分别选取洮河流域岷县站、李家村站和红旗站1945~2001年、1957~2001年和1957~2001年的月平均径流资料,采用Mann—Kendall趋势检验法来检验径流的趋势变化,结果表明:近半个世纪以来,洮河流域的径流呈现出明显的减少趋势。应用功率谱分析方法,得出了洮河流域不同径流序列的变化周期。
Discharge trends in the Tao River basin were analyzed based on monthly discharge. The Mann - Kendall statistical method was used to test the runoff trend. The results indicated that there was obvious decrease since 1950s. Then the power chart analysis was used to test the runoff periodic, and the change periodic of different series was obtained.