淮河流域和长江中下游流域旱涝年的划分

利用1951—2007年国家气象信息中心提供的756站逐日降水资料,通过计算6—7月降水标准差,确定淮河流域和长江中下游流域降水变率最大的站点,分别计算各站与这两个流域降水变率最大的站点相关系数,把通过显著性检验的站点分别作为淮河流域和长江中下游流域的代表站。利用两流域代表站的标准化降水指数确定了1951—2007年的旱涝年份:淮河流域的旱年为1952年、1959年、1961年等共10 a,涝年为1954年、1956年、1957年等共9 a;长江中下游流域的旱年为1952年、1958年、1961年等共11 a,涝年为1954年、1969年、1980年等共10 a。结合水文资料进行修订后,确定了1951—2007年淮河流域和长江流域因梅雨季降水而导致的洪涝年份。

Identification of Floods and Droughts Years over Huaihe River Basin and over the Middle and Lower Reaches of the Yangtze River Basin

Using the daily rainfall amounts data-sets of 756 stations in 1951-2007 provided by National Meteorological Information Center,the stations that precipitation variation were biggest were found over Huaihe River Basin(HRB) and over the middle and lower reaches of the Yangtze River Basin(YRB-MLR) after computing precipitation standard deviation in June-July period.By computing the simultaneous correlation of all stations over the two basins and the two stations of the biggest precipitation variation,the stations that correlation was significant were regarded as representative stations of HRB and YRB-MLR respectively.The floods and droughts years in 1951-2007 were identified with the help of standardized rainfall index of the representative stations over the two basins.There were 10 droughts years over HRB,such as 1952,1959 and 1961,etc.,and 9 floods years,such as 1954,1956,1957,and so on.11 droughts occurred in YRB-MLR,such as 1952,1958,etc.,and 10 floods,such as 1954,1969,1980,and so on.With the aid of hydrological reference,the floods and droughts years were revised.The years of floods and droughts in the rainy season in the periods of 1950-2007 were finally defined.