Researchers demonstrate that current models underestimate role of subsurface heterogeneity
A team of international researchers led by University of Freiburg hydrologist Dr. Andreas Hartmann suggests that inclusion of currently missing key hydrological processes in large-scale climate change impact models can significantly improve our estimates of water availability. The study shows that groundwater recharge estimates for 560 million people in karst regions in Europe, the Middle East and Northern Africa, are much higher than previously estimated from current large-scale models.
A karst region in Andalusia, Southern Spain. Photo: Matías Mudarra, Universität Malaga/Spanien
The scientists have shown that model estimates based on entire continents up to now have greatly underestimated in places the amount of groundwater that is recharged from fractions of surface runoff. This finding suggests that more work is needed to ensure sufficient realism in large-scale hydrologic models before they can be reliably used for local water management. The team has published their research findings in the scientific journal “Proceedings of the National Academy of Sciences (PNAS).“
Groundwater is a vital resource in many regions around the globe. For managing drinking water, the recharge rate is an important quantity for securing sustainable supplies. The researchers have compared two hydrological models that simulate groundwater recharge. One is a long-established global model with limited accounting for subsurface heterogeneity.
The other is a continental model the researchers have developed themselves that includes, for example, variability in the thickness of soils and different subsurface permeabilities. They have carried out the comparison for all of the karst regions in Europe, North Africa and the Middle East. Karst regions are known for their great degree of subsurface heterogeneity, because carbonate rock shows greater susceptibility to chemical weathering – a process that is known as karstification.
Karstification leads to varying soil depths and permeabilities. A comparison of the models' calculations with independent observations of groundwater recharge at 38 sites in the regions has shown that the model that accounts for heterogeneity produces more realistic estimates.
The researchers explain the reason for the difference between the two models as follows: In simulation, their newly developed model shows reduced fractions of surface According to the new model, a farmer in the Mediterranean region would potentially have up to a million liters more groundwater for extraction available in a year than the established model estimates, dependent on actual subsurface composition and the water demands of the local ecosystems.
When applied to the example of karst regions, the researchers' approach shows how it is possible to adapt global models used to predict water shortages, drought or floods to account more realistically for regional conditions. Scientists from the University of Freiburg, Canada's Victoria University, the University of Bristol in England and International Institute for Applied Systems Analysis in Austria took part in the study.
Hartmann, A., Gleeson, T., Wada, Y., Wagener, T., 2017. Enhanced groundwater recharge rates and altered recharge sensitivity to climate variability through subsurface heterogeneity. In: “Proceedings of the National Academy of Sciences”; doi:10.1073/pnas.1614941114.
Dr. Andreas Hartmann
Chair of Hydrology
University of Freiburg
Rudolf-Werner Dreier | Albert-Ludwigs-Universität Freiburg im Breisgau
Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Complex neurotechnological devices are required to directly select and influence brain waves inside the skull’s interior. Although it has become relatively...
Plant pollen and fungal spores can be found at variable heights in the air, even at elevations up to 2000 meters. This is the conclusion of a report by researchers of Helmholtz Zentrum München and Technical University of Munich together with Greek colleagues, which was published in the journal ‘Scientific Reports’. Hitherto it was assumed that such allergens are mainly present close to where they are released, namely near ground level.
One in every five Europeans currently already suffers from allergies – and the trend is increasing. Plant pollen and fungal spores contribute considerably to...
By comparison, a blink lasts a lifetime – atoms can rearrange themselves within one 350 quadrillionths of a second. As reported in the latest issue of the prestigious journal Nature, scientists at the Center for Nanointegration (CENIDE) at the University of Duisburg-Essen (UDE), together with their colleagues from the University of Paderborn, have been able to observe the movement of a one-dimensional material in real-time. Their research confirms that the acceleration of the atoms could leave even a Porsche standing.
Everything that surrounds us in our everyday life is three-dimensional, no matter how small: salt crystals, pollen, dust – even aluminium foil has a certain...
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
03.04.2017 | Event News
20.03.2017 | Event News
14.03.2017 | Event News
05.04.2017 | Power and Electrical Engineering
05.04.2017 | Life Sciences
05.04.2017 | Physics and Astronomy