How isotopic fractionation of snowmelt affects hydrograph separation

Susan Taylor, Xiahong Feng, Mark Williams, James McNamara

Research output: Contribution to journalArticlepeer-review

100 Scopus citations

Abstract

We present the isotopic composition of meltwater samples from four seasonal snowpacks: a warm, maritime snowpack in California; a temperate continental snowpack in Vermont; a cold continental snowpack in Colorado; and an Arctic snowpack in Alaska. Despite the very different climate conditions the δ18O of meltwater from all four snowpacks increased as melting progressed. This trend is consistent with theoretical results that model isotopic exchange between water and ice as meltwater percolates through a snowpack. We have estimated the systematic error in the hydrograph separation if the isotopic composition of a snow core were used in place of that of meltwater. Assuming no error in the old water or stream water values, the error in the new water fraction depends on: (1) the isotopic difference between the snow core and the old water; (2) the isotopic difference between the snow core and the meltwater; and (3) the new water fraction contributing to the stream flow, during a spring melt event. the error is large when snowmelt contributes a dominant fraction of the stream flow, which may be expected where infiltration of snowmelt is limited (e.g. permafrost, urban areas). A particular challenge will be how to incorporate the changes in isotopic composition of meltwater measured at a point into hydrograph separation models conducted at the watershed scale. Published in 2002 by John Wiley and Sons, Ltd.

Original languageEnglish
Pages (from-to)3683-3690
Number of pages8
JournalHydrological Processes
Volume16
Issue number18
DOIs
StatePublished - 30 Dec 2002

Keywords

  • O
  • Error analysis
  • Hydrograph separation
  • New water component
  • Snowmelt

Fingerprint

Dive into the research topics of 'How isotopic fractionation of snowmelt affects hydrograph separation'. Together they form a unique fingerprint.

Cite this