联合干旱指数在干旱监测中的应用——以广东韶关地区为例

气候变化影响了水循环与地区的水量平衡过程,一定程度上改变了干旱的形成与演变条件。以标准化降水量与蒸散发量差值表征水分偏离正常程度的标准化降水蒸散发指数(SPEI)为基础,从多时间尺度联合的视角建立联合干旱指数(JDI),并以广东韶关为例分析修正的新指数JDI在干旱监测中的准确性和有效性。结果表明,综合了不同时间尺度干旱特征信息的JDI能够较全面地反映干旱的形成与演进过程。通过对干旱监测的评价以及与实际旱情的对比分析,验证了联合干旱指数JDI在实际干旱监测中的准确性和有效性,其可作为未来干旱监测的新理想指标。

Application of Joint Drought Index in Drought Monitoring-A Case Study in Shaoguan of Guangdong Province

It is accepted that climate change has a great impact on water cycle and regional water balance,and thus it would change the formation and evolution of drought conditions in some degree.In this context,the standardized precipitation evapotranspiration index （SPEI）,which has also taken another important factor evapotranspiration in the process of regional water balance into consideration, would be more suitable for drought monitoring than the standardized precipitation index （SPI）.The different time scales SPEI can re-flect the duration informations of drought,so the single SPEI of a certain time scale can only indicate a fraction of drought information. In order to form an overall judgement in drought monitoring,a new index called joint drought index （JDI）was established by the com-bination with different SPEIs.The accuracy and effectiveness of JDI in drought monitoring were then verified by the forecast evaluation system and comparison with the actual drought.In conclusion,JDI can be used as a new ideal index for future drought monitoring.