Flood Risk Assessment in Asian Flood Prone Area with Limited Local Data – Case Study in Pampanga River Basin, Philippines –
Miho Ohara†, Naoko Nagumo, Badri Bhakta Shrestha, and Hisaya Sawano
International Centre for Water Hazard and Risk Management, Public Research Works Institute
1-6 Minamihara, Tsukuba, Ibaraki 305-8516, Japan
Disaster risk assessment is vital to determining needs for disaster countermeasures and promoting their implementation. However, it is difficult to conduct evidence-based risk assessment in flood-prone areas of Asia due to area-specific characteristics such as limited local data on natural and societal conditions and local lifestyles of persons who have adapted to frequent floods. This paper proposes basic flood risk assessment considering these characteristics and explores a case study conducted in a flood-prone area of the Pampanga River basin in the Republic of the Philippines to verify our method. We surveyed local household members as part of the study to understand local situations, finding that past flood damage cost little thanks to building structures adapted to frequent flooding and to local ways of protecting property during floods. We also found that the use of depth-damage curves developed for urban areas may overestimate anticipated damage expected in future floods when these curves are applied to flood-prone rural areas. For this reason, we propose a method of flood risk assessment for evaluating the societal impact on residents’ lives using observed thresholds of inundation depth by flood simulation, rather than using a method that estimates damage cost. Application of our proposal to the case study area confirmed its applicability and effectiveness in evidence-based planning for reducing flood risk.
-  UN World Conference on Disaster Risk Reduction, Sendai Framework for Disaster Risk Reduction, Mar. 18, 2015.
-  FEMA:Hazus-MH 2.2, https://www.fema.gov/hazus [accessed August 15, 2016]
-  CAPRA (Central American Probabilistic Risk Assessment), http://www.ecapra.org/ [accessed August 15, 2016]
-  RiskScape, https://riskscape.niwa.co.nz/ [accessed August 15, 2016]
-  MLIT, A manual for an economic evaluation of a flood control investiment, 2005 (in Japanese).
-  MLIT, A guideline for flood damage indicators, 2011 (in Japanese).
-  Australian Government, Project Document: Enhancing Greater Metro Manila’s Institutional Capacities for Effective Disaster/Climate Risk Management towards Sustainable Development (GMMA READY Project).
-  R. Badilla et al., “Flood Risk Analysis for Pasig-Marikina River Basin, Enhancing Risk Analysis Capacities for Flood, Tropical Cyclone Severe Wind, and Earthquakes for Greater Metro Manila Area (Greater Metro Manila Area Risk Assessment Project),” Draft Report, 2014.
-  T. Okazumi et al., “Uncertainty Estimation During the Process of Flood Risk Assessment in Developing Countries – Case Study in the Pampanga River Basin –,” J. of Disaster Research, Vol.9, No.1, pp. 69-77, 2014.
-  B. B. Shrestha et al., “Fundamental Analysis for Flood Risk Management in the Selected River Basins of Southeast Asia,” J. of Disaster Research, Vol.9, No.5, pp. 858-869, 2014.
-  UNISDR, terminology, https://www.unisdr.org/we/inform/terminology [accessed August 15, 2016]
-  ICHARM, http://www.icharm.pwri.go.jp/research/rri/rri_top.html [accessed August 15, 2016]
-  T. Sayama et al., “Rainfall-runoff-inundation analysis of the 2010 Pakistan flood in the Kabul River basin,” Hydrological Sciences J., Vol.57, No.2, pp. 298-312, 2012.
-  Congress of the Philippines, The Philippine Disaster Risk Reduction and Management Act of 2010 (Republic Act No.10121), 2010.
-  Culumpit Municipality, Culumpit Municipal Disaster Risk Reduction and Management Contingency Plan, 2014.
-  PAGASA, Project NOAH, http://noah.dost.gov.ph/ [accessed August 15, 2016]
-  National Disaster Risk Reduction and Management Council, Situation Report website.
-  Global Facility for Disaster Reduction and Recovery (GFDRR), Understanding Risk in an Evolving World – A Policy Note, 2014.
-  Philippine Statistics Authority, http://web0.psa.gov.ph/ [accessed August 15, 2016]
-  B. Shrestha, T, Okazumi, M. Miyamoto, and Hisaya Sawano, “Development of Flood Risk Assessment Method for Data-Poor River Basins: a Case Study in the Pampanga River Basin, Philippines,” Proc. of 6th Int. Conf. on Flood Management (ICFM6), 2014.
-  M. Muto, K. Morishita, and L. Syson, “Impacts of Climate Change upon Asian Coastal Areas:The case of Metro Manila,” JICA
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