新疆洪旱灾害与大尺度气候强迫因子的联系

Potential Links of Flood and Drought Disasters in Xinjiang to some Larger-scale Climatic Driving Forces

通过对新疆洪灾灾害历史资料和太阳黑子、ENSO事件年数据以及北大西洋涛动指数的分析 ,表明在太阳黑子极低值年或不活跃年 ,新疆易发生重大洪灾 ,而在太阳黑子低值年或相对不活跃年 ,新疆也易发生重大旱灾。近 2 0 0a来 ,新疆重大洪旱灾害绝大部分都发生在太阳黑子的低谷时期。ENSO事件对新疆夏季降水的影响效应明显。因而该事件对新疆的洪旱灾害也产生了影响。对近 5 0年来灾害统计资料分析显示 ,与拉尼娜年相比 ,在厄尔尼诺年新疆更易发生洪旱灾害。 2 0世纪后半段新疆洪旱灾害指数与北大西洋涛动指数进行对比可以发现 ,夏季NAO指数与新疆洪水灾害之间存在大致上的反相关系。而冬季NAO指数与新疆干旱灾害之间存在比较明显的反相关系。

This paper aims to analysis links of flood and drought disasters in Xinjiang to some larger-scale climatic driving forces,including sunspots,El Nino and Southern Oscillation. Based on some compiled historical records on floods and droughts,heavy catastrophic flood and drought years in past 200 years were distinguished using some indicators,such as damaged cropland areas and houses,etc. Indexes of flood and drought damaged cropland areas were also calculated. Then,figures and maps were drawn for purpose of comparison between flood and drought disasters in Xinjiang and some larger-scale climatic driving forces mentioned above. The analyzed results showed that Xinjiang was susceptible to heavy catastrophic floods in years with lowest sunspot numbers,and to heavy catastrophic droughts in years with lower sunspot numbers. In past 200 years,most of the heavy catastrophic floods and droughts in Xinjiang occurred in years with lowest or lower sunspot numbers. ENSO has significant effects on summer precipitation,and thus flood and drought in Xinjiang. The analyzed results of the disaster records showed that Xinjiang was more susceptible to heavy catastrophic floods and droughts in El Nino years than in La Nina years during past 50 years. There was an obvious negative correlation between index of Northern Atlantic Oscillation in summer and index of flood disasters in the same period. Moreover,significant negatively correlation between index of NAO in winter and index of drought disasters in Xinjiang can be seen.