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
• Introduction, Aim and Objectives • Research Methodology • The Case Of Glasgow • Simulation Procedure • Data Analysis and Discussion O v e r v i e w
Un d esirab le Th e Growth O f Form, Climate Urb an Livin g Th ermal Comp ac t An d Urb an Qu ality Imp acts Cities Plan n in g I n t r o d u c t i o n
Implementing urban climatic research findings? https://britevans.weebly.com/contact.html R a t i o n a l e
The Urban Designers’ Approach Level Of Compactness Development Plan Principles of reading physical for 2050 form 1. Three fundamental Sustainable physical elements: neighbourhoods 1. Streets 2. Plots of land and buildings Open spaces . 3. 2. Resolution Street Design 1. Buildings/plots 2. Street blocks 3. Cities and regions. 3. Time (Moudon, 1997 ) Action Plan density measures used through history (Berghauser and Haupt, 2009) 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) L i t e r a t u r e R e v i e w
1. Explore Intra LCZ zone temperature variation in compact urban form 2. Investigate the possibility of using LCZ parameters for climate sensitive street design (Stewart and Oke, 2012) R e s e a r c h O b j e c t i v e s
Compact Urban Form Features Urb an Desig n • Street types Openness – LCZ c lasses • Lane • Sky view factor E lement • High street • Aspect ratio • • Mew Lane Height of roughness elements Land Features • Boulevard • Building surface fraction Density of elements • Surface Properties • surface cover Defined by resolution • Impervious surface fraction • structure • Pervious surface fraction and time • Terrain roughness class • Material • human activity 1 . Tr a v e r s e Explore Intra LCZ zone temperature variation between street typologies S t u d y Investigate the impact of modifying the LCZ parameters on street comfort 2 . N u m e r i c a l through urban design interventions S i m u l a t i o n R e s e a r c h M e t h o d o l o g y
• 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
(Glasgow City Council, 2018) 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’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 overhangs, Glass facades for ground floor) Urban Design Strategies for improving environmental quality ( Ng, Edward and Ren, Chao, 2015) 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
Location SVF SVF Digram 1 Sauchiehall street 0.39 2 Blythswood square 0.571 3 Bothwell Ln 0.1 4 Gordon Street 0.2 • The data used were measured for a typical summer condition on 4th of July 2018 5 Mitchel Lane, Lighthouse 0.05 between 2pm -4pm when the air temperatures were most stable • The 6 Royal Exchange Square 0.3 average air temperature was measured at 10 points obtained from 5- min sampling resolutions worth of data in 7 George Square 0.6 each location. • temperatures were recorded at 2 second 8 Buchanan/ St Vincent St Junction 0.45 intervals. • Measurements were taken using tiny tag 9 Buchanan Street House of Fraser 0.38 air temperature data logger fixed to the backpack comprising of a foil with 10 Jamaica / Clyde Street Junction 0.6 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
Location SVF SVF Digram 1 Sauchiehall street 0.39 1 2 Blythswood square 0.571 2 3 Bothwell Ln 0.1 4 Gordon Street 0.2 • The data used were measured for a typical summer condition on 4th of July 2018 8 4 7 5 Mitchel Lane, Lighthouse 0.05 between 2pm -4pm when the air 3 temperatures were most stable 6 • The 5 6 Royal Exchange Square 0.3 average air temperature was measured at 10 points obtained from 5- 9 min sampling resolutions worth of data in 7 George Square 0.6 each location. • temperatures were recorded at 2 second 8 Buchanan/ St Vincent St Junction 0.45 10 intervals. • Measurements were taken using tiny tag 9 Buchanan Street House of Fraser 0.38 air temperature data logger fixed to the backpack comprising of a foil with 10 Jamaica / Clyde Street Junction 0.6 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. 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 Tr a v e r s e S t u d y F i n d i n g s
East West Orientation North- South Street Typology Base cases 20m 10m 4m Mew Lane High street Openness Façade Geometry Surface Properties LCZ Parameters GCD Design Strategy Overhangs Mouldings Sun sails Planters Trees Cobble Glass 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
• 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
ENVI-met model Parameter value section Main data Domain size and Cell size 50 x 60 x 30 in 2m x 2m x 2m Nesting Grids 3 03.07.2018 Time and Date Date 18.00 Start time Tot Simu. T 30 Output Intervals 60 min Meteorology Wind speed (m/s) and direction (deg) 4, 45 Street data Orientation N-S and E-W Roughness length (m) 0.01 Types (width) 20, 10, 4 Initial temperature of atmosphere (c) 25 Length 80m Relative humidity (%) 47 Soil Profile Asphalt Specific Humidity (g/kg) 9.1 Building data Dimensions ( H, W,L) 20m x 10m x 40m Simple forcing Force temperature and Humidity Walls Stone – moderate insulation Sun height for switching dt(0) and Sun height for 40, 50 Time steps switching dt(1) Roof Tile Time step (s) for interval 1 dt(0) (s) 2 dt(1) (s) and 10,5,2 3 dt(2) (s) S i m u l a t i o n M o d e l
P a r a m e t r i c A n a l y s i s
Impact of Street Orientation • The impact of LCZ Parameters on air temperature are heavily influenced by street orientation • Even though orientation plays an important role in street design its influence within one LCZ is overwritten by other from parameters P a r a m e t r i c A n a l y s i s
Aspect Ratio Vs. Air Temperature Aspect Ratio Vs. PMV 26.5 1.6 1.4 R² = 0.4462 26 R² = 0.517 1.2 R² = 0.7692 1 25.5 R² = 0.6565 0.8 R² = 0.2727 25 0.6 R² = 0.0148 0.4 24.5 0.2 24 0 0 2 4 6 8 10 12 14 16 0 2 4 6 8 10 12 14 16 High St. Mew Lane High St. Mew Lane Linear (High St.) Linear (Mew) Linear (Lane) Linear (High St.) Linear (Mew) Linear (Lane) Impact of Street Aspect Ratio • 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
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
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