The Joint research unit G-eau, France, is accepting applications for a 6-month internship in hydrology. The subject will be centered around the assessment of impacts of irrigation infrastructure on hydrological processes and ecosystem service in the Crau region in the South of France, in the context of climate change. The exact research questions may be adapted to the profile of successful applicants. 

Subject Outline

Across the globe, irrigation systems fundamentally alter local and regional hydrological processes. The water requirements of the over 3.6 million km² of irrigated land make up roughly 70% of worldwide freshwater withdrawals. Irrigation modifies surface energy balances, biogeochemical processes, as well as land-atmosphere feedbacks (McDermid et al. 2023). These impacts can be observed extensively in areas where irrigation is indispensable to agricultural practices, such as the Crau region in the South of France (Bailleux et al. 2015). The Crau is well-known for its hay production, which is even protected by a high-quality label. To sustain production during the hot, dry summer months, grasslands are irrigated using an extensive network of canals and gravity irrigation. This type system, used in the major part of the irrigated lands worldwide,  has considerable impacts on local hydrological cycles and ecosystem services, by changing the spatial distribution of water resources and increasing evapotranspiration. The decreasing water availability for human activities questions the possible adaptations of these infrastructures (e.g., lining earthen canals or replacing them by pipes) and even their sustainability, questioning in turn the sustainability of the related ecosystem services (see e.g. Oyonarte et al. 2022).

The goal of this internship is to delve into the role of irrigation infrastructure in the water cycle in the Crau region, and to make links to larger-scale processes. The exact research questions can be defined by the student chosen for the position, but some general aspects that could be addressed include: 

• How to detect irrigation infrastructure in the Crau using remote sensing
• Assessing the role of vegetation surrounding irrigation infrastructure for evapo(trans)piration and infiltration using in-situ measurements and modelling approaches; assessing the effect of climate change on the identified processes
• Assessing the distribution of water in irrigation canals when it is not actually used for irrigation, including the effects on ecosystems at the tail ends of canals. 
• Harnessing and extending existing models of hydrological processes in the region, for instance those constructed in OpenFluid, or developing new approaches to model hydrological processes in the Crau 

Literature (selection of references):

Baillieux, A., Alcazar, C., Villesseche, D., Monière, C., Trolard, F., Bourrie, G., ... & Fénart, P. (2016). Groundwater resource management facing global changes: from the European Directive to the local action plan for the Crau aquifer (SE France). In 43. IAH Congress “Groundwater and society: 60 years of IAH” (pp. 915-p).

McDermid, Sonali, et al. "Irrigation in the Earth system." Nature Reviews Earth & Environment (2023): 1-19.

Orieschnig, C. A., Belaud, G., Venot, J. P., Massuel, S., & Ogilvie, A. (2021). Input imagery, classifiers, and cloud computing: Insights from multi-temporal LULC mapping in the Cambodian Mekong Delta. European Journal of Remote Sensing, 54(1), 398-416.

Oyonarte, N. A., Gómez-Macpherson, H., Martos-Rosillo, S., González-Ramón, A., & Mateos, L. (2022). Revisiting irrigation efficiency before restoring ancient irrigation canals in multi-functional, nature-based water systems. Agricultural Systems, 203, 103513.

Vandôme, P. (2023) Rendre l'innovation technologique accessible aux systèmes irrigués : co-conception, évaluation et implications de la low-tech numérique pour accompagner la gestion de l'eau en agriculture. PhD thesis, Institut Agro, Montpellier.

Keywords: irrigation infrastructure, hydrological processes, ecosystem services, evapotranspiration, infiltration, hydrological modelling, 

Working Conditions 

Supervision: Prof. Gilles Belaud (Institut Agro) & Dr. Christina Orieschnig (IRD) 

Duration: 6 months, starting in February/March 2024

Salary:  according to national rules for internships (around 600€/month)

Fieldwork: While the student will be based at the Institut Agro in Montpellier, fieldwork in the Crau region is expected. The temporal and spatial scale of the fieldwork ultimately depends on the exact research questions the student chooses to address. A field site belonging to the Institut Agro - the Domaine du Merle, an experimental farm - can serve as the basis of fieldwork operations. Irrigation experiments and in-situ measurements can also be carried out there, if necessary, and ground-truthing data for remote sensing approaches can be gathered. 

Applicant Profile

Ideally, applicants should:

• be in the final year of their Master’s degree (the research might be continued with a PhD programme through a competitive application in 2024).
• have a background in hydrology and/or agronomy 
• have a thorough understanding of hydrological processes, from overland flow and ET to infiltration
• be familiar with irrigation systems and their connection to agricultural practices  
• have experience with remote sensing approaches 
• possess knowledge of hydrological modelling approaches 
• have experience with field measurements of different hydrological variables (eg. soil moisture, ET, …) 
• have coding skills in scientific languages (Python, R, or C++) 
• have a driving licence category B (for fieldwork) 
• be independent, inquisitive, and willing to define their own research question, methodology, and work plan