太阳活动与ENSO事件对汉江谷地旱涝灾害影响分析

Analysis of the influence of solar activities and ENSO events on the drought and flood in river Hanjiang valley

为探究汉江谷地旱涝灾害发生机理,根据18个代表站点1960-2010年气象资料,运用Z指数法界定出旱涝灾害等级和年份后,分析太阳黑子活动和ENSO事件对汉江谷地旱涝灾害的关系。结果表明:1)研究时段内汉江谷地呈暖干化趋势,气温以0.136℃/10a的速度上升,降水以15.7mm/10a的速度减少,旱涝灾害的发生呈增加趋势。2)20世纪70-80年代旱涝灾害指数与太阳黑子数呈负相关,80年代后二者呈正相关,太阳黑子的减少趋势与研究区域干旱化趋势相同。3)厄尔尼诺强度增大时研究区域的涝灾增多,拉尼娜发生强度增大时旱灾增多。

In order to explore the mechanism of droughts and floods in Hanjiang river valley,according to the 18 representative stations,meteorological data in the Southern Shaanxi Hanjiang river valley,we used Z-index tocalculate the precipitation,define the level years of drought and flood disasters and analyzed the influence of sunspot activity and ENSO events on drought and flood in Southern Shaanxi Hanjiang river valley.The results indicate： Firstly,in the scope of study period the Hanjiang river valley was warming and drying with the speed of 0.136℃ per ten years up of temperature and 15.7mm per ten years down of precipitation,and the occurrence of drought and flood disasters increased.Secondly,the drought and flood indices and the sunspot number were negatively correlated from 1960-1979,and after 1980 the two turn to positively correlated;the same sunspots decreasing trend was as the drought trend.Thirdly,in the study area the Ei Nino intensity increased with the flood disasters increase,and the LaNina intensity increased with the drought disasters increase.