A study on the method of setting tropical cyclone intensity-precipitation parameters for the probable maximum flood-storm surge composite scenario

To set probable maximum flood-storm surge composite disaster scenario, the parameter of tropical cyclone precipitation was added to previous studies．Thus, constructing a methodological framework to set tropical cyclone intensity-precipitation parameter is explored．Best track dataset of tropical cyclones from China Meteorological Administration, the radius of maximum winds from the Joint Typhoon Warning Center, and precipitation data obtained by fusing observations from Chinese automatic stations with CMORPH products, were used to statistically analyze the quantitative relationships between key parameters of tropical cyclones and to construct a method to set parameters (maximum sustained wind, central minimum pressure, radius of maximum wind, and hourly precipitation)．Previous methods to set parameters for probable maximum tropical cyclones were used, addition of precipitation as a meteorological parameter could better develop critical parameters at different levels of tropical cyclone landfall and provide input data for probable maximum flood-storm surge composite scenarios．The upper limit of probable maximum intensity could be effectively determined by linear fit of parameter relationship plus multiple standard deviations．Central maximum wind speed was found negatively correlated to central minimum pressure and radius of maximum wind．Significant negative outer envelope correlations to maximum hourly precipitation, 99th percentile of hourly precipitation, and total hourly precipitation were found．If sample distribution is scattered, uncertainty of data distribution and correlation between parameters could be explored by a combination of interval discussion and extreme value function fitting．Total hourly precipitation at different probability levels and outer envelope could then be investigated．The present study provides some basis for decision-making on tropical cyclone prevention, mitigation, relief, and risk management in coastal areas．