter used in parameterizing in-canyon radiative energy exchange process as well as in characterizing local climate over urban environments. For realistic representation of the in-canyon radiative processes, a complete set of view factors at the horizontal and vertical surfaces of urban facets is required. Various analytical and numerical methods have been suggested to determine the view factors for urban environments, but most of the methods provide only sky-view factor at the ground level of a specific location or assume simplified morphology of complex urban environments. In this study, a numerical method that can determine the sky-view factors (ψ ga and ψ wa ) and wall-view factors (ψ gw and ψ ww ) at the horizontal and vertical surfaces is presented for application to real urban morphology, which are derived from an analytical formulation of the view factor between two blackbody surfaces of arbitrary geometry. The established numerical method is validated against the analytical sky-view factor estimation for ideal street canyon geometries, showing a consolidate confidence in accuracy with errors of less than 0.2 %. Using a three-dimensional building database, the numerical method is also demonstrated to be applicable in determining the sky-view factors at the horizontal (roofs and roads) and vertical (walls) surfaces in real urban environments. The results suggest that the analytically based numerical method can be used for the radiative process parameterization of urban numerical models as well as for the characterization of local urban climate.

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References

  • Arnfield AJ (2003) Two decades of urban climate research: a review of turbulence, exchanges of energy and water, and the urban heat island. Int J Climatol 23:1–26. doi:10.1002/joc.859

    Article  Google Scholar 

  • Bärring L, Mattson JO, Lindqvist S (1985) Canyon geometry, street temperatures and urban heat island in Malmö, Sweden. J Climatol 5(4):433–444. doi:10.1002/joc.3370050410

    Article  Google Scholar 

  • Cheung HKW, Coles D, Levermore GJ (2016) Urban heat island analysis of greater Manchester, UK using sky view factor analysis. Building Serv Eng Res Technol 37(1):5–17. doi:10.1177/0143624415588890

    Article  Google Scholar 

  • Gál T, Lindberg F, Unger J (2009) Computing continuous sky view factors using 3D urban raster and vector database: comparison and application to urban climate. Theor Appl Climatol 95:111–123. doi:10.1007/s00704-007-0362-9

    Article  Google Scholar 

  • Grimmond CSB, Potter SK, Zutter HN, Souch C (2001) Rapid methods to estimate sky-view factors applied to urban areas. Int J Climatol 21:903–931. doi:10.1002/joc.659

    Article  Google Scholar 

  • Fortuniak (2008) Numerical estimation of the effective albedo of an urban canyon. Theor Appl Climatol 91:245–258. doi:10.1007/s00704-007-0312-6

    Article  Google Scholar 

  • Hämmerle M, Gál T, Unger J, Matzarakis A (2011) Comparison of models calculating the sky view factor used for urban climate investigations. Theor Appl Climatol 105:521–527. doi:10.1007/s00704-011-0402-3

    Article  Google Scholar 

  • Holmer B (1992) A simple operative method for determination of sky view factors in complex urban canyon from fisheye photographs. Meterol Z 1:236–239

    Google Scholar 

  • Holmer B, Postgård U, Eriksson M (2001) Sky view factors in forest canopies calculated with IDRISI. Theor Appl Climatol 68:33–40. doi:10.1007/s007040170051

    Article  Google Scholar 

  • Johnson GT, Oke TR, Lyons TJ, Steyn DG, Watson ID, Voogt JA (1991) Simulation of surface urban heat islands under ‘IDEAL’conditions at night part 1: theory and tests against field data. Boundary-Layer Meteorol 56:275–294. doi:10.1007/BF00120424

    Article  Google Scholar 

  • Johnson GT, Watson ID (1984) The determination of view-factors in urban canyons. J Climate Appl Meteor 2:329–335. doi:10.1175/1520-0450(1984)023<0329:TDOVFI>2.0.CO;2

    Article  Google Scholar 

  • Krayenhoff ES, Voogt JA (2007) A microscale three-dimensional urban energy balance model for studying surface temperatures. Boundary-Layer Meteorol 123:433–461. doi:10.1007/s10546-006-9153-6

    Article  Google Scholar 

  • Krayenhoff ES, Christen A, Martilli A, Oke TR (2014) A multi-layer radiation model for urban neighbourhoods with trees. Boundary-Layer Meteorol 151:139–178. doi:10.1007/s10546-013-9883-1

    Article  Google Scholar 

  • Kusaka H, Kondo H, Kikegawa Y, Kimura F (2001) A simple single-layer urban canopy model for atmospheric models: comparison with multi-layer and slab models. Boundary-Layer Meteorol 101:329–358. doi:10.1023/A:1019207923078

    Article  Google Scholar 

  • Lee S-H, Park S-U (2008) A vegetated urban canopy model for meteorological and environmental modelling. Boundary-Layer Meteorol 126:73–102. doi:10.1007/s10546-007-9221-6

    Article  Google Scholar 

  • Lindberg F, Holmer B, Thorsson S (2008) SOLWEIG 1.0–modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings. Int J Biometeorol 52:697–713. doi:10.1007/s00484-008-0162-7

    Article  Google Scholar 

  • Martilli A, Clappier A, Rotach MW (2002) An urban surface exchange parameterization for mesoscale models. Boundary-Layer Meteorol 104:261–304. doi:10.1023/A:1016099921195

    Article  Google Scholar 

  • Marciotto ER, Oliveira AP, Hanna SR (2010) Modeling study of the aspect ratio influence on urban canopy energy fluxes with a modified wall-canyon energy budget scheme. Build Environ 45:2497–2505. doi:10.1016/j.buildenv.2010.05.012

    Article  Google Scholar 

  • Masson V (2000) A physically-based scheme for the urban energy budget. Boundary-Layer Meteorol 94:357–397. doi:10.1023/A:1002463829265

    Article  Google Scholar 

  • Oke TR (1981) Canyon geometry and the nocturnal urban heat island: comparison of scale model and field observation. J Climatol 1:237–254. doi:10.1002/joc.3370010304

    Article  Google Scholar 

  • Oke TR (1987) Boundary layer climates. Routledge, London, p. 435

    Google Scholar 

  • Panão MJNO, Gonçalves HJP, Ferrão PMC (2007) A matrix approach coupled with Monte Carlo techniques for solving the net radiation balance of the urban block. Boundary-Layer Meteorol 122:217–241. doi:10.1007/s10546-006-9088-y

    Article  Google Scholar 

  • Ratti C, Richens P (1999) Urban texture analysis with image processing techniques. Proceedings of the 8th International Conference on Computer Aided Architectural Design Futures, Atlanta, Georgia, USA, 7–8 June, 1999, 49–64

  • Rzepa M, Gromek B (2006) Variability of sky view factor in the main street canyon in the center of Łódz. The 6th International Conference on Urban Climate, Götenborg, Sweden, 12–16 June, 2006, 854–857

  • Sparrow EM, Cess RD (1978) Radiation heat transfer, Augmented Ed. Harper Collins, London, UK, 349 pp

  • Steyn DG (1980) The calculation of view factors from fisheye-lens photographs. Atmosphere Ocean 18:254–258. doi:10.1080/07055900.1980.9649091

    Article  Google Scholar 

  • Steyn DG, Hay JE, Watson ID, Johnson GT (1986) The determination of sky-view factors in urban environments using video imagery. J Atmos Ocean Tec 3:759–764. doi:10.1175/1520-0426(1986)003<0759:TDOSVF>2.0.CO;2

    Article  Google Scholar 

  • Svensson MK (2004) Sky view factor analysis—implications for urban air temperature differences. Meteorol Appl 11:201–211. doi:10.1017/S1350482704001288

    Article  Google Scholar 

  • Unger J (2009) Connection between urban heat island and sky view factor approximated by a software tool on a 3D urban database. Int J Environment and Pollution 36:59–80. doi:10.1504/IJEP.2009.021817

    Article  Google Scholar 

  • Wang ZH (2014) Monte Carlo simulations of radiative heat exchange in a street canyon with trees. Sol Energy 110:704–713. doi:10.1016/j.solener.2014.10.012

    Article  Google Scholar 

  • Zakšek K, Oštir K, Kokalj Ž (2011) Sky-view factor as a relief visualization technique. Remote Sens 3:398–415. doi:10.3390/rs3020398

    Article  Google Scholar 

Download references

Acknowledgments

The authors are grateful to two anonymous reviewers for thorough reviews and valuable comments. This study was funded by the Korea Meteorological Administration Research and Development Program under Grant KMIPA2015-5043.

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Correspondence to Sang-Hyun Lee.

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Lee, DI., Woo, JW. & Lee, SH. An analytically based numerical method for computing view factors in real urban environments. Theor Appl Climatol 131, 445–453 (2018). https://doi.org/10.1007/s00704-016-1966-8

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  • DOI: https://doi.org/10.1007/s00704-016-1966-8

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