A COUPLED APPROACH OF SURFACE HYDROLOGICAL MODELLING AND WAVELET ANALYSIS FOR UNDERSTANDING THE BASEFLOW COMPONENTS OF RIVER DISCHARGE IN KARST ENVIRONMENTS

This work examines the possibility of using a surface hydrology model in a karst environment. In these kinds of environments, deterministic models such as SWAT, and the majority of surface hydrology models, are unable to compute the added contribution due to subsurface circulation. This can result in a substantial under-estimation of the river flows. Therefore such models are generally not applied by researchers to complex watersheds. Often the simulation of spring discharges is in itself very complex, making it even more difficult to simulate river discharge in karst environments, where the flow contribution coming from karst conduits cannot be directly measured. The present paper investigates the advantages of applying Wavelet Analysis (WA) to this field. The statistical method of WA has been recently applied in hydrogeology for interpreting spring discharges, and in hydrology to describe the variability of streamflows, thus providing insights into their dynamical link with the dominant modes of climate variability. However it has not yet been directly used to support the understanding of river flow components in karst environments. What is more, the present work proposes using WA not merely to assist in the analysis of experimental series, but also as a tool for interpreting the data series generated by the modelling process. In this paper we shall describe how WA can potentially be applied to help define the nature and behaviour of the karst contribution to river flows, thereby improving the future performance of surface hydrological modelling.