A Multi-scale Perspective on Drought Monitoring and Assessment for the Pearl River Basin

• 作者: Chen Qixin Chen Zishen Huang Qiang Wu Lei
• 来源期刊: 气象与环境研究：英文版
• 学科: 地球科学
• 关键词: 干旱监测 珠江流域 多尺度 评估 气象观测站 水资源规划 气候变化 时间尺度
• 年，卷（期）: 2014,（10）
• 页码范围: 25-32
• 页数: 8页
• 分类号: P41

摘要

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 conditions of drought in some degree. By using data at 42 meteorological stations of the Pearl River Basin,the Standardized Precipitation Evapotranspiration Index( SPEI) at different time scales was calculated. Based on the SPEIs of 1- 12 months,a newly proposed index for drought——Joint Drought Index( JDI) was established under the multi-scale perspective through the copula function. Since short-term SPEIs are essential for the identification of emerging droughts and long-term SPEIs are useful for prolonged droughts,the JDI,which integrates all the usefull informations of drought and can thus form an overall judgement,is superior than the single SPEI in drought monitoring. By the forcast evaluation system and comparison to the actual drought,the accuracy and effectiveness of JDI in drought monitoring were verified. In general,JDI can be used as a new ideal index for future drought monitoring and assessment. Additionly,we analyzed the spatio-temperal characteristics of drought across the Pearl River Basin using the JDI. The results indicate that mild drought was the most frequent drought occurred in the Pearl River Basin over the past half century,and moderate drought followed. Severe drought and extreme drought would appear occasionally while exceptional drought could hardly be found. A dry-wet-dry interdecadal variation pattern had been found from the 1960 s to the 2000 s. Since the 21 stcentury,an obvious trend toward drought can be observed in the whole basin,especially in the Xijiang subbasin,which,consequently,poses an increasing challenge for the water resource planning and management.