Description du sujet de thèse

Background to the study:
The development of agrivoltaic systems stems from the desire to combine agricultural and energy production on the same surface, in order to reduce land pressure and optimize surface productivity (Dupraz et al. 2011). For the installation of photovoltaic panels, priority is given to roof surfaces or degraded land, but these represent a limited and constrained resource. Furthermore, agriculture is seeking new revenues and greater energy autonomy to cope with the erosion of their margins and fluctuations in the prices of agricultural products, inputs and energy. The presence of photovoltaic shading systems could also protect animal and plant production from the vagaries of the weather (heat waves, violent storms). Nevertheless, it remains difficult to define the potential of each agricultural area for the installation of agrivoltaics, as well as the associated risks. In particular, the impact on biodiversity and landscape integration are largely ignored in current development plans and legislation. Given the current enthusiasm for the mass deployment of these installations, it is urgent to put in place strategies for assessing the potential of these territories, in order to minimize the impact on biodiversity and the environment, and limit the risk of societal rejection.
Due to the different driving forces affecting agriculture and local communities, farmers in different parts of the world are more or less likely to want to install agrivoltaic systems on their land. On the one hand, this may be to preserve agricultural services, such as improving yield potential and the agronomic impact of plots, adapting to climate change, protecting agriculture against hazards (climatic in particular), or improving the welfare of livestock (Dinesh and Pearce 2016; Andrew et al. 2021; Weselek et al. 2021). It may also be to diversify income and economic activities in the region, or to reduce environmental impact by producing low-carbon energy (Malu et al. 2017; Irie et al. 2019; Handler and Pearce 2022). Other, external factors can also motivate farmers to develop agrivoltaics on their land. For example, developing energy supply services, to combat vulnerability to access to electrical energy (in particular to electrify communities not connected to the electricity grid, or to supply territories under-supplied with low-carbon energy production) (Malu et al. 2017; Kostik et al. 2020; Randle-Boggis et al. 2021). However, agrivoltaic installations could be disservices, in the sense that they degrade other services already rendered. For example, landscapes can provide cultural services (recreational and tourist services, aesthetic or heritage value) or regulatory services (biological regulation, pollination), which could be considerably reduced if the installations are visible to all or cut across ecological networks, which could restrict the willingness to install them (Gasparatos et al. 2017; Oudes et al. 2022; Barré et al. 2023). Assessing the carrying capacity of an area according to multifunctional criteria that directly concern farmers, but also by integrating external parameters that affect the area more broadly, is therefore essential to ensure a sustainable siting strategy and societal acceptance of agrivoltaics (Fattoruso et al. 2024). Nevertheless, such studies remain scarce and only partly integrate all these dimensions.

Objectives and expected results:
The main objective of this PhD proposal is to develop a multi-criteria approach to model the degree of suitability of different territorial contexts for agrivoltaics. A comparative approach will be developed between agricultural areas in France and in Arizona (USA), and insights to a generalization on a global scale will be proposed. More precisely, we will (1) identify the relevant criteria to be taken into account with a view to global application of the approach; (2) model landscape-level indicators for each of these criteria using a coarse-graining approach (eco-landscapes); and (3) carry out a multi-criteria spatial analysis for a regional to national assessment of eligible areas for sustainable agrivoltaic systems in France and in Arizona, with possible extensions to Europe and the USA.
Using such an integrative approach, it is intended to identify the trade-offs emerging from the characteristics of the different areas under consideration and the consequences that agrivoltaic systems would have on them. Also, this method is primarily aimed at regional and national authorities for planning the sustainable development of agrivoltaic systems at local level, helping them to identify the areas to be prioritized for the implementation of agrivoltaics.

Methodology and organization:
The first step will be to conduct a literature review on (1) societal considerations and (2) related variables that can be considered to calculate further landscape indicators. Societal considerations can be categorized into three groups: nature and ecology (e.g., barriers for species movement, microclimatic impact, control of water surface run-off), socioeconomic (e.g., loss of existing land use, tourism and effect on local economy, sufficient capacity on the grid, sustained balance between energy and food), and landscape (from a human perspective; e.g., aesthetic impact, artificializing of landscape, historic landscape character) (Oudes et al. 2022). The related variables and data sources to be used to compute landscape indicators will be identified from the existing literature as well as public databases of land use, land cover or socioeconomic censuses.
Combining these societal considerations with pedoclimatic and environmental variables (e.g., solar radiation, temperature, elevation, slope, aspect/orientation, water deficit), the second step will be to compute eco-landscape indicators for each of the criteria. Eco-landscapes are coarse-grained representations of landscapes that define ecologically and geographically delimited territorial zones, divided into classes, in which the diversity of ecosystems and the impacts of each variable are relatively homogeneous, and which tend to be distinct from one another (Tournant et al. 2017). The approach is similar to that used to define biomes and large ecological regions, but on a finer scale. For each variable/group of variables, landscape structure metrics will be calculated in sliding windows of different sizes (e.g. from 1 km² to 10 km²) covering the study area. This approach makes the window size independent of the final resolution (pixel size), and allows the landscape gradient to be finely integrated to better define the spatial fronts of landscape change. Then, by integrating the metrics calculated for each pixel in the study area, the pixels can be grouped into equidistant categories according to their values — the number of groups (or eco-landscapes) being optimized, for example using a k-means approach. Finally, the eco-landscapes will be "translated" from an ecological and geographical point of view, using multivariate analysis (PCA) to identify which initial landscape dimensions distinguish the eco-landscapes from one another.
Based on all this information, it will be possible in a third step to establish scores for each locality, associated with each criterion and socio-ecological pressure, and to represent them in the form of maps. On the basis of these scores, the suitability of the localities can be quantified in terms of the synergies and trade-offs to be made in relation to the various dimensions considered.
The development of such an approach may be of particular interest to help decision-making in the context of development plans. In order to make it easier to use, a possible extension to the project will be to develop a dynamic application, which would make it possible to (1) aggregate the scores obtained by agricultural areas into larger zones as required (e.g., at the scale of a farm, a municipality, a township) and (2) cumulate the services/disservices potentially rendered by agrivoltaics by combining the scores obtained for each dimension considered. The tool will need to be sufficiently flexible to allow users to choose the dimensions they wish to integrate into their final analysis, depending on the issues they wish to address.

Contexte de travail

This CNRS-funded doctoral research is part of a CNRS “80 PRIME” national research contract “Agrivoltaic installations: green infrastructure 2.0? The intersection of law and ecology” and is also part of the Graduate Research Fellowship and International Mobility Program “Agrivoltaics at Scale: An Opportunity for Resilience across Food, Energy and Water Systems” proposed by the CNRS and the University of Arizona. The new recruit will benefit from this interdisciplinary research environment and will directly integrated to associated research consortia.
The EDYSAN unit (UMR CNRS 7058) has expertise in ecology, agroecology, and geography, and works in particular on the impacts of agricultural management practices and landscaping on biodiversity. Agrivoltaics as a management component is under study in the lab for the past five years, from field to landscape. The development of multidimensional eco-landscape methodology is currently undergoing in the context of the MOTIVER project, and the PhD student will also benefit from this interdisciplinary consortium to be trained on the eco-landscape approach.
The PhD candidate will also be co-supervised by Greg Barron-Gafford, biogeographer at UArizona, who is building the field of agrivoltaics for more than a decade.
The student will be registered with the Amiens Sciences, Technologie, Santé doctoral school (UPJV EDSTS 585).

Application:
- Curriculum Vitae
- A cover letter outlining your interest in working on an innovative technical subject that meets sustainability requirements (1 page)
- A presentation of the scientific implications associated with the thesis project (1 to 2 pages maximum).
- Transcripts of Master's grades
- The dissertation produced following the Master 1 or 2 internship (or, for foreign students, the thesis associated with the last research experience). If the candidate is currently doing a Master 2 internship, add a one-page summary of the internship's objectives, context and methodology.

Application selection procedure:
The first stage of selection will be based on the excellence of the applicant's academic record and the quality of their research project in line with the proposed research theme.
At the end of this first stage, selected candidates will be interviewed. During the interview, they will be asked to present their academic background, their motivation and then to elaborate on their research project using a 10-min presentation.

Contraintes et risques

The object of the study does not a priori require data collection in the field. The aim is to make the most of public data available on a large scale (national, continental or global). To this end, the student will be provided with a personal desk and computer.
Given the theme of the thesis, the student should have recognized skills in landscape ecology, GIS and geography, and a mastery of the associated software. They should have a Master's degree (or equivalent) in ecology or geography, ideally with an interest, or even specialization, in agroecosystems and an understanding of their issues.
More broadly, the student should have a strong interest in environmental issues, a taste for teamwork, a high degree of autonomy, an interest in interdisciplinary research and, lastly, fluency in English, both written and spoken.
A stay of a few weeks or months at UArizona is worth considering, in particular to exchange ideas with local colleagues and familiarize oneself with the local context. The student must be available and willing to make such an extended trip.