Earthquake Preparedness and Countermeasures in Osaka Municipal Waterworks Bureau Osaka Municipal Waterworks Bureau Kazuya YAMANO 1 大阪市水道局 Osaka Municipal Waterworks Purification plants: 3 plants Distribution pipes: 5,000 km Water supply capacity: 2,430,000 m3/day Area: 211km2 Population:2.6 million Kobe City OSAKA City Japan OSAKA Municipal Waterworks Bureau 2 大阪市水道局 Outline of Earthquake Preparedness Efforts Kobe Earthquake (1995) Earthquake Preparedness Improvement Plan 21(1996) Review of scenario earthquakes (2004~) Investigation of Tsunami seismic motion Estimation Estimation Damage of Influence on distribution pipes purification plants Improving earthquake preparedness OSAKA Municipal Waterworks Bureau 3 大阪市水道局 Outline of Earthquake Preparedness Efforts Kobe Earthquake (1995) Earthquake Preparedness Improvement Plan 21(1996) Review of scenario earthquakes (2004~) Investigation of Tsunami seismic motion Estimation Estimation Damage of Influence on distribution pipes purification plants Improving earthquake preparedness OSAKA Municipal Waterworks Bureau 4 Osaka Municipal Waterworks Earthquake Preparedness Improvement Plan 21 大阪市水道局 8 Basic Elements (1) Improving Earthquake Resistance of Key Facilities (2) Establishing a Water Supply and Distribution Center Network (3) Improving Compatibility among Different Distribution Systems (4) Countermeasures against Power Failure (5) Expanding Emergency Material Stock System (6) Establishing Stable Water Supply Routes to Man-made Islands (7) Improving Reliability of Information and Communication System (8) Improving Earthquake Resistance of Headquarters Necessary for Disaster Relief and Recovery Activities OSAKA Municipal Waterworks Bureau 5 Earthquake Preparedness (1) 大阪市水道局 Improving earthquake resistance of distribution pipe network Length of cast iron pipes 1,278 km (1997) 870 km (2005) OSAKA Municipal Waterworks Bureau Ductile Iron Pipe 6 大阪市水道局 Earthquake Preparedness (2) Increasing capacity of drinking water reservoirs Capacity of distribution reservoir Nagai KUNIJIMA : 42,000 ㎥ Sakishima : 30,000 ㎥ JOTO Total : 72,000 ㎥ UP OYODO OTEMAE Sakishima Distribution Plant MINATO Osaka City TATSUMI SUMIYOSHI SAKISHIMA SUMINOE OSAKA Municipal Waterworks Bureau Nagai Distribution Plant NAGAI Distribution Plant (existing) Distribution Plant (newly-built) 7 大阪市水道局 Earthquake Preparedness (3) Sufficiency of emergency materials Water Supply Truck Temporary Water Tank(4m3) OSAKA Municipal Waterworks Bureau Polyethylene Bag (3L, 10L) Pipe Stock 8 Earthquake Preparedness (4) 大阪市水道局 Realization of effective emergency activity Headquarter s Disaster Information Management System OSAKA Municipal Waterworks Bureau Disaster Site 9 大阪市水道局 Outline of Earthquake Preparedness Efforts Kobe Earthquake (1995) Earthquake Preparedness Improvement Plan 21(1996) Review of scenario earthquakes (2004~) Investigation of Tsunami seismic motion Estimation Estimation Damage of Influence on distribution pipes purification plants Improving earthquake preparedness OSAKA Municipal Waterworks Bureau 10 Scenario Earthquakes 大阪市水道局 (c) (a) (b) (d) Tsunami (e) OSAKA Municipal Waterworks Bureau (a) Uemachi fault (b) Ikoma fault (c) Arima-Takatsuki-kozosen fault (d) Chuo-kozosen fault (e) Nankai trough (TonankaiNankai Earthquake) 11 大阪市水道局 Outline of Earthquake Preparedness Efforts Kobe Earthquake (1995) Earthquake Preparedness Improvement Plan 21(1996) Review of scenario earthquakes (2004~) Investigation of Tsunami seismic motion Estimation Estimation Damage of Influence on distribution pipes purification plants Improving earthquake preparedness OSAKA Municipal Waterworks Bureau 12 Tonankai & Nankai Earthquake (1) 大阪市水道局 Earthquake Occurrence Probability (within next 30 years) - Tonankai Earthquake : about 60% - Nankai Earthquake : about 50% Kobe Nankai Japan Osaka Tonankai Scenario Earthquake Committee on Tonankai & Nankai Tsunami OSAKA Municipal Waterworks Bureau 13 Tonankai & Nankai Earthquake (2) 大阪市水道局 Earthquake Occurrence Probability Scenario Earthquake - Simultaneous Occurrence of Tonankai & Nankai Earthquakes - JMA Magnitude : 8.4 Kobe Nankai Japan Osaka Tonankai Committee on Tonankai & Nankai Tsunami OSAKA Municipal Waterworks Bureau 14 Tonankai & Nankai Earthquake (3) 大阪市水道局 Earthquake Occurrence Probability Scenario Earthquake Committee on Tonankai & Nankai Tsunami Chairperson: Prof. Kawata ( Kyoto Univ. ) Members: Osaka City, Osaka Pref., Wakayama Pref. Making map of inundation by Tsunami Possibility of tsunami going over Yodo River Large Weir revealed OSAKA Municipal Waterworks Bureau Osaka City Inundation map 15 Preparedness against tsunami caused by Tonankai & Nankai Earthquake 大阪市水道局 Committee on the Influence on Water Treatment by Tsunami in Yodo River Examination of Intake of Kunijima purification plant along Yodo River : (2) Turbidity (1) Chloride ion Upper Flow Yodo River Intake of Kunijima P.P Kunijima P.P 1,180,000m3/day OSAKA Municipal Waterworks Bureau Overflow Yodo River Large Weir Lower Flow (Osaka Bay) 16 Tsunami simulation 大阪市水道局 Tsunami simulation Model of seismic source Yodo River Kobe Osaka Japan Nankai Tonankai JMA Magnitude : 8.4 Osaka Bay Yodo River Large Weir (River flow : 196m3/s) Tsunami arrives at the Yodo River estuary within 2 hours and the Yodo River Large Weir within 2.5 hours after the earthquake. OSAKA Municipal Waterworks Bureau 17 Chloride Ion Concentration Tsunami simulation 大阪市水道局 Chloride ion concentration Yodo River Kobe Osaka Intake point Adjustment gate Upper Flow Lower Flow tsunami ( m ) (Osaka Bay) Maximum height ofYodo River Large Main gate Weir Adjustment gate Kema Lock Gate Kema Water Gate Yodo River Large Weir (River flow : 196m3/s) Okawa River OSAKA Municipal Waterworks Bureau 18 Conclusion Chloride ion(mg/L) 100000 10000 1020mg/L 1000 Chloride ion 100 10 0 100 200 300 400 500 600 700 800 900 Flow (m 3/s) Time of concentration being over standards (h) 大阪市水道局 4 3 2 0.90h 1 0 0 100 200 300 400 500 600 700 800 900 Flow(m3/s) At Intake point, maximum concentration of Chloride ion is about 1,000 mg/L and maximum duration of concentration level exceeding water quality standards is about 1 hour. Necessity of preparedness against tsunami OSAKA Municipal Waterworks Bureau 19 大阪市水道局 Outline of Earthquake Preparedness Efforts Kobe Earthquake (1995) Earthquake Preparedness Improvement Plan 21(1996) Review of scenario earthquakes (2004~) Investigation of Tsunami seismic motion Estimation Estimation Damage of Influence on distribution pipes purification plants Improving earthquake preparedness OSAKA Municipal Waterworks Bureau 20 Investigation Flow Chart STEP1 大阪市水道局 Collection and organization of data relevant to seismic damage of distribution pipes STEP2 Making damage ratio equations STEP3 Damage estimation of distribution pipes based on scenario earthquakes OSAKA Municipal Waterworks Bureau 21 Points of the Review 大阪市水道局 Upgraded seismic damage data obtained from recent research on earthquake engineering New estimation of the seismic damages of distribution pipes in liquefied area OSAKA Municipal Waterworks Bureau 22 Data Utilized (1) 大阪市水道局 ◆ Previous research ◆ = 29 areas OSAKA Municipal Waterworks Bureau 【2km×2km data near seismometers (JWWA1996,1998)】 23 大阪市水道局 Data Utilized (2) ◆Present research◆ Seismic Motion of Kobe Earthquake Reproduced = about 4,800 meshes OSAKA Municipal Waterworks Bureau Damage Ratio of Distribution Pipes during Kobe Earthquake 【250m×250m data(JWWA1996)】 24 Damage Ratio Equation 大阪市水道局 D0 = a x (PGV - b) D0 : Average Ratio of Damage (points/km) PGV : Peak Ground Velocity (cm/s) a, b : Coefficient Constant D = D0 x C 1 x C 2 D C1 C2 : Rate of Damage (points/km) : Diameter Correction Factor : Ground Correction Factor OSAKA Municipal Waterworks Bureau 25 大阪市水道局 Classification of Liquefaction (1) Liquefaction Assessment PL-value calculated by Osaka Municipal Waterworks Bureau 液状化状況 250m メッシュ ■ 非液状化 ■ 半液状化 ■ 液状化 Liquefaction Level as Classified by JWWA OSAKA Municipal Waterworks Bureau Non-Liquefaction Half-Liquefaction Liquefaction 26 大阪市水道局 Classification of Liquefaction (2) ◆Liquefied Ground◆ PL value Relation between PL value and liquefied area OSAKA Municipal Waterworks Bureau Liquefaction frequency (%) Liquefaction frequency (%) 1 log x 2 exp ,x0 f ( x) 2 x 2 2 0 ,x0 - : cumulo-probability density function z ( z ) f ( z )dz 0 PL value Relation between PL value and liquefied area 27 大阪市水道局 Damage Ratio Equation (Non-Liquefied Ground) <Ductile Iron Pipe> <Cast Iron Pipe> 4 □ 2km mesh area data ● 250m×250m data 2 Damage ratio (points/km) Damage ratio (points/km) 【Kobe earthquake】 【function】 ━ Osaka(2006) ━ Osaka(1997) ━ JWWA(1998) 1 3 2 1 0 0 50 100 150 200 PGV (cm/s) D0=0.0065 x (PGV-15) OSAKA Municipal Waterworks Bureau 0 0 50 100 150 200 PGV (cm/s) D0=0.0153 x (PGV-15) 28 Damage Ratio (Liquefied Ground) <Ductile Iron Pipe> <Cast Iron Pipe> 10 【Kobe earthquake】 □ 2km mesh area data ● 250m×250m data 8 Damage ratio (points/km) Damage ratio (points/km) 10 【function】 ━ Osaka(2006) ━ JWWA(1998) 6 4 2.56 2 0 0 大阪市水道局 8 6 4 4 2 50 100 150 200 PGV (cm/s) [Reference] Average Damage Ratio=2.56 OSAKA Municipal Waterworks Bureau 0 0 50 100 150 200 PGV (cm/s) [Reference] Average Damage Ratio=4.00 29 Investigation Flow Chart STEP1 STEP2 STEP3 大阪市水道局 Collection and organization of the data relevant to seismic damage of distribution pipes Making damage ratio equations Examining upper value of damage ratio Examining value of damage ratio in liquefied ground Damage estimation of distribution pipes based on scenario earthquakes OSAKA Municipal Waterworks Bureau 30 Advanced Investigation Plan 大阪市水道局 1 Damage Estimation of Distribution Pipes 2 Simulation of Areas Affected by Water Suspension 3 Estimation of Seismic Damage to the Water Supply System 4 Examination of Effective Earthquake Countermeasures OSAKA Municipal Waterworks Bureau 31 Thank you for your attention! 大阪市水道局 OSAKA Municipal Waterworks Bureau 32 Vertical Two-Dimensional Box Model 大阪市水道局 Depth Direction Flow Direction Cell: Move of water and suspended solid is ignored OSAKA Municipal Waterworks Bureau 33 Tsunami Simulation OSAKA Municipal Waterworks Bureau 大阪市水道局 34 Equations and Conditions (Tsunami Simulation) Items of setting Equations Conditions 大阪市水道局 Setting value Basic Equation Nonlinear Long Wave Equation Difference Scheme Staggered Grid and Leap-Flog Method Overflow Equation Honma Equation Fault Model Shown in Slide No.4 Grid Scale 1350m→450m→150m→50m→25m→12.5m Initial Tidal Height H.W.L.(O.P.+2.10m) ※T.P.±0.0m=O.P.±0.0m+1.30m River Flow 62m3/s, 196m3/s, 300m3/s, 500m3/s, 820m3/s, 3000m3/s Gate Height Decide the Gate Height every River Flow Time Step Δt=0.3s Reproduce Time 6hours, 12hours Offshore Boundary Condition Permeable Condition Onshore Boundary Condition Reflect Condition Eddy Viscosity Coefficient AH=0.0 Roughness Coefficient n=0.025 OSAKA Municipal Waterworks Bureau 35 大阪市水道局 Equations and Conditions (Calculation of the chloride ion concentration) Calculation Model Vertical 2-D Box Model Flow Direction Dx = 200m Depth Direction Dz = 1m Grid Scale Time Step Velocity Distribution Overflow Equation Dt = 1s Tsunami Run-up Uniform Velocity Profile Other Logarithmic Velocity Profile Honma's Equation Applying the pick-up rate of mud and clay Pick-up Mass of Bed Material Multiplying the mass fraction of clay component material in bed to pick-up mass Bed material only pick-up from the river estuary to 11 km upper point Manning's roughness 0.025 Fall Velocity Tsuruya's Equation OSAKA Municipal Waterworks Bureau 36 Seismic Motion & Damage of pipes 大阪市水道局 Seismic Motion of Kobe Earthquake Reproduced Strongest Shaking Area Damage Ratio of Distribution Pipes during Kobe Earthquake OSAKA Municipal Waterworks Bureau 37 大阪市水道局 PL Value PL =∫0 F x w(z) dz w(z) =10 – 0.5 x z F= 1 – FL (FL<1.0) 0 ( FL>=1.0) OSAKA Municipal Waterworks Bureau z : Depth from surface 20 38 Disaster Information Management System 大阪市水道局 Integrated Management Seismic damage simulation function Disaster Emergency Activities Information Management Functions Pipeline restoration Emergency water supply Facility restoration Support for information to citizens and Osaka City Disaster Countermeasures Headquarters OSAKA Municipal Waterworks Bureau 39