Using a high resolution flood model to prioritize civil protection services

A risk assessment methodology was recently developed for the Civil Protection services in Haiti to prioritize emergency planning and investments for contingency management. Using a high resolution flood hazard model that was developed on the basis of a LiDAR Digital Elevation Model, the methodology identifies people and buildings residing in flood zones for a variety of return periods. For each community, a head count of "people at risk" is conducted as a basis for planning emergency evacuations and investments in temporary shelter capacity. With respect to the latter, the methodology is used to compare "people at risk" relative to available shelter capacity to temporarily accommodate people. Assuming that each evacuated person requires 1-2 square meter of shelter space, a risk/service ratio is calculated for "people at risk" in relation to available sheltering capacity.

In many communities, it was found that a disproportionate number of people are "at risk" but do not have access to temporary shelter accommodation. These communities with a high risk/service ratio are prioritized to identify additional public spaces (such as public schools) that could be designated as shelters to improve the risk-shelter ratio in the high risk communes. A field verification programme is required to assess that the functional needs of a shelter for each location is met. A structural assessment for existing shelters and prospective shelters is required to evaluate structural integrity and resilience of the public space.

If the structural integrity is not met, the construction of new shelter or the retrofitting of existing public spaces in prioritized in a long-term capital investment plan. The capital investment plan uses the risk/service ratio to prioritize investments to rehabilitate, retrofit/upgrade, reconstruct or construct new shelters.

At the same time, the high resolution flood hazard model is used to verify that existing shelters are not affected by flooding. If they are affected, they are earmarked for deselection as official shelter and - depending on priority - substituted.