Mapping surface water-groundwater interactions and associated geological faults using temperature profiling

In this study temperature profiling was used as a mapping tool to investigate surface water-groundwater interactions associated with low-permeability faults in the south-eastern part of the Netherlands. Data obtained from temperature profiling were simulated using a simple water and energy balance model. The model was used to quantify groundwater seepage rates near the faults. The model simulated the surface water temperature transects very well, but the model-based seepage rates are much higher than those reported in the literature for comparable hydrological settings. Of all the assumptions made in the model, the adopted values for the parameters that control the heat exchange between the water and the atmosphere are believed to be the most uncertain. Despite these uncertainties, temperature profiling proved to be a very useful tool to investigate surface water-groundwater interactions and to map groundwater seepage zones. The strength of using temperature as a tracer is that it is measured directly in the field with relative ease and using low cost equipment.