典型表层岩溶水系统降水量与泉流量的交叉小波分析

利用2002年3月至2008年12月龙怀表层岩溶水系统降水量与2个表层岩溶泉泉流量资料,采用连续小波变换、交叉小波变换与小波相干方法,对龙怀表层岩溶水系统降水量及表层岩溶泉泉流量多时间尺度特征及相关关系进行了分析。结果表明:龙怀表层岩溶水系统降水量主振荡周期为0.77～1.16a,布洋1号泉与龙何下泉泉流量的主振荡周期均为0.82～1.23a,而其高频部分周期变化均不连续,其动态特征均以年际变化为主;交叉小波变换揭示COI区域外降水量与布洋1号、龙何下泉泉流量的主共振周期均为0.77～1.23a,且涵盖全部时域,2个表层岩溶泉对降水的响应是显著和稳定的;表层岩溶泉泉流量存在稳定的落后于降水量的相位变化,布洋1号、龙何下泉分别落后于降水量0.61d、2.63d左右,表层岩溶泉径流过程为其泉域特征所制约;小波相干谱表明降水量与布洋1号泉流量在0.17～2.45a的全频域均显著共振,与龙何下泉在0.17～1.55a的周期上显著共振,且二者均涵盖了大部分时域,降水量与泉流量动态高度相关。

Cross Wavelet Analysis of Relationship between Precipitation and Spring Discharge of a Typical Epikarst Water System

Multi-time scale characteristics and correlation of precipitation and epikarst spring discharge sequence of the Longhuai epikarst water system were analyzed by the continuous wavelet transform,cross-wavelet transform and wavelet coherence method using precipitation and two epikarst spring discharge data of the Longhuai epikarst water system from Mar.,2002 to Dec.,2008.The results showed that the main oscillation period of precipitation of the Longhuai epikarst water system is within the range of 0.77~1.16 a while the periods of discharge sequence of Buyang No.1 spring and Longhexia spring are both within the range of 0.82~1.23 a.The periods in high frequency band are all uncontinuous,so the dynamic characteristics of all periods are mainly of annual variation.The cross wavelet transforms revealed that the main in-phase resonance oscillation periods between the precipitation and both discharges of Buyang No.1 spring and Longhexia spring are within the range of 0.77~1.23 a and they cover the entire time domain.The responses of the two epikarst springs to precipitation are significant and steady.There is a steady phase relationship between precipitation and spring discharge.The variation of Buyang No.1 spring discharge occurs for about 0.61 d after that of the precipitation,while the variation of Longhexia spring discharge occurs at about 2.63 d after that of the precipitation.The runoff processes of the epikarst springs are restricted by their spring region characteristics.Wavelet coherence spectral analysis showed that the precipitation and Buyang No.1 spring discharge have significant resonance oscillation relationship in 0.17~2.45 a,which is the entire frequency domain,while the precipitation and Longhexia spring discharge have significant resonance oscillation relationship in 0.17~1.55 a.Both the relationships cover most of the time domain.The precipitation and the spring flux dynamics are highly correlated with each other.