On the driving forces of historical changes in the fatalities of tropical cyclone disasters in China from 1951 to 2014

Tropical cyclone (TC) disasters have frequently caused casualties in the coastal areas of China. According to the statistics of dead and missing people due to TCs from 1951 to 2014, the number of fatalities has been significantly decreasing over time. However, deadly TC events have still caused great losses of life in recent years, which are characterized as significant abrupt fluctuations superimposed along the downward trend of the long-term fatality time series. The numbers of fatalities caused by TC disasters are influenced by variables such as the intensity of TC hazards, the population exposed to TCs and the vulnerability of people to TC hazards. It is thus of great significance to analyze their temporal characteristics and understand the forces driving these changes. First, the time series of the TC wind, precipitation, spatial distribution of population, fatality and disaster risk reduction (DRR) measures of China from 1951 to 2014 are reconstructed. Second, the improved power dissipation index, total precipitation, integrated intensity and index of exposed population are calculated, and the population vulnerability indices, including mean and relative fatality rates, are derived. Third, the change trend of each index is detected using the Mann–Kendall test. Finally, the main driving factors of the long-term change trend and fluctuations of the TC fatalities are analyzed by a negative binomial regression model and standard deviation statistics. It is found that the decrease in vulnerability based on the improvement in structural and non-structural measures is the main driving force of the decreases in fatalities over the past six decades. Although the total population and exposure have increased dramatically in the coastal areas of China, their contributions to the increase in the fatality risk were counteracted by the decrease in vulnerability. Abrupt and catastrophic disasters were mostly caused by TCs with hazards of high intensity that surpassed the capacity of structural measures; the lack of forecasting or early warning, as well as improper emergency response actions, may also have triggered the great loss of lives. To reduce the fatalities of future TCs, especially those that may exceed the capacity of structural measures, the enhancement of non-structural measures and the adaptation of resilience strategies should be priorities for future people-centered disaster management.