不同干旱指数在唐山地区旱情评价中的应用

基于唐山地区1957—2011年的气象资料,比较分析标准化降水指数（S SPI）、标准化降水蒸散发指数（S SPEI）和帕默尔水文干旱指数（P PHDI）3种不同干旱指数的相关性,并评价了各个指数在唐山地区连旱期间的适用性。结果表明：各时间尺度（年、季、月）的S SPI和S SPEI均显著相关;P PHDI与年尺度的S SPI和S SPEI均显著相关。P PHDI对长期干旱判断效果明显优于短期干旱。年尺度S SPEI和S SPI对干旱事件识别效果比较接近,二者对长期干旱判断偏涝,对短期干旱判断效果明显优于P PHDI。在气温偏低的年份,季尺度的S SPI能很好地反映旱情的严重程度,在气候变暖的背景下,季尺度S SPEI比S SPI更能准确地判断和评价旱情。

Drought evaluation of Tangshan region using multiple drought indices

Based on meteorological data from 1957 to 2011 in the Tangshan region,correlation analysis between the standardized precipitation index（SSPI）,the standardized precipitation evapotranspiration index（SSPEI）,and the Palmer hydrological drought index（ P PHDI） was conducted,and the applicability of these indices to drought evaluation of the Tangshan region during a continuous drought period was investigated.The results are as follows：the SSPI and SSPEI show good correlation at different time scales（monthly,seasonal,and yearly）; the P PHDI is significantly correlated with the S SPI and S SPEI at an annual scale; the P PHDI can detect multiple-year continuous drought better than short-term drought,while the annual SSPEI and SSPI can identify separate drought events better than the P PHDI; the seasonal S SPI can detect drought well in the years with low air temperature; and the seasonal SSPEI is more sensitive to the drought induced by the rising air temperature than the seasonal S SPI.