近期从水利部黄河水利委员会与海河水利委员会在银川联合主特召开的黄、海河流域汛期水文气象长期预报会商会上获悉,今年前期大气、海洋、高原积雪、气象要素、地温、地震、天文等物理因子和冬春以来气候出现不少异常特征,这些异常特征主要表现在:1997年春季发生的本世纪最强的厄尔尼诺现象至少还要持续到1998年夏季;北半球副热带高压从1998年1月以来异常偏强(历史最强);去冬今春,青藏高原积雪偏多,部分地区出现严重雪灾;1997年11月至1998年4月,长江流域及其以南地区降水异个偏多,不少地区出现了同期的历史极大值;1997～1998冬季气温较常年明显偏高,入春以来气温变化剧烈.3～4月南方出现了雷打雪的奇特现象;4月北方出现沙尘暴,其强度和范围也超出了历史记录;1998年太阳活动处在上升期……会议认为,1998年前期海洋、大气环流、降水、气温和天文背景都出现了极端异常现象,这些异常事件和现象将不可避免地会给黄、海河流域汛期带来重大影响作 Recently, the Yellow River Conservancy Commission of the Ministry of Water Resources and the Haihe River Conservancy Commission convened jointly by Yinchuan and the main special meeting of the Yellow River and Haihe River Basin Hydrological and Meteorological Long-term Forecast Chamber of Commerce was informed that early this year, the atmosphere, oceans, plateau snow cover, meteorological elements, geothermal, earthquakes, astronomy Such as the physical factors and the climate since winter and spring, there are a lot of anomalous features. These anomalies are mainly manifested in that the strongest El Niño phenomenon of this century that occurred in the spring of 1997 will last at least until the summer of 1998; the northern subtropical high will change from January 1998 Since the spring and early spring, the snow cover on the Qinghai-Tibet Plateau is more than normal, with severe snowstorms in some areas. From November 1997 to April 1998, the precipitation in the Yangtze River valley and the south of the Yangtze River Basin is quite different, In many areas, the historical maximum appeared over the same period; the temperature in 1997-1998 winter was significantly higher than that of normal years, and the temperature had changed drastically since spring. From March to April, there was a strange phenomenon of thunder and snow in the south; in April, Its intensity and range also exceeded the historical record; solar activity in 1998 is on the rise ... The meeting held that the pre-1998 ocean, atmospheric circulation, precipitation, temperature and weather Background extreme anomalies have emerged, these unusual events and phenomena will inevitably give yellow, have a major impact for Haihe River Basin flood