The day-to-day monitoring of the 2011 severe drought in China

• 作 者: Er Lu Wenyue Cai Wayne Higgins
• 机 构: Nanjing University of Information Science & Technology,Nanjing,Jiangsu,China;NOAA Climate Prediction
• 出 处: 2013年高原山地气象研究暨西南区域气象学术交流会
• 发表日期: 2013年9期
• 关键词: drought the Weighted Average of Precipitation (WAP) Precipitation

　　Precipitation has large interannual variability.Decision-makers need to know the onset,duration,and intensity of drought,and require drought be monitored at a daily to weekly scale.However,previous tools cannot monitor drought well at this short timescale.The Palmer Drought Severity Index (PDSI) has been dissatisfaction in monitoring with its limitations and complexity.The Standardized Precipitation Index (SPI),which always needs a timescale to make a simple average of precipitation over the period,can only monitor droughts at scales of a month and longer.The Weighted Average of Precipitation (WAP) developed by Lu (2009) overcomes the discrepancy of the SPI,and is the index really “versatile for all timescales”; it can monitor droughts at scales from daily,and even hourly,to monthly and longer.In this study,the standardized WAP (SWAP) is used to monitor the 2011 drought over China.Droughts swept the country during the year from north to south and from east to west.In spring,a once-in-a-fifty-year drought occurred over the Yangtze River basin and the southern region,which caused serious shortage of drinking water for people and livestock and tremendous losses in agriculture and shipping industry.Results demonstrate that the monthly mean plots of SWAP can well illustrate the seasonal shift of the drought across the country,consistent with the visible events.The animation of daily SWAP is used to monitor the day-to-day variation of the spring drought,and show how drought emerged and maintained over the Yangtze River basin,with drought area moving back and forth and extending to the southern region,and finally relieved over the basin.