1st LIAISE Conference and
determining evapotranspiration CrossCut Workshop

Mar 27 - 29, 2023 | Lleida, Spain


LIAISE Field Campaign

One of the largest challenges facing the Environmental Science community is understanding future changes in the terrestrial water cycle and the subsequent impact on water resources. It has also been recognized by international organizations such as the World Climate Research Programme (WCRP) that human activities are playing a key role in modifying the continental water cycle, and therefore must be accounted for in projections.

Under the auspices of international HYdrological cycle in the Mediterranean Experiment (HyMeX),  the overall objective of the international Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment (LIAISE) project aims to improve the understanding of land-atmosphere-hydrology interactions in a semi-arid region characterized by strong surface heterogeneity owing to contrasts between the natural landscape and intensive agriculture.

The LIAISE study area is located over the Catalan counties of Urgell and Pla d’Urgell within the Ebro basin in northeastern Spain which is characterized by a semi-arid hot, dry Mediterranean climate. There is a sharp delineation between a vast, nearly continuous intensively-irrigated region and the dryer natural zone to the east. The main water source consists of artificial reservoirs located to the north in the Pyrenees mountains, and this water is brought into the irrigated area using a highly anthropized river and canal network.

Understanding the impact of anthropization on the lower atmosphere and representing it in models have been inhibited due to a lack of consistent and extensive observations. In recent years, the irrigated land area has been increasing, leading to a renewed need for dedicated field campaigns over these highly heterogeneous areas, ideally in contrasting (climate) semi-arid regions, especially over so-called breadbasket areas where climate change is directly threatening our food production. Fortunately, land surface and atmospheric observation capabilities have advanced concurrently, as well as the variety, quality and resolution of remotely-sensed data, to help improve our understanding of key natural and anthropogenic land processes and the subsequent feedbacks with the boundary layer and basin-scale hydrological cycle.

Determining EvapoTranspiration (dET) CrossCut Workshop

Evapotranspiration (ET) is a principal term in the Earth’s budgets of water and energy, and it is inextricably linked with the carbon budget. The determination of ET is still a challenge, both from a measurement and a modelling perspective, where the methods used differ depending on the circumstances and application. The study of ET has been undertaken from very different perspectives, ranging from a focus on process understanding and prediction by Earth System modelers, to quantification at a range of spatio-temporal scales for hydrological or agricultural applications such as reservoir dam regulation or crop irrigation. The dET (“determining ET”) GEWEX Cross-cut aims to bring together experts from diverse disciplines to discuss key questions and methods to allow the community to communicate in an efficient manner, and to advance ET-related science.

Embracing the interdisciplinary nature of ET, the dET Cross-cut has been preliminarily organized in four main working groups:

Working Group 1:
Measuring ET and its role in the Surface Budgets and their coupling (energy, water, carbon)

Working Group 2:
Models and parameterizations of ET (including their use in numerical models and remote sensing methods), validation and networks

Working Group 3:
The partitioning of ET over the different elements of the terrestrial hydro- and biosphere: soil evaporation, vegetation (transpiration and interception), open-water (reservoirs & lakes)

Working Group 4:
Heterogeneity, irrigation, varying spatial and temporal scales, extreme events.


The overall goal of this meeting is to bring together researchers specializing in estimating ET experimentally using in-situ observations, via remote sensing data and/or models, from the leaf to the regional scale. The emphasis will be on semi-arid bread-basket regions, notably those with anthropogenically-enhanced surface heterogeneity due to irrigation, crop variability and other activities. A particular focus will be on the domain studied by an international team of researchers during the LIAISE field campaign, which took place in July 2021 in the Ebro basin of the northwestern part of the Iberian Peninsula.

Call for Abstracts

This conference invites contributions covering topics that include:

  • modeling studies aimed at including anthropogenic processes (land surface, meteorological or hydrological) within or including the LIAISE area addressing the main project objectives, studies using observational data from the LIAISE field campaign
  • applications using remote sensing data (from planes, drones or satellites) to estimate irrigation requirements or evapotranspiration over the region
  • contributions from the GEWEX determining EvapoTranspiration (dET) Crosscutting Project.

Registration and Abstract Submission

To participate in the 1st LIAISE Conference and dET CrossCut Workshop, we ask you to register.
Registration is open from 5 September 2022 to 17 February 2023.
For additional information go the Registration page and to register click on the Subscribe button.

If you want to register now, click

Abstract submission is open between 5 September 2022 and 13 January 2023.
To submit your abstract, you have to register first. After registration click here to access your account to submit your abstract.

Registration and Abstract submission fees:

RegistrationUSD $100
Abstract SubmissionUSD $25


The agenda will become available mid February 2023 and can be accessed here.

27–28 March 20231st LIAISE Conference and dET CrossCut Workshop
29 March 2023Dedicated to LIAISE Working Group activities
30 March 2023Outreach activities (by invitation only)


The 1st LIAISE Conference and dET CrossCut Workshop (27–29 March, 2023), will take place at:

Parc Científic i Tecnològic Agroalimentari de Lleida
Lugar Parc Gardeny, 23
25003 Lleida

Parc Científic i Tecnològic Agroalimentari de Lleida.
Courtesy of IRTA

Travel to Spain


There are different types of visas for Spain depending on your nationality and reason for visiting. Importantly, Spain is a part of the Schengen Area which means they share a visa policy and a common, external border with the other participating countries.

More information about the Schengen Visa and how to apply can be found here.


Please visit the Spain Travel Health portal for the current health requirements for traveling to Spain.

Accommodation and transportation

Information about accommodations and transportation and what to see and do in the province of LIeida can be found here.

Organizing Committee

Joaquim Bellvert, Institute of Agrifood Research and Technology (IRTA) (Local Organizer)

Aaron Boone, National Center for Meteorological Research (CNRM), France

Josep Ramon Miró, Meteorological Service of Catalonia (SMC), Spain

Joan Cuxart, The University of the Balearic Islands (UIB), Spain

Oscar Hartogensis, The Wageningen University and Research institute (WUR), The Netherlands

Jan Polcher, Dynamic Meteorology Laboratory /Ècole Polytechnique in Palaiseau (LMD), France

Martin Best, United Kingdom Meteorological Office (UKMO), UK

Pere Quintana Segui, Ebro Observatory, Roquetes (Observatori de l’Ebre), Spain

Anne Verhoef, University of Reading (UoR), United Kingdom


ANR-HILIAISE run at CNRM, France

Meteorological Service of Catalonia (SMC), Spain

Dynamic Meteorology Laboratory (LMD), France