Can high-resolution isotope data help identify and model dominant runoff processes at different catchment scales?
Abstract
New techniques of stable isotope analysis offer tremendous potential for generating inexpensive, high temporal resolution data that can provide integrated insights into dominant runoff processes at a range of catchment scales. Here we present, results from 18 month of daily isotope sampling that were used to conceptualize rainfall-runoff processes in two nested (2.3 km2 and 122 km2) Scottish catchments. This fine resolution data reveals important dynamics in precipitation and in streamflow, which are not always evident in more usual weekly samples. Incorporating daily variation of precipitation inputs was critically important in simulating the stream isotope response - at both scales - using a low parameter conceptual rainfall-runoff model .The simple model was able to simulate isotope dynamics at the 122km2 scale, but much less successful at the 2.3 km2 scale. This appears to be related to the relative difficulty in capturing important process heterogeneity and non-linearity at the small scale, compared to simpler, emergent behavior at the larger mesoscale.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.H32D..05B
- Keywords:
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- 1041 GEOCHEMISTRY / Stable isotope geochemistry;
- 1847 HYDROLOGY / Modeling