TY  - JOUR
A1  - Zimmermann, Beate
A1  - Zimmermann, Alexander
A1  - Turner, Benjamin L.
A1  - Francke, Till
A1  - Elsenbeer, Helmut
T1  - Connectivity of overland flow by drainage network expansion in a rain forest catchment
T2  - Water resources research
N2  - Soils in various places of the Panama Canal Watershed feature a low saturated hydraulic conductivity (K-s) at shallow depth, which promotes overland-flow generation and associated flashy catchment responses. In undisturbed forests of these areas, overland flow is concentrated in flow lines that extend the channel network and provide hydrological connectivity between hillslopes and streams. To understand the dynamics of overland-flow connectivity, as well as the impact of connectivity on catchment response, we studied an undisturbed headwater catchment by monitoring overland-flow occurrence in all flow lines and discharge, suspended sediment, and total phosphorus at the catchment outlet. We find that connectivity is strongly influenced by seasonal variation in antecedent wetness and can develop even under light rainfall conditions. Connectivity increased rapidly as rainfall frequency increased, eventually leading to full connectivity and surficial drainage of entire hillslopes. Connectivity was nonlinearly related to catchment response. However, additional information on factors such as overland-flow volume would be required to constrain relationships between connectivity, stormflow, and the export of suspended sediment and phosphorus. The effort to monitor those factors would be substantial, so we advocate applying the established links between rain event characteristics, drainage network expansion by flow lines, and catchment response for predictive modeling and catchment classification in forests of the Panama Canal Watershed and in similar regions elsewhere.
KW  - connectivity
KW  - overland flow
KW  - stormflow
KW  - suspended sediment
KW  - phosphorus
KW  - drainage network expansion
Y1  - 2014
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/38068
SN  - 0043-1397
SN  - 1944-7973
VL  - 50
IS  - 2
SP  - 1457
EP  - 1473
PB  - American Geophysical Union
CY  - Washington
ER  -