Contents lists available at ScienceDirect International Journal of Disaster Risk Reduction journal homepage: www.elsevier.com/locate/ijdrr Increasing communities’ resilience to disasters: An impact-based approach Tim R.H. Davies ⁎ , Alistair J. Davies Dept. of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand ARTICLE INFO Keywords: Disaster risk reduction Disaster impact reduction Resilience Planning timeframe Scenario development Scenario selection ABSTRACT The conventional processes of science, and the incorporation of science into policy and practice, appear not to be resulting in improved disaster reduction solutions for communities, despite intense research into hazards and risk. Resilience to disasters is increased when the societal impacts of disasters are reduced. On this basis, the contribution that Disaster Risk Reduction (DRR) can make to Disaster Impact Reduction (DIR) is assessed, and it is demonstrated that reducing event risk by reducing event probability only reliably reduces community disaster impacts for events that occur frequently. Such events do not fit the UNISDR definition of a disaster. Therefore, DRR cannot reliably improve DIR. Instead, DIR can be addressed directly by way of community adaptation, based on carefully selected impact scenarios derived by community-expert-official collaborations considering a broad range of event and asset damage scenarios. Probabilistic risk is a useful tool in insurance and re-insurance, and possibly in national policy-making, but such national policies are likely to be undermined by inevitable failures of risk-based approaches at the local level. This work clarifies the common usage of “risk” as meaning either impact, or impact x probability. 1. Introduction Well into the 21st century, society is still attempting to come to grips with its ever-increasing vulnerability to extreme events resulting from the natural processes of planet Earth. This vulnerability has re- cently been demonstrated by extreme naturally-triggered disasters such as the 2004 Indian Ocean tsunami (e.g. [3]), the 2011 Tohoku earth- quake-tsunami (e.g. [22]) and hurricane Harvey in 2017 (e.g. [27]). Over the last few decades, the global policy and research commu- nity has come together several times to progress the task of reducing the impacts of disasters on society. This challenge was first taken up at the 2005 UN World Conference on Disaster Reduction (WCDR) in Kobe, Japan, only days after the 2004 Indian Ocean tsunami. International agencies and national governments then began to move toward setting clear targets and commitments for disaster reduction. The first step in this process was the formal approval, at the World Conference on Disaster Reduction, of the Hyogo Framework for Action (HFA: 2005–2015). The World Conference on Disaster Risk Reduction held on March 14–18, 2015, in the Japanese city of Sendai, adopted the suc- cessor accord to the Hyogo Framework. It is known as the Sendai Framework for Disaster Risk Reduction (2015–2030; https://www. unisdr.org/we/coordinate/sendai-framework). The global policy and research area by means of which nations are attempting to reduce vulnerability is thus “Disaster Risk Reduction” (DRR: e.g. [1]). While less prominent in the official rhetoric, resilience has become a key concept in promulgating vulnerability reduction worldwide during the present century (e.g. [23]). Compared to DRR, the term resilience conveys better to non-experts the concept that they can be less affected by future disasters if they can become “resilient”. The term conveys a sense of merit in the context of disasters, in much the same way that “sustainability” implies environmental merit. Accordingly, a number of research and operational initiatives worldwide presently focus on resilience to disasters: for example, the New Zealand National Science Challenge “Resilience to Nature's Challenges”; the establishment of Durham University (UK)’s Institute for Hazard, Risk and Resilience; the National Disaster Resilience Strategy under development by the Ministry of Civil Defence and Emergency Management, New Zealand (Ministry of Civil Defence and Emergency management, 2018); the Queensland Strategy for Disaster Resilience, Australia (Queensland Government, 2014); and the Los Angeles County Community Disaster Resilience Project, USA (Rand Corporation,2018). The substantial effort among global agencies to try to mitigate disaster effects has been matched by plentiful academic discussions and analyses of both “DRR” and “resilience”. While DRR appears to be the better defined and understood term, perhaps because of its relationship with the well-established discipline of Risk Management (e.g. [30,15,18]), clarity in the usage and meaning of “resilience” is less https://doi.org/10.1016/j.ijdrr.2018.07.026 Received 21 May 2018; Received in revised form 25 July 2018; Accepted 26 July 2018 ⁎ Corresponding author. E-mail address: tim.davies@canterbury.ac.nz (T.R.H. Davies). International Journal of Disaster Risk Reduction 31 (2018) 742–749 Available online 27 July 2018 2212-4209/ © 2018 Elsevier Ltd. All rights reserved. T