Increasing Urban Disaster Resilience in Tokyo

Transcription

1 Ver.17 Increasing Urban Disaster Resilience in Tokyo Tetsuro FUJISAKI Deputy Director, Disaster Prevention city planning Section Bureau of Urban Development Tokyo Metropolitan Government

2 Tokyo s Approach for Urban Resilience Step 1 Step 2 Step 3 Scientific-based Risk Assessment Community Risk Assessment Study Planning and Prioritization of Action Urban Development Plan for Disaster- Resistant Implementation 10-Year Project to Advance fire Resistance 2

3 Earthquake Risks Fire Building Collapse Overview of the Great Hanshin-Awaji Earthquake (January 17, Magnitude of 7.3) - 6,437 died or missing - Building damage: 249,180 buildings 3

4 Current status of Densely Built-up Wooden Residential Areas 4

5 Densely Built-up Wooden Residential Areas State of densely built-up wooden residential areas 5

6 Distribution of the Densely Built-up Wooden Residential Areas Approx. 16,000 ha in Tokyo (Approx. 25% of the 23-ward area) There is a high concentration of aging wooden buildings in a torus shape along the outer areas of the Yamanote Line. JR Chuo Line JR Yamanote Line Tama 23 wards 6

7 Densely Built-up Wooden Residential Areas Time for renewal Challenges: Aging residents Aging wooden housing Narrow and small sites No compliance with the Building Standards Act for the contacts zones of buildings and roads, etc. The renovation process has been delayed 7

8 Community Risk Assessment Study (7 th ) Community Earthquake Risk Assessment Study 8

9 Community Earthquake Risk Assessment Study Version 7: Released on September 2013 Purpose of the study To learn about areas at high risk of earthquakes. Select priority implementation areas. Provide better understanding of earthquake disasters and raise awareness of disaster prevention for Tokyo residents. Relationship diagram of the measurement studies Building collapse risk Fire risk Comprehensive risks Low Risk High Risk 9

10 How to calculate Building Collapse Risk? Ground classification collapse risk Comprehensive risks Building classification Fire risk 1) Classification of ground types 2) Amplification factors by ground type No. Construction type Category 1 By to Wooden 1981 to to From st to 3rd floor 7 By th to 7th floor 8 From 8th floor 9 1st to 3rd floor Reinforced-Concrete to th to 7th floor structure 11 From 8th floor 12 1st to 3rd floor 13 From th to 7th floor 14 From 8th floor 15 1st to 3rd floor 16 By th to 7th floor 17 From 8th floor 18 1st to 3rd floor 19 Steel structure 1971 to th to 7th floor 20 From 8th floor 21 1st to 3rd floor 22 From th to 7th floor 23 From 8th floor 24 Lightweight steel By structure From Others Stone construction, concrete block construction, mortar walled construction 1) Building distribution per structure type and year of construction 10

11 Building collapse risk Results: Building Collapse Risk Assessment Comprehensive risks Fire risk 5 (1st to 84th place) 4 (85th to 368th) 3 (369th to 1,181st) 2 (1,182nd to 2,815th) 1 (2,816th to 5,133rd) Tama 23 wards 11

12 How to calculate Fire Risk? Building collapse risk Comprehensive risks Fire risk Fire Outbreak Risk Expected number of fires during winter and the evening - most flammable period Fire Spread Risk (Fire spread simulation) Expected number of buildings totally burned down in 6 hours Fire Risk 12

13 Result: Fire Risk Assessment Building collapse risk Comprehensive risks Fire risk 5 (1st to 84th place) 4 (85th to 368th) 3 (369th to 1,181st) 2 (1,182nd to 2,815th) 1 (2,816th to 5,133rd) Tama 23 wards 13

14 Results: Comprehensive Risk Building collapse risk Comprehensive risks Fire risk 5 (1st to 84th place) 4 (85th to 368th) 3 (369th to 1,181st) 2 (1,182nd to 2,815th) 1 (2,816th to 5,133rd) Tama 23 wards Yamanote Line 14

15 Implementation of Countermeasures Disaster-Resilient Urban Development 10-Year Transformation Project: from High Risk Wooden Area to Fireproof Districts 15

16 Promotion Plan for Disaster-Resilient Urban Development The Basic Plan for Urban Disaster Prevention Facilities Disasterresistant living area Firebreak Belts City planning roads Fireproof buildings along roads Park Fireproofing & Open Space Residential roads Enough open spaces for evacuation Fireproof and quake-resistant buildings 16

17 Promotion Plan for Disaster-Resistant Urban Development Firebreak belt concept Urban areas within disasterresistant living areas Fire-resistant building, etc. Introduce fireproofing in buildings. Ensure open spaces. Develop roads. Urban planning road Disaster-resistant living area Firebreak belt Ensure safety in surrounding disaster-resistant living areas. Disaster-resistant living area Ensure safety for disaster-resistant living areas. Prevent large-scale fires in urban areas during disasters. 17

18 10-Year Project to Fireproof Districts Densely Built-up Wooden Residential Areas Approx. 16,000 ha Development area Fireproof Zones Approx. 3,020 ha Area size: approx. 7,000 ha (Approx. 11% of the ward area size) Population: approx. 1.8 million (Approx. 20% of the ward area size) Development area criteria Community risk degree (building collapse or fire): 5 Aging wooden building rate: 45% or more Fireproof zone rate: Below 60% 18

19 1 9 Tokyo s Approach for Urban Resilience Step 1 Step 2 Step 3 Scientific-based Risk Assessment Community Risk Assessment Study Planning and Prioritization of Action Urban Development Plan for Disaster- Resistant Implementation 10-Year Project to Advance fire Resistance

20 Fin. 20