L o c a l C l i m a t e Z o n e P a r a m e t e r s f o r S t r - - PowerPoint PPT Presentation

L o c a l C l i m a t e Z o n e P a r a m e t e r s f o r S t r e e t D e s i g n i n C o m p a c t U r b a n A r e a s

Nusrath Maharoof, R. Emmanuel and C. Thomson

School of Engineering and Built Environment, Glasgow Caledonian University, UK; Noorul.Maharoof@gcu.ac.uk, Rohinton.Emmanuel@gcu.ac.uk

O v e r v i e w

• Introduction, Aim and Objectives
• Research Methodology
• The Case Of Glasgow
• Simulation Procedure
• Data Analysis and Discussion

I n t r o d u c t i o n

Th e Growth O f Comp ac t Cities Un d esirab le Th ermal Imp acts Urb an Livin g Qu ality Form, Climate An d Urb an Plan n in g

R a t i o n a l e

https://britevans.weebly.com/contact.html

Implementing urban climatic research findings?

L i t e r a t u r e R e v i e w

The Urban Designers’ Approach

density measures used through history

(Berghauser and Haupt, 2009)

Level Of Compactness Principles of reading physical form

• 1. Three fundamental

physical elements:

1. Streets 2. Plots of land and buildings 3. Open spaces.

• 2. Resolution

1. Buildings/plots 2. Street blocks 3. Cities and regions.

• 3. Time

(Moudon, 1997 )

Development Plan for 2050 Sustainable neighbourhoods Street Design Action Plan

L i t e r a t u r e R e v i e w

The LCZ Classification System Climate Sensitive Urban Design

(Stewart and Oke, 2012)

1. Explore Intra LCZ zone temperature variation in compact urban form 2. Investigate the possibility

• f

using LCZ parameters for climate sensitive street design

R e s e a r c h O b j e c t i v e s

(Stewart and Oke, 2012)

R e s e a r c h M e t h o d o l o g y

1 . Tr a v e r s e S t u d y 2 . N u m e r i c a l S i m u l a t i o n

Explore Intra LCZ zone temperature variation between street typologies

Urb an Desig n E lement LCZ c lasses

Features

• Openness –
• Sky view factor
• Aspect ratio
• Height of roughness elements
• Building surface fraction
• Surface Properties
• Impervious surface fraction
• Pervious surface fraction
• Terrain roughness class

Investigate the impact of modifying the LCZ parameters on street comfort through urban design interventions

Compact Urban Form Density of elements Defined by resolution and time Land Features

• surface cover
• structure
• Material
• human activity

Street types

• Lane
• High street
• Mew Lane
• Boulevard

• The city centre area (Glasgow City Centre West and

Glasgow City Centre East) fall under the LCZ class ‘compact midrise’. (Emmanuel & Loconsole 2015)

• The City Development Plan seeks to move away from

the traditional land use based approach of previous local plans. Instead it promotes a placed based approach.

C a s e S t u d y – G l a s g o w C i t y C e n t e r

C a s e S t u d y – G l a s g o w C i t y d e v e l o p m e n t P l a n

(Glasgow City Council, 2018)

C a s e S t u d y – G l a s g o w C i t y A v e n u e s P r o g r a m

(Glasgow City Council, 2018)

G l a s g o w C i t y A v e n u e s P r o g r a m - d e s i g n s t r a t e g i e s

(Glasgow City Council, 2018)

Glasgow’s City Centre Lane Strategy - attention to microclimate and shelter in order to create comfortable environments

• Sun

sails, Pop-Ups and Temporary Interventions ( temporary shading )

• Avenue of trees (vegetation)
• Parklet Programme (urban pockets)
• surface finishes (cobbled streets)
• ground floor uses that contribute to activity

and which animate lanes (Shopfronts with

• verhangs, Glass facades for ground floor)

C l i m a t e S e n s i t i v e S t r e e t d e s i g n s t r a t e g i e s

Urban Design Strategies for improving environmental quality

( Ng, Edward and Ren, Chao, 2015)

Tr a v e r s e S t u d y

Location SVF SVF Digram 1 Sauchiehall street 0.39 2 Blythswood square 0.571 3 Bothwell Ln 0.1 4 Gordon Street 0.2 5 Mitchel Lane, Lighthouse 0.05 6 Royal Exchange Square 0.3 7 George Square 0.6 8 Buchanan/ St Vincent St Junction 0.45 9 Buchanan Street House of Fraser 0.38 10 Jamaica / Clyde Street Junction 0.6

• The data used were measured for a typical

summer condition on 4th of July 2018 between 2pm

• 4pm

when the air temperatures were most stable

• The

average air temperature was measured at 10 points obtained from 5- min sampling resolutions worth of data in each location.

• temperatures were recorded at 2 second

intervals.

• Measurements were taken using tiny tag

air temperature data logger fixed to the backpack comprising

• f

a foil with naturally ventilated solar radiation shields

• The loggers were located 1.5m above

ground level

Tr a v e r s e S t u d y

1 2 3 4 5 6 7 8 9 10

Location SVF SVF Digram 1 Sauchiehall street 0.39 2 Blythswood square 0.571 3 Bothwell Ln 0.1 4 Gordon Street 0.2 5 Mitchel Lane, Lighthouse 0.05 6 Royal Exchange Square 0.3 7 George Square 0.6 8 Buchanan/ St Vincent St Junction 0.45 9 Buchanan Street House of Fraser 0.38 10 Jamaica / Clyde Street Junction 0.6

• The data used were measured for a typical

summer condition on 4th of July 2018 between 2pm

• 4pm

when the air temperatures were most stable

• The

average air temperature was measured at 10 points obtained from 5- min sampling resolutions worth of data in each location.

• temperatures were recorded at 2 second

intervals.

• Measurements were taken using tiny tag

air temperature data logger fixed to the backpack comprising

• f

a foil with naturally ventilated solar radiation shields

• The loggers were located 1.5m above

ground level

Tr a v e r s e S t u d y F i n d i n g s

• 1. Weak Co-relation between SVF and Temperature

within one LCZ zone

• 2. The North South Oriented streets had a greater

incline in temperature with increasing SVF

Tr a v e r s e S t u d y F i n d i n g s

• 3. Even though ‘openness’ ( determined by SVF, St

Width and Aspect Ratio are important the surface properties play an important role in determining the local climatic conditions

Tr a v e r s e S t u d y F i n d i n g s

• 4. The Façade Geometry can contribute the

street microclimate

N u m e r i c a l S i m u l a t i o n P r o c e d u r e

High street Mew Lane LCZ Parameters Surface Properties Base cases Openness Façade Geometry GCD Design Strategy Street Typology Orientation North- South East West

20m 10m 4m

Cobble Glass Trees Planters Sun sails Overhangs Mouldings

• Design interventions selected to be studied were limited to the approaches applicable to listed

buildings of the CBD

• Study was limited to only the pedestrian streets/ avenues and lanes

N u m e r i c a l S i m u l a t i o n P r o c e d u r e - C o n s t r a i n t s

S i m u l a t i o n M o d e l

ENVI-met model section Parameter value

Main data

Domain size and Cell size 50 x 60 x 30 in 2m x 2m x 2m Nesting Grids 3

Time and Date

Date 03.07.2018 Start time 18.00 Tot Simu. T 30 Output Intervals 60 min

Meteorology

Wind speed (m/s) and direction (deg) 4, 45 Roughness length (m) 0.01 Initial temperature of atmosphere (c) 25 Relative humidity (%) 47 Specific Humidity (g/kg) 9.1 Simple forcing Force temperature and Humidity

Time steps

Sun height for switching dt(0) and Sun height for switching dt(1) 40, 50 Time step (s) for interval 1 dt(0) (s) 2 dt(1) (s) and 3 dt(2) (s) 10,5,2 Street data Orientation N-S and E-W Types (width) 20, 10, 4 Length 80m Soil Profile Asphalt Building data Dimensions ( H, W,L) 20m x 10m x 40m Walls Stone – moderate insulation Roof Tile

P a r a m e t r i c A n a l y s i s

P a r a m e t r i c A n a l y s i s

• The impact of LCZ Parameters on air temperature are heavily influenced by street
• rientation
• Even though orientation plays an important role in street design its influence within one

LCZ is overwritten by other from parameters Impact of Street Orientation

• A fixed design strategy cannot be applied across all street typologies within one

climatic zone.

P a r a m e t r i c A n a l y s i s

R² = 0.2727 R² = 0.6565 R² = 0.517 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 2 4 6 8 10 12 14 16

Aspect Ratio Vs. PMV

High St. Mew Lane Linear (High St.) Linear (Mew) Linear (Lane) R² = 0.4462 R² = 0.7692 R² = 0.0148 24 24.5 25 25.5 26 26.5 2 4 6 8 10 12 14 16

Aspect Ratio Vs. Air Temperature

High St. Mew Lane Linear (High St.) Linear (Mew) Linear (Lane)

Impact of Street Aspect Ratio

Impact of surface properties

• level of impact is determined by the aspect ratio of

street with significant impact only being present in the high street case Impact of Openness -

• reduction of air temperature is more significant in the

high street and mew cases. the impact is more diluted in lane case. Impact of Façade Geometry

• show the most complex correlations to PMV and Ta.

P a r a m e t r i c A n a l y s i s

• LCZ parameters would need to be coupled with street orientation to

determine thermal comfort within the compact midrise zone.

• one fixed design strategy would not be applicable for all street cases

within a zone and would need to be modified according to the aspect ratio of the street

• LCZ classification would need further classify the façade properties in
• rder to be integrated as a tool for climate sensitive street design.
• The wind speed is a comfort parameter that cannot be ignored when

studying the impact of LCZ parameters on street design

I m p l i c a t i o n s o f U s i n g L C Z P a r a m e t e r s f o r S t r e e t D e s i g n

The study implies that further refinement of the classification method/mapping procedure is necessary to improve the classification accuracy to be used in climate sensitive street design

Further studies need to be conducted

• Across different LCZ classes to further refine the research findings
• On the impact of seasonal variations and the impact of the findings in a heterogeneous urban

environment such as in Asian / Developing city (built fabric is quite homogeneous in European cities such as Glasgow – 19th century urban plan)

• Across latitude variations to identify the impacts of solar angles and shading.

C o n c l u s i o n s A n d F u t u r e Wo r k

T h a n k Yo u !

Referen c es

Berghauser Pont, M.Y. And Haupt, P.A. (2009). Space, Density and Urban Form. Delft University of Technology. Doctoral thesis. Emmanuel,R. and Loconsole, A. (2015). Green infrastructure as an adaptation approach to tackling urban overheating in the Glasgow Clyde Valley Region, UK. Landscape and Urban Planning 138 (2015), 71–86. Glasgow City Council. (2018, 06 15). City Development Plan. Retrieved from Glasgow City Council: https://www.glasgow.gov.uk/CHttpHandler.ashx?id=35882&p=0 Moudon, A. (1997). Urban Morphology as an Emerging Interdisciplinary Field. . Urban Morphology, 1, 3-10. Ng, Edward and Ren, Chao. (2015). The Urban Climatic Map: A Methodology for Sustainable Urban Planning. Routledge; 1 edition . Stewart, I.D.; Oke, T.R. (2012). Local climate zones for urban temperature studies. Bulletin American Meteorological Society., 93, 1879– 1900.