地理科学 ›› 2015, Vol. 35 ›› Issue (10): 1333-1340.doi: 10.13249/j.cnki.sgs.2015.010.1333

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近60年来西南地区旱涝变化及极端和持续性特征认识

杨金虎1,2(), 张强1, 王劲松1, 姚玉璧2, 尚军林2   

  1. 1.中国气象局兰州干旱气象研究所甘肃省干旱气候变化与减灾重点实验室中国气象局干旱气候变化与减灾重点开放实验室,甘肃 兰州 730020
    2.甘肃省定西市气象局,甘肃 定西 743000
  • 收稿日期:2014-03-15 修回日期:2014-06-21 出版日期:2015-10-25 发布日期:2015-10-25
  • 作者简介:

    作者简介:杨金虎(1974-),男,甘肃会宁人,博士,高级工程师,主要从事区域气候变化研究工作。E-mail: yjh740701@sina.com

  • 基金资助:
    国家重点基础研究发展计划项目(2013CB430206)和公益性行业(气象)科研专项(GYHY201306027)资助

Extreme and Persistent Feature of Drought and Flood of Southwest China in Past 60 Years

Jin-hu YANG1,2(), Qiang ZHANG1, Jin-song WANG1, Yu-bi YAO2, Jun-lin SHANG2   

  1. 1.Key Laboratory of Arid Climate Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Climate Change and Disaster Reduction of China Meteorological Administration, Institute of Arid Meteorology of China Meteorological Administration, Lanzhou, Gansu 730020 China
    2. Dingxi Meteorological Bureau of Gansu Province, Dingxi, Gansu 743000, China
  • Received:2014-03-15 Revised:2014-06-21 Online:2015-10-25 Published:2015-10-25

摘要:

利用1953~2012年中国西南地区44个气象台站的逐日降水、温度资料,通过降水和潜在蒸发均一化旱涝指数,从旱涝的年代际、年际、季节内变化以及极端和持续性特征等方面进行了分析,结果表明:从旱涝的空间趋势变化来看,西南近60 a来秋季和年变化呈显著的一致变旱趋势,而春、夏、冬3季旱涝变化趋势表现出一定的区域性特征;从旱涝的时间演变来看,在温度与降水双重因子驱动下春、夏、秋、冬均表现为干旱化趋势,相比较秋季的干旱化程度最强,而春季的最弱,夏、冬两季相当,而全年的干旱程度比四季的程度更强;从极端旱涝的多时间尺度来看,在年代际和年际尺度上,极端洪涝发生频次逐渐减少,而极端干旱发生频次逐渐增多,从季节尺度看,春、冬两季极端干旱发生频次较多,而夏季最少,极端洪涝发生频次夏季最多,春季次之,秋季最少。从旱涝的持续性特征来看,持续性干旱事件的持续时间有增长趋势,发生频率有增多趋势,发生强度有增强趋势,并且主要发生在冬春两季,而持续性洪涝事件的持续时间、发生强度没明显变化趋势,发生频率有减少趋势,发生的季节也没明显差异。

关键词: 中国西南, 旱涝, 演变, 极端, 持续性

Abstract:

Using 44 stations temperature and precipitation data of day by day in Southwest China in 1953-2012, latency evaporation is calculated by Thornthwaite method, from inter-decadal, inter-annual, inter-seasonal variability, extreme and persistent characteristic of drought and flood analyzed over southwest China in past 60 years by homogenized drought-flood index of precipitation and latency evaporation. The results showed that: From the point of view of space trends to see, it displayed consistent drought trend in autumn and whole year over southwest China in past 60 years, but it displayed regional drought-flood trend feature in spring, summer and winter. Precipitation is main driven factor of drought-flood change in spring and summer, temperature is main driven factor of drought-flood change in winter and whole year, but driven function of precipitation and temperature are all notable in autumn. Therefore it is not objective to analyze drought-flood change only by precipitation, driven function of temperature must be considered. From the point of view of time evolution to see, it displayed drought trend by driven of temperature and precipitation double factor in spring, summer, autumn and winter over southwest China in past 60 years. By comparison, drought degree is strongest in autumn, but it is weakest in spring, and it is quite in spring and winter. However annual drought degree is stronger than that of seasons. From multiple time scales of view of extreme drought-flood to see, on interannual and decadal scales, extreme floods occur frequency gradually decreased, and extreme drought occur frequency gradually increased in past 60 years over southwest China. From inter-seasonal scales of view of extreme drought-flood to see, there is a greater probability of extreme drought in spring and winter, but it is smaller in summer, and there is a greater probability of extreme flood in summer, followed by spring ,but it is smaller in autumn. From month scales of view of extreme drought-flood to see, there is a greater probability of extreme drought on August, followed by February, but it is smaller in June, and there is a greater probability of extreme flood on August, followed by February, but it is smaller in January. Therefore it is most unusual month of drought-flood on August and February. From the point of view of persistent characteristic to see, from trend of persistent drought and flood event to see, duration of persistent drought event gradually lengthen, frequency gradually increased, intensity gradually strengthen, and it occurs mainly in winter and spring, but duration and strength of persistent flood event have not clear trend, frequency gradually decreased, and season of appearance have not significantly difference. In addition by comparing frequency of persistent drought and flood event to south China and southwest China in the past 60 years, nine times is consistent in the time of occurrence of persistent drought, especially it is entirely consistent autumn winter and spring drought in 1998, nine times is not consistent. Seven times is consistent in the time of occurrence of persistent flood, eleven times is not consistent, therefore affect system of persistent drought and flood is not entirely consistent over southwest and south China.

Key words: southwest China, drought-flood, evolution, extreme, persistent

中图分类号: 

  • P426.616