云南洛甸河径流量的时间特征分析

利用经验模态分解(Empirical Mode Deposition,简称EMD)及Pettit突变检验方法,分析了昭通地区洛甸河水文站1961~2014年的年均径流量、年最大径流量、年最小径流量序列变化的周期、趋势、突变规律。结果表明:洛甸河水文站年均径流量经过EMD得到3个IMF分量和一个趋势项,各IMF分量反映的周期为3,6.5a及17 a,趋势项表明年均径流量在1961~1980年存在上升趋势,1980年后存在下降趋势。最大、最小径流量分解得到4个IMF分量和一个趋势项,各IMF分量反映的小尺度周期信息为3,6.5 a及12~17 a,大周期尺度为27 a及45 a,趋势项RES反映序列呈现出明显的下降趋势,在1980年后下降趋势较明显。Pettit突变检验结果表明洛甸河年均径流量及年降水量在1986年存在一个不明显的突变点,最大、最小径流量的突变点可能发生在1991年附近。

Runoff temporal characteristics of Luodian River in Yunnan Province

Empirical Mode Decomposition (EMD) and Pettit mutation test were used to analyze the runoff variation at Luodian station in Zhaotong City, Yunnan Province from 1961-2014, including the variation cycle, variation tendency, mutation of annual average runoff, annual maximum runoff and minimum runoff. The results show that the annual runoff can be decomposed into three Intrinsic Mode Functions (IMFs) components and one tendency component, the IMFs represent the periods of 3a, 6.5a and 17a. The residual component indicates an increasing tendency from 1961 to 1980, and a decreasing tendency from 1980 to 2014. The maximum runoff and minimum runoff can be decomposed into four IMFs components and one tendency component. The IMF represent the small periods of 3a, 6.5a, 12~17a, and a large periods of 27a and 45a. The tendency component indicates an obvious decreasing tendency after 1980. The results from Pettit mutation test show that the annual average runoff and annul precipitation has a mutation point around 1986, while the annual maximum and minimum runoffs have a mutation point around 1991.