Drought Indices and Univariate Analysis
摘要
Several studies have highlighted the advantages of the SPI index for drought detection, including its simplicity, reliability, and ability to forecast short-term events. However, due to the increasing trend in ET0 in the twenty-first century, SPI may not be suitable for detecting the frequency and severity of drought events. Instead, drought indices based on ET0 or T and P, such as SPEI and PDSI, should be used. Research has shown that SPEI and CI are particularly useful in detecting drought conditions, but little is known about their drought return periods across Chinese mainland at different timescales.