Census Tract-Level Outdoor Human

Transcription

1 Census Tract-Level Outdoor Human Thermal Comfort Modelling and Heat- Related Morbidity Analysis During Extreme Heat Events in Toronto: The Impact of Design Modifications to the Urban Landscape Drs. Drew A. Graham, Jennifer K. Vanos, Natasha A. Kenny, and Robert D. Brown

2 Extreme heat events (EHE) Temperature > 32 o C, duration > 3 d Humidex > 40 o C, duration > 2 d Excess heat-related t mortality Health Canada 2011, Kent 2002, Toronto Public Health 2011b, Sheridan 2004

3 69% of Canadians 85% of population growth Statistics Canada 2012

4 Heat-Related Morbidity Causes Over-exposure/-exertion Symptoms Heat/cold exposure Light-headedness Headache Difficulty breathing Fainting/unconsciousness Stroke/heat stroke Chest pain Cardiac/respiratory arrest Outcomes Long-term health issues Death Health Canada 2011

5 Physiological/Physical Inputs: Physical activity Clothing properties Landscape characteristics Meteorological Inputs: Air temperature Wind speed Relative humidity Absorbed radiation COMFA (COMfort FormulA) W m HOT WARM Energy Budget (in W m 2 ) NEUTRAL 20 Perceived Thermal Comfort Brown 1986, Kenny 2009a, Kenny 2009b, Vanos 2009

6 Vanos 2012

7 Bassil 2009

8 Goal Define the relationship between human thermal comfort and heat-related morbidity at the Census Tract spatial scale in Toronto so as to inform cooling design solutions Objectives Further validate relationship between COMFA-derived EB and heat-related EMS calls during EHE in Toronto observed previously Identify and analyse problematic areas of Toronto for heat-related illness Apply cooling design strategies to problematic areas and assess post-design effectiveness using COMFA modelling

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10 7.0 Typical EHE Selected EHE 6.0 Number of Days Duration Weekdays Weekend days Heat Alert days Extreme Heat + Holidays Alert days All p > 0.05

11 80 70 Pre EHE 60 Post a b a a b a a b a 10 0 Mean Air Temperature ( C) Minimum Air Temperature ( C) Maximum Air Temperature ( C) Relative Humidity (%) Wind Speed (m/s) Different letters indicate p < 0.05 within a measurement.

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13 Mean Daily Ambula ance Calls * Pre EHE Post 0 Total Calls Heat-related Calls * p < 0.05

14 City-Wide Baseline Energy Budget (beb)

15 250 b ean Cit ty-wide beb, W m a a Pre EHE Post M 0 All years Different letters indicate p < 0.05.

16 City-Wide e beb, W m r = p = Mean Daily Heat-Related EMS Calls City-Wide beb, W m r = p = Mean Daily Heat-Related EMS Calls EB, W m -2 City-Wide b r = p = a Mean Daily Heat-Related EMS Calls EB, W m -2 City-Wide b r = p = b Mean Daily Heat-Related EMS Calls

17 Census Tract (CT)-Level Baseline Energy Budget (beb)

18 Mean CT T-level beb, W m b 200 a a a b a Pre EHE Post 0 Non-shoreline CT Shoreline CT Different letters indicate p < 0.05 within a measurement.

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20 Census Tract (CT)-Level Predicted Energy Budget (peb)

21 250 peb, W m a b a Pre Mean CT T-level EHE Post 0 All Years Different letters indicate p < 0.05.

22 at-related EMS alls Mean Daily Hea Ca ρ = ρ = p < p < at-related EMS alls Mean Daily Hea Ca CT-Level peb, W m -2 CT-Level peb, W m -2 Mean Daily Heat-R Related EMS Calls 2010a Mean Daily Heat-R Related EMS Calls 2010b ρ = ρ = p < p = CT-Level peb, W m -2 CT-Level peb, W m -2

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26 Daily Heat-rela ated Calls per CT ρ = p < Canopy Cover, %

27 CT (Downtown) CT (Scarborough)

28 Scarborough CT ( ) Land Class Tree Canopy Grass/Shrub Bare Earth Water Buildings Roads Other Paved Surfaces m

29 Scarborough CT

30 Scarborough CT

31 Downtown CT

32 Downtown CT

33 250 a a a a 200 b b EB, W m -2 pe Toronto Land Cover Existing Proposed 50 0 Downtown Scarborough Different letters indicate p < 0.05 within a measurement.

34 Daily He eat-relate ed Calls per CT Both CTs (existing) Downtown o CT (proposed) Scarborough CT (proposed) Canopy Cover, %

35 Limitations Indicator of heat-related morbidity used Call locations Buildings Constants: physical activity level and clothing ensemble

36 Summary Heat-related morbidity and EB increase during EHE Unevenly across Toronto peb developed to incorporate fine spatial scale land cover into EB calculations beb and peb related to heat-related morbidity Event-to-event fluctuations peb perhaps p a more predictable relationship Canopy cover inversely related to heatrelated morbidity Design proposals reduced d peb

37 Three Significant Points Extreme Heat Events: Increasing Exacerbated in urban landscapes Heat illness Human thermal comfort modelling: Tool for examining the urban landscape-heat illness relationship Human thermal comfort is modifiable Key for designing comfortable and healthy outdoor spaces for a changing climate

38 Drew Graham Full Study available at: Thank-you.