海河流域近500年旱涝演变规律分析

研究海河流域近500年旱涝演变规律能为流域防汛抗旱、防灾减灾提供科学依据。基于海河流域内1470—2000年间11个序列较完整站点的旱涝等级数据，采用小波分析、功率谱分析以及经验正交分解方法对海河流域旱涝时空演变规律进行了分析研究。结果表明:（1）海河流域1470—2000年期间经历了干旱（1470—1644年）-湿润（1645—1898年）-干旱（1899—2000年）的旱涝转换；（2）1470—2000年流域旱涝呈现出2~7年、10.4年、19年、22年和25年左右的周期性变化特征，其中10.4和22年周期变化显著；（3）EOF第一模态表现为全流域性的干旱或洪涝，其方差贡献率为44%；第二模态为流域自西向东涝-旱-涝（或旱-涝-旱）的分布特征，其方差贡献率为12%。

Evolution of drought and flood in the Haihe Rvier Basin for the last 500 years

The study on the evolution of drought and flood in the Haihe River Basin for the last 500 years can provide a scientific basis for regional flood control and drought relief, disaster prevention and mitigation. Based on the dryness/wetness grade data of 11 stations with complete sequence from 1470 to 2000 in the Haihe River Basin, the temporal and spatial evolution of drought and flood has been detected, using the methods of wavelet analysis, power spectrum analysis and empirical orthogonal decomposition. The results show that: (1) the Haihe River Basin has experienced obvious fluctuation of dry (1470－1644) - wet (1645－1898) - dry (1899－2000); (2) from 1470 to 2000, the occurrence of drought/flood has periodicity of 2~7 a, 10.4 a, 19 a, 22 a and 25 a, of which 10.4 a and 22 a are particularly significant; (3) the first mode of EOF analysis is characterized by drought or flood over the whole basin, and its variance contribution rate is 44%. The second mode, explaining 12% of total variance, shows the distribution characteristics of flood-drought-flood (or drought-flood-drought) from west to east.