Windhorst, D.; Kraft, P.; Timbe, E.; Frede, H. & Breuer, L. (2014): <b>Stable water isotope tracing through hydrological models for disentangling runoff generation processes at the hillslope scale</b>. <i>Hydrol. Earth Syst. Sci.</i> <b>18</b>(10), 4113-4127.
Resource Description
Title:
Stable water isotope tracing through hydrological models for disentangling runoff generation processes at the hillslope scale
FOR816dw ID:
1310
Publication Date:
2014-10-16
License and Usage Rights:
PAK 823-825 data user agreement. (www.tropicalmountainforest.org/dataagreementp3.do)
email:
edison_timbe <at> yahoo.com
Victor Manuel Albornoz - Quinta Balzay
Universidad de Cuenca Cuenca
Ecuador
Individual:
Hans-Georg Frede
Contact:
email:
hans-georg.frede <at> umwelt.uni-giessen.de
Heinrich-Buff-Ring 26
Institute for Landscape Ecology and Resources Management
Justus-Liebig-University Gießen
35392 Gießen
Germany
Individual:
Lutz Breuer
Contact:
email:
lutz.breuer <at> umwelt.uni-giessen.de
Heinrich-Buff-Ring 26
Institute for Landscape Ecology and Resources Management
Justus-Liebig-University Gießen
35392 Gießen
Germany
Abstract:
Hillslopes are the dominant landscape components<br/>
where incoming precipitation becomes groundwater, streamflow<br/>
or atmospheric water vapor. However, directly observing<br/>
flux partitioning in the soil is almost impossible. Hydrological<br/>
hillslope models are therefore being used to investigate<br/>
the processes involved. Here we report on a modeling<br/>
experiment using the Catchment Modeling Framework<br/>
(CMF) where measured stable water isotopes in vertical<br/>
soil profiles along a tropical mountainous grassland hillslope<br/>
transect are traced through the model to resolve potential<br/>
mixing processes. CMF simulates advective transport of<br/>
stable water isotopes 18O and 2H based on the Richards equation<br/>
within a fully distributed 2-D representation of the hillslope.<br/>
The model successfully replicates the observed temporal<br/>
pattern of soil water isotope profiles (R2 0.84 and Nash–<br/>
Sutcliffe efficiency (NSE) 0.42). Predicted flows are in good<br/>
agreement with previous studies. We highlight the importance<br/>
of groundwater recharge and shallow lateral subsurface<br/>
flow, accounting for 50 and 16% of the total flow leaving the<br/>
system, respectively. Surface runoff is negligible despite the<br/>
steep slopes in the Ecuadorian study region.
Keywords:
| isotopes | isotope tracers | hydrological catchment model |
