Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Development of bioindicators for the assimilation of terrestrial nutrient inputs in coastal ecosystems as a tool for watershed management Technical Report

Savage, C.
Journal / Source
New Zealand Aquatic Environment and Biodiversity Report
Publisher / Organisation
Department of Marine Science, University of Otago
Tsunami, inundation modelling, land use planning, risk-based approach, uncertainty, mapping, pre-event recovery.
This report provides guidance to land use planners and decision makers on how tsunami inundation modelling can be included into land use planning. After a brief overview of tsunami basics, Figure 6 presents a decision tree for including tsunami risk into land use planning, and forms the basis for this report. The purpose of this figure is to lead the decision maker through a process of tsunami modelling, risk assessment, review of data quality and inclusion into Land Information Memorandums (LIMs), emergency management, and land use planning. Guidance on tsunami modelling levels for evacuation purposes is already available. To ensure consistency with this approach, the recommended modelling levels for land use planning are based on the same approach. Level 1 modelling is not recommended for land use planning purposes; Level 2 modelling is recommended for inclusion into LIMs and emergency management readiness; and Levels 3 and 4 are also recommended for land use planning purposes. Pre-event recovery planning for land use is also recommended for areas already developed. Options are provided on how the Level 3 and 4 modelling can be incorporated into land use planning. We also discuss managing uncertainty, including one potential solution for mapping tsunami inundation zones that acknowledges scientific uncertainty. Three planning approaches are available, and can be used in combination: risk-based approach, precautionary approach, and participatory approach. An adaptive three-step risk-based approach is outlined, which involves determining severity of consequences; evaluating the likelihood of an event occurring relevant to the consequences; then the resource consent activity status is determined based on quantifying levels of risk. Resource consents become more restrictive as the consequences increase. Regulatory and non-regulatory options for including tsunami risk into land use planning are outlined.