lessons learnt from urban human-biometeorology of urban...
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ASI1_Lecture 1_5/12/2011
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Lessons learnt fromurban human-biometeorology
of urban areas in Central Europe
• Helmut Mayer• full professor• Meteorological Institute /
Albert-Ludwigs-University of Freiburg,Germany
Croucher Advanced Study Institute 2011-2012Urban Climatology for Tropical & Sub-tropical Regions
Lecturer’s Photo
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Location of Freiburg, Germany (I)
Freiburg
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Location of Freiburg, Germany (II)
Freiburglocated atthe eastern borderof the southernUpper Rhine valley
≈ 220.000 inhabitants
48° 00' N, 7° 51' E269 m a.s.l.
atmospheric backgroundsituation:warmest within Germany
FR
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
interdisciplinary science
dealing with the impacts of
- weather
- climate
- air pollutants
on living organisms
Biometeorology: definition
ASI1_Lecture 1_5/12/2011
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Biometeorology: international
December 5-9, 2011
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
according to the target groups
- human-biometeorology
- plant-biometeorology
- agricultural meteorology
- forest meteorology
- phenology
- animal-biometeorology
Biometeorology: fields
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
- target group: citizens
- general objective
maintaining quality of life for citizens
- within urban open spaces
- indoors
even under poor atmospheric background conditions
objective requires
- identification of problematic urban spaces
- application of appropriate methods
- validation of applied methods
Urban human-biometeorology
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Atmospheric background of cities (I)
Cities are embeddedinto specific atmospheric background conditions
on regional scale.
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Atmospheric background of cities (II)
is related to
- thermal situation
- air quality
- …
dependent on
- topography
- land use
- pattern of large-scale weather
- …
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
urban land use, structures and processes
modification of regional atmospheric backgroundconditions by
∆ (z.B. ∆Ta, ∆VP, ∆v, ∆Tmrt, ∆NO2, …)
∆: no constant, but a function
dependent on
- weather
- time of day and the year
- urban land use (site on micro-scale)
- …
Urban climate: causes
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consequences of ∆:
- urban climate
city is considered as a whole in contrast
to the rural surroundings
- different urban micro-climates within a city
local climate zones (Stewart and Oke, 2009)
Urban climate: features
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Human-biometeorological conditions
different urban micro-climates
specific human-biometeorological conditions for citizens
characteristics:
strain for citizens
- impairment of efficiency
- limited well-being
- health hazard
- elevated morbidity
- elevated mortality
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Regional climate change
characteristics of regional climate change:
- trends of climate variables(air temperature, precipitation, …)
- embedded severe weather atmospheric- heat waves background- drought in summer conditions- convective rainfall- severe storms (?)- …
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Heat waves in Central Europe (I)
example: heat waves in southwest Germany:
2003, 2006, 2009, 2010, 2011, … in the future?
accumulation effects
Freiburg, 22-08-2011
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Heat waves in Central Europe (II)
characteristics:
- cloudless sky high K* (daytime) and L* (night)
- high mean radiant temperature Tmrt
- high near-surface air temperature Ta
- low near-surface wind speed v
- near-surface vapour pressure VP
< 18 hPa dry heat
> 18 hPa humid heat
- high concentrations of O3 and PM10
- …
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Central European cities: heat waves
significant problem currently
- urban structures in Central Europe:
not adapted to severe heat
- citizens in Central Europe:
not adapted to severe heat
- demographic development in Central European cities:
citizens become elder
elevated vulnerability of citizens to severe heat
in the future?
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Problem in Central Europe: heat waves
projections from regional climate models for Central Europe:
severe heat waves
- more frequent
- more intense
- longer lasting
starting in about 2040/2050:
- annually heat waves in the intensity of 2003 in SW Europe
- each 6th-8th year heat waves
with the intensity of the 'Moscow heat wave' in 2010
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Regional climate Change - citizens
regional climate change: changed atmospheric backgroundconditions
severe heat waves+
dynamic of cities: modified urban micro-climates- conversion of urban spaces- structural concentration- combustion processes- …
citizens: strain severe health stress
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Measures against heat waves
- preventive on a short-term basis:
heat health warning system (e.g. German Weather Service)
- current situation:
individual behaviour of citizens
- preventive on a long-term basis:
methods of urban planning
design of urban spaces
adapted to new challenges
by regional climate change
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Individual behaviour against heat (I)
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Individual behaviour against heat (II)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Urban planning
increasing need for urban planning:
- to develop
- to apply
- to validate
methods
to mitigate the negative health effects of severe heat on citizens
possible at all and to what extend?
dry heat - humid heat
in the daytime (outdoors) - at night (indoors)
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Assessment methods
- urban planning needs:human-biometeorologically significant assessment
of impacts of urban design on human thermal comfortduring severe summer heat
- assessments methodsbased on the human energy balance thermo-physiological assessment indices (e.g. PET)
- available- well tested- applicable
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Thermal index
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Meteorological input variables
methods to obtain the meteorological input variables
required to calculate a thermal assessment index
- experiments (point measurements)
- numeric simulations for an appropriate spatial grid
(e.g. ENVI-met model, vers. 4.0, spatial resolution: 1 m)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Experiments
human-biometeorologicalmeasuring system,
used in Freiburg
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Investigation design
methods to obtain basic results on the impacts of
- urban design
- street geometry
on the perception of heat by citizens:
co-ordinated approach consisting of
- experiments
- questionnaires
- numeric simulations
- statistic analyses
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Questionnaires
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Numeric simulationsOrientation
E-W
N-S
NE-SW
NW-SE
Height-to-width ratio H/W
street: 8 x 1 m
2 m1.2 m
WH
0.5 1 2 43
Ali-Toudert and Mayer, 2006
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Ta vs. Tmrt
- “despite the tendency of many researchersto focus on air temperature,
it is radiant exchangethat is mostly the dominant factor
affecting human thermal comfort”(Shashua-Bar et al., 2010)
mean radiant temperature Tmrt:most significant meteorological variable
for human thermal comfort during severe heatnot air temperature Ta or UHI
(but similar processes that govern Ta, UHI and Tmrt!)
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Definition of Tmrt (ASHRAE, 2001)
Tmrt is defined as:
- uniform temperature of an imaginary enclosure
- in which the radiant heat transfer from the human body
equals
- the radiant heat transfer in the actual non-uniform enclosure
Tmrt represents the amount of radiation heat
absorbed by humans
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Assessment concepts
- human-biometeorological conceptsto assess the thermal urban environment
are mostly related to a collective of citizens
- collective of citizens is representedby a standardised standing person
(cylinder-like shape)
consequences of the standing position?
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Angle factorsconsequences of the standing position
for absorbed radiant flux densities:
definition of angle factors Wi
to estimate the radiant flux densities
received by the standing person
Wi = 0.22 for the four lateral radiant flux densities
Wi = 0.06 for the up- and downwelling radiant flux densities
increased significance of lateral radiant flux densities
manipulations of vertical walls by urban planning
impact on lateral radiant flux densities
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Mean radiant temperature Tmrt
273.15σε
ST
0.25
radmrt
Tmrt: mean radiant temperature (°C)
Srad: total of all absorbed radiant flux densities (W m-2)
ε: emissivity of the human body (0.97)
σ: Stefan-Boltzmann constant (5.67 · 10-8 W m-2 K-4)
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Radiant flux density Srad
6
1iilikirad LαKαWS
Srad: total of all absorbed radiant flux densities (W m-2)
Ki: short-wave radiant flux densities
Li: long-wave radiant flux densities
αk: short-wave absorption coefficient (0.7)
αl: long-wave absorption coefficient (0.97)
Wi: angle factors (percentage of Ki and Li,received by the human body in each direction i)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
How to determine Ki and Li?
within urban street canyons and open spaces by use of
a) simulation models(e.g. RayMan, SOLWEIG)
b) measurementsof short- and long wave radiant flux densities
- from the four horizontal cardinal directions (E, S, W, N)- as well as from the upper and the lower hemisphere
paper “Different methods for estimating the mean radiant temperature in an outdoor urban setting” by Thorsson et al., 2007, IJC
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Measurements of Ki and Li (I)
system “Freiburg” (Germany) system “Gothenburg” (Sweden)Thorsson, 2011
system “Gothenburg” (Sweden)Thorsson, 2011
system “Gothenburg” (Sweden)Thorsson, 2011Thorsson, 2011
system “Gothenburg” (Sweden)Thorsson, 2011
system “Gothenburg” (Sweden)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Measurements of Ki and Li (II)
system “Taichung” (Taiwan)
Lin, 2011
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Globe thermometer
to measure globe temperature Tg
a) calculation of Tmrt from Tg
with the help of Ta and v
b) differentiation between
short- and long-wave radiant flux densities
is impossible
c) differentiation between the radiant flux densities
according to their directions
is impossible
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Results from simulations (I)
Ali-Toudert and Mayer, 2006
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Results from simulations (I)
conclusions:
- thermal stress in general:
strongest in E-W street canyon
with low aspect ratio (H/W)
- thermal stress per orientation of street canyon:
decrease with increasing aspect ratio
- thermal stress for constant aspect ratio:
in total strongest in E-W street canyonparticularly on the northern sidewalk ( oriented to S)
Ali-Toudert and Mayer, 2006
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Results from simulations (II)
ENVI-met simulationsPET: Freiburg, Rieselfeld
(a) 15-07-2007, 12 CET
(b) „worst case“
(c) „worst case“ + 30 a
Huttner and Bruse, 2009
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Case study in Freiburg
Germany: Freiburg, Vauban
WNW-ESE street canyonNNE oriented sidewalk
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Ki, typical summer dayFreiburg, Vauban, 15-07-2007
0
200
400
600
800
1000
8 10 12 14 16 18 20 22
CET (hrs)
K
(W
m-2
)
K
K
K(S)
K(W)
K(E)
K(N)
WNW-ESE street canyonH/W = 0.10; SVF = 0.48 NNE oriented sidewalk
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
absorbed Ki, typical summer dayFreiburg, Vauban, 15-07-2007
0
30
60
90
120
150
8 10 12 14 16 18 20 22
CET (hrs)
Ka
bs
orb
ed
by
a s
tan
din
g p
ers
on
(
W m
-2)
KK
K(S)
K(W)K(E)
K(N)
WNW-ESE street canyonH/W = 0.10; SVF = 0.48 NNE oriented sidewalk
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Li, typical summer dayFreiburg, Vauban, 15-07-2007
400
430
460
490
520
550
8 10 12 14 16 18 20 22CET (hrs)
L
(W
m-2
)
L
L
L(S)
L(E)
L(W)
L(N)
WNW-ESE street canyonH/W = 0.10; SVF = 0.48 NNE oriented sidewalk
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
absorbed Li, typical summer dayFreiburg, Vauban, 15-07-2007
0
30
60
90
120
8 10 12 14 16 18 20 22
CET (hrs)
La
bs
orb
ed
by
a s
tan
din
g p
ers
on
(
W m
-2)
L
L
L(S)
L(E) L(W)L(N)
WNW-ESE street canyonH/W = 0.10; SVF = 0.48 NNE oriented sidewalk
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
absorbed K* and L* (%)
Freiburg, Vauban, 15-07-2007
0
20
40
60
80
100
8 10 12 14 16 18 20 22
CET (hrs)
K*,
L
*
(%)
L*totally absorbed by a standing person
K*totally absorbed by a standing person
WNW-ESE street canyonH/W = 0.10; SVF = 0.48 NNE oriented sidewalk
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Tmrt and PET, typical summer day
Freiburg, Vauban, 15-07-2007
10
20
30
40
50
60
70
8 10 12 14 16 18 20 22
CET (hrs)
Ta,
Tm
rt,
PE
T
(°C
);
RH
(
%)
0.2
0.6
1.0
1.4
1.8
2.2
2.6
v (m
s-1)
WNW-ESE street canyonH/W = 0.10; SVF = 0.48 NNE oriented sidewalk
v
Tmrt
Ta
PET
RH
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
What do we learn from all data sets?
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
PET vs. Tmrt
Freiburg, typical summer days 2007
PET = 0.582*Tmrt + 8.0
R2 = 0.863
10
20
30
40
50
60
20 30 40 50 60 70Tmrt (°C)
PE
T
(°C
)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
PET vs. Ta
Freiburg, typical summer days 2007
PET = 1.665*Ta - 11.5
R2 = 0.657
10
20
30
40
50
60
15 20 25 30 35 40Ta (°C)
PE
T
(°C
)
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
PET vs. VPFreiburg, typical summer days 2007
PET = 0.289*VP + 28.4
R2 = 0.014
10
20
30
40
50
60
10 15 20 25 30
VP (hPa)
PE
T
(°C
)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
PET vs. vFreiburg, typical summer days 2007
10
20
30
40
50
60
0.0 0.5 1.0 1.5 2.0 2.5v (m/s)
PE
T
(°C
)
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Tmrt vs. SVF90-270
Freiburg, 2007-2009, typical summer days
Tmrt = 0.378*SVF90-270° + 32.6
R2 = 0.764
20
30
40
50
60
70
0 20 40 60 80 100
SVF90-270 (%)
Tm
rt
(°C
)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Cities in Central Europe (I)
severe heat:
occurs in summer daytime hours exceed night hours
double strategy of planning methodsto maintain local thermal comfort for citizens
under severe regional heat
- first priority: methods aiming at the daytime situation
- second priority: methods aiming at the night hours
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Cities in Central Europe (II)
double strategy of planning methods:
- first priority (methods aiming at the daytime situation):
lowering of the heat input into all urban spaces
- in accordance with environmental protection goals –
- second priority (methods aiming at the night hours):
maintaining sufficient ventilation
at night: mountain wind, cold air drainage on slopes
in the daytime: sea breeze
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Planning methods
lowering of the heat input into urban spaces (in the daytime)
primarily by shading:
optimised street and building design
more „green“
- green roofs and facades
- street trees
- front gardens
- large urban green areas
- …
…
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Shading ty street tree canopy
from experimental investigationsat different sites in Freiburg
during typical Central European summer days (2007-2009):
reduction of SVF90-270 by 10% due to the shading by street tree canopies
results in:
lowering of Ta by 0.2 °C
lowering of Tmrt by 3.8 °C
lowering of PET by 1.4 °C
(mean values: 10-16 CET)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Conclusions (I)
- urban climate:
modification of the atmospheric background situation
- regional climate change (trends, extreme weather):
aggravation of the atmospheric background situation
- cities in Central Europe:
pattern of urban land use, buildings and citizens:
not adapted to severe heatdemographic development risk group “elderly people” is increasing
health stress for citizens is increasing
urgent need for methods against severe heat
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Conclusions (II)
methods against severe heat:
- preventive on a short-term basis:
heat health warning system
- current situation:
individual behaviour of citizens
- preventive on a long-term basis:
methods of urban planning (double strategy)
design of urban spaces
adapted to new challenges
by regional climate change
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Conclusions (III)
- Tmrt: most important meteorological variable
for human thermal comfort during severe heat
- several methods to measure and simulate Tmrt outdoors
- from measurements:
distinct significance of horizontal radiant flux densities
for Tmrt
particularly for the long-wave radiant flux densities
reason: standing position of reference person
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Conclusions (IV)
- higher significance of L* compared to K* for Tmrt
L*: total of absorbed long-wave radiant flux densities from six directionsK*: total of absorbed short-wave radiant flux densities from six directions
K*/(K* + L*): ≈ 30% (sunlit)
K*/(K* + L*): ≈ 8% (shaded)
- high potential of vertical surfaces (walls)(material, colour, “green” coverage, …)
to influence Tmrt PET(maintaining of human thermal comfort during severe heat)
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Conclusions (V)What should urban planning do?
- to consider and apply lessons learned fromurban climate master plans (urban climate function maps)
- to consider, adapt to cities and applylessons learned from urban human-biometeorology
- to offer advanced training to planners in urban human-biometeorology
- to challenge existing concepts of urban climate,if they are quantified in an insufficient way up to now e.g. cold air drainage on slopes, mountain wind
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ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Conclusions (VI)
What should urban planning do?
- to develop, apply and validate planning methodsagainst severe heat (target group: citizens)
- suited methods from urban human-biometeorology are- developed- tested- validatedcan be applied
- necessary:permanent quality control by independent experts
ASI 1: URBAN CLIMATE FOR HUMAN COMFORT School of Architecture, The Chinese University of Hong Kong, Hong Kong, 5-6 Dec 2011
Prof. Dr. Helmut MayerMeteorological InstituteAlbert-Ludwigs-University of Freiburg(Werthmannstr. 10,D-79085 Freiburg, Germany)Tel: +49/761/2033590 Email: [email protected] Website: www.meteo.uni-freiburg.de
End, Thank YouEnd, Thank You
Prof. Dr. Helmut MayerMeteorological InstituteAlbert-Ludwigs-University of Freiburg(Werthmannstr. 10,D-79085 Freiburg, Germany)Tel: +49/761/2033590 Email: [email protected] Website: www.meteo.uni-freiburg.de