Impacts of a future city master plan on

on thermal and wind environmentsin Vinh city, Vietnam

Satoru Iizuka, Nagoya University, Japan

Tatsunori Ito, Nagoya University, Japan

Masato Miyata, Mitsubishi UFJ R&C, Japan

in Vinh city, Vietnam

1

Background: Vietnam's recent growth

02468

1012[%]

ベトナムの経済成長率

400005000060000700008000090000

100000

[×1000] ベトナムの人口増加の割合

Economic growth rate Population

Average: 6% Growth rate: 1.2%

2

-6-4-20

1980

1983

1986

1989

1992

1995

1998

2001

2004

2007

2010

2013

Source: IMF-World Economic Outlook Databases

010000200003000040000

1 1 1 1 1 1 1 1 1 1 2 2 2 2

Source: The World Bank

Under the situation of Vietnam's recent growth,many city master plans have been proposed.

City master plan for Vinh city, Vietnam

By Nikken Sekkei Civil Engineering Ltd., Japan

Target period : 2030Planned population : 900,000

3

Vinh city, Vietnam (1)

Population 450,000

Land Area 105 km2

N Vinh city

Hanoi

Ho Chi Minh

4

Vinh city, Vietnam (2)

200250300350400450500

15

20

25

30

35

Pre

cipi

tatio

n [m

m]

tem

pera

ture

[℃]

Air temperature of Vinh Air temperature of Tokyo

050100150200

0

5

10

15

Pre

cipi

tatio

n [m

m

Air

tem

pera

ture

In Vinh city,June is the hottest month. Sep. and Oct. are rainy months.

5

Introduction of city master plan

Grassland

CBD (Central Business District)

Cropland/Grassland Mosaic

Water Bodies

New Urban District

Cropland/Woodland Mosaic Shrubland

Existing Urban District

Irrigated Cropland and Pasture Dryland Cropland and Pasture

Deciduous Broadleaf Forest

Present land use City master plan(2030; 900,000 people) 6

Development of downscaling model

Global scale

Regional scale

Urban scale

Nagoya

Ise Bay

Urban scale

Building scale

7

GCM + WRF + LES downscaling

Computational domains and grid design

52.5 km

46.5 km

Citymaster

plan

Vietnam

Domain 1

SouthChina

Domain 2

Domain 3

8

Size Grid points Horizontal grid

Domain 1 585 km×540 km×21 km 130×120×34 4.5 km

Domain 2 177 km×159 km×21 km 118×106×34 1.5 km

Domain 3 52.5 km×46.5 km×21 km 106×94×34 0.5 km

kmplanarea

Laos

ChinaSea

Simulated cases (1)

Period Land use

Case 0 June in 2011 (Present) Present land use

Case 1

June in the 2030s(Future)

Present land use

Case 2 City master plan

Case 3Northern concentration

of the new urban districts

9

of the new urban districts

Case 4Southern concentration

of the new urban districts

Three categories in the urban area:

1. Central business district (CBD)Average height of buildings: 26 m, Building (green) coverage ratio: 50% (50%)

2. Existing urban districtAverage height of buildings: 12 m, Building (green) coverage ratio: 70% (30%)

3. New urban districtAverage height of buildings: 12 m, Building (green) coverage ratio: 70% (30%)

Simulated cases (2)

10

Present land use (Cases 0 and 1) Master plan (Case 2)

Northern concentration (Case 3) Southern concentration (Case 4)

Future projection by pseudo global warming method

General circulation model: GFDL-CM3

Pseudo global warming databased on RCP 8.5 scenario

Initial and boundary conditions for WRF simulations

Laos

Vietnam

Domain 1

SouthChinaSea

11

52.5 km

46.5 km

Domain 3

Domain 2

Future (the 2030s) climate with present land use (Case 1)– Present (2011) climate with present land use (Case 0)

Effect of global warming in the 2030sdi

ffere

nce

[°C

]

2

2.5

Space- and monthly-averaged diurnal variation of the difference in air temperature (at 2 m)

12Time [h]

Tem

pera

ture

diff

eren

ce

0

0.5

1

1.5

2

0 1 2 3 4 5 6 7 8 9 1011121314151617181920212223

1.76℃ Present land use

0.4

0.5

Future (the 2030s) climate with city master plan (Case 2)– Future (the 2030s) climate with present land use (Case 1)

Effect of introducing city master plandi

ffere

nce

[°C

]

Space- and monthly-averaged diurnal variation of the difference in air temperature (at 2 m)

0.85℃

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6 7 8 9 1011121314151617181920212223Time [h]

Tem

pera

ture

diff

eren

ce

0.33℃0.17℃

Present land useCity master plan

Source: IPCC Fifth Assessment Report, Synthesis Report (SPM)

0.85℃(1880-2012)

13

Future (the 2030s) climate with modified master plan (Case 3)– Future (the 2030s) climate with city master plan (Case 2)

Effect of new urban district structure (1)di

ffere

nce

[°C

]

Space- and monthly-averaged diurnal variations of the difference in air temperature (at 2 m)

0.4

0.5 CBD New urban (North) Existing urban

14Time [h]

Tem

pera

ture

diff

eren

ce

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6 7 8 9 1011121314151617181920212223

0.23℃Northern concentrationCity master plan

Future (the 2030s) climate with modified master plan (Case 4)– Future (the 2030s) climate with city master plan (Case 2)

Effect of new urban district structure (2)di

ffere

nce

[°C

]

Space- and monthly-averaged diurnal variations of the difference in air temperature (at 2 m)

0.4

0.5 CBD New urban (South) Existing urban

15Time [h]

Tem

pera

ture

diff

eren

ce

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6 7 8 9 1011121314151617181920212223

0.11℃

Southern concentrationCity master plan

Summary

2. By introducing the proposed city master plan, the averaged air temperature in the urban areas was

℃

1. With the continuous progress of global warming, the future (the 2030s) thermal environment in Vinh city was about 1.8℃ hotter than that in the present status.

16

averaged air temperature in the urban areas was 0.17℃ higher than that in the case with the present land use.

3. The future (the 2030s) thermal environment in the case with the original city master plan was better than that with the northern or southern concentration of the new urban districts.

17

RCP scenarios IPCC 5th assessment report

RCP: Representative Concentration Pathway

Source: IPCC AR5 Working Group I Summary for Policymakers

18

Pseudo global warming data (1)

Components of global warming

1. Horizontal wind components

2. Potential temperature

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3. Geopotential height

4. Sea surface temperature

5. Ground surface temperature

Pseudo global warming data (2)

1) Monthly variations of 10-year averageddata from 2030 to 2039 based onthe RCP 8.5 scenario

2) Monthly variations of 10-year averaged

20

2) Monthly variations of 10-year averageddata from 2000 to 2009

1) − 2) was added to the present (June 2011)NCEP Final Operational Global Analysis data.