Considering Hydraulic Hazard Potentials To Determine Critical Emergency Routes In The Comprehensive Land Use Plan

Road networks play an important role in transport operations but are vulnerable to the effects of typhoons which can bring about immense damage and adversely affect travel.Planning principles prioritize safety standards over accessibility standards when it comes to location of infrastructure.Accessibility needs to be maintained in a country that is situated in a very active typhoon belt like the Philippines to ensure uninterrupted delivery of services during disaster response operations.Identifying vulnerable road networks is an initial step in implementing proper risk mitigation measures that are based on the understanding on how the network absorbs disturbances.Previous studies have measured vulnerability of road networks using distance-based or cost-based indices which can be applied to sparse and dense road networks,respectively.The study provides a simple distance-based approach to determine vulnerable road networks in Zarraga,Philippines using the result of FLO-2D flood simulations as polygon barriers in Arc GIS Road Network Analyst.The study identified critical road networks leading to the designated and/or closest evacuation centers on the premise that consequences on accessibility are severe if critical road segments are flooded during rain events.Based on the methodology,10 out of the 24 barangays in the municipality were found to have been designated to the closest evacuation centers and have the optimum predetermined emergency routes specified in the disaster response plan.The result of the study can be used as basis for the(1)recommendation of alternat ive locations for exposed critical facilities,(2)identification of detours and alternative routes to and from the critical facilities according to existing road network availability,and(3)determination of road segments that need to be prioritized in terms of climate proofing to help improve and optimize accessibility.