November 2021: First in-person meeting of the IDEWA team
Most of the project meetings since the beginning of IDEWA in October 2020 have taken place remotely by teleconference, due notably to the COVID-19 pandemic situation. Fortunately, the almost complete IDEWA team could gather in Lleida on 4-5 November to have face-to-face discussions on the research topics of the PhD and postdoc involved as well as on the project implementation strategies. In particular, we took this opportunity to organize three brainstorming sessions about 1) defining the data and model requirements for investigating relationships between drainage and river water quality and 2) defining a strategy to build (actual and potential) irrigation scenarios for SURFEX simulation. Josep Maria and Victor from the Universitat de Lleida also took the team to visit the IDEWA experimental sites and the hydraulic infrastructures of the Algerri-Balaguer area.

September 2021: Shooting the first IDEWA movie
Arnaud Mansat, a professional videographer specialized in scientific documentaries, accompanied us in the Lleida region to produce some video footage from 16th to 18th June 2021. We took the opportunity of the installation of lysimeters in the Algerri-Balaguer area to illustrate through field work the scientific objectives of the project. Additionally Arnaud could interview several IDEWA participants from LabFerrer, Universitat de Lleida, CESBIO and isardSAT. The nice pictures below give a flavor of the 4-minute long IDEWA video that will be shortly available for communication and dissemination activities.

May to August 2021: Three-month stay of Pierre Laluet at LabFerrer, University of Lleida and IRTA (Institute of Agrifood Research and Technology)
My PhD aims at developing a tool to retrieve the dates and quantities of drainage water at the scale of irrigation districts (several tens of thousands of hectares) by combining an agro-hydrological model and remote sensing data. To reach this goal, I am using unprecedented drainage data measured at an integrated scale in drains buried under a large part of the Algerri-Balaguer irrigation district located north of Lleida in Catalonia. It is in this framework and thanks to the ACCWA project (funded by the European Union’s H2020 RISE program) that I got the opportunity to spend three months in Lleida to work on this study area.
Among the many meetings, trainings, field trips, and various encounters, the key elements of my stay are: 1) the installation of four passive lysimeters on two plots, which are now also equipped with meteorological stations and water counters, allowing to calibrate a method at the plot level; 2) the launch of a sampling campaign for isotopic analysis to better understand the flow observed in the buried drains; 3) various trainings received (HYDRUS-1D, passive lysimeters, Sen4ET evapotranspiration products), and trainings given on the SAMIR model; 4) a better understanding of the area (geology, pedology, hydro(geo)logical functioning), and of the realities of the field and its specific challenges; 5) numerous meetings, including with managers of the irrigation district, farmers, the IRTA and LabFerrer teams.

May – August 2021: Three-month stay of Luis Olivera at LabFerrer, University of Lleida and IRTA
Luis Olivera, postdoctoral researcher at CESBIO, was seconded to LabFerrer near Lleida from 16th May to 15th August 2021 as part of the Horizon 2020 Research and Innovation Staff Exchange (RISE) ACCWA project. Among the many field trips realized in the study area, north of Lleida, he took the opportunity to participate together with IDEWA participants in the installation of METER G3 lysimeters and the isotopic measurements campaign in the Algerri-Balaguer area. Luis received a training by IRTA members about the utilization of Sen4ET data. SEN4ET is a high resolution remotely sensed evapotranspiration product that will be assimilated in a crop water balance model (SAMIR for SAtellite Monitoring of IRrigation) to better estimate evapotranspiration, root-zone soil moisture and the irrigation water actually applied over the Algerri-Balaguer district. Additionally, Luis gave a training to IDEWA and ACCWA participants about the SAMIR model for the mapping of water balance components over agricultural areas.

July 2021: Participation to the HILIAISE (Human imprint on Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment) soil moisture campaign
In July 2021, two members of the IDEWA project, Pierre Laluet and Luis Olivera Guerra, had the opportunity to participate in the intensive measurement campaign of the HILIAISE project, carried out in the framework of the HYMEX (HYdrological cycle in the Mediterranean Experiment) program. This vast experiment involved many laboratories (CNRM, CESBIO, University/ of the Balearic Islands, UK Met Office, LMD-IPSL, Observatori de l’Ebre, IRTA, Wageningen University and Research,…), some of which are members of the IDEWA project, and took place in the Urgell irrigation district located a few tens of kilometers from the IDEWA study (Algerri-Balaguer) area. It is in this context that Pierre Laluet and Luis Olivera Guerra participated in a one-week measurement campaign on 23 different plots, to collect in-situ data of surface soil moisture using TDR probes, and LAI (Leaf Area Index) by taking hemispherical photos.  Those measurements will provide reference data for calibration and validation activities. They were carried out on each pass date of the Sentinel-1 satellite (every 6 days) and on each pass date of the airborne GLORI instrument (Zribi et al. 2018), which was flown to estimate surface soil moisture at high spatial resolution by GNSS reflectometry.

July 2021: Isotopic measurements in Algerri-Balaguer
A new experimental protocol was proposed in the frame of IDEWA in collaboration with Nicolas Patris from Hydro Sciences Montpellier lab. The science question here is to trace the origins of the drained water measured at the wells of Algerri-Balaguer district, i.e. to determine the partitioning of the drained volume that comes from irrigation water and the drained volume that comes from natural precipitations. Addressing this key issue will greatly help validate model estimates at the integrated scale –several thousand of hectares- of the drainage measurements. A possible solution to this problem is to use isotopic techniques to try and trace back the water pathways from the measurement of the isotopic composition of water molecules.  This experiment started in July 2021 and is planned to last for at least 12 months. It involves the collection of water samples once per month in different reservoirs (raingauges, irrigation reservoir, drain wells and lysimeter drainage bottles) by the University of Lleida team.

June 2021: Installation of METER G3 lysimeters in Algerri-Balaguer
One main objective of IDEWA is to monitor and predict the water drainage below the root zone over irrigated areas. Modeling tools of the crop water budget, like SAMIR (Satellite Monitoring of Irrigation) model, operate at the scale of agricultural practices. There is thus a need to assess SAMIR drainage estimates at the crop field scale. To meet this need, four passive G3 type lysimeters were installed in two experimental fields of Algerri-Balaguer, occupied by corn and wheat crops respectively. The installation took place on 16th and 28th June 2021. It was made so efficient by the help and know-how of LabFerrer team and the excavator kindly lent by the Canal Algerri-Balaguer irrigation agency.  LabFerrer is collaborating with several IDEWA partners as part of the ACCWA consortium.