1998和2010年长江流域汛期洪涝成因对比分析

1998年和2010年长江流域均出现区域性大洪水,水位均超警戒线。2010年长江上游嘉陵江、岷沱江流域支流渠江发生超历史性洪水,虽然江苏省沿江地区汛期降水量正常略多,但汛期有降水较集中的时段,上游客水和江苏省的强降水时段叠加,造成长江下游超警水位。对比分析了1998年与2010年夏季长江流域区域性洪涝的的成因,这两年,前冬都表现为厄尔尼诺事件,而南海夏季风爆发早晚虽不同,但南海夏季风都明显偏弱,副热带高压强度指数偏强,位置明显偏南,冬季积雪偏多。

Comparative analysis of the flooding causes over Yangtze River in 1998 and 2010

Two floods occurred in 1998 and 2010 in the Yangtze River. The coincidence of heavy rain occurred within Jiangsu province and stream which came from upper reach of the Yangtse River led to super warning water level. Comparative analysis indicated that the following factors played important role in the flooding which broke the historical record:appearance of EI Nino in the previous winter;weaker South China Sea summer monsoon locating further south than normal; higher level of subtropic high intensity index; scarcity of typhoon;more frequent snow in winter.