Timbe, E.; Windhorst, D.; Celleri, R.; Timbe, L.; Crespo, P.; Frede, H.; Feyen, J. & Breuer, L. (2015): <b>Sampling frequency trade-offs in the assessment of mean transit times of tropical montane catchment waters under semi-steady-state conditions</b>. <i>Hydrology and Earth System Sciences</i> <b>19</b>(3), 1153-1168.
Resource Description
Title:
Sampling frequency trade-offs in the assessment of mean transit times of tropical montane catchment waters under semi-steady-state conditions
FOR816dw ID:
1343
Publication Date:
2015-03-02
License and Usage Rights:
PAK 823-825 data user agreement. (www.tropicalmountainforest.org/dataagreementp3.do)
Resource Owner(s):
Individual:
Edison Timbe
Contact:
email:
edison_timbe <at> yahoo.com
Victor Manuel Albornoz - Quinta Balzay
Universidad de Cuenca Cuenca
Ecuador
email:
rcelleri <at> gmail.com
Dirección de Investigación
Cuenca
Ecuador
Individual:
Luis Timbe
Contact:
email:
webmaster <at> tropicalmountainforest.org
Individual:
Patricio Crespo
Contact:
email:
pcrespos <at> yahoo.com
168 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:
Jan Feyen
Contact:
email:
webmaster <at> tropicalmountainforest.org
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:
Precipitation event samples and weekly based water samples from streams and soils were collected in a tropical montane cloud forest catchment for 2 years and analyzed for stable water isotopes in order to understand the effect of sampling frequency in the performance of three lumped-parameter distribution functions (exponential-piston flow, linear-piston flow and gamma) which were used to estimate mean transit times of waters. Precipitation data, used as input function for the models, were aggregated to daily, weekly, bi-weekly, monthly and bi-monthly sampling resolutions, while analyzed frequencies for outflows went from weekly to bi-monthly. By using different scenarios involving diverse sampling frequencies, this study reveals that the effect of lowering the sampling frequency depends on the water type. For soil waters, with transit times on the order of few weeks, there was a clear trend of over predictions.<br/>
In contrast, the trend for stream waters, which have a more damped isotopic signal and mean transit times on the order of 2 to 4 years, was less clear and showed a dependence on the type of model used. The trade-off to coarse data resolutions could potentially lead to misleading conclusions on how water actually moves through the catchment, notwithstanding that these predictions could reach better fitting efficiencies, fewer uncertainties, errors and biases. For both water types an optimal sampling frequency seems to be 1 or at most 2<br/>
weeks. The results of our analyses provide information for the planning of future fieldwork in similar Andean or other catchments.
