黄石市近60 a降水时空分布特征分析

An analysis on precipitation characteristics in Huangshi city in the last 60 years

利用黄石市2005年以来建设的95个区域气象站和原有的3个国家气象站降水资料,选取黄石国家气象站为基准点,采取各站候降水量与黄石站气温等12个要素进行逐步回归的方法,模拟出1958年至各站建站前的候降水量,使各站建站前缺测的月、年等时间尺度降水资料得以插补。并采用REOF方法分析了黄石市年降水量的时空变化特征,按照取绝对值最大的特征值所处序号为站点分类值的区划方法,将黄石市划分为丘陵及水体影响区(Ⅰ区)和山地陆面影响区(Ⅱ区)两个区域。结果表明:(1)黄石市年降水量年代际变化明显,20世纪60年代至90年代降水量逐渐增多,21世纪初明显偏少,2010年至今恢复至20世纪80—90年代的水平;(2)黄石市年降水量具有明显的地域特征,年降水受地形的影响较大,西南部山区年降水量大于丘陵区和大型水体影响区;(3)Ⅰ区和Ⅱ区降水强度同步的年数占72%,不同步的年数占28%。

Based on the precipitation data from 95 regional meteorological stations in Huangshi City since 2005 and 3 national meteorological stations,a stepwise regression analysis was conducted to simulate and impute the missing precipitation data of each station from 1958 to date,with national meteorological stations data benchmarked and 12 factors adjusted including the precipitation of each station and the temperature of Huangshi station.After imputing the missing precipitation data in different time scales,the REOF method was used to analyze the temporal and spatial annual precipitation variation in Huangshi City.The zoning method of taking the eigenvalue with the largest absolute value as the site classification value was used to divide Huangshi City into hills and water body affected areas(Area I)and mountain land affected area(Area II).The results show that(1)decadal variation of annual precipitation is obvious,as the precipitation gradually increased from 1960s to 1990s,decreased at the beginning of 21st century and recovered to the level of 1980s and 1990s from 2010 to date.(2)Distinct regional characteristics were founded in annual precipitation data with greater influence of topography.The annual precipitation in the mountainous area of southwestern Huangshi is larger than that of hilly area and large water body affected area.(3)Precipitation intensity in Zone I and Zone II is synchronized 72%of all the years in records,while unsynchronized years only constitute 28%.