State Starts Development of Probabilistic Tsunami Design Zone Maps

Posted on Jan 28, 2019 in News

Office of Planning
For Immediate Release: January 28, 2019

Coastal Zone Management Program color logoHONOLULU—The Office of Planning’s Coastal Zone Management Program (OP-CZM) has begun developing comprehensive high resolution probabilistic Tsunami Design Zone (TDZ) maps for the Island of Oahu.

The current 2018 State of Hawaii Multi-Hazard Mitigation Plan (SHMHMP) and the previous 2013 SHMHMP identified tsunamis as a hazard of high concern for Hawaii and a significant coastal hazard risk to the state.

However, there were no national standards for designing facilities against the effects of a tsunami. As a result, in 2016, the American Society of Civil Engineers (ASCE) developed ASCE 7-16, Chapter 6 – Tsunami Loads and Effects – the first national, consensus-based standard for tsunami resilience in Hawaii and Western states. The new ASCE 7-16 tsunami design provisions will be referenced in the 2018 International Building Code (IBC 2018) and will apply to a limited class of residential, commercial and critical and emergency facilities to ensure Hawaii’s resilience to coastal hazards.

To assist in the use of the ASCE 7-16 tsunami design standards in Hawaii, maps of 2,500-year probabilistic tsunami inundation for Hawaii will be developed through OP-CZM’s high resolution (10-meter) probabilistic TDZ mapping project for the Island of Oahu. OP-CZM is working with Ian Robertson, Ph.D., SE, and his expert team to develop the mapping products.

“The high-resolution maps to be produced are important because they replace the low-resolution TDZ maps currently in the ASCE 7-16 standard so that future tsunami design on Oahu will benefit from more accurate and informative maps,” Robertson said. “Some areas that are currently considered by ASCE 7-16 to fall within the Tsunami Design Zone may in fact not need tsunami design at all. Development of the high-resolution maps will clarify exactly what areas are exposed to the tsunami hazard.”

Thomas Travis, Hawaii Emergency Management Agency (HI-EMA) Administrator, said, “HI-EMA is excited for this project to get underway. HI-EMA and OP-CZM have been great partners in mitigation efforts. This project is an excellent example of how to leverage resources to proactively address coastal hazards in Hawaii.”

Justine Nihipali, CZM Program Manager, added, “The high resolution, probabilistic Tsunami Design Zone mapping project will help Oahu become more resilient and better able to withstand a tsunami event. OP-CZM is fortunate to work with engineering and tsunami experts like Dr. Robertson and this team. The project was made possible with the support of our federal partners at NOAA. This project is just one part of our five-year Coastal Hazards Strategy.”

OP-CZM will seek to develop high resolution probabilistic TDZ maps for all the major Hawaiian Islands once maps for Oahu are completed.

For more information about the project, contact the state’s Office of Planning at (808) 587-2846.

About the State Office of Planning
The Office of Planning is a state agency, attached to the Department of Business, Economic Development and Tourism (DBEDT), that gathers, analyzes and provides information to the governor to assist in the overall analysis and formulation of state policies and strategies. Its purpose is to: (1) provide central direction and cohesion in the allocation of resources and effectuation of state activities and programs; and (2) effectively address current or emerging issues and opportunities. The office works closely with local, state and federal government agencies; the University of Hawaii; and various community stakeholders to achieve these objectives.

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Media Contact:
Justine Nihipali
Office of Planning
Department of Business, Economic Development and Tourism
Phone: (808) 587-2846
Website: planning.hawaii.gov