近50年来淮河流域降水时空变化特征分析

摘要

以淮河流域及周边地区48个气象站点1961年-2010年共50年逐日降水过程为基础资料,以地理信息系统技术为数据处理平台,结合Mann-Kendall秩次相关检验、Morlet小波变换和集对分析法(SPA)等,分析淮河流域年降水量时间序列趋势性、周期性以及降水集中度、集中期、降水质心、旱涝发生频率、旱涝交替在空间上的分布特征.结果表明:①近50年来,年降水量整体呈略微减少趋势,南部地区降水增加,北部地区降水减少；②年际变化上存在27年的主周期,年内分配集中在夏季,且北部地区降水更为集中；③干旱易发区分布面积较广,洪涝易发区分布相对较集中,上游和中游部分地区为旱涝交替易发区.%Based on the daily precipitation data of 48 weather stations in the Huaihe river basin and its surrounding area from 1961 to 2010, the characteristics of spatial and temporal patterns of precipitation were determined by the methods of Mann-Kendall rank correlation test,Morlet wavelet transform,and set pair analysis on the data processing platform of geographic information system. The spatial variations of the trend,periodicity,concentration degree,concentration period,and centroid of precipitation, the frequency of drought and flood,and the alternation of drought and flood were investigated. The results showed that (1) the precipitation decreased on the whole during the time period and it increased in the south but decreased in the north of the area; (2) the interannual variation of the precipitation had a 27-year primary period,and the precipitation occurred mainly in summer within a year and it was concentrated in the north of the area; (3) the drought-prone area was distributed widely whereas the flood-prone area was concentrated. The alternation of drought and flood existed mainly in the upper and middle reaches of the Huaihe river basin.