TY  - JOUR
A1  - Kordilla, J.
A1  - Sauter, M.
A1  - Reimann, T.
A1  - Geyer, T.
T1  - Simulation of saturated and unsaturated flow in karst systems at catchment scale using a double continuum approach
Y1  - 2012-10-30
VL  - 16
IS  - 10
SP  - 3909
EP  - 3923
JF  - Hydrology and Earth System Sciences
DO  - 10.5194/hess-16-3909-2012
DO  - 10.23689/fidgeo-2497
N2  - The objective of this work is the simulation of saturated and unsaturated flow in a karstified aquifer using a double continuum approach. The HydroGeoSphere code ( Therrien et al. , 2006 ) is employed to simulate spring dis- charge with the Richards equations and van Genuchten pa- rameters to represent flow in the (1) fractured matrix and (2) conduit continuum coupled by a linear exchange term. Rapid vertical small-scale flow processes in the unsaturated conduit continuum are accounted for by applying recharge boundary conditions at the bottom of the saturated model do- main. An extensive sensitivity analysis is performed on sin- gle parameters as well as parameter combinations. The tran- sient hydraulic response of the karst spring is strongly con- trolled by the matrix porosity as well as the van Genuchten parameters of the unsaturated matrix, which determine the head dependent inter-continuum water transfer when the con- duits are draining the matrix. Sensitivities of parameter com- binations partially reveal a non-linear dependence over the parameter space. This can be observed for parameters not belonging to the same continuum as well as combinations, which involve the exchange parameter, showing that results of the double continuum model may depict a certain de- gree of ambiguity. The application of van Genuchten pa- rameters for simulation of unsaturated flow in karst systems is critically discussed.
UR  - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/6810
ER  -