Cross-sphere modelling to evaluate impacts of climate and land management changes on groundwater resources
Author(s)
Date issued
August 2021
In
Science of the Total Environment
No
798
From page
148759
To page
148775
Reviewed by peer
1
Subjects
Agriculture Irrigation Water resources Water use conflict Integrated modelling Climate change
Abstract
Climate change affects both water resources and agricultural production.With rising temperatures and decreasing
summer precipitation, it is expected that agricultural production will be increasingly limited by drought.
Where surface- or groundwater resources are available for irrigation, an increase inwaterwithdrawals for irrigation
is to be expected. Therefore, quantitative approaches are required to anticipate and manage the expected
conflicts related to increased water abstraction for irrigation. This project aims to investigate how agricultural
production,water demand for irrigation, runoff and groundwater dynamics are affected by future climate change
and howclimate change impacts combinedwith changes in agriculturalwater use affect groundwater dynamics.
To answer these research questions, a comprehensive, loosely coupled model approach was developed, combining
models from three disciplines: an agricultural plant growth model, a hydrological model and a
hydrogeological model. The model coupling was implemented and tested for an agricultural area located in
Switzerland inwhich groundwater plays a significant role in providing irrigationwater. Our suggested modelling
approach can be easily adapted to other areas.
The model results show that yield changes are driven by drought limitations and rising temperatures. However,
an increase in yieldmay be realized with an increase in irrigation. Simulation results showthat thewater requirement
for irrigation without climate protection (RCP8.5) could increase by 40% by the end of the century with an unchanged growing season and by up to 80%with varietal adaptations. With climate changemitigation (RCP2.6)
the increase inwater demand for irrigationwould be limited to 7%. The increase in irrigation (+12mm) and the
summer decrease in recharge rates (~20mm/month)with decreasing summer precipitation causes a lowering of
groundwater levels (40 mm) in the area in the late summer and autumn. This impact may be accentuated by an
intensification of irrigation and reduced by extensification.
summer precipitation, it is expected that agricultural production will be increasingly limited by drought.
Where surface- or groundwater resources are available for irrigation, an increase inwaterwithdrawals for irrigation
is to be expected. Therefore, quantitative approaches are required to anticipate and manage the expected
conflicts related to increased water abstraction for irrigation. This project aims to investigate how agricultural
production,water demand for irrigation, runoff and groundwater dynamics are affected by future climate change
and howclimate change impacts combinedwith changes in agriculturalwater use affect groundwater dynamics.
To answer these research questions, a comprehensive, loosely coupled model approach was developed, combining
models from three disciplines: an agricultural plant growth model, a hydrological model and a
hydrogeological model. The model coupling was implemented and tested for an agricultural area located in
Switzerland inwhich groundwater plays a significant role in providing irrigationwater. Our suggested modelling
approach can be easily adapted to other areas.
The model results show that yield changes are driven by drought limitations and rising temperatures. However,
an increase in yieldmay be realized with an increase in irrigation. Simulation results showthat thewater requirement
for irrigation without climate protection (RCP8.5) could increase by 40% by the end of the century with an unchanged growing season and by up to 80%with varietal adaptations. With climate changemitigation (RCP2.6)
the increase inwater demand for irrigationwould be limited to 7%. The increase in irrigation (+12mm) and the
summer decrease in recharge rates (~20mm/month)with decreasing summer precipitation causes a lowering of
groundwater levels (40 mm) in the area in the late summer and autumn. This impact may be accentuated by an
intensification of irrigation and reduced by extensification.
Publication type
journal article
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