Field investigation of preferential fissure flow paths with hydrochemical analysis of small-scale sprinkling experiments

The unsaturated zone largely controls groundwater recharge by buffering precipitation while at the same time providing preferential flow paths for infiltration. The importance of preferential flow on landslide hydrology is recognised in the literature; however, its monitoring and quantification remain difficult. This paper presents a combined hydrological and hydrochemical analysis of small-scale sprinkling experiments. It aims at showing the potential of such experiments for studying the spatial differences in dominant hydrological processes within a landslide. This methodology was tested in the highly heterogeneous black marls of the Super-Sauze landslide. The tests were performed in three areas characterised by different displacement rates, surface morphology and local hydrological conditions. Special attention was paid to testing the potential of small-scale sprinkling experiments for identifying and characterising preferential flow patterns and dominant hydrological processes.