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CLIMATE-SMART PLANNING AND MANAGEMENT TRAINING PROGRAM MODULES
Hazard characterization The most important aspect of the hazard characterization step is the collection of basic information on the hazard – specifically, hazard maps. Theoretically, the hazard map11 should provide the spatial extent or distribution of the hazard event of a specific/certain probability of occurrence. The hazard map is used to determine the specific parts or areas that will be affected by the hazard. Methodology Depending on the capability of the planner and/or the planning team, available hazard maps may be refined and/or validated using the following methodology: • • •
Morphostructural interpretation of available satellite imagery, aerial photographs, 1:50,000 scale NAMRIA topographic maps Site visit and field validation Review of historical data
Sourcing Information Maps sourced from mandated government agencies As mentioned earlier, available hazard information from mandated agencies may be limited to certain hazard types only. DOST Philippine Institute of Volcanology and Seismology (PHIVOLCS) • Volcanic hazards • Earthquake-induced landslide • Other earthquake-related hazards
Elements of a good base map In addition to the hazard maps, a base map also serves as the foundation to the entire DRA process. A good base map is complete, accurate and current as possible. In addition, it must have sufficient planimetric characteristics to allow measurement of accurate horizontal distances. Finally, the base map must also include the appropriate administrative boundaries that will adequately cover the entire study areas. The topographic map as produced by NAMRIA shall serve as the preferred base map for the entire DRA process. At the end of this step, the list of natural hazards that may affect the area shall have been refined. In addition to obtaining the base map, the list should be refined in terms of the hazards that will be included in the DRA. Such refinement is essentially governed by data limitation – note that DRA may only be undertaken for hazards with the corresponding hazard map/s. In refining the list of hazards, the following should be considered: • Availability of hazard maps – the type of hazard maps available and the scheme of determining susceptibility or spatial extent of the hazard events • In case of non-availability of hazard maps (especially for hazards with potentially significant effects on the area), assistance from the relevant government agencies should be solicited for the preparation of an indicative hazard map/s that will be used for the assessment.
DOST Philippine Atmospheric Geophysical & Astronomical Services Administration (PAGASA) • Storm surge (or hydro-meteorological hazards) • Flood maps, Scale 1:10,000 DENR-Mines and Geosciences Bureau (MGB) • Flood maps, Scale 1:50,000 • Rainfall-induced landslide For technical guidance and assistance, consult the nearest offices of these agencies in your area, or visit the following websites: www.phivolcs.dost.gov.ph www.pagasa.dost.gov.ph www.mgb.gov.ph www.phivolcs.dost.gov.ph
11 Hazard map is defined as the map with predicted or documented extent of a hazard, with an indication of probability of occurrence, adapted from Ben Gouldby and Paul Samuels, Integrated Flood Risk Analysis and Management Methodologies: Language of Risk (FLOODsite Consortium)