Zero-Plane Displacement Height in a Highly Built-Up Area of Tokyo

Tanaka, So; Sugawara, Hirofumi; Narita, Kentaro; Yokoyama, Hiroyuki; Misaka, Ikusei; Matsushima, Dai

doi:10.2151/sola.2011-024

Cited by 9 publications

(9 citation statements)

References 20 publications

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“…This conclusion is supported by numerical and physical experiments (e.g. Jiang et al 2008;Hagishima et al 2009;Zaki et al 2011;Millward-Hopkins et al 2011;Tanaka et al 2011;Kanda et al 2013) indicating the taller roughness elements in a heterogeneous mix exert a disproportionate amount of drag on the flow (Xie et al 2008;Mohammad et al 2015b) lifting the drag-profile centroid (Jackson 1981) above z = H av . The results verify Kanda et al's (2013) proposition that the maximum height (H max ) is a more suitable scaling parameter for z d and the standard deviation of the roughnesselement height (σ H ) (also used by Millward-Hopkins et al 2011) is useful to parametrize roughness-element height heterogeneity.…”

Section: Discussionmentioning

confidence: 63%

“…5a-c). Previous studies found z d may be larger than H av in urban areas using both the temperature (Grimmond et al 1998(Grimmond et al , 2002Feigenwinter et al 1999;Kanda et al 2002;Christen 2005;Chang and Huynh 2007;Tanaka et al 2011) and velocity (Tsuang et al 2003) Table 3). …”

Section: Z D Determined By Anemometric Methodsmentioning

confidence: 92%

“…This suggests z d can be greater than the average roughness-element height (e.g. Jiang et al 2008;Xie et al 2008;Hagishima et al 2009;Zaki et al 2011;Millward-Hopkins et al 2011;Tanaka et al 2011;Kanda et al 2013), with a peak z 0 up to five times greater and displaced to higher λ f (Hagishima et al 2009;Zaki et al 2011). Roughness-element staggering, orientation and most importantly height heterogeneity therefore need to be considered in morphometric calculations; especially in complex city centres, such as the current study site (Sect.…”

Section: Relations Between Aerodynamic Parameters and Roughness-elemementioning

confidence: 93%

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Evaluation of Urban Local-Scale Aerodynamic Parameters: Implications for the Vertical Profile of Wind Speed and for Source Areas

Kent

Grimmond

Barlow

et al. 2017

Boundary-Layer Meteorol

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Nine methods to determine local-scale aerodynamic roughness length (z 0 ) and zero-plane displacement (z d ) are compared at three sites (within 60 m of each other) in London, UK. Methods include three anemometric (single-level high frequency observations), six morphometric (surface geometry) and one reference-based approach (look-up tables). A footprint model is used with the morphometric methods in an iterative procedure. The results are insensitive to the initial z d and z 0 estimates. Across the three sites, z d varies between 5 and 45 m depending upon the method used. Morphometric methods that incorporate roughness-element height variability agree better with anemometric methods, indicating z d is consistently greater than the local mean building height. Depending upon method and wind direction, z 0 varies between 0.1 and 5 m with morphometric z 0 consistently being 2-3 m larger than the anemometric z 0 . No morphometric method consistently resembles the anemometric methods. Wind-speed profiles observed with Doppler lidar provide additional data with which to assess the methods. Locally determined roughness parameters are used to extrapolate wind-speed profiles to a height roughly 200 m above the canopy. Wind-speed profiles extrapolated based on morphometric methods that account for roughness-element height variability are most similar to observations. The extent of the modelled source area for measurements varies by up to a factor of three, depending upon the morphometric method used to determine z d and z 0 .

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Section: Discussionmentioning

confidence: 63%

Section: Z D Determined By Anemometric Methodsmentioning

confidence: 92%

Section: Relations Between Aerodynamic Parameters and Roughness-elemementioning

confidence: 93%

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Evaluation of Urban Local-Scale Aerodynamic Parameters: Implications for the Vertical Profile of Wind Speed and for Source Areas

Kent

Grimmond

Barlow

et al. 2017

Boundary-Layer Meteorol

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“…As with previous applications, z d determined using the temperature and wind variance methods at both sites indicates z d is larger than H av (e.g. Grimmond et al 1998 , 2002 , Feigenwinter et al 1999 , Kanda et al 2002 , Tsuang et al 2003 , Christen 2005 , Chang and Huynh 2007 , Tanaka et al 2011 , Kent et al 2017b ). Additionally, morphometric z d results are consistently smaller than anemometric results.…”

Section: Resultssupporting

confidence: 73%

Aerodynamic roughness variation with vegetation: analysis in a suburban neighbourhood and a city park

et al. 2017

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Local aerodynamic roughness parameters (zero-plane displacement, z d , and aerodynamic roughness length, z 0 ) are determined for an urban park and a suburban neighbourhood with a new morphometric parameterisation that includes vegetation. Inter-seasonal analysis at the urban park demonstrates z d determined with two anemometric methods is responsive to vegetation state and is 1–4 m greater during leaf-on periods. The seasonal change and directional variability in the magnitude of z d is reproduced by the morphometric methods, which also indicate z 0 can be more than halved during leaf-on periods. In the suburban neighbourhood during leaf-on, the anemometric and morphometric methods have similar directional variability for both z d and z 0 . Wind speeds at approximately 3 times the average roughness-element height are estimated most accurately when using a morphometric method which considers roughness-element height variability. Inclusion of vegetation in the morphometric parameterisation improves wind-speed estimation in all cases. Results indicate that the influence of both vegetation and roughness-element height variability are important for accurate determination of local aerodynamic parameters and the associated wind-speed estimates.

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“…For example, [8] used catastral databases, whereas [14] applied a characterization of buildings in urban terrains. In particular, [84] estimated d in Tokyo considering buildings of different heights. Most of these methods require costly field works.…”

Section: Land Cover Databasesmentioning

confidence: 99%

Characterization of Geographical and Meteorological Parameters

Montero

Rodríguez

Oliver

2018

Wind Field and Solar Radiation Characterization and Forecasting

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This chapter is devoted to the introduction of some geographical and meteorological information involved in the numerical modeling of wind fields and solar radiation. Firstly, a brief description of the topographical data given by a Digital Elevation Model and Land Cover databases are provided. In particular, the Information System of Land Cover of Spain (SIOSE) is considered. The study is focused in the roughness length and the displacement height parameters that appear in the logarithmic wind profile, as well as in the albedo related to solar radiation computation. An extended literature review and characterization of both parameters are reported. Next, the concept of atmospheric stability is introduced from the Monin-Obukhov similarity theory to the recent revision of Zilitinkevich of the Neutral and Stable Boundary Layers (SBL). The latter considers the effect of the free-flow static stability and baroclinicity on the turbulent transport of momentum and of the Convective Boundary Layers (CBL), more precisely, the scalars in the boundary layer, as well as the model of turbulent entrainment. 2.1 Geographical data The main geographical information for wind and solar radiation modeling may be classified into two general databases, the topographical data related to the orography of the region to be studied and the land cover databases containing the information of the land uses. In this section, both are introduced.

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Zero-Plane Displacement Height in a Highly Built-Up Area of Tokyo

Cited by 9 publications

References 20 publications

Evaluation of Urban Local-Scale Aerodynamic Parameters: Implications for the Vertical Profile of Wind Speed and for Source Areas

Evaluation of Urban Local-Scale Aerodynamic Parameters: Implications for the Vertical Profile of Wind Speed and for Source Areas

Aerodynamic roughness variation with vegetation: analysis in a suburban neighbourhood and a city park

Characterization of Geographical and Meteorological Parameters

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