The continuum of chronic to episodic natural hazards: Implications and strategies for community and landscape planning

Natural hazards present challenges for community and rural planning. In this perspective essay hazards are categorized in the continuum from chronic to episodic to help guide the planning process. While episodic hazards garner most attention because of their immediate destructive nature, chronic hazards like sea-level rise and drought also have important implications for planning and can exacerbate episodic hazards like landfall typhoons, flooding, and wildfire. Both hazard types require long-term planning horizons, which have not been readily or optimally adopted. In the continuum between these two types, hazards differ with respect to maximum spatial extent of impacts, influences of anthropogenic effects, and risk of disaster. Issues warranting consideration that affect the vulnerability of communities and rural landscapes to natural hazards include demographic shifts and patterns, land use change, generational experience with hazards, adaptation measures, wealth, and community resilience. Of particular concern to planning in areas susceptible to disasters are cascading hazards, where one hazard (e.g., typhoon) triggers a series of other hazards (e.g., landslides, debris flows, floods). We present a DAIR (Design-Analyze-Implement-Reassess) framework that could be used in early stages of planning to minimize the impacts of natural hazards. Examples of how multiple hazards have been and need to be incorporated into the planning process are presented for the Brisbane River catchment (Australia) and the Kagoshima Bay area (Japan) - regions with complex disaster histories that have been affected by past and recent anthropogenic pressures.