1960～2012年中国东南沿海地区降水变化特征及重涝灾害趋势判断

基于东南沿海地区46个气象站点逐年实测降水数据,采用线性回归、Mann-Kendall检验法、Z指数法等气候诊断方法分析了1960~2012年东南沿海降水量时空变化特征,利用可公度、蝴蝶结构图和可公度结构系等灾害时间对称性方法,对重涝灾害未来趋势进行判断。结果表明:1)1960~2012年东南沿海地区降水整体呈增加趋势,增加速率为1.91mm/a;2)在空间变化上,降水量高值区域,降水呈现下降趋势,而降水量低值区域,降水则呈现上升趋势;降水呈下降趋势的区域集中在降水高值区,由南向北降水呈下降趋势站点逐渐减少,区域洪涝灾害风险逐渐增大;3)东南沿海旱涝变化具有明显的年际变化趋势,主要表现为20世纪60~70年代整体偏旱,80~90年代涝灾逐年增多,2000年后旱涝灾害频发,形成"重旱-重涝并重"的格局;4)东南沿海地区重涝时间序列具有明显的时间对称结构,经可公度、蝴蝶结构图和可公度结构系三种方法综合判断,2016年重涝信号较强,有可能发生较严重的涝灾,需要相关部门予以重视,完善区域自然灾害防御应急体系。

Precipitation Characteristics of Flooding from 1960 to 2012 and Serious Flooding Judgment for the Southeast Coast of China

On the basis of linear regression, Mann-Kendall Method, the Z-test method and commensurability, by using yearly precipitation data from 46 meteorological stations from 1960 to 2012 on the southeast coast of China, spatio-temporal characteristics of precipitation and flooding tendency for the southeast coast of China were investigated. Results indicate that 1) precipitation of the southeast coast of China has an increasing trend and the increasing rate is 19.1mm/10a; 2) precipitation has a decreasing trend in high precipitation regions but an increasing trend in low precipitation regions. Most of the regions, where precipitation has a decreasing trend, are high precipitation regions, and meteorological stations, where precipitation has a decreasing trend from south to north. Risk of regional flooding disasters is increasing gradually; 3) droughts and floods have an obviously inter-annually changing trend. It was the droughts period from 1960s to 1970s. Flooding has increased annually from 1980s to 1990s. Droughts and floods disasters happened frequently after 2000; and 4) time series of severe droughts have a distinctive symmetric structure. Via commensurability, map of butterfly structure (MBS) and commensurable structure, we claim that flooding would happen again in 2016 on the southeast coast of China.