资源环境科技发展态势分析平台

Karstified carbonate aquifers are highly heterogeneous systems characterised by multiple recharge, flow and discharge components. The quantification of the relative contribution of these components, as well as their numerical representation, remains a challenge. This paper identifies three recharge components in the time and frequency domain. While the analysis in the time domain follows traditional approaches, the analysis of the power spectrum allows frequencies associated with specific spectral coefficients and noise types to be distinguished more objectively. The analysis follows the presented hypothesis that the different frequency‐noise components are the result of aquifer heterogeneity transforming the random rainfall input into a sequence of non‐Gaussian signals. The distinct signals are then numerically represented in the context of a semi‐distributed pipe network model in order to simulate recharge, flow and discharge of an Irish karst catchment more realistically. By linking the power spectra of the modelled recharge components with the spectra of the spring discharge, the information usually gained by classical performance indicators is significantly widened. The modelled spring discharge is well matched in the time and frequency domain, yet, the different recharge dynamics explain the signal of the aquifer outlet in different noise domains across the spectrum. This study demonstrates the conjunctive use of frequency analysis in conceptualisation of a hydrological system together with modelling and evaluation.