Details
| Original language | English |
|---|---|
| Pages (from-to) | 4041-4059 |
| Number of pages | 19 |
| Journal | Hydrology and Earth System Sciences |
| Volume | 25 |
| Issue number | 7 |
| Publication status | Published - 9 Jul 2021 |
Abstract
Fully integrated three-dimensional (3D) physically based hydrologic models usually require many computational resources. For many applications, simplified models can be a cost-effective alternative. The 3D models of subsurface flow are often simplified by coupling a 2D groundwater model with multiple 1D models for the unsaturated zone. The crucial part of such models is the coupling between the two model compartments. In this work we compare two approaches for the coupling. One is iterative where the 1D unsaturated zone models go down to the impervious bottom of the aquifer, and the other one is non-iterative and uses a moving lower boundary for the unsaturated zone. In this context we also propose a new way of treating the specific yield, which plays a crucial role in linking the unsaturated and the groundwater model. Both models are applied to three test cases with increasing complexity and analyzed in terms of accuracy and speed compared to fully integrated model runs. The non-iterative approach is faster but does not yield a good accuracy for the model parameters in all applied test cases, whereas the iterative one gives good results in all cases. Which strategy is applied depends on the requirements: computational speed vs. model accuracy.
ASJC Scopus subject areas
- Environmental Science(all)
- Water Science and Technology
- Earth and Planetary Sciences(all)
- Earth and Planetary Sciences (miscellaneous)
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In: Hydrology and Earth System Sciences, Vol. 25, No. 7, 09.07.2021, p. 4041-4059.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Coupling saturated and unsaturated flow
T2 - Comparing the iterative and the non-iterative approach
AU - Brandhorst, Natascha
AU - Erdal, Daniel
AU - Neuweiler, Insa
N1 - Funding Information: Deutsche Forschungsgemeinschaft in the framework of research unit FOR 2131 (grant no. NE 824/12-1) and the Collaborative Research Center CAMPOS (CC 1253 CAMPOS – Catchments as Reactors) (grant no. CRC 1253). Funding Information: Financial support. This research has been supported by the
PY - 2021/7/9
Y1 - 2021/7/9
N2 - Fully integrated three-dimensional (3D) physically based hydrologic models usually require many computational resources. For many applications, simplified models can be a cost-effective alternative. The 3D models of subsurface flow are often simplified by coupling a 2D groundwater model with multiple 1D models for the unsaturated zone. The crucial part of such models is the coupling between the two model compartments. In this work we compare two approaches for the coupling. One is iterative where the 1D unsaturated zone models go down to the impervious bottom of the aquifer, and the other one is non-iterative and uses a moving lower boundary for the unsaturated zone. In this context we also propose a new way of treating the specific yield, which plays a crucial role in linking the unsaturated and the groundwater model. Both models are applied to three test cases with increasing complexity and analyzed in terms of accuracy and speed compared to fully integrated model runs. The non-iterative approach is faster but does not yield a good accuracy for the model parameters in all applied test cases, whereas the iterative one gives good results in all cases. Which strategy is applied depends on the requirements: computational speed vs. model accuracy.
AB - Fully integrated three-dimensional (3D) physically based hydrologic models usually require many computational resources. For many applications, simplified models can be a cost-effective alternative. The 3D models of subsurface flow are often simplified by coupling a 2D groundwater model with multiple 1D models for the unsaturated zone. The crucial part of such models is the coupling between the two model compartments. In this work we compare two approaches for the coupling. One is iterative where the 1D unsaturated zone models go down to the impervious bottom of the aquifer, and the other one is non-iterative and uses a moving lower boundary for the unsaturated zone. In this context we also propose a new way of treating the specific yield, which plays a crucial role in linking the unsaturated and the groundwater model. Both models are applied to three test cases with increasing complexity and analyzed in terms of accuracy and speed compared to fully integrated model runs. The non-iterative approach is faster but does not yield a good accuracy for the model parameters in all applied test cases, whereas the iterative one gives good results in all cases. Which strategy is applied depends on the requirements: computational speed vs. model accuracy.
UR - http://www.scopus.com/inward/record.url?scp=85109714634&partnerID=8YFLogxK
U2 - 10.5194/hess-25-4041-2021
DO - 10.5194/hess-25-4041-2021
M3 - Article
AN - SCOPUS:85109714634
VL - 25
SP - 4041
EP - 4059
JO - Hydrology and Earth System Sciences
JF - Hydrology and Earth System Sciences
SN - 1027-5606
IS - 7
ER -