宜昌站1882-2007年径流变化规律分析

Runoff Change Rule Analysis of Yichang Station from 1882 to 2007

以长江流域宜昌站1882-2007年的天然径流序列为基础数据,采用Mann-Kendall检验法和小波分析等统计方法,对径流序列各年代年内变化和年际分配变化进行了分析。结果表明,年内变化中,宜昌站径流分配不均匀,各个年代径流量集中在汛期;不均匀性和集中程度以20世纪20-50年代最明显,21世纪初最不明显,其他年份均介于二者之间,差别不大。在年际变化中,宜昌站多年径流量呈现减少的趋势,但并不显著;1935年左右为径流突变年份,径流量由突变前的14432 m3/s减少到突变后的13471 m3/s,减少了961 m3/s;多年径流量均存在12 a和27 a的变化周期。

Mann-Kendall inspection and wavelet analysis methods were used to analyze runoff change data during 1882--2007 of Yichang station. The results showed that： the runoff distribution was nonuniform during the year, runoff mainly concentrated in flood season in each year. The inhomogeneity and concentration degree of the runoff were most obvious from 1920s to 1950s, while were most unobvious at the beginning of the 21st century, the rest of the years were little difference. In the interannual variation, the annual runoff of Yichang station showed a decreasing trend, but it was not significant. The mutation year was 1935 and the runoff reduced from 14432 m3/s to 13471 m3/s, and the cycle of annual runoff of Yichang station is 12 and 27 years .