Assessment of cascading effects of typhoons on water and sanitation services: A case study of informal settlements in Malabon, Philippines
International Journal of Disaster Risk Reduction
A R T I C L E I N F O Keywords: Cascading effects Water and sanitation Informal settlements Service chain management framework A B S T R A C T Urban infrastructures are critical, highly interconnected, and interdependent systems of services that physically tie metropolitan areas, communities, and neighbourhoods together. When such highly inter-related systems are affected by a disaster, cascading effects may result in the failure of infrastructure systems. This paper presents a method to
... the complexity of cascading effects, which can be applied in situations where documented information of the hazardous event is limited. A service chain management framework is used to examine how services for water supply, sanitation, electricity and solid waste interact. The analysis provides a breakdown of the primary service system into a chain and service elements, which characterises the inter-relatedness of these services. We study the case of Barangay Catmon (neighbourhood) in Malabon, a densely developed urban area, located on Manila Bay that is exposed to various natural hazards. Many of Malabon's low-income households reside in informal settlements that are prone to flooding from the combined effects of land subsidence, pluvial flooding from the river network and storm surges. Our empirical study reveals the temporal spread of a typhoon's cascading effects on essential services and the subsequent impact on informal settlers, that may potentially counteract their hope for sustainable improvement through the upgrading of their settlement. Therefore, to complement the ongoing efforts of disaster risk reduction, service chain management framework may further guide the local authorities and other stakeholders to understand the characteristics of cascading effects varying with time and nature of the impact.