韶关市极端降水变化趋势分析

Analyzing the Variation Tendency of Extreme Precipitation in Shaoguan

基于韶关市分布较均匀的8个雨量站1970—2009年日降水资料,参考世界气象组织(WMO)提出的指标,选取了6个极端降水指标(R1d、R5d、CDD、CWD、R95ptot、R95p),然后针对这些指标进行多年平均值、变异系数、Mann-Kendall变化趋势空间分析及滑动t检验变异年份分析。结果表明:(1)极端降水各指标都存在着较大的年际变化;多年平均值方面,R1d、R5d表现为从东南向西北递减,其余各指标主要表现为西多东少;(2)变化趋势上,R1d、R5d、CDD为不显著增加,R95ptot主要为不显著减少,CWD、R95p主要为显著减少;(3)各指标大多在20世纪90年代初期(1992、1993年)出现显著增加变点。

Basing on the daily precipitation data of eight meteorological stations during 1970 and 2009 in Shaoguan, the paper selected6 extreme precipitation indexes consulting World Meteorological Organization. Then this paper analyzed the spatial-temporal change trend of extreme precipitation based on annual mean values, variable coefficients, Mann-Kendall trend test and moving t-test technique. The results were shown as follows：（1）The annual variation of extreme precipitation is relatively great; In terms of annual mean values, R1 d and R5 d indexes decreased from the southeast to the northwest of Shaoguan, and the other four indexes decreased from west to east;（2）In terms of change trends, R1d、R5d、CDD were not significantly increase, R95 ptot was mainly not significantly decrease, and CWD, R95 p were mainly significantly decrease;（3）Almost all extreme indexes have shown significant increasing variation in the early 1990s（ 1992, 1993）.