 |
| Titel |
Extending a rainfall-runoff model for lowland catchments from lumped to semi-distributed |
| VerfasserIn |
Claudia Brauer, Paul Torfs, Ryan Teuling, Remko Uijlenhoet |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250129845
|
| Publikation (Nr.) |
 EGU/EGU2016-10014.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Wageningen Lowland Runoff Simulator (WALRUS) is a parametric rainfall-runoff
model for catchments with shallow groundwater (Brauer et al., 2014ab). WALRUS was
developed using data and experience from two Dutch experimental catchments: the Hupsel
Brook catchment (6.5 km2) and the Cabauw polder (0.5 km2). We identified key processes
for runoff generation in lowland catchments, notably (1) groundwater-unsaturated zone
coupling, (2) wetness-dependent flow routes, (3) groundwater-surface water feedbacks
and (4) seepage and surface water supply, and accounted for these in the model
structure.
Up to now, WALRUS has been used in a lumped manner. However, water managers and
researchers have expressed an interest in a semi-distributed version for application to larger
catchments with varying forcing and catchment characteristics and to investigate the effect of
groundwater flow within the catchment on modelled variables (e.g. groundwater
depth).
We combined WALRUS and a model for 2-dimensional groundwater flow into a simple
modelling framework. WALRUS was already designed to cope with groundwater flow into or
out of the model domain, because seepage and lateral groundwater flow are common in
lowlands. In the semi-distributed version, we used this feature to couple different WALRUS
elements (grid cells or subcatchments) to each other. Groundwater flow was computed using
a digital elevation model, groundwater depths computed by WALRUS, soil transmissivity
data and Darcy’s law. Finally, we implemented a surface routing model including
backwater effects, which are relevant in areas with little relief. With respect to the
lumped version, the semi-distributed requires more data. Therefore, we investigated
the added value of different data sources (forcing, elevation, soil, surface water)
separately.
We will present the rationale behind the semi-distributed model and show how
the model structure compares to observations and and simulations without lateral
transport.
C.C. Brauer, A.J. Teuling, P.J.J.F. Torfs, R. Uijlenhoet (2014a): The Wageningen Lowland
Runoff Simulator (WALRUS): a lumped rainfall-runoff model for catchments with shallow
groundwater, Geosci. Model Dev., 7, 2313-2332.
C.C. Brauer, P.J.J.F. Torfs, A.J. Teuling, R. Uijlenhoet (2014b): The Wageningen Lowland
Runoff Simulator (WALRUS): application to the Hupsel Brook catchment and Cabauw
polder, Hydrol. Earth Syst. Sci., 18, 4007-4028. |
|
|
|
|
|
|