In Transition – Climate, Water and Society

This year’s Hydrology Day focused on the interfaces between hydrology, practitioners, politicians and society. At this important meeting of the hydrological community that was held in Munich on 22 and 23 March, experts came together to discuss the contribution and role of science in addressing today’s pressing challenges. The BfG and the ICWRGC participated with a keynote speech and were present at the poster exhibition and with two booths.

For the first time since the beginning of the Covid crisis, Hydrology Day was held again as an in-person event to coincide with World Water Day. In previous years, the hydrological community had to meet online or in the late summer when Covid numbers were low. The desire to meet and talk in person was strong, so that more than 260 people accepted the invitation to attend in Munich on 22 and 23 March. Hydrology Day 2022 was jointly organised by the Technical University of Munich (TUM) and Ludwig Maximilian University (LMU).

The extreme events of recent years, some of which are also related climatic changes, are an indication of the new challenges facing hydrological research and practice. In this context, Hydrology Day was dedicated to the latest findings from hydrological process research, providing information on methodological advances in the field of hydrological monitoring and modelling.

The nexus between water, food and energy

The event also focused on how the paths from hydrological science to practice, politics and society can be shaped more efficiently and effectively. Dr. Marianela Fader, Deputy Director of the International Centre for Water Resources and Global Change (ICWRGC) at the BfG in Koblenz, for instance, chaired a lecture session on the so-called Water-Food-Energy Nexus.

In her keynote speech, Dr. Fader began by asking whether research on the interfaces between water, energy and food as resources (‘nexus’) made a relevant contribution to scientific policy advice or was it merely an academic one-way street. In her presentation, she emphasised that the nexus concept had already been successfully applied many times in the past, but also rightly met with criticism. In order for the nexus approach to continue to play a relevant role in political decision-making in the future, it must be substantially expanded, according to the geographer: In addition to improved operationalisation, a functional, dynamic and adaptable nexus system model needed new methods to take into account relevant aspects, such as the distribution of power and responsibility, as well as international interdependencies. At the end of her presentation, Dr. Fader emphasised that there was no alternative to the water-food-energy nexus when it comes to understanding the reciprocal influences and the system as a whole.

Organic trace substance pollution of federal waterways during low water periods

This year’s Hydrology Day also focused on process understanding, modelling and prediction of extreme hydrological events, such as floods and low water. BfG scientists Dr. Gerd Hübner and Dr. Daniel Schwandt (Fundamental Questions of Qualitative Hydrology Department) and Dr. Michael Schlüsener and Dr. Arne Wick (Water Chemistry Department) presented a poster on this topic, showing the results of studies on low water levels in the river Elbe in summer and autumn 2019. The experts investigated the question of which loads of poorly degradable organic trace substances from sewage treatment plants are transported in the river during periods of low water flow and whether these are subject to specific changes. Based on monitoring data from the Czech Republic, the Elbe River Basin Community and supplementary analyses by the BfG, more than 800 km of the river Elbe were considered. The focus was on a selection of drugs, including carbamazepine, used for epilepsy, which was also modelled for the German part of the Elbe, as well as the corrosion protection agent benzotriazole.

In two poster sessions, the participants had the opportunity to talk to the BfG experts and discuss the results. One finding of the work is that during low water periods in summer, a relatively low load can be assumed for many, but not all, of the trace substances studied, although emissions remain constant. These lower loads may be due to higher degradation rates in sewage treatment plants and water bodies as a result of greater exposure to light, higher water temperatures and longer residence times due to lower flow velocities.

Networking at the trade exhibition

As a point of contact for questions, the BfG and the ICWRGC were each present with their own booth at the accompanying trade exhibition. Participants made use of this opportunity to find out about theses, job opportunities, current projects and the tasks of the two institutions. At its booth, the BfG presented its vision for water (eco)systems in 2030 on a poster and distributed the new BfG image brochure to a wide audience for the first time.