T257 Watershed-Based Research and Education: The State of the Science (Posters)

Wednesday, 5 November 2003
1:30 PM - 5:30 PM

ANALYZING APPROPRIATE SAMPLING SCHEMES FOR d18O IN HYDROGRAPH SEPARATIONS

Paper number: T257-4
Program: Technical Sessions
Time: 1:30 PM – 5:30 PM

Authors

Abstract

d18O IS A WIDELY ACCEPTED CONSERVATIVE TRACER USED IN SEPARATING EVENT HYDROGRAPHS INTO NEW AND OLD WATER CONTRIBUTIONS TO STREAMFLOW. SNOWMELT EVENTS REQUIRE A LARGE NUMBER OF d18O MEASUREMENTS BECAUSE THE CONCENTRATION OF SNOWMELT IS TEMPORALLY VARIABLE THROUGHOUT A SPRING MELT. OBTAINING A LARGE NUMBER OF d18O SAMPLES IS LABOR INTENSIVE AND LABORATORY RESULTS ARE EXPENSIVE. THE NUMBER OF SNOWMELT d18O SAMPLES ANALYZED MAY BE MINIMIZED IF A SYSTEMATIC DIFFERENCE OR LACK OF DIFFERENCE IS OBSERVED BETWEEN SAMPLE LOCATIONS. SNOWMELT SAMPLES HAVE BEEN COLLECTED FROM TWELVE BUCKETS BURIED AT DIFFERENT ELEVATIONS AND ASPECTS IN A 0.2 KM2 MOUNTAINOUS CATCHMENT WITHIN THE DRY CREEK EXPERIMENTAL WATERSHED NORTH OF BOISE, ID. THIRTY-SIX SAMPLES FROM 6 DIFFERENT DAYS DURING A MELT EVENT WILL BE ANALYZED FOR d18O AND THE BENEFITS OF HAVING A HIGH SPATIAL AND TEMPORAL SAMPLING DENSITY WILL BE EVALUATED. BY MINIMIZING THE NUMBER OF SAMPLES ANALYZED THE COST OF AN EFFECTIVE HYDROGRAPH SEPARATION MAY BE MINIMIZED.