Study of runoff generation on hillslopes using tracer experiments and a physically based numerical model

Presented at the HeadWater’98 Conference
Merano, Italy, 1998

abstract

Artificial rainfall and tracer experiments were conducted on two hillslope sites to identify runoff processes and to test a double porosity physically based numerical hillslope model (QSOIL). The results show good agreement between the measured and the predicted runoff components, matric potential and water content. The spatial and temporal behaviour of the different runoff generation processes was determined. A distinct vertical macropore system, resulting in bypass flow, and as the major contributing region for surface flow a highly permeable structured A horizon were attributed to one hillslope site. In contrast, the soil of the other site showed a bimodal pore size distribution, assumed to be a combination of mesopores and micropores developed by plant roots, and resulting in a higher subsurface flow response.

© Markus Weiler 4/2001