Multi-hazard risks in New York City

<p><strong>Abstract.</strong> Megacities are predominantlyconcentrated along coastlines, making them exposed to a diverse mix ofnatural hazards. The assessment of climatic hazard risk to cities rarely hascaptured the multiple interactions that occur in complex urban systems. Wepresent an improved method for urban multi-hazard risk assessment. We thenanalyze the risk of New York City as a case study to apply enhanced methodsfor multi-hazard risk assessment given the history of exposure to multipletypes of natural hazards which overlap spatially and, in some cases,temporally in this coastal megacity. Our aim is to identify hotspots ofmulti-hazard risk to support the prioritization of adaptation strategies thatcan address multiple sources of risk to urban residents. We usedsocioeconomic indicators to assess vulnerabilities and risks to threeclimate-related hazards (i.e., heat waves, inland flooding and coastal flooding) at high spatial resolution.The analysis incorporates local experts' opinions to identify sources ofmulti-hazard risk and to weight indicators used in the multi-hazard riskassessment. Results demonstrate the application of multi-hazard riskassessment to a coastal megacity and show that spatial hotspots ofmulti-hazard risk affect similar local residential communities along thecoastlines. Analyses suggest that New York City should prioritize adaptationin coastal zones and consider possible synergies and/or trade-offs tomaximize impacts of adaptation and resilience interventions in the spatiallyoverlapping areas at risk of impacts from multiple hazards.</p>