Stable and radioactive isotopes and other natural and artificial tracers are useful tools to (i) fingerprint the sources of water and solutes in catchments, (ii) trace flow pathways, and/or (iii) quantify exchanges of water, solutes and particulates between hydrological compartments both in the natural and simulated environments. We invite contributions that demonstrate novel applications and recent developments of isotope and other tracer techniques in hydrological field studies and data driven or physical modelling in the areas of surface water-groundwater interactions, unsaturated and saturated zone, rainfall-runoff processes, cold-region hydrology, nutrient or contaminant transport, ecohydrology or other catchment processes.