摘要
基于相对湿润度的干旱指数分析方法,应用中国西南1958-2012年气候资料,分析近55年中国西南春季干旱10年际时空分布和演变特征。结果表明:1958-2012年西南春季干旱发生频率呈东北向西南递增分布特征,春季干旱发生频率80%以上区域分布于云南高原、川西高原和川西南山地区域;川西高原和川西南山地的部分区域几乎每年春季均会出现轻度干旱。重旱和特旱主要分布于川西高原南部、川西南山地和云南高原北部区域。西南春季轻旱、中旱和重旱以上干旱平均发生区域占研究区域总面积分别为42%-45%、16%-29%和1%-8%,春季轻旱发生面积呈波动变化,中旱和重旱发生面积呈略减少趋势。云南高原、川西高原和川西南山地春季干旱强度大,但干旱强度振荡幅度小,年际波动小;川东盆地、贵州高原春季干旱强度虽然相对较小,但干旱强度振荡幅度大,年际波动大。西南春季干旱变化经历了5个明显的变化阶段,即20世纪60年代,干旱强度逐渐增强;70年代,干旱强度逐渐减弱;80年代到90年代初,干旱强度又一次加强;在90年代中期到2004年,干旱强度再次减弱。西南春季干旱指数存在显著的2-3 a和7-8 a周期振荡,春季轻旱发生面积呈波动变化,中旱和重旱发生面积呈略减少趋势。2005年后干旱指数累积距平呈负增长趋势,干旱强度逐渐增强,预计未来10年干旱强度可能将增强。
Drought index analytical method which was based on relative moisture index was used to study the decadal variation characteristics of temporal-spatial distribution of spring drought in recent 55 years in southwest China according to southwest China’s climatological information between 1958 and 2012. The result showed that the frequency of spring drought in southwest China had a distribution character of progressively increase from northeast to southwest, regions where have more than 80% of the emergence frequency of spring drought are distributed on Yunnan Plateau, Chuanxi Plateau and southwest mountainous areas of Sichuan, on Chuanxi Plateau and some part of southwest mountainous areas of Sichuan, low-grade drought appears almost every spring. Severe drought and extreme drought are more likely to appear on south part of Chuanxi Plateau, southwest mountainous areas of Sichuan and north regions of Yunnan Plateau. The average area where low-grade drought, medium-grade drought and heavy drought in southwest spring appeared take over 42%-45%、16%-29%和1%-8% of the total research area respectively. The appearance area of low-grade spring drought has a character of fluctuating change, while medium-grade drought and heavy drought had decreasing trends on their appearance areas. The intensity of spring droughts are higher in Yunnan Plateau, Chuanxi Plateau and southwest mountainous regions of Sichuan, but the oscillation amplitude in these regions are small and the interannual fluctuations are small too. The spring drought intensity in Chuandong Basin and Guizhou Plateau are relatively smaller, but the oscillation amplitude in these regions are greater as well as the interannual fluctuations. The spring drought in southwest had gone through five obvious varying stages, that is, in 60s of twentieth century the drought intensity gradually enhanced; in 70s the drought intensity gradually weakened; in 80s and the beginning of 90s, drought intensity enhanced again; from the middle of 90s till 2004, the drought intensity weakened again. The index of southwest spring drought had an obvious 2-3a and 7-8a periodical oscillation. Low-grade spring drought occurred in a fluctuation way, for severe and extreme drought, their occurred areas had a receded trend. After the year 2005, drought index cumulative departurehad a negative growth trend and drought intensity enhanced gradually. It is predicted that next decade drought intensity will be enhanced.
出处
《生态环境学报》
CSCD
北大核心
2014年第4期547-554,共8页
Ecology and Environmental Sciences
基金
国家重点基础研究发展计划(973计划)(2013CB430200(2013CB430206)
2012CB955903)
公益性行业(气象)科研专项(GYHY201106029
GYHY201006023)
国家自然科学基金项目(41175081
41275118)
关键词
春季干旱
空间分布
10年际演变
中国西南
spring drought
spatial distribution
10a decadal variations
southwest China