Snowmelt runoff from measurements of tritium and oxygen‐18

Abstract

During 1965–1967 the snowmelt runoff in a small mountain basin in Northern Czechoslovakia was studied by measuring the tritium and oxygen‐18 content of precipitation, snowpack, and runoff, in addition to an improved degree‐day method which was used as a standard tool. The results showed that about two‐thirds of the meltwater infiltrated to the soil, and the displaced water recharged during the previous years toward the stream channels. The tritium content of the baseflow and the subsurface runoff indicated that the mean residence time of the subsurface water in the basin was approximately 2.5 years with a standard deviation of 1.25 years. The volume of the subsurface storage was estimated to be 2.6×10 6 m 3 . The oxygen‐18 content of snow samples was in agreement with the tritium results on the relative contribution of the meltwater and subsurface runoff to the total runoff from the basin.