**2. Proposal of evidence-based flood contingency planning**

The "ISO22301 Societal security—Business continuity management systems" specifies requirements for all types of organisations to plan, implement, review and improve a documented management system to prepare for, respond to and recover from disruptive incidents [2]. It requires the organisations to select business continuity strategy based on the outputs from the risk assessment and business impact analysis. The risk assessment aims to identify and evaluate the risk of disruptive incidents to the organisations, while the business impact analysis assesses the impacts of disrupting activities that support organisation's services. To conduct evidence-based flood contingency planning in reference to the procedures employed in the ISO22301, six steps are proposed, as shown in **Figure 1**.

The first step of this planning is to understand the current conditions of the target communities such as topography, land use, population and structures, as well as

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**Figure 2.**

*Evidence-Based Contingency Planning to Enhance Local Resilience to Flood Disasters*

should be updated constantly through the Plan-Do-Check-Act cycle.

past flood records in the area. At the second step, flood hazards and risks are identified through flood and inundation simulations conducted by national or provincial governments. Flood scenarios are presented with two key components, i.e. a flood inundation map and a time-series inundation water chart, to illustrate dynamic changes in inundation depth for residents to easily understand how the inundation may expand, linger and recede in their communities. The third step is flood impact analysis, in which the numbers of residents and houses at risk are estimated based on the average ground-floor height of houses, and possible problems the community may face due to the flood are identified. At the fourth step, the communities in the target area should develop a response strategy. Necessary actions should be discussed according to the time sequence of "before the flood", "during the flood" and "after the flood". The fifth and sixth steps are documentation and sharing of the plan among the community members. It is also important that the produced plan

Among the Asian flood-prone areas, a municipality called Calumpit was selected as the first case study area. It is in Bulacan Province in Pampanga River basin located northwest of Metro Manila in Central Luzon Island, Philippines. The municipality lies at the junction of several rivers, including Pampanga, Angat and Labangan, as illustrated in **Figures 2** and **3**. This topography makes Calumpit one of the most flood-prone municipalities in the Philippines. As of 2010, 101,068 people live in an area of 5625 ha, or 2.03%, of the province. The municipality has 29 barangays, the smallest administrative units. The recent largest flood was caused by Typhoons

*Location of Calumpit in Pampanga River basin. (a) Luzon Island and (b) Pampanga River basin).*

*DOI: http://dx.doi.org/10.5772/intechopen.82312*

**3. Case study area**

**Figure 1.**

*Six steps of evidence-based flood contingency planning.*

*Evidence-Based Contingency Planning to Enhance Local Resilience to Flood Disasters DOI: http://dx.doi.org/10.5772/intechopen.82312*

past flood records in the area. At the second step, flood hazards and risks are identified through flood and inundation simulations conducted by national or provincial governments. Flood scenarios are presented with two key components, i.e. a flood inundation map and a time-series inundation water chart, to illustrate dynamic changes in inundation depth for residents to easily understand how the inundation may expand, linger and recede in their communities. The third step is flood impact analysis, in which the numbers of residents and houses at risk are estimated based on the average ground-floor height of houses, and possible problems the community may face due to the flood are identified. At the fourth step, the communities in the target area should develop a response strategy. Necessary actions should be discussed according to the time sequence of "before the flood", "during the flood" and "after the flood". The fifth and sixth steps are documentation and sharing of the plan among the community members. It is also important that the produced plan should be updated constantly through the Plan-Do-Check-Act cycle.
