The contribution of D. A. Burns to this article was prepared as part of his official duties as a United States Federal Government employee.
How does landscape structure influence catchment transit time across different geomorphic provinces?
Article first published online: 28 JAN 2009
Copyright © 2009 John Wiley & Sons, Ltd.
Volume 23, Issue 6, pages 945–953, 15 March 2009
How to Cite
Tetzlaff, D., Seibert, J., McGuire, K. J., Laudon, H., Burns, D. A., Dunn, S. M. and Soulsby, C. (2009), How does landscape structure influence catchment transit time across different geomorphic provinces?. Hydrol. Process., 23: 945–953. doi: 10.1002/hyp.7240
- Issue published online: 24 FEB 2009
- Article first published online: 28 JAN 2009
- Manuscript Accepted: 21 NOV 2008
- Manuscript Received: 18 AUG 2008
- NSF LTER. Grant Number: DEB 021-8088
- Swedish Science Foundation, Formas and the Swedish EPA
- Rural and Environment Research and Analysis Directorate of the Scottish Government
- catchment transit times;
- landscape structure;
- geomorphic provinces;
- isotopic tracers;
- quantitative landscape analysis;
- northern temperate regions
Despite an increasing number of empirical investigations of catchment transit times (TTs), virtually all are based on individual catchments and there are few attempts to synthesize understanding across different geographical regions. Uniquely, this paper examines data from 55 catchments in five geomorphic provinces in northern temperate regions (Scotland, United States of America and Sweden). The objective is to understand how the role of catchment topography as a control on the TTs differs in contrasting geographical settings. Catchment inverse transit time proxies (ITTPs) were inferred by a simple metric of isotopic tracer damping, using the ratio of standard deviation of δ18O in streamwater to the standard deviation of δ18O in precipitation. Quantitative landscape analysis was undertaken to characterize the catchments according to hydrologically relevant topographic indices that could be readily determined from a digital terrain model (DTM). The nature of topographic controls on transit times varied markedly in different geomorphic regions. In steeper montane regions, there are stronger gravitational influences on hydraulic gradients and TTs tend to be lower in the steepest catchments. In provinces where terrain is more subdued, direct topographic control weakened; in particular, where flatter areas with less permeable soils give rise to overland flow and lower TTs. The steeper slopes within this flatter terrain appear to have a greater coverage of freely draining soils, which increase sub-surface flow, therefore increasing TTs. Quantitative landscape analysis proved a useful tool for inter-catchment comparison. However, the critical influence of sub-surface permeability and connectivity may limit the transferability of predictive tools of hydrological function based on topographic parameters alone. Copyright © 2009 John Wiley & Sons, Ltd.