Use of univariate clustering to identify transport modalities in karst aquifers

Transport modalities in karst aquifers are complex. Current methods do not allow quantification and identification of transport processes occurring over very short time scales. Resuspension and deposition of sediment occurring during flood conditions must be analysed at a high temporal resolution. These phenomena, occurring over very short time scales, can affect the water balance at the scale of the hydrologic year. This paper presents the application of univariate clustering for a hydrologic year at a karst spring. The results are consistent with those obtained by usual methods at the flood time scale. Moreover, this new method allows decomposition of the annual volume of spring water into its various transport modalities. For this example, the discharge of water from the spring over the course of a year was decomposed into four components: groundwater (47.7%), surface storm-derived water accompanied by the direct transfer of particles (23.7%), whereas 28.6% of the annual water balance is associated with periods of deposition (February to May, 13.2%) or resuspension (June to August, 15.4%).