【摘要】 利用十堰市7个代表站1953~2006年的降水资料和气温资料,用降水距平百分率(R指标)这一传统的干旱等级划分方法,并考虑到气温引入了P指标对干旱等级进行了划分,揭示了该区域干旱发生的基本特征。结果表明:十堰是我国中部地区干旱频发地区之一,干旱存在自身的周期性和连续发生的规律,地理分布是北部重于南部。造成十堰干旱的主要天气系统是东亚大槽、副热带高压和青藏高压(大陆高压)。这3个系统交替影响并控制该市:春季主要是东亚大槽稳定;夏季副热带高压控制为主、大陆高压控制次之;秋季大陆高压控制为主、副热带高压控制次之。根据不同季节和不同类型的干旱,给出了具体的预报指标。更多还原

【Abstract】 By means of monthly rainfall and temperature data from 1953 to 2006 at seven stations in Shiyan,the summer droughts are divided by the traditional method(R index).Considering that besides rainfall,temperature has also important effect on droughts,P index is designed to divide summer droughts.The results indicate that Shiyan is one of areas attacked by droughts frequently;there exists periodicity and continuity in Shiyan droughts;droughts are severer in the northern part than those in the southern part.The main influencing weather systems include the East Asia trough,subtropical high,Qinghai-Tibet high(mainland high),which influence Shiyan alternately,controlled by East Asia trough in spring,by the subtropical high and mainland high in summer,and by the mainland high and subtropical high in autumn.Detailed forecast indexes are given according to different seasons and drought types.更多还原