Measures Against Storm Surges in Japan

7/31/2019 Measures Against Storm Surges in Japan

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Measures against Storm Surges in Japan

Hiroyuki Kishida,

Director of Seacoast Office

River BureauMinistry of Land, Infrastructure and

Transport


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Most of typhoons in June and November to

December move westward. From July to

October, they change course in the mid-

latitude and head toward Japan. As a result,

Japan frequently suffers storm surgedisasters during this period.

SourceHome page of the Meteorological Agency

http://www.kishou.go.jp/know/typhoon/1-4.html

Japan is located along the course of typhoons.

Source: Scientific chronological table

Broken lines show the course of pre-1981 typhoons with casualties and missing of 1,500 or more.

Solid lines show the course of post-1982 typhoons with casualties and missing of 40 or more.

9 54 44 06 24 8

A u g . 2 . 1 9 8 2S e p t . 2 8 . 1 9 8 3S e p t . 1 9 . 1 9 9 0S e p t . 2 7 . 1 9 9 1S e p t . 3 . 1 9 9 3

No.10 in 1982No.10 in 1983No.19 in 1990No.19 in 1991No.13 in 1993

3 , 0 3 63 , 7 5 61 , 9 3 01 , 7 6 15 , 0 9 8

S e p t . 2 1 . 1 9 3 4S e p t . 1 7 . 1 9 4 5S e p t . 1 5 . 1 9 4 7S e p t . 2 6 . 1 9 5 4S e p t . 2 6 . 1 9 5 9

MurotoMakurazakikathleenToyamaruIsewan

Casualties,missing

Year/month/dateof landing or

closest approachName of typhoonNo.


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SourceHome page of the Okinawa observatory http://www.okinawa-jma.go.jp/

1116

11

36

13

10 3

Note: Numbers inside the area show the percentage of occurrencerelative to the global level.

The worlds tropical cyclone generating areas


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Location of principal areas below sea level in Japan

Legend

Area below sea level

Sendai Bay

Tokyo Bay

Ise Bay

Osaka Bay

Seto Inland Sea

The sea of Ariake


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Tokyo Bay Ise Bay Osaka Bay

1:500000

137E

35N

137E

35N

135E

34N

135E

34N

Area 116km2

Population 1.76 millionArea 336km2

Population 0.9 million

Area 124km2


1:500000

140E

35N

36N

140E

N

N

T.P.0m or belowHWL or below

Design high tide level (HHWL) or below

*Water surface area of rivers and lakes/marshes is not included.

*Prepared on the basis of digital national land information Shown above are areas whose three-dimensional mesh 1km1km altitude data is below the

tidal level.

Aggregate calculation of the area and population was made using the three-dimensional mesh data.

Area 577km2


Total for three big baysActual state of areas below

sea level

SourcePrepared by the Ministry of Land, Infrastructureand Transport on the basis of Geographical Survey Institute map

The value of area and populaton is for the caseat the HWL or below.

Japanese population and property isconcentrated in the three big bay areas, which

are core areas in national economy.

Storm surge hazard areas in three big bays


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Source Lowland River Project of Tokyo, Oct. 2001River Department, Construction Bureau, Tokyo

Flood condition during Typhoon Kitty inKinshicho, Sumida Ward, Tokyo

Inundation damage by past typhoons

952.7985.9Atmospheric pressurehPa

1,324160Casualties, missingpersons

180,338137,878Total No. of floodedhouses

49,00464,127Houses inundatedbelow the floor

131,33473,751Houses inundatedabove the floor

8,6608,121Inundated area ha

3.082.02Tide level T.P. m

39.624.9Maximum wind speed

161.664.9Total amount of

rainfall mm

16.512.6Maximum hourlyrainfall mm

Year

1917 TyphoonTyphoon Kitty

Inundation damage of coastal areas of Tokyo Bay caused by storm surges

Tokyo Bay average sea level (T.P.)abbreviation of Tokyo peil

This refers to the benchmark of survey in Japan.Originally, this was the bench mark determined from the results of tide level

observation of Tokyo Bay in the Meiji Era and does not agree to the currentaverage level of Tokyo Bay.

Inundation map by Typhoon Kitty ( )

Legend

Inundated area

Rivers

Overtopping pointBreak and fracture points

Inundation depth


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Inundation map

Ise Bay

Inundation condition

*Total of Mie, Aichi and Gifu prefectures

Damages

Typhoon data

T.P.3.9

mHighest sea level

3.4m

Sea-level

departure(from astronomical

tide)

55m/sMax instantaneous

wind speed

45m/sMax wind speed

929hPaCentral pressure

310Km2Inundation damage

190,135 housesInundated

159,641 houses

Total or

partial

destruction

4,651 housesRun-offHouses

66,442 personsInjured

158 personsMissing

4,487 personsCasualties

Source Interaction between Nature and People (40 years from Ise Bay Typhoon) September, 1999,Kiso River Downstream Work Office, Chubu Regional Construction Bureau, Ministry of Construction

Inundation damage caused by the Ise Bay Typhoon (September 1959)

Inundation damage of coastal area of Ise Bay caused by storm surges

Inundation map by

Ise Bay Typhoon

Flooding duration

Less than one day

One day to 30 days

31 days to 120 days

More than 120 days

Flow line (seawater)

Ditto (river water)

Dike break point


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SourceMeasures against Storm Surges in the Western Osaka Areas,March 2002, River Office, Civil Engineering Department, Osaka

Inudation damage by typhoons in the past

Inundation damage of coastal areas of Osaka Bay caused by storm surges

Typhoon Jane inundation area map Muroto Typhoon No.2 inundation area map

7221990 41Casualties (persons) inOsaka

2,16521,46517,898

No. of sufferers (persons)

in Osaka

126,98080,464166,720Total of inundated houses(houses) in Osaka

67,78235,058Houses with below thefloor flooding (houses) inOsaka

59,19845,406

166,720

Houses with above thefloor flooding (houses) inOsaka

3,1005,6254,921Inundation area (ha)

2.82(2.55)(2.90)Tide level T.P.

33.328.142.0Maximum wind speed(m/s)

42.864.722.3Total amount of rainfall(m/s)

-19.8-Maximum hourly rainfall(mm)

937.3970.3954.5Atmospheric pressure(mb)

196119501934Year

MurotoTyphoon No.2

TyphoonJane

MurotoTyphoon

( ): Estimate

[ ]: Missing

Legend

118 dikes

No. of damaged civil

engineering facilities

899 vesselsNo. of damaged marinevessels

123,209 housesNo. of damagedhouses

18,794 personsNo. of suffers

Legend

804

No. of damaged civil

engineering facilities

464 vesselsNo. of damaged marinevessels

85,811 housesNo. of damagedhouses

2,165 personsNo. of suffers


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Typhoon No.16 caused abnormal tide level along the Coast of Inland Sea, resulting in inundation of about 44,000 homes, mainly in Kagawa, Okayama, andHiroshima Prefectures.

Particularly, the central portion of Takamatsu City of Kagawa Prefecture was submerged, resulting in paralyzed urban functions.

On the coast of Takamatu Port, the tide level of 2.45 m exceeded the previous observation record of 1.94 m observed in Muroto Typhoon No.2 in 1961) by51 cm was observed.

This is considered due to multiplexing of factors; coincidence of typhoon approach with the time of high tide, coincidence of typhoon approach withthe time of spring tide, and the center of the typhoon was as low as 970 hPa at a time of closest approach.

Central portion

of TakamatsuCity was

submerged,

resulting in

paralyzed urban

functions

Typhoon passed

through the

coastal areas ofSeto Inland Sea

while

maintaining the

central pressure

of 970 hPa,

causing storm

surge disaster

over the entire

area

Inundation area

Inundation of

the urban areaof Takamatsu

City

Storm surge caused disaster due to abnormal tide level in Takamatsu City, Kagawa

Prefecture, by Typhoon No.16 (August 2004)

Houses with above the floor flooding 6,094 houses

Houses with below the floor flooding 9,468 houses

Total 15,562 houses

Inundation area

Takamatsu City

0:00 Aug. 31

9:00 Aug. 31

21:00 Aug. 30

9:00 Aug. 30


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Damage suffered: (Below) Houses where three deaths occurred

(below).Upper rightFurniture scattered in the back of houses

under force of overtopping wave. Lower right) Fractured dike

Graphical illustration of dike fracture

Typhoon No. 23 generated abnormal high sea in Kochi Prefecture, causing fracture of the dike in Muroto City and resulting in the deaths of threesenior citizens.The Murotsu Misaki Observatory recorded T.P. + 2.86 m exceeding the design tide level (T.P. + 2.20 m) by 66 cm. In addition, the Murotsu wave

observation gauge recorded 13.5 m (significant wave height) exceeding the record for observed maximum wave height (9.45 m: Typhoon No.131993) by 4.1 m.Probable factors were the (1) long stationary period of Typhoon No. 23 in the Pacific, readily causing sea waves; (2) extremely wide storm and that

included high-wind zones, readily generating high sea waves; and (3) re-landfall of the typhoon at Muroto City, Kochi Prefecture, without losingstrength.

Coastal disaster in Muroto City, Kochi Prefecture, caused by abnormally high waves due

to Typhoon No. 23 (October 2004)

Damaged facilities L=30mm

Damages

Dike: Completed in 1967


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Design crest height = HWL + High water departure + Run-up height + Free board

m m mHWL

mm to mHigh water departure

Muroto and Jane Typhoons were compared, andthe Muroto Typhoon course with expected largedamage was set.

Actual Ise Bay Typhoon courseParallel courses of Ise Bay, Kitty, and othertyphoons were compared and the worst coursewas set.

Course setting

mm to mDesign high tide level

Ise Bay Typhoon .9Ise Bay Typhoon .9Ise Bay Typhoon .9Design external forces

Osaka Bay (Osaka Port)Ise Bay (Nagoya Port)Tokyo Bay (Tokyo Port)

Concept to set the target and course in the plan against storm surges

Syzygetic average

high tide level

Run-up

height

Free board

Design crest height

Design high water line

Sea bottom

High water

departure

Design concept for height of storm surge barrier coastal dike

Water level rise amount

due to storm surgeAttacking wave component

Revetment


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Present situation in sections of areas below sea level in Tokyo that will not be inundated high tide level

How to read

The figure shows the building height asmeasured from upper atmosphere. Buildings

indicated in red may suffer submersion of the

first floor when the surrounding area is

indicated in blue.

However, residents can evacuate to the upper

floor or to the roof.

Altitude 1.0 m or less Section submerged at HWL

Altitude 1.04.0m Section whose totalsubmersion may be avoided at HWL

Altitude 4.0 m or more Section where inundationabove the first floor of homes can be avoided in the event

of inundation at HWL

Legend


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In Japans three big bays, storm surge barrier are created by assuming a surge equivalent to the Ise Bay Typhoon class concurrent

with a high tide.Of the coastal dikes in the three big bays, 89%, 90%, and 100%, respectively, have been developed with the required height for

Tokyo Bay, Ise Bay, and Osaka Bay.

Nationwide (13,792m) Tokyo Bay (150km) Ise Bay (54km) Osaka Bay (103km)

Height of coastal dikes

1,176km

657km

9,000km 134km

7km9km

103km49km

5km1km

Tokyo Bay (157km)Nationwide (1,269km) Ise Bay (87km) Osaka Bay (79km)

Height of river dikes

For seacoast preservation areaFor Nationwide, the lowest height of a consecutive

sections is calculated as representative for the section.

Dike height is sufficient.

Current dike height design dike height

Dike height is tentatively sufficient.

Design high tide level current dike height

Measures Against Storm Surges in Japan

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