Isotope Hydrograph Separation in Alpine Catchments:A Review

Isotope hydrograph separation(IHS) is a basic tool in applied hydrology.Its application has expanded to surface water and groundwater interaction,eco-hydrological processes,etc.In this paper,the progress made in IHS for alpine catchments is reviewed,with an emphasis on its statistical significance in reflecting the impact of global change on water resources.Meanwhile,the principle of ISH and its uncertainties are explained in details.The mechanism of variation of stable isotopes in snow meltwater is discussed and then the methods to improve the separation during snowmelt,such as volume weighted average method,current meltwater method and runoff-corrected event water approach,are suggested,considering their advantages and disadvantages.New approaches may expand the applications of IHS,for example,large basin studies in combination with GIS,new theories of runoff generation in combination with other parameters such as deuterium excess,DOC and so on.