Press releases – July 2014

FRANKFURT. In what parts of the world and to what degree have groundwater reservoirs been depleted over the past 50 years? The Frankfurt hydrologist Prof. Petra Döll has been researching this using the global water model WaterGAP. Her conclusion: The rate at which groundwater reservoirs are being depleted is increasing, but that the rate is not as high as previously estimated.

In what parts of the world and to what degree have groundwater reservoirs been depleted over the past 50 years? The Frankfurt hydrologist Prof. Petra Döll has been researching this using the global water model WaterGAP. She has arrived at the most reliable estimate to date by taking into consideration processes which are important in dry regions of the world. The values calculated were compared with monitoring data from many different wells and data from the GRACE satellites. These satellites measure changes in the Earth's gravity field. Döll has come to the conclusion that the rate at which groundwater reservoirs are being depleted is increasing, but that the rate is not as high as previously estimated.

90 percent of water consumption is due to irrigation for farming purposes. Only the comparatively small remainder is used for potable water and industrial production. As an example, 40 percent of the cereals produced around the world is irrigated. However, in many cases this results in increased scarcity of water resources and puts a burden on ecosystems. In dry regions, the amount taken from groundwater reservoirs can easily exceed the amount being replenished, so that the groundwater reservoir is overused and depleted.

"By comparing the modelled and measured values of groundwater depletion, we were able for the first time to show on a global scale that farmers irrigate more sparingly in regions where groundwater reservoirs are being depleted. They only use about 70 percent of the optimal irrigation amounts", explains Petra Döll from the Institute of Physical Geography at the Goethe University.

The rate at which the Earth's groundwater reservoirs are being depleted is constantly increasing. Annual groundwater depletion during the first decade of this century was twice as high as it was between 1960 and 2000. India, the USA, Iran, Saudi Arabia and China are the countries with the highest rates of groundwater depletion. About 15 percent of global groundwater consumption is not sustainable, meaning that it comes from non-renewable groundwater resources. On the Arabian Peninsula, in Libya, Egypt, Mali, Mozambique and Mongolia, over 30 percent of groundwater consumption is from non-renewable groundwater.

The new estimate of global groundwater depletion is 113,000 million cubic meters per year for the period from 2000 to 2009, which is lower than previous, widely varying estimates. This can be considered to be the most reliable value to date, since it is based on improved groundwater consumption data which takes the likely deficit irrigation into account, and since the model results correlate well with independent comparative data.

The increased use of groundwater for irrigation also results in a rise in sea levels: According to Döll's calculations, sea level rise due to groundwater depletion was 0.31 millimetres per year during the period from 2000 to 2009. This corresponds to roughly one tenth of the total sea level rise.

The work was funded by the Deutsche Forschungsgemeinschaft through the priority program "Mass transport and Mass distribution in the System Earth".

Publication Döll, P., Müller Schmied, H., Schuh, C., Portmann, F.T., Eicker, A., (2014): Global-scale assessment of groundwater depletion and related groundwater abstractions: Combining hydrological modelling with information from well observations and GRACE satellites. Water Resour. Res. 50, doi: 10.1002/2014WR015595.

Online publication: http://dx.doi.org/10.1002/2014WR015595

Information Prof. Petra Döll, Institute of Physical Geography, Riedberg Campus, Phone: (069)798-40219: p.doell@em.uni-frankfurt.de.

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The antibiotic-resistant bacterium Acinetobacter baumanii often causes fatal nosocomial infections.  A research unit approved by the German Research Foundation, under the leadership of researchers based in Frankfurt, has made it their goal to throw light on the infection process and the adaptation mechanisms of the bacterium. The fundamental insights gained by the research unit will pave the way for the clinical management of this bacterium.

FRANKFURT. Multi-drug resistant bacteria have increased dramatically in hospitals in recent years and present immense challenges to staff and patients, often with fatal results. New pathogens have come to light in the past few years in addition to the bacteria that are already well-known, such as Staphylococcus aureus. One of these is the Gram negative bacterium Acinetobacter baumannii. Today, the German Research Foundation has now approved a new research unit, under the leadership of researchers based in Frankfurt, which will uncover the molecular basis for the dramatic increase in multi-drug resistant A. baumannii strains.

A. baumannii has become a common and excellently adapted nosocomial pathogen in developed countries. It causes 5% to 10% of nosocomial pneumonias and 2% to 10% of all infections in intensive care wards in European clinics. The increase in antibiotic resistance is alarming. The bacterium belongs to the group of six "ESKAPE" organisms that evade antibiotic treatment. Therefore, infections with A. baumannii are frequently fatal.

Several institutes from the Goethe University are involved in the research unit 2251 "Adaptation and persistence of Acinetobacter baumannii": the Department of Molecular Microbiology & Bioenergetics, the Institute of Medical Microbiology and Hygiene, the Institute for Cell Biology and Neuroscience, and the Institute for Biochemistry. The Universities of Cologne and Regenburg, as well as the Robert Koch Institute, are additional collaborators. The researchers will study the biology, infection process and the basis for multi-drug resistance of A. baumannii using a highly interdisciplinary approach. The objective is to determine how it has adapted so well to the hospital environment and what its multi-drug resistance is based on. The answers to these questions will facilitate treatment related to this dramatically increasing nosocomial pathogen.

Information: Prof. Volker Müller, Coordinator of the Research Unit 2251, Molecular Microbiology and Bioenergetics, Riedberg Campus, Tel: (069)798-29507; vmueller@bio.uni-frankfurt.de., http://www.bio.uni-frankfurt.de/51172482

The Goethe University is an institution with particularly strong research capabilities based in the European financial metropolis of Frankfurt. It celebrates its 100th year of existence in 2014. The university was founded in 1914 through private means from liberally-orientated citizens of Frankfurt and has devoted itself to fulfilling its motto "Science for the Society" in its research and teaching activity right up to the present day. Many of the founding donors were of Jewish origin. During the last 100 years, the pioneering services offered by the Goethe University have impacted the fields of social, societal and economic sciences, chemistry, quantum physics, neurological research and labour law. On January 1st, 2008, it achieved an exceptional degree of independence as it returned to its historical roots as a privately funded university. Today it is one of the ten universities that are most successful in obtaining external research funding and one of the three largest universities in Germany with centres of excellence in medicine, life sciences and humanities.

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