Abstract
This paper presents 19 months of stable isotope (delta H-2 and delta O-18) data to enhance understanding of water and solute transport at two spatial scales (2.3 km(2) and 122 km(2)) in the agricultural Lunan catchment, Scotland. Daily precipitation and stream isotope data, weekly lake and spring isotope data and monthly groundwater isotope data revealed important insights into flow pathways and mixing of water at both scales. In particular, a deeper groundwater flow path significantly contributes to total streamflow (25-50%). Upstream lake isotope dynamics, susceptible to evaporative fractionation, also appeared to have an important influence on the downstream isotope composition. This unique tracer data set facilitated the conceptualization of a lumped catchment-scale flow-tracer model. The incorporation of hydrological, mixing and fractionation processes based on these data improved simulations of the stream delta H-2 isotope response at the catchment outlet from 0.37 to 0.56 for the Nash-Sutcliffe statistic. The stable isotope data successfully aided model conceptualization and calibration in the quest for a simple water and solute transport model with improved representation of process dynamics. (C) 2010 Elsevier Ltd. All rights reserved.
Original language | English |
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Pages (from-to) | 383-394 |
Number of pages | 12 |
Journal | Advances in Water Resources |
Volume | 34 |
Issue number | 3 |
Early online date | 17 Dec 2010 |
DOIs | |
Publication status | Published - Mar 2011 |
Keywords
- stable isotopes
- conceptual models
- fractionation
- spatial scale
- hydrological processes
- storm runoff
- transit-time
- water
- uncertainty
- transport
- future
- deuterium
- tracers
- precipitation
- groundwater