摘要
我国是一个干旱及旱灾频繁发生的国家,近年来干旱已成为影响我国社会经济可持续发展的重要制约因素。文中应用经验模态分解(EMD)方法分析了1950-2006年全国干旱灾害受灾面积波动情况。结果表明:(1)干旱灾害受灾面积存在准3年、准8.5年、准14年左右特征时间尺度的周期性波动;(2)各时间尺度的周期性振荡的贡献率中以准3年时间尺度的受灾面积振荡的贡献最大,说明干旱灾害受灾面积波动以准3年时间尺度为主;(3)从各时间尺度的振荡来看,大致分三个阶段,80年代中期以前,干旱灾害受灾面积的波动频率较慢,周期长,振幅大;80年代中期以后,波动频率变快,周期缩短,振幅减小;而90年代中期之后,振幅又有所增加。从各时间尺度振荡的趋势看,干旱灾害受灾面积仍处在增加阶段;而且近年来干旱灾害受灾面积振荡的幅度增大,说明干旱灾害强度加剧,频度增加。因此,应认识和了解旱灾发生和发展规律,并进行有效的防治,尽可能减小旱灾对社会经济发展造成的损失。
The aridity and drought disasters occur frequently in our country. In recent years, aridity has become an important restricting factor affecting the sustainable development of society and economy in our country. Empirical mode decomposition （EMD） method had been used to study the fluctuation of arid area of drought disaster from 1950 to 2006 in China in this article. The results showed that： （1） there were fluctuations at around 3 years, 8.5 years and 14 years time scale ; （2） By analyzing the contribution ratio of fluctuations at different time scale , contribution ratio of around 3 years period was the largest, which meant the fluctuation at around 3 years was the most prominent; （3） Shown from fluctuations at different time scale, the overall duration from 1950 - 2006 were divided into three stages approximately. Before the mid - 80s, the frequency of fluctuation of drought disaster area was slower, the cycle was longer, the fluctuation amplitude was larger; After the mid -80s, the frequency of the fluctuation changed quickly, the cycle shortened, the amplitude lessened; But after the mid - 90s, the fluctuation amplitude largened. From the trends of each fluctuation at different time - scale, the arid area suffered from drought disaster in China was still increasing. Moreover, due to the increase of fluctuation amplitude of the arid area, a conclusion was drawn that frequency and intensity of aridity strengthened. Therefore, we should know the law on development of drought, and carry out effective preventive measures to reduce the the loss of society and economy caused by drought as far as possible.
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2009年第5期90-93,共4页
Journal of Arid Land Resources and Environment
