River 1/8

CHARACTERISTICS IN JAPAN’S RIVERS
Steep gradient in Japan’s rivers causes floodwater quickly flow down and water level abruptly rise.

Comparison of River GradientComparison of Water Discharge

ELEVATION (m)
LOIRE
1,000

800

COLORADOJOGANJI

KISO

600400YOSHINOSHINANOSEINE
MEKONGRHONE
MOGAMI
200NILETONEMISSISSIPPIAMAZON

0 100 200

400600800

1,000

1,2001,400

DISTANCE (km)Copy right (c) 2013 Ministry of Land, Infrastructure, Transport and Tourism, Japan, All rights reserved .

River 2/8

VULNERABLE LAND TO FLOOD – GEOGRAPHICAL FEATURES

High concentration of population and assets will bring about serious damages at possible embankment
collapse.
Flood levels in Japan are higher than the elevations of highly populated area
London and the ThamesTokyo and Three Major Rivers

KANTO Urban Area –Eastern Center incl. Tokyo

綾瀬川

Approx. 2.9 million people residein below MSL 0m in three majorurban areas.

KINKI Urban Area –Western Center incl. Osaka

上野駅

ELEVATION

尼崎駅

亀戸駅

新宿駅
東京駅

新大阪駅

旧江戸川

錦糸町駅

渋谷駅
荒川

大阪駅

77m

寝屋川0m
3 - 4m
1- 3m

大阪城 平野川

0- 1m-1- 0m< -1m

Copy right (c) 2013 Ministry of Land, Infrastructure, Transport and Tourism, Japan, All rights reserved .

River/BayRiver 3/8

RIVER MANAGEMENT – EMBANKMENT

Embankment was formed by repeating earth-fill in many years in its history. While simple application ofavailable soil at every fill, un-uniformity remained in material composition.
Bank Section Transition of the YODO in KINKI

1940～

1896～1910

1500’s（16世紀）

1918～1932

Bank Top higher than Houses

1940～

The EDO in KANTO – Flood level is higher than
populated ground elevation at Typhoon No.15 in 2001.

Example in KINKI

Example in KANTO
Copy right (c) 2013 Ministry of Land, Infrastructure, Transport and Tourism, Japan, All rights reserved .

RIVER MANAGEMENT – PATROL & INSPECTION

River 4/8

Embankments expose various deformation caused by high pressure and erosion force at floods in steep rivers.

Embankment Deformation

Patrol & Inspection

Piping to leak

Patrol & inspection on daily changing deformation leads to early detection
and proper treatment.

River bank erosion
Bank inspection

River patrol

Coring inspection

Slope slide at rains and floods
Copy right (c) 2013 Ministry of Land, Infrastructure, Transport and Tourism, Japan, All rights reserved .

Crack inspection by sonar

River 5/8

RIVER MANAGEMENT – EQUIPMENT STRUCTURES
Various structures are equipped to function for river management.

There are many equipment structures including sluice gates and pipes, and drainage pump stations installed for blocking
backward flow at high-water from main streams to their tributaries.

Structures under Central Government’sadministration counts 10,000 approx.
Weir
堰等 揚排水機場
Drainage Pump

349

468

Purifier
浄化施設
52

Sluicegate & pipe
樋門樋管等

Sluice gate

9360

Sluice pipe

02000

堰等

Weir

Drainage pump station

Pumps at station

Copy right (c) 2013 Ministry of Land, Infrastructure, Transport and Tourism, Japan, All rights reserved .

その他
Others
116

4000

6000

8000

Drainage
Station

揚排水機場

10000

12000

Sluice
樋門樋管等
pipe

14000

16000

Purifier
浄化施設

18000

Weir
その他

20000

River 6/8

PRESENT AGING STATE OF EQUIPMENT STRUCTURES

Among equipment structures installed during rapid economic growth period, ones above 40 years of age will
progressively increase in number.
年 300
別設
置数
（箇所 250）

2011年度末時点
As of FY2011

累計施設数（箇10,000 所）
12,000

Annual
年別設置数
Cumulative
累計

Reach40 years of age 20 years later = 80%
２０年後、設置後４０年以上になる施設約８割
2008,000

Reach 40 years of age 10 years later = 60%
１０年後、設置後４０年以上になる施設約６割
150

6,000

Reach
40 years of age at Present = 40%
現在、設置後４０年以上になる施設約４割
4,000

50

2,000

00

大正以前
昭和元年
２３４５６７８
９１０
１１１２１３１４１５１６１７１８
１９２０
２１２２２３２４２５２６２７２８２９３０
３１３２３３３４３５３６３７３８３９４０
４１４２４３４４４５４６４７４８４９５０
５１５２５３５４５５５６６７６８６９６０６１６２６３
平成元年
２３４５６７８９１０１１１２１３１４１５１６１７１８１９２０２１２２２３100

1930

1940

1950

1960

1970

1980

1990

2000

2010

Counted in this table includes weirs, groundsills, lock gates, sluice gates and pipes, pump stations, drainage stations,land locks, purifier stations, dams and retarding basins.
Copy right (c) 2013 Ministry of Land, Infrastructure, Transport and Tourism, Japan, All rights reserved .

PROMOTE STRATEGIC MAINTENANCE OF RIVER MANAGEMENT FACILITY– FROM “TIME DEPENDENT” TO “AT-MONITORING” AND/OR “AT-OCCURRENCE”

River 7/8

Maintenance used to implement renewal by periodic replacement in time-dependent Program
Milestones achieved in full-scale introduction of At-monitoring and/or At-occurrence Maintenance Prepared manuals for Gates and Pumps in 2008
 Stated full development of lifetime improvement plan for major equipment structures by 2016 in Infrastructure
Development Policy 2012

Equipment critical for facility
function at breakdown but withpossible monitoring on conditions

Equipment critical for facility
function at breakdown and withdifficult monitoring on conditions

Equipment non-criticalfor facility function atbreakdown

Time Dependent Maintenance

At-Monitoring Maintenance

At-Occurrence MaintenanceTarget Electric control equipment
 Major parts of pumps

Target Major parts of gates (roller gates andcontrollers
 Motor lubrication system at pumps

Target Pump lubrication system at gates Backup generators for pumps
 Meters for pumps

Implement preventive measures to assure
optimum repair and renewal on
evaluating operating values andinspection results

Maximize cost effectiveness at non-criticaldevices by utilizing them till mail-function
to reveal

Avoid functionally critical damages byperiodic replacement and renewal

Control panelImpeller

At improvement on condition monitoring,
shift to At-Monitoring Maintenance

Gate wire rope

Gate

Motor oil leakage

Fail-safe standby

Needed budget must be maintained in parallel with cost reduction by asset management
Copy right (c) 2013 Ministry of Land, Infrastructure, Transport and Tourism, Japan, All rights reserved .

River 8/8

REDEVELOPMENT OF RIVER MANAGEMENT TECHNOLOGY
Develop technology in river management including Inspection, degradation diagnosis, condition monitoring
Hollow detection at river walls and bank crowns byelectromagnetic waves
Portable device detection

Research on river bed profiling technology by aerial laser
surveying system
Apply well-established system for land topography to 3D bathymetricsurvey by verifying applicable conditions like river water turbidity for
implementing easier and more economical periodic survey than ever

Example detection chart

Research on bank deformation detection technology bymobile mapping system

Probe embankment soundness by geophysical survey

Develop long–distance scanning device with high precision plus density
and its data processing software to detect existing and potentialdamages, deformation and settlement on embankments by highresolution cameras and laser scanners mounted vehicles

Comparison of in-situ survey and resistivity sounding
Resistivitysounding
In-situ survey

Challenges –Innovate scanners to meet theabove spec from 100 meter
distance and data processing
software to grasp 3D deformation

Example scanned andprocessed data

Copy right (c) 2013 Ministry of Land, Infrastructure, Transport and Tourism, Japan, All rights reserved .

比抵抗レンジ（Ω-M）