Frontier in Civil Engineering

Integrated River Basin Management

Dept. Civil Engineering, Nagoya University15 June 2012

Prof. Tetsuro TSUJIMOTO

Elementary Concepts and Definitions:Elementary Concepts and Definitions:

①Precipitation ⇔ Evapo-transpiration ←weather, climate……meteorology

②Divide→ River basin (Catchment, Watershed)←geography

③Run-off process surface runoff, subsurface runoff (intermediate), groundwater ←hydrology

④River flow ←hydraulics

⑤Flux (flow) and stockWater, sediment, materials (biophilic elements)

⑥Landscape connected one another by flux networks in river basinGeographical characteristics – Land use with human activities

related to ecosystem

⑦Ecosystem ←interrelating system

Ecosystem structure

physical background - habitat suitability - biological aspect space-peculiar elementary events production and decomposition

material cycle

Ecological function →Ecosystem service

River basin = various landscapes are connected bynatural water/material flux network

⑧River basin complex=multiple river basins connected by artificial networks

Bio aspect

life historygrowth, breedingFood webCompetition

Material Cycleassimilationfiltering(de)nitrificationdecomposition

Habitat

Energy supply

Ecosystem function

Peculiar landscapefor material cycle

Physical basementPhysical basementSediment

Flow transport

Vegetation Morphology

Ecosystem function

EcosystemEcosystemA

B C

Each Landscape has Structures and Functions as Ecosystem

Concepts of River Basin and River Basin Complex

Distributing landscapes connected by flux networks(water, sediment, materials)

Artificial flux net works connected multiple river basins → River Basin Complex

Several Viewpoints Several Viewpoints on on IntegrationIntegration in River Basin Managementin River Basin Management①Functions:

Human activities:Safety against flood (heavy rainfall) ←Flood mitigation (flood control, drainage, disaster management)

Water resources against draught←Water resources management

(demand management, supply management)Preferable environments←Basin environment management

(pollution control, amenity & recreation, ecosystem)

Sustainability :Resources depletion (fossil fuels)Global warming ←Green gas emissionBio-diversity loss

Functions↑

②Institutions (responsible organizations)laws, funds, organizations “Governance”Central and/or local government, community, NGO, individuals

Public → Private↑

③Spatial Scale:Community - region - along a river - river basin - river basin complex

④Time (Temporal Scale)Long term – short term

Safety against FloodSafety against Flood

①Local flood managementLevee (discontinuous)

“Waju tei”=embankment asurrounding village against river flood

Drainage from agricultural area ←Agricultural administrationUrban drainage

Sewage system(drainage + waste water treatment) ←Municipality

Pumping station←Local rainfall density (mm/hr) 50mm，Return period 1/10

Flood fighting team bridging hardware and software

Evacuation system ← Municipality, Community↓↑ Inter-villages along river, Inter-agency

②Flood protection along a river

②Flood protection along a riverFlood protection of the area with higher activities

in the downstream of major rivers↓ (infrastructure equipped in upstream)Continuous flood levee + Flood control dam ←River

+ Sabo projects (erosion control) management←Mountain sediment management

Planning procedures:Design rainfall (basin average accumulated rainfall during event)↓ ←Return period 50-200yrs↓ (long term plan, master plan within 20-30years)Runoff analysis↓ ←rapid runoff due to land use of catchment↓ hostile land-use should be regulated!Design flood discharge without dam control (peak cut)↓

Design flood discharge without dam control↓ Design of dam & reservoir or Detention pond (Retarding basin)

Design flood discharge after dam control↓

HWL (high water level) → Levee design ←Channel design (cross section) ←dredging

Height of levee (HWL+free board), cross section geometrychannelization

discontinuity between river and floodplain →habitat degradation

Safe flood convey without over-topping and levee breach←revetment, groyns (overflow, erosion or scouring, seepage)

Flood control to avoid inundation↓

③Disaster management←Local government, Municipality, Flood fighting team

Flood Protection for target reach (area)by Levee and Dams

Urban Area

Levee Urban Drainage(Pumping Station)

Retention Pond

Dam & ReservoirTarget Area

Hazard Level(Rainfall-Return period)5 years 20 years 100

Present Defense

Master plan for 30 years

Long-term goal

Protection (Hardware) Software (Evacuation)

Response forExtra-Hazard

Temporal stepwise flood protection

③Disaster management←Local government, Municipality, Flood fighting team

Disaster= Discharge or rainfall > infrastructurally equipped levelLevel of design, Achievement level

↑Depending on “Exposure” (population, property, productivity,...)

Propagation of disaster：Local disaster Ex. Over topping levee, Levee breach

↓Propagation of inundation (wide area) vulnerable region

Risky (masochistic) land-use should be regulated!

④Risk management, Incident ManagementRisk = occurrence probability of hazard (magnitude)

Equipment level of infrastructure Preparedness for evacuation (survival) ⇔Vulnerability

Self assist, community assist, public assistPotential for rescue, recovery, restoration, … (Resilience)

Risk management by Hazard map←Inundation map ：Design flood (rainfall) in long-term vision

Present preparedness (infrastructures) Appropriate guide for evacuation = Evacuation order by Mayor

↑ coordination of city office and river managerAppropriate information on rainfall and river discharge (stage)

↓ by weather bureau by river managerAppropriate performance for evacuation (inhabitants)

Extraordinary weather = guerilla heavy rainfall locally concentrated heavy rainfall

Not included in statistical discussion related to “return period”

Unrealized dangerous spots (dangerous tarp) ←Risky action, masochistic land-use

Insufficient resolution of weather monitoring→higher resolution ←X band MP radar

Difficulty of weather-runoff-flood forecasting →no lead-time for response

C-type Guerrilla rainfall ← >100mm/hr

Iga River (Okazaki city) Toga River (Kobe city)

“Pitfall” or “trap” which were not recognized before disaster.But, it is possible to recognize them carefully, and remove them.

Excess heavy rainfall or flood (including storm surge) for vulnerable area (super typhoon)

(area below sea level with high population)

↓catastrophe with lower frequency than designed return period↑accurate forecasting of super typhoon landing (1.5days before)↓

①pre-evacuation strategy in wide area←agreements among communities

(evacuation means, shelter and refuge, emergency response resources) ↑

United command②Emergency response ←ESF (Emergency Support Functions)

SWEAT (security, water, energy, access, telecom)↑

Coordination of various organizations in various stages

エリア８

50000

エリア１

エリア２エリア３

エリア４

エリア５

エリア６ エリア７

エリア９エリア内で収容

エリア内で収容

エリア内で収容

25400

31700

78400

160500

5700

桑名市川越町朝日町

大垣市海津市養老町輪之内町

津島市愛西市稲沢市

七宝町,美和町甚目寺町,大治町

名古屋市北,西,中,中村,熱田,中川区

名古屋市瑞穂,緑区

弥富市木曽岬町飛島村

名古屋市港区

東海市

Area 1 with inside Shelter

Area 2 Area 3 withInside shelter

Area 4

Area 5

Area 6 Area 7 Area 8

Area 9

Inundation Areacity function will be damagedthen, evacuation is necessary

Zoning of evacuation strategy・direction of evacuation・with possible inside shelter

In action program, there are “4 Phases”:One for before Typhoon landing: Phase 0;three for after disaster happens: Phases I～III

復興

施設（堤防・交通・ライフライン）応急復旧

排水、緊急輸送路確保

救命・救助医療・救護

水防活動避難活動

復興

施設（堤防・交通・ライフライン）応急復旧

排水、緊急輸送路確保

救命・救助医療・救護

水防活動避難活動

フェーズⅠ１日～３日

フェーズⅡ４日～２週間

フェーズⅢ２週間～１ヶ月

フェーズ０

自然排水 ポンプ排水発災発災発災

フェーズⅠ１日～３日

フェーズⅡ４日～２週間

フェーズⅢ２週間～１ヶ月

フェーズ０

自然排水 ポンプ排水発災発災発災

フェーズⅠ１日～３日

フェーズⅡ４日～２週間

フェーズⅢ２週間～１ヶ月

フェーズ０

自然排水 ポンプ排水発災発災発災

RestoraionProcess

Phase 0 Phase I 1-3 days

Phase II4days-2weeks

Phase III 2-4 weeks

Natural drainage Pumping drainage

Flood fightingEvacuation

Rescue, Relief,Medical support

Unwatering,Emergency acess

Emergent Recovery of InfrastructuresLevees, Roads, Lifelines,…..

TyphoonLanding

Pre-FEO(proposed) FEO (legally to be organized)

Phase 0 (=Before typhoon landing isSeparated into “Stages 0～4”

名古屋

■09:00時点■北緯29.9度,東経136.4度

■18:00時点■北緯33.4度,東経135.9度伊勢湾岸にて高潮越流

による浸水開始

■ステージ０（1日半前～1日前の18:00）情報共有本部を設立し、関係機関で情報を共有する。

■12:00時点■北緯31.0度,東経136.0度

■ステージ４（12:00-18:00）避難指示を発令する。間に合わない地区や時間によっては緊急避難を指示する。

■ステージ３（9:00-12:00）避難勧告を発令する。広域避難を行う。

■ステージ２（6:00-9:00）要援護者の避難を準備・開始・完了する。

■ステージ１（1日前18:00-当日の6:00）自主避難を呼びかける。精度の高い台風進路予測、高潮予測が発表される。

名古屋

■09:00時点■北緯29.9度,東経136.4度

■18:00時点■北緯33.4度,東経135.9度伊勢湾岸にて高潮越流

による浸水開始

■ステージ０（1日半前～1日前の18:00）情報共有本部を設立し、関係機関で情報を共有する。

■12:00時点■北緯31.0度,東経136.0度

■ステージ４（12:00-18:00）避難指示を発令する。間に合わない地区や時間によっては緊急避難を指示する。

■ステージ３（9:00-12:00）避難勧告を発令する。広域避難を行う。

■ステージ２（6:00-9:00）要援護者の避難を準備・開始・完了する。

■ステージ１（1日前18:00-当日の6:00）自主避難を呼びかける。精度の高い台風進路予測、高潮予測が発表される。

Stage 4 (-6:00～0:00)Evacuation command

Stage 1 (-24:00～-12:00)Voluntary evacuation

Stage 3 (-3:00～-6:00)Wide Range Evacuation

Stage 2 (-12:00～-9:00)Evacuation of HC

Stage 0 (-36:00～-24:00)Set Pre-JFO

18:00Inundation

12:00

09:00

Water Resources ManagementWater Resources Management←IWRM (Integrated Water Resources Management

including flood management, ecosystem management

Water resources management = Drought risk managementWater resources: (many stakeholders)

agriculture, industry, hydropower, city water,…….＋ ←”water rights”

Traditional water use, navigation, environment, etc.＝”normal discharge”↑ 10days minimum discharge is shared

by issuing “water rights” through river managerRiver flow (surface flow)

fairness=visible distribution10years return period for draught risk

New demand of water resources is authorized (users’ side)Necessary water resources development

New demand of water resources is authorized (users’ side)↓

Dam & reservoir to release water to share water among usersis planned, constructed and operated.

(by river manager)

Integrated management of river flow discharge ←”New river law” (1964)

“multi-purpose” damwith reservoir capacities for water-use and flood control

(resources) (peak cut)

From capacity of reservoir, two purposes are in “trade-off” relation.

Integrated management (operation) in multi-purpose damalso among several dams along the same river system

↓ Environmental impacts as another trade-off in functions

Multi-purpose dam (flood control, water resources)↓Environmental impacts

No environmental flow (downstream of water withdrawal facilities)Instream flow discharge regulation in downstream river

→ Degradation of habitat, scenery

Changes of water quality (turbidity, temperature, eutrophication)

↑←countermeasures in reservoir, release pattern improvement※agreements among river manager and water users

Guideline release of water based on agreement among MLIT and METI

EIA (environmental impact assessment) before constructionMitigation of environmental degradation (follow-up)

Environmental Management of Environmental Management of River and River BasinRiver and River Basin

①Preferable environmentUse of river space for citizen

(public space, privately owned space)Recreation, sports, amenity, joy with nature, nature preservation

↓②Eco-compatible management river and river basins

↓③River ecosystem conservation

→preferable river basin environment↑

Ecosystem serviceBio-diversity conservation

Ecosystem Service

Key of river ecosystem①River landscape – river ecosystem

Structure and functions②Connectivity supported by water/material flux networks

Longitudinal connectivity headwater→various segments→river mouth

Transverse connectivity river⇔various landscape units⇔floodplain

Vertical connectivity surface water⇔subsurface flow (hyphoreic zone)

③Hierarchy in scales of landscapesRiver basin⇔river⇔segment⇔reach⇔unit⇔sub-unit scale

(micro habitat)

④Disturbance for renewal and maintenance(flood and draught)

Segment A Segment B Segment CHead-Water

River-Mouth

Reach B1 Reach B2

Reach B3

Reach B2 or Unit B2-1

Subunit B21Subunit B23

Subunit B22 Subunit B23

Subunit B24

Subunit B25

Surface flowSubsurface flow

River River

River BasinRiver Basin Flood plainFlood plain

Farmland(paddy field)

Forest

Wet landUrban area

植生

本流旧二次流路二次流路ワンドたまり

分級

伏流筋

vegetation

main streamsecondary channelembaymentside pools

sorting

subsurface flow route“TextureTexture”

Ecosystem degradationdirect change

aquatic →terrestrialbrackish→fresh water

Indirect change ←discontinuity of water/material flux network

Human activities in floodplain

↑

mitigation against ecosystem degradationin river management

Close-to-nature river improvementRiver restoration (rehabilitation) on siteRiver ecosystem refreshment along a river

Advanced Integrating Management of River BasinsAdvanced Integrating Management of River Basins①River basin=unit of hydrological cycle② Hydrological cycle is closely related to functions

required in river basinflood mitigation, water resources and environment

③Hydrological cycle is most dynamic in river, and river management is most powerful to maintain the above functions.

④Even for each function, various organizations (agencies) are responsible in respective aspects. Inter-agency

⑤Each functions are in relation of trade-off Inter-function⑥Problems cannot be completely solved

only in river management but river basin management is necessary for the next step.(land-use, agricultural area, urban area management)

⑦Particularly under the situation of Aging and population decreasingLow development in economicsDangers in sustainability

(global warming, resources depletion, bio-diversity loss)⑧Coordination of hardware (infrastructures) and software⑨New governance

Inter-agencies (governmental structure) without hierarchyNGO

Forests

River

Upper Rea

ch

Water Intake Sluice

AgricultureLand

+

out

River

Middle Rea

ch

+out＝in+

Brackish waterArea

out

Brackish Lake

Reservoir

inEstu

ary

Tideland

Tideland

Bay Area Coastal Area

B

Precipitation

ＥＳ ＥＳ

ＥＳ

ＥＳ

ＥＳ

ＥＳＥＳ

Background(Tool Box 1)

Precipitation in

Precipitation

Forests

River

Upper Rea

ch

Water Intake Sluice

AgricultureLand

+

out

River

Middle Rea

ch

+out＝in+

Brackish waterArea

out

Brackish Lake

Reservoir

inEstu

ary

Tideland

Tideland

Bay Area Coastal Area

B

Precipitation

ＥＳ ＥＳ

ＥＳ

ＥＳ

ＥＳ

ＥＳＥＳ

Background(Tool Box 1)

Precipitation in

Precipitation

Ex.1) Forested AreaModeling the quantity of CO2 extractionby the treesES: CO2 extraction: water (Q), T-N,SSPM: Change of the tree class, Forest

thinning (Forest Management)

Ex.3) Tidal AreaModeling the quantity of ecological production due to the conditions of physical basementES: Food provision, Water purification: water (Q), T-NPM: Creation of tideland, Settled of Nori-net

Ex.2) Sand River -Middle Reach-

Modeling the effect of water purification by attached algaeES: water purificationwater (Q), T-NPM: Control of water discharge by dam operation change

ES: Ecosystem ServiceFlux changePM: Policy Menu

Image of Coupling various Landscapes with Flux NetworksImage of Coupling various Landscapes with Flux Networks