TY - JOUR

T1 - Drainage networks in soils. A concept to describe bypass-flow pathways

AU - Deurer, M.

AU - Green, S. R.

AU - Clothier, B. E.

AU - Böttcher, J.

AU - Duijnisveld, W. H.M.

N1 - Funding information: Financial support was given by the Deutsche Forschungsgemeinschaft. The results originated from a project of the Priority Program 546, Geochemical processes with long-term effects in anthropogenically affected seepage and groundwater. We thank Horst Evermann for the accurate laboratory investigation of the water characteristic functions, Gunther Klump for his support with the tracer experiment and Karin Müller and Ross Woods for helpful discussions. We also thank the two anonymous reviewers for their detailed and constructive comments.

PY - 2003/3/10

Y1 - 2003/3/10

N2 - By using linear scaling factors of water characteristic functions we have been able to reconstruct a probable long-term drainage network through a sandy soil under coniferous forest in the north of Germany. The topology of the drainage network closely resembles one of mountainous streams. The fractional area of the entire profile occupied by the network was found to decrease exponentially with depth. For solutes preferentially travelling through such a network, the transport volume will therefore decrease exponentially with depth, and so the effective velocity should increase correspondingly. Assuming one-dimensional (1D), piston-flow through this effective transport volume of the network, we have been able to predict how much cumulative infiltration is, on average, needed for inert solutes to reach any given depth. Comparing our predictions with the results of a tracer experiment, we were able to estimate well the arrival time of the peak concentration of the tracer. We consider that this network analysis can be improved further by using more dynamic transport properties to define the pathways of the network.

AB - By using linear scaling factors of water characteristic functions we have been able to reconstruct a probable long-term drainage network through a sandy soil under coniferous forest in the north of Germany. The topology of the drainage network closely resembles one of mountainous streams. The fractional area of the entire profile occupied by the network was found to decrease exponentially with depth. For solutes preferentially travelling through such a network, the transport volume will therefore decrease exponentially with depth, and so the effective velocity should increase correspondingly. Assuming one-dimensional (1D), piston-flow through this effective transport volume of the network, we have been able to predict how much cumulative infiltration is, on average, needed for inert solutes to reach any given depth. Comparing our predictions with the results of a tracer experiment, we were able to estimate well the arrival time of the peak concentration of the tracer. We consider that this network analysis can be improved further by using more dynamic transport properties to define the pathways of the network.

KW - Bypass-flow

KW - Drainage network

KW - Tracer experiment

UR - http://www.scopus.com/inward/record.url?scp=0242684662&partnerID=8YFLogxK

U2 - 10.1016/S0022-1694(02)00261-5

DO - 10.1016/S0022-1694(02)00261-5

M3 - Article

AN - SCOPUS:0242684662

VL - 272

SP - 148

EP - 162

JO - Journal of hydrology

JF - Journal of hydrology

SN - 0022-1694

IS - 1-4

ER -