Applying Hazard Maps to Urban Planning
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Applying Hazard Maps to Urban Planning September 10th, 2014 SAKAI Yuko Disaster Management Expert JICA Study Team for the Metro Cebu Roadmap Study on the Sustainable Urban Development 1 Contents 1. Outline of Metro Cebu Roadmap Study 2. Development of GIS Database 3. Methodology of Development Suitability Analysis 4. Preparation of Thematic Maps 5. Overlay Analysis 6. Necessary Actions 2 1.1 Roadmap Toward The Vision Vision Roadmap 1. Metropolitan Development Framework 2. Roadmap Development Plans 3. Short-term Priority Projects 3 1.2 Objectives of the Study 1. To draw up a roadmap and detailed action plans based on “Mega Cebu Vision 2050” with time- framework of: Short-term (2016), Med-term (2020), and Long term (up to 2030 up to 2050) 2. To formulate priority projects in association with institutional and organizational options for the materialization 4 1.3 Study Area The study area covers Metro Cebu consisting of 13 LGUs : • 7 cities (Cebu, Danao, Mandaue, Lapu-Lapu, Talisay, Naga and Carcar) and • 6 municipalities (Compostela, Metro Cebu Liloan, Consolacion, Cordova, Minglanilla and San Fernando). 72 km Danao, San Fernando and Carcar are new comers to the old Metro Cebu boundary 5 1.4 DEMOGRAPHIC FRAME Land Area Population Growth Population Rate (%/year) LGUs 2 (km ) 2000 2007 2010 ’00-‘07 ’07-‘10 Cebu 315 718,821 798,809 866,171 1.5 2.7 Lapu-Lapu 58 217,019 292,530 350,467 4.4 6.2 Mandaue 25 259,728 318,575 331,320 3.0 1.3 Talisay 40 148,110 179,359 200,772 2.8 3.8 Cities Danao 107 98,781 109,354 119,252 1.5 2.9 Carcar 117 89,199 100,632 107,323 1.7 2.2 Naga 102 80,189 96,163 101,571 2.5 2.2 Compostela 54 31,446 39,167 42,574 3.2 2.8 Consolacion 147 62,296 87,544 106,649 5.0 6.8 Cordova 17 34,032 45,066 50,353 4.1 3.8 Liloan 46 64,970 92,181 100,500 5.1 2.9 Minglanilla 66 77,268 101,585 113,178 4.0 3.7 Municipalities San Fernando 69 48,235 54,932 60,970 1.9 3.5 Metro Cebu 1,163 1,930,096 2,314,897 2,551,100 2.6 3.3 Philippines 343,448 76,506,928 88,566,732 92,337,852 2.1 1.4 Source: PS 6 2. TECHNICAL1.5 Roadmap APPROACHES Development Plans 4 Strategies 7 Sub-roadmaps 1 Metropolitan Competitiveness Enhancement Competitiveness 2 Urban Structure and Land Use 3 Urban Transport and Mobility Highway Network An Overall Roadmap integrating 4 Water Supply and Disposal 7 sub-roadmaps Management Livability 5 Solid Waste Management Metropolitan 6 Smart SRP Development Management 7 Metropolitan Administration 7 1.6 Work Plan of Phase 1 Schedule Work Items Participatory Activity I-1. Preparatory Works 11 I-2. Analysis of Existing Conditions and Issues 12 st I-3. I-4. I-5. 1 Seminar 2014/1 Conceptual Preparation Conduct of Roadmap of Short- Home Phase 1 Phase towards term Priority Interview 2030 and Projects Survey 2 2050 3 I-6. Finalization of Phase I Activities 1st Workshop 1.7 Work Plan of Phase 2 Schedule Work Items Training 4 II-1. Development Frameworks for Sub-roadmap Planning Works 5 II-2. II-3 II-4 II-5. II-6 1st Training in Japan Metropolitan Urban Urban Water Supply Solid Waste 6 Competitivenes Spatial Transport and Disposal Management s Planning Network Management 7 II-7. Intermediate Wrap-up of Roadmap Works nd 8 2 Workshop II-8. Sub-roadmap for Smart SRP II-9. Sub-roadmap for Metropolitan Development Administration 9 Phase 2 Phase 10 II-10. Overall Evaluation of Mega Cebu Roadmap 2nd Training in 11 Japan II-11. Finalization of Phase II Activities 12 Comments from the Philippine 2nd Seminar 2015/1 Side 2/3 II-12. Study Finalization 2. Development of GIS Database • Purchase of satellite image with resolution of 0.6m • Preparation of Topographic Map in 1:10,000 based on the satellite image and LIDAR with the following specification Items Specification Attribute 1 Roads Center line, road edge line Name, Width (m) 2 Water River bank line, canal line, coastal line - 3 Contour 1m interval line in coastal area and 5m Height (m) interval line in the rest areas 4 Vegetation Polygon Type (agriculture, forest, shrub and pasture, vacant land, mangrove, wetland, sand, urbanized area, and others) 5 Building Footprint in polygon, smaller buildings in Name of public facility building point 6 Public Location and area of school, hospital, Name Facilities government office, fire station, police, church and park 10 3. Methodology of Development Suitability Analysis Topographic Maps and Data from Relevant Agencies 1st Processing: Thematic Maps Slope Mountain Area Sea Level Rise Flood Landslide Earthquake 2nd Processing: Overlay and Grid Analysis Land Use Constraints Natural Disaster Hazards 3rd Processing: Grid Analysis Development Suitable Area 11 • Thematic maps: Those are prepared using topographic map in 1:10,000 and data from relevant agencies. • Overlay analysis: That is implemented to clarify the critical areas for development caused by constraints and natural disaster hazards. • Grid analysis: That is implemented to accumulate the assessment scores of constraints and natural disaster hazards. • Development suitable area shall be provided for future urban development. Those areas should be defined in urban planning map accurately. 12 4. Preparation of Thematic Maps and Hazard Maps 1) Existing Land Use 2) Slope and Mountain Areas 3) Sea-level Rise Hazard - 1m, 3m: Caused by Expected Climate Change by NAMRIA 4) Flood Hazard 5) Landslide Hazard 6) Earthquake Hazard 13 1) Existing Land Use • 15% of Metro Cebu’s land has been urbanized. 14 2) Slope and Mountain Areas • Construction in steep slope area more than 18% is restricted. These areas and mountain areas are covering 72% of the Study Area. 15 3) Sea-level Rise • 1m, 3m: Caused by expected climate change scenario, covering 0.04%, 0.3% of the Study Area 16 4) Geo-Hazard • MGB provided the Geo- hazard map in 1:50,000 only because they are still compiling the results of field survey of 1:10,000 map. • Therefore, JICA Study Team conducted hazard mapping using our GIS database and assessed flood and landslide hazards in 3 levels. 17 5) Flood Hazard • Flood hazard level was assessed based on river flow simulation targeting 14 rivers of which river basin spreads more than 10km2 and covered the expected flood scale over once a 50 years return period. Hazard Level Definition Low (blue) Flood is expected to be occurred (Alluvial Plain) Moderate (yellow) Sheet flood and drainage-caused flood High (red) Flash flood and road embankment-caused flood (possible to 18 take a long flood duration) 5) Landslide Hazard • Landslide hazard area was assessed based on interpretation of remotely sensed data from satellite image, digital terrain model (DTM) and contours. This work followed the MGB criteria for landslide susceptibility. Hazard Level Typical Areas Low Slope gradients are below 18 degrees Moderate Slope gradients are 18-35 degrees High and Very Steep to very steep slopes (>35 degrees) and evident active High landslides, where inactive landslides are evident (old landslide debris deposits, collapsed sinkholes, old landslide complexes), 19 actively worked mining areas, high erosion along the riverbanks 6) Earthquake Hazard • Original maps comes from responsible agencies and digitized by JICA Study Team. • Earthquake hazard will be assessed using grid analysis methodology which gives scores for each grid according to hazard level and accumulate the 20 scores in same cell and reclassified. The grid size will be 250m x 250m. 5. Overlay Analysis 1) Existing Land Use and Hazard Map • Urbanized area which is overlaid by hazard area amount to 1.9% of the Study Area. 21 2) Public Facilities and Hazard Map • Location of public facilities can be assessed using hazard map by overlaying several layers. • Those facilities located in hazardous areas should be prioritized for disaster resistant construction. 22 6. Necessary Actions • Development Control System should be achieved by laws and enforcement system. • Disaster Management Master Plan should be prepared based on risk assessment using detailed and accurate maps. It should include identification of shelters and emergency transport road network. • Securement of Public Facilities should be implemented based on development of strategy for site and structural safety of public facilities, including existing facilities. • Integrated Data Sharing System should be developed to share outputs of hazard maps and GIS analysis within government agencies and relevant organizations. It should be updated and maintenance periodically. Further assessment will be implemented in the following phase, applying population density and infrastructure & social service level 23 indicators. At last, a future land use plan will be proposed. Thank you… 24 .