The Richter Scale measures the magnitude of the seismic activity for an earthquake; however, it does not quantify the humanitarian need at the point of impact. This poses a challenge for humanitarian stakeholders in decision and policy making, especially in risk reduction, response, recovery, and reconstruction. The new disaster metrics tool titled “The YEW Disaster Severity Index” (DSI) was developed and presented at the 2017 World Congress of Disaster and Emergency Medicine, May 2017, Toronto, Canada. It uses a median score of three for vulnerability and exposure indicators, a median score percentage of 100%, and medium YEW DSI scoring of four to five as baseline, indicating the ability to cope within local capacity. Therefore, scoring more than baseline coping capacity indicates that external assistance is needed. This special real-time report was presented at the 2nd National Pre-Hospital Care Conference and Championship, October 2018, Malaysia.

The aim of this analysis is to present the real-time humanitarian impact and response to the 2018 earthquake and tsunami at Donggala and Palu, Sulawesi in Indonesia using the new disaster metrics YEW DSI. Based on the earthquake (measuring 7.7 on the Richter Scale) and tsunami at Donggala, the humanitarian impact calculated on September 29, 2018 scored 7.4 High in the YEW DSI with 11 of the total 17 indicators scoring more than the baseline coping capacity. The same YEW DSI score of 7.4 was scored on the earthquake and tsunami at Palu, with 13 of the total 17 indicators scoring more than baseline ability to cope within local capacity. Impact analysis reports were sent to relevant authorities on September 30, 2018.

A State of Emergency was declared for a national response, which indicated an inability to cope within the local capacity, shown by the YEW DSI. The strong correlation between the earthquake magnitude, intensities, and the humanitarian impact at Donggala and Palu reported could be added into the science of knowledge in prehospital care and disaster medicine research and practice. As a conclusion, the real-time disaster response was found to be almost an exact fit with the YEW DSI indicators, demonstrating the inability to cope within the local capacity.

The Richter Scale measures the magnitude of a seismic occurrence, but it does not feasibly quantify the magnitude of the “disaster” at the point of impact in real humanitarian needs, based on United Nations International Strategy for Disaster Reduction (UNISDR; Geneva, Switzerland) 2009 Disaster Terminology. A Disaster Severity Index (DSI) similar to the Richter Scale and the Mercalli Scale has been formulated; this will quantify needs, holistically and objectively, in the hands of any stakeholders and even across timelines.

An agreed terminology in quantifying “disaster” matters; inconsistency in measuring it by stakeholders posed a challenge globally in formulating legislation and policies responding to it.

A quantitative, mathematical calculation which uses the median score percentage of 100% as a baseline, indicating the ability to cope within the local capacity, was used. Seventeen indicators were selected based on the UNISDR 2009 disaster definition of vulnerability and exposure and holistic approach as a pre-condition. The severity of the disaster is defined as the level of unmet needs. Thirty natural disasters were tested, retrospectively, and non-parametric tests were used to test the correlation of the DSI score against the indicators.

The findings showed that 20 out of 30 natural disasters tested fulfilled the inability to cope, within local capacity in disaster terminology. Non-parametric tests showed that there was a correlation between the 30 DSI scored and the indicators.

By computing a median fit percentage score of 100% as the ability to cope, and the correlation of the 17 indicators, in this DSI Scale, 20 natural disasters fitted into the disaster definition. This DSI will enable humanitarian stakeholders to measure and compare the severity of the disaster objectively, as well as enable future response to be based on needs.

YewYY, Castro DelgadoR, HeslopDJ, Arcos GonzálezP. The Yew Disaster Severity Index: A New Tool in Disaster Metrics. Prehosp Disaster Med. 2019;34(1):8–19.