摘要
利用Hurst指数和小波分析工具对中国农作物干旱灾情的1950～2010年的变化动态作了分析，揭示了灾情序列的趋势持续性、特征时间尺度、周期特征和突变点，同时还定性地预测了农作物干旱灾情的未来走势。研究结果发现：1）根据Hurst指数计算结果，过去60年农作物干旱灾情变化有着很好的自相似性，受灾面积时间序列的Hurst指数为0．793；成灾面积和粮食损失时间序列的Hurst指数分别为0．8634和0．9449，过程均具有很强的正持续性。2）中国农作物干旱灾情都存在多时间尺度特征，不同的时间尺度表现为不同的循环交替，大尺度的周期变化嵌套着小尺度的周期变化。3）小波分析显示，受灾面积在6a和13a上分别存在着第1和第2主周期；成灾面积在6a和18a上分别存在着第1和第2主周期；粮食损失在8a和18a上分别存在着第1和第2主周期。
Drought is a disaster which occurs in the broadest area most frequently and has the most severe impact among natural disasters, so it is very important to research the drought especially for China which is a country suffering from serious drought. In China agriculture is the worst drought-affected sector and the study of drought have received special attentions in the past and recent years. The result of study of drought especially for drought management from a reactive,crisis management approach and so on has received increasing attentions from governments,international and regional organizations, and nongovernmental organizations （NGO）. But in the past the study of time series of drought is mainly based on the single scale before, and few is on the multiple time scales. The wavelet analysis lie in good part characteristics in focusing attention on signal details for time or spatial domain and frequency domain, so it is good at extracting implicit periodical characteristics and trends qualitatively of time series. The Hurst exponent has been extensively applied in geology, climatology and hydrology and so on because of the major superiorities in quantificationally measuring the long range dependence and revealing self-similarity which are widespread phenomena in nature. This paper analyzed the change of the time series of drought damage using wavelet analysis and Hurst exponent from 1950 to 2010, revealed multiple time scales, periodicity characteristics and mutation of time sequence of drought damage, calculated the trend qualitatively. The data in this paper is offered by bulletin of flood and drought disasters in China which is published by the ministry of water resources of the People＇s Republic of China and the state flood control and drought relief headquarters. Statistical data show that area covered by drought was 13258.61 ×10^3hm2 in China in 2010 ,area affected by drought was 8986.47×10^3hm2 in China in 2010, grain loss result from drought was 150.92 billion Yuan. What＇s worse, the drought oc
出处
《第四纪研究》
CAS
CSCD
北大核心
2013年第6期1183-1190,共8页
Quaternary Sciences
基金
国家自然科学基金项目(批准号:41270513)
西北大学科学研究基金项目(批准号:12NW32)
西北大学科研启动基金项目(批准号:PR12076)
陕西省社会科学界2012年度重大理论与现实问题研究项目(批准号:2012Z029)共同资助
