TY  - JOUR
A1  - Jing, Miao
A1  - Kumar, Rohini
A1  - Heße, Falk
A1  - Thober, Stephan
A1  - Rakovec, Oldrich
A1  - Samaniego, Luis
A1  - Attinger, Sabine
T1  - Assessing the response of groundwater quantity and travel time distribution to 1.5, 2, and 3 °C global warming in a mesoscale central German basin
JF  - Hydrology and Earth System Sciences
N2  - Groundwater is the biggest single source of high-quality freshwater worldwide, which is also continuously threatened by the changing climate. In this paper, we investigate the response of the regional groundwater system to climate change under three global warming levels (1.5, 2, and 3 ∘C) in a central German basin (Nägelstedt). This investigation is conducted by deploying an integrated modeling workflow that consists of a mesoscale hydrologic model (mHM) and a fully distributed groundwater model, OpenGeoSys (OGS). mHM is forced with climate simulations of five general circulation models under three representative concentration pathways. The diffuse recharges estimated by mHM are used as boundary forcings to the OGS groundwater model to compute changes in groundwater levels and travel time distributions. Simulation results indicate that groundwater recharges and levels are expected to increase slightly under future climate scenarios. Meanwhile, the mean travel time is expected to decrease compared to the historical average. However, the ensemble simulations do not all agree on the sign of relative change. Changes in mean travel time exhibit a larger variability than those in groundwater levels. The ensemble simulations do not show a systematic relationship between the projected change (in both groundwater levels and travel times) and the warming level, but they indicate an increased variability in projected changes with adjusting the enhanced warming level from 1.5 to 3 ∘C. Correspondingly, it is highly recommended to restrain the trend of global warming.
KW  - climate change impacts
KW  - hydrological models
KW  - coupled surface
KW  - water fluxes
KW  - catchment
KW  - recharge
KW  - dynamics
KW  - aquifer
KW  - flow
KW  - parameterization
Y1  - 2020
U6  - https://doi.org/10.5194/hess-24-1511-2020
SN  - 1607-7938
SN  - 1027-5606
VL  - 24
IS  - 3
SP  - 1511
EP  - 1526
PB  - Copernicus Publ.
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Baroni, Gabriele
A1  - Schalge, Bernd
A1  - Rakovec, Oldrich
A1  - Kumar, Rohini
A1  - Schüler, Lennart
A1  - Samaniego, Luis
A1  - Simmer, Clemens
A1  - Attinger, Sabine
T1  - A Comprehensive Distributed Hydrological Modeling Intercomparison to Support Process Representation and Data Collection Strategies
JF  - Water resources research
N2  - The improvement of process representations in hydrological models is often only driven by the modelers' knowledge and data availability. We present a comprehensive comparison between two hydrological models of different complexity that is developed to support (1) the understanding of the differences between model structures and (2) the identification of the observations needed for model assessment and improvement. The comparison is conducted on both space and time and by aggregating the outputs at different spatiotemporal scales. In the present study, mHM, a process‐based hydrological model, and ParFlow‐CLM, an integrated subsurface‐surface hydrological model, are used. The models are applied in a mesoscale catchment in Germany. Both models agree in the simulated river discharge at the outlet and the surface soil moisture dynamics, lending their supports for some model applications (drought monitoring). Different model sensitivities are, however, found when comparing evapotranspiration and soil moisture at different soil depths. The analysis supports the need of observations within the catchment for model assessment, but it indicates that different strategies should be considered for the different variables. Evapotranspiration measurements are needed at daily resolution across several locations, while highly resolved spatially distributed observations with lower temporal frequency are required for soil moisture. Finally, the results show the impact of the shallow groundwater system simulated by ParFlow‐CLM and the need to account for the related soil moisture redistribution. Our comparison strategy can be applied to other models types and environmental conditions to strengthen the dialog between modelers and experimentalists for improving process representations in Earth system models.
KW  - hydrological models
KW  - assessments
KW  - monitoring strategies
KW  - improvements
Y1  - 2019
U6  - https://doi.org/10.1029/2018WR023941
SN  - 0043-1397
SN  - 1944-7973
VL  - 55
IS  - 2
SP  - 990
EP  - 1010
PB  - American Geophysical Union
CY  - Washington
ER  -