The Analysis of Different Spatial-temporal Rainfall Characteristics and Drought Disaster Risk Assessment in Penghu Area

The Analysis of Different Spatial-temporal Rainfall Characteristics and Drought Disaster Risk Assessment in Penghu Area

 

Keywords: Empirical Orthogonal Function, Wavelet Analysis, Standardized Precipitation Index, Drought

 

Under the impact of extreme climate and the trend of global warming, the frequency of natural disasters has increased, and extreme rainfall and extreme drought events have gradually increased, causing threats to human life, food shortages, and ecological catastrophes. In recent years, with the development of tourism industry in Penghu, the demand for water resources has increased, but available surface water sources are very scarce. At present, Penghu’s freshwater source is mainly seawater desalination, but this method is likely to affect Penghu’s unique coral reef marine ecology.

This study uses data mining methods to analyze rainfall characteristics and drought trends. Rainfall characteristic analysis uses empirical orthogonal function (EOF) and wavelet analysis (WA), and drought trend analysis uses the Standardized Precipitation Index (SPI) at different time scales. The results show that the rainfall characteristics of South Penghu Marine National Park and Penghu Island are different, and the rainfall difference between drought years and non-drought years is large. The drought index shows that in recent years, South Penghu Marine National Park is still in a relatively dry state, with a higher drought frequency than Penghu Island and Taiwan Island. The risk of agricultural drought and hydrological drought is high on a medium to long time scale. Therefore, special attention needs to be paid to the rainfall situation in South Penghu Marine National Park.