Population 050 000100 000150 000200 000250 000 Tree Cover (percent) 15 20 25 30 35 40 Figure 30.1 Ecological Climatology © 2008 G. Bonan.

Population

0 50 000 100 000 150 000 200 000 250 000

Tre

e C

over

(pe

rcen

t)

15

20

25

30

35

40

Figure 30.1Ecological Climatology © 2008 G. Bonan

Forest Grassland Desert

Tre

e C

over

(pe

rcen

t)

Park Vacant Residential CommercialIndustrial

Tre

e C

over

(pe

rcen

t)0

5

10

15

20

25

30

35

0

10

20

30

40

50

60

ForestGrasslandDesert

Ecoregion

Figure 30.2Ecological Climatology © 2008 G. Bonan

business buildings, shopping centers, parking lots

Contour from 1oC to 7oC by 1oC

4 October 19741930 - 2050

1

1

3

4

4

3

65

2

2

71

1

13 August 19682030 - 2135

Contour from 1oC to 3oC by 1oC

3

1 km

Legend

detached houses and apartments

Figure 30.3Ecological Climatology © 2008 G. Bonan

0

2

4

6

8

10

12

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Sky View Factor

0

2

4

6

8

10

12

1000 10 000 100 000 1 000 000 10 000 000

Population

Ma

xim

um

Urb

an

-Ru

ral T

em

pe

ratu

re D

iffe

ren

ce (C

)

Europe

North America

Figure 30.4Ecological Climatology © 2008 G. Bonan

13.0

13.5

14.0

14.5

15.0

15.5

16.006

00

1000

1400

1800

2200

0200

0600

Time of Day (hours)

Air

Tem

pe

ratu

re (C

)

Rural (23.8C)

Urban (25.5C)

18

20

22

24

26

28

30

Mix

ing

Ra

tio (

g k

g-1)

Time of Day (hours)

Rural (14.5 g kg-1)

Urban (14.0 g kg-1)

0600

1000

1400

1800

2200

0200

0600

Figure 30.5Ecological Climatology © 2008 G. Bonan

-6-5-4

-3-2-10

1234

56

1000 10 000 100 000 1 000 000 10 000 000

Population

Ave

rage

Urb

an-R

ural

Te

mpe

ratu

re D

iffer

ence

(C

)

Daily mean

Daily minimum

Daily range

Figure 30.6Ecological Climatology © 2008 G. Bonan

SS

L

858 W m-2838 W m-2

L L

300 W m-2

L

468 W m-2593 W m-2lE

209 W m-2

H 84 W m-2

H 70 W m-2

G 168 W m-2 G 447 W m-2

S

209 W m-2S

300 W m-2

48 W m-2

Field (1200 hours) Parking Lot (1200 hours)

Air temperature 25C

Ts 32C Ts 48C

Winds calm

albedo: 0.25Rn: 461 W m-2

Bowen ratio (H/E): 0.40Evaporative fraction (lE/Rn): 0.45

albedo: 0.06Rn: 517 W m-2

Bowen ratio: -Evaporative fraction: 0

Figure 30.7Ecological Climatology © 2008 G. Bonan

-100

0

100

200

300

400

500

600

0 0300 0600 0900 1200 1500 1800 2100 2400

Ene

rgy

Flu

x (W

m-2)

0.0

0.6

1.2

1.8

2.4

3.0

3.6

4.2

Bow

en R

atio

Net Radiation

Sensible Heat

Latent Heat

Storage

Bowen Ratio

Rural

-150

-100

-50

0

50

100

150

0 0300 0600 0900 1200 1500 1800 2100 2400Time Of Day (hours)

Ene

rgy

Flu

x (W

m-2)

Net Radiation

Sensible Heat

Latent Heat

Storage

Suburban - Rural

-100

0

100

200

300

400

500

600

0 0300 0600 0900 1200 1500 1800 2100 2400

Ene

rgy

Flu

x (W

m-2)

0.0

0.6

1.2

1.8

2.4

3.0

3.6

4.2

Bow

en R

atio

Net Radiation

Sensible Heat

Latent Heat

Storage

Bowen Ratio

Suburban

Figure 30.8Ecological Climatology © 2008 G. Bonan

Storage 12 W m-2

Latent Heat 187 W m-2Sensible Heat

86 W m-2

Sensible Heat 129 W m-2 Latent Heat

101 W m-2Storage 65 W m-2

Net Radiation283 W m-2

Net Radiation295 W m-2

Suburban: 25% building, 11% paved, 64% greenspaceRural: managed grassland

albedo: 0.20Bowen ratio (H/E): 0.46Evaporative fraction (lE/Rn): 0.66

albedo: 0.13Bowen ratio: 1.28Evaporative fraction: 0.34

Figure 30.9Ecological Climatology © 2008 G. Bonan

wallwall

sky

wall

road

sky

wallwall

sky

wall

sky

road

Road view factors

Wall view factors

Bui

ldin

g H

eigh

t, H

Street Width, W

Street Width, W

Bui

ldin

g H

eigh

t, H

Bui

ldin

g H

eigh

t, H

Bui

ldin

g H

eigh

t, H

Street Width, W

Street Width, W

Bui

ldin

g H

eigh

t, H

Bui

ldin

g H

eigh

t, H

Bui

ldin

g H

eigh

t, H

Bui

ldin

g H

eigh

t, H

Figure 30.10Ecological Climatology © 2008 G. Bonan

0.0

0.10.2

0.30.4

0.5

0.60.7

0.80.9

1.0

0 1 2 3 4 5 6 7 8 9 10

Canyon H/W Ratio

Vie

w F

acto

rSky

Wall

Figure 30.11Ecological Climatology © 2008 G. Bonan

Figure 30.12

Roof

Wall

0

10

20

30

40

50

60

70

80

0 1 2 3 4 5 6 7 8 9 10

Canyon H/W Ratio

Ne

t L

on

gw

ave

Ra

dia

tion

(W

m-2)

Road

Canyon

Emissivity:Roof = 0.90Road = 0.94Wall = 0.85

Ecological Climatology © 2008 G. Bonan

small wood lot

5-story building complex with paved courtyard

(32 m 42 m)

grass lawn

24

25

26

27

28

29

30

31

1600 1700 1800 1900 2000 2100 2200

Time of Day (hours)A

ir Te

mpe

ratu

re (C

)

20

25

30

35

40

45

50

1600 1700 1800 1900 2000 2100 2200

Time of Day (hours)

Sur

face

Tem

pera

ture

(C

)

Courtyard

Grass

Woods

Courtyard

Grass

Woods

Figure 30.13

courtyard

Ecological Climatology © 2008 G. Bonan

Figure 30.14Ecological Climatology © 2008 G. Bonan

NW Residential Area

Rock CreekPark

Urban/IndustrialArea East ofRock Creek

16th StBusiness

Area

DowntownParks

2315 hours

19

20

21

22

23

24

25

26

Air

Tem

pera

ture

(C

)

Figure 30.15Ecological Climatology © 2008 G. Bonan

0

1

2

3

4

5

6

7

0 25 50 75 100 125 150 175

Park Size (hectares)

Urb

an-P

ark

Tem

pera

ture

Diff

eren

ce (C

) TemperateArid

Tropical

Figure 30.16Ecological Climatology © 2008 G. Bonan

Figure 30.17

CBDIND RES

RUR

0 10 20 30 40 50 60 70 80 90 100

Vegetated Cover (%)

0

1

2

3

4

5

H /

E

U1U2

U3

S1

R1

R2R3

R3

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0 10 20 30 40 50 60 70 80 90 100

Vegetated Cover (%)

H /

Rn

Łódź

Basel

CBD

IND RES

RUR

U1U2

U3

S1

R1

R2

CBD

IND

RES

RUR

U1U2

U3

S1R2R3R1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

H / W Ratio

H /

Rn

S1CBD

IND

RESRUR

U1U2

U3

R2R3R1

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

H / W Ratio

0

1

2

3

4

5

H /

E

Ecological Climatology © 2008 G. Bonan

+5%

0%

-5%

+5%

0%

-5%

-5%

0%-5%

+5%

+10%

St. Louis

North40 km

Contour from -5% to +15% by 5%

+15%

Figure 30.18Ecological Climatology © 2008 G. Bonan

530

550

570

590

610

630

650

670

Sun Mon Tue Wed Thu Fri Sat

Da

ily P

reci

pita

tion

(m

m)

-1.4

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

Da

ily M

ea

n C

O+

O3

Ind

ex

Precipitation

CO+O3

Figure 30.19Ecological Climatology © 2008 G. Bonan

30

40

50

60

70

80

90

100

30 40 50 60 70 80 90 100

Pervious Curve Number

Com

posi

te C

urve

Num

ber

30% impervious0% to 100% unconnected

0% to 100% unconnected10% impervious

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Impervious Area (percent)

Com

posi

te C

urve

Num

ber

CN 30

CN 40

CN 50

CN 60

CN 70

CN 80

CN 90

CN 98

Figure 30.20Ecological Climatology © 2008 G. Bonan

100 mm 100 mm

100 mm100 mm

87 mm

13 mm

50 mm

50 mm

83 mm

17 mm

31 mm

69 mm

Forest Pasture

Residential Business District

CN=55 CN=69

50% imperviousCNpervious=61CNcomposite=80

90% imperviousCNpervious=61CNcomposite=94

Figure 30.21Ecological Climatology © 2008 G. Bonan

2

4

6

8

10

12

14

16

18

20

0.1 1.0 10 100 200

Recurrence Interval (years)

Impervious area = 20%

3

20

Impe

rvio

us A

rea

(per

cent

)10

20

30

40

50

60

0

115

2

10

Recurrence Interval (years)

4

0.1 2001.0 10 100

Figure 30.22

Urban-to-rural discharge ratio

Urb

an-t

o-ru

ral d

isch

arge

rat

io

Ecological Climatology © 2008 G. Bonan