Global change, landscape ageing and the pulse of catchments

EGU Leonardo Conference Series on Earth's Hydrological Cycle

From 16-18 October 2019, as part of the "EGU Leonardo Conference Series on Earth's Hydrological Cycle", the Luxembourg Institute of Science and Technology (LIST), in partnership with the University of Luxembourg and the Karlsruhe Institute of Technology (KIT), will organize the conference "Global change, landscape ageing and the pulse of catchments" at the Belval Innovation Campus.

A cardinal challenge in hydrological sciences is how global change is going to affect/impact the ‘pulse of catchments’. The design and implementation of any future water resources management strategy is indeed tightly bound to the challenges posed by non-stationarity. Hydrological systems are known to be subject to continuous changes. This variability eventually determines the diversity of catchments, as well as their intrinsic property of changing systems (e.g. through the transfer of energy (evaporation) and water (erosion)). While we are still struggling with the natural variability of hydrological systems, we are facing a much bigger challenge with the increasing influence of anthropogenic pressures (expressed for example through changes in climate and land use, pollution of soils and water bodies). In this context, stationarity of hydrological systems as a fundamental assumption clearly stands out. Having provided a conceptual backbone for a (rather successful) engineering-centric approach to hydrological problems (e.g. floods, droughts), this assumption does not withstand the effects of two phenomena that have recently emerged: the rapid increase of global change related impacts on hydrological systems and the increasing complexity of processes and feed-back mechanisms that are directly or indirectly related to these impacts.

It seems obvious that catchments as open geo-ecosystems will likely react to global change with ecological and morphological adaptions to climate and human induced changes. However, the kind and degree of these adaptions and their feedbacks on the catchment hydrological functioning are far from being from being obvious. This implies that hydrological projections into the future might be more than uncertain – they might be biased and thus systematically wrong. This is because all currently available model concepts rely on a stationary catchment “skeleton” represented by stationary parameterizations. As these have been trained on past datasets they represent the past transformation properties of the catchments. Inevitably, the cardinal challenge for hydrological sciences is now to provide new ways to deal with non-stationarity of hydrological systems.

     

Objectives

During the 2019 EGU Leonardo topical conference, we intend to assess the current status quo and potential ways forward on (i) catchment evolution conceptualization, (ii) conciliation of (dynamic) catchment complexity and (static) model complexity, as well as (iii) re-connection of field research and hydrological modelling.

We plan to wire the conference around three complementary sessions:

  • Session 1: Catchment ageing and changing water cycles – a matter of co-evolution, randomness or both?
  • Session 2: Moving beyond the diagnosis of catchment complexity and heterogeneity
  • Session 3: Mesoscale experiments and environmental simulators – the missing link between models and field research?

Abstracts submission

Abstracts will only be accepted though the online abstract submission system.

Abstract submission closes on July 31, 2019. All abstracts should be submitted by this date.

All manuscripts must be in English and are limited to 500 words.
See the topics for which authors are invited to submit research papers and posters in the section "Topical Sessions" below.

Important dates

  • Deadline for abstract submission: 31 July 2019
  • Notifications to the authors: 3 September 2019
  • Authors registration: 9 September 2019
  • EGU Leonardo Conference: 16-17-18 October 2019

Scientific Committee

  • Markus Hrachowitz (TU Delft, The Netherlands)
  • Sibylle Haßler (KIT Karlsruhe, Germany)
  • Uwe Ehret (KIT, Karlsruhe, Germany)
  • Ralf Loritz (KIT, Karlsruhe, Germany)
  • Conrad Jakisch (TU Braunschweig, Germany)
  • Lieke Melsen (Wageningen University, The Netherlands)
  • Anke Hildebrandt (University of Jena, Germany)
  • Núria Martínez-Carreras (LIST, Luxembourg)
  • Hubert Savenije (TU Delft, The Netherlands)
  • Ulrike Scherer (KIT Karlsruhe, Germany)

Programme

Tentative schedule and scientific visibility

The Conference will last 3 days with oral presentations during the day, followed by poster sessions in the late afternoon. After the poster session on the second day of the conference, we will organize a Town Hall meeting, providing a platform for open discussions on the most pressing research questions in hydrology, pending knowledge/conceptual gaps or technological limitations, as well as potential new avenues to be explored in the future. We plan to have Prof. Murugesu Sivapalan (The School of Earth, Society & Environment - Illinois), Prof. Hubert H.G. Savenije (TU Delft) and Prof, Jeff McDonnell (University of Saskatchewan) to lead the discussions during the Town Hall meeting. A summary and outlook session (presented by the session chairs), followed by a plenary discussion, will close the conference on day three.

Currently there are two ongoing Special issues in leading EGU Journals, which are well aligned with the topics of this Leonardo Conference and thus provide an ideal outlet for key contributions.

  • Linking landscape organisation and hydrological functioning: from hypotheses and observations to concepts, models and understanding. Joint SI Hydrology and Earth System Sciences and Earth System Science Data. Guest Editors: L. van Schaik, T. Hohenbrink, C. Jackisch, H. Laudon, L. Pfister, S.K. Hassler, M. Renner, H. McMillan, T. Blume, P. Gentine, and P. Saco.
  • Thermodynamics and optimality in the Earth system and its subsystems. Joint SI Earth System Dynamics and Hydrology and Earth System Sciences. Guest Editors: A. Kleidon, P. Cox, H. Savenije, E. Zehe, M. Crucifix, and S. Hergarten.
     

Invited talks

  • Session 1: Patricia Saco
  • Session 2: Axel Kleidon
  • Session 3: Martijn Westhoff
  • Townhall meeting: Brian Berkowitz

Topical Sessions

Session 1: Catchment ageing and changing water cycles – a matter of co-evolution, randomness or both? (Conveners: Erwin Zehe, Anke Hildebrandt, Markus Hrachowitz)

A catchment’s water cycle holds the fingerprint of the landscape, it equally has been shaped by the water cycle in the past. While most catchments are strongly heterogeneous, it is striking how spatially organized they are. Spatial organization manifests for instance through systematic and structured patterns of catchment properties, leading to a systematic variability of many processes. The most prominent ev Model concepts may be proven wrong, either because of wrong descriptions of the underlying processes, or because of a poor representation of the hydrological system. In a similar way, organising principles are both supported and rejected in the almanac that contains manifold studies from countless experimental catchments distributed all over the world and spanning an wide range of physiographic contexts. Here we ask for the missing link in turning process descriptions and organising principles into testable hypotheses. When testing the latter, we may fail because of multiple reasons: lack of knowledge on the targeted catchments, too little processes knowledge, etc. Ultimately, conventional approaches – based on experimental catchment studies – have hampered our progress in this respect (with the involved time scales being too long, boundary conditions being essentially uncontrollable, etc.). In order to disentangle the current limitations and test new hypotheses, controlled environmental simulators may be the way forward. This type of simulator is capable of accounting for the characteristics of natural systems, as expressed through their heterogeneity, turbulence, changes, etc. The B2 LEO and TESS simulators are telling examples in this respect.idence of spatial organization is, however, the omnipresence of flow networks ranging from preferential pathways, veining the subsurface, to rill and river networks connecting across multiple scales. All these networks exhibit a similar topology and functioning characteristics, and this even holds true when being compared to vascular networks in biota. Here we ask: are the co-development of the landscape and its hydraulic functioning purely random ? – or are they governed by co-evolution and organizing principles ?

If catchments are organised, they are supposedly more than the sum of their elements, albeit not at all times. This may well appear at first sight as an apparent paradox – for example if we ask when is a catchment less than the sum of its potential processes? On a different note, it is known that not the entire amount of heterogeneity in a catchment is relevant for its hydrological functioning. This is because river basins are complex, dissipative and non-chaotic systems with a very short memory.

This causes them to be difficult to forecast/predict with uncertainties changing relentlessly. Ultimately, one could conclude that heterogeneity, organisation and complexity appear as intrinsic and yet very distinct properties of river basins. Here we suggest that those properties are strongly interrelated and that catchment complexity seems to change at its own pulse.

In this session, we invite submissions dealing with either one or several of the following questions:

  • Can we define catchment age from a functional perspective and do organizing principles constrain ageing of catchments?
  • If structural and functional ageing of catchments is a matter of co-evolution, what are possible objective functions defining the selection criteria and how does selection happen?
  • Can we infer constraints for catchment aging and co-evolution from catchment inter-comparison studies?
  • Can we build the next generation of models that treat the process skeleton (the catchment structure) and the processes operating on this skeleton as a dynamic entity?
  • Are the concepts of co-evolution and organisation useful to project catchment functioning under change?

 

Session 2: Moving beyond the diagnosis of catchment complexity and heterogeneity, (Conveners: Laurent Pfister, Ralf Loritz, Uwe Ehret, Lieke Melsen)

The vast majority of past (and ongoing) hydrological processes research has been focusing at diagnosing the heterogeneity and complexity of hydrological systems - essentially documenting what diversity, heterogeneity and complexity characterises the studied systems. Several decades of research has left us with countless, well documented, catchment idiosyncracies about the interplay of their structure and functioning. Taken as a whole, the collection of these studies certainly stands as an invaluable almanac. However, we expect more fundamental insights when shifting our focus from ‘how systems function’ to ‘why systems function’.

Progress has been stymied by the fact that hydrology has always been and still remains a measurement limited discipline. Despite significant progress made in the past decades through the advent of new tracers, remote sensing, Internet-of-Things, field deployable instruments measuring at unprecedented spatial and temporal resolutions and frequencies, we nonetheless remain with the same challenges: How to overcome scale limitations? How fine is fine enough? How to extrapolate from one catchment to another under stationary conditions? How precisely can we project the future catchment functioning from knowing its past? These challenges have - together with the cumbersome character of field work - gradually let to a decrease in interest in experimental hydrology. In the meantime virtual experiments/modelling studies have gained tremendous interest. Some of these studies reveal that predictive uncertainty is highly variable, passing from periods where many details/information are needed to periods when much less information is required. Here again, catchment complexity seems to change at its own pulse, while complexity of our models is mostly static. Understanding this pulse calls for a second generation of field and experimental studies, geared towards ‘testing outrageous hypotheses’.

So what is what is the way forward? More instruments, higher frequencies, higher resolution, more data, new methods?

In this session we invite contributions on the following questions:

  • How to analyse the almanac of available catchment studies to distil the “why” underling the “how”?
  • How to design and optimise future field research well beyond the simple deployment of new generations of environmental monitoring systems operating at unprecedented spatial and temporal scales?
  • What are new ways to condense information and knowledge from increasing amounts of measured data and from catchment inter comparison?
  • How fine is fine enough?
  • How to infer changing complexity and its pulse from data?
  • Can we build models of adaptive complexity to capture changing complexity of catchments as a generic system characteristic?

 

Session 3: Mesoscale experiments and environmental simulators – the missing link between models and field research? (Conveners: Conrad Jackisch, Sibylle Hassler, Núria Martínez-Carreras, Sajad Tabibi)

Model concepts may be proven wrong, either because of wrong descriptions of the underlying processes, or because of a poor representation of the hydrological system. In a similar way, organising principles are both supported and rejected in the almanac that contains manifold studies from countless experimental catchments distributed all over the world and spanning an wide range of physiographic contexts. Here we ask for the missing link in turning process descriptions and organising principles into testable hypotheses. When testing the latter, we may fail because of multiple reasons: lack of knowledge on the targeted catchments, too little processes knowledge, etc. Ultimately, conventional approaches – based on experimental catchment studies – have hampered our progress in this respect (with the involved time scales being too long, boundary conditions being essentially uncontrollable, etc.). In order to disentangle the current limitations and test new hypotheses, controlled environmental simulators may be the way forward. This type of simulator is capable of accounting for the characteristics of natural systems, as expressed through their heterogeneity, turbulence, changes, etc. The B2 LEO and TESS simulators are telling examples in this respect.

While having proven useful in many respects, controlled laboratory experiments are clearly a limitation to make further progress – also because of the difficulties when it comes to translate findings to larger scales. In order to disentangle the current limitations and test new hypotheses, controlled environmental simulators may be the way forward. This type of simulator is capable of accounting for the characteristics of natural systems, as expressed through their heterogeneity, turbulence, changes, etc. The BIOSPHERE-2 LEO and TESS simulators are telling examples in this respect.

In this session, we invite contributions on:

  • Experiments carried out in environmental simulators
  • New avenues for mesoscale experiments in the field, including manipulations to simulate change
  • New ways to collect orthogonal data e.g. moving cars as rain gauges, commercial micro wave links
  • Experimental strategy to test organizing principles.

 

Partners

 

 

 

Accomodation

A given number of rooms are blocked in the following hotels:

Hotel Address Contact Fees/night/room

Cutt-off dates & Booking-form

Ibis Esch Belval 3*

12 Avenue du Rock’n Roll– L-4361 Esch/Alzette

Tel.: +352 26 17 31
Email: h7071@accor.com

Single room: 103 €/night
Double room: 118 €/night
==> Including Breakfast buffet

14 rooms available until September 2nd, 2019

Booking form

Hotel de la Poste 107, Rue de L’Alzette, L-4011 Esch-Sur-Alzette

Tel : (+352) 54 00 18
Email: hoteldelaposteluxembourg@gmail.com

Single room: 95 €/night
Double room: 115 €/night
Breakfast buffet: 17 €/pers.

20 rooms available until September 5th, 2019

Booking form

         

 

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Summary

    Global change, landscape ageing and the pulse of catchments

    Register here!

    Practical Infos

    Venue: University of Luxembourg | Maison du Savoir - 2, avenue de l'Université | L-4365 ESCH-SUR-ALZETTE

    Dates: 16-17-18 October 2019

    Language: English

    Contact: event@list.lu

    Registration fee:
    Standard fee: 200 € VAT excl.
    Student fee: 140 € VAT excl.
    Gala dinner: 70 € VAT excl.

    Contact

    Dr habil. Laurent PFISTER
    Dr habil. Laurent PFISTER
    Send an e-mail
    Register here!