In order to address the major societal issues on which NAÏLA is positioned (i.e., vulnerability of agricultural environments and adaptability or resilience via a panel of innovations), the disciplinary activities carried out within the axes are articulated with cross-cutting actions that mobilize complementary skills on all or part of these areas. These transversal actions, which illustrate the added value of NAÏLA, correspond to concrete work over several years (5-10 years, corresponding to the succession of 2 to 3 doctoral students / post-doctoral students), with a view to conducting integrated analyses, and thus contribute to the design of new methods of water resource management in agricultural territories, in connection with public policies. We present these actions here, distinguishing between (1) the characterization of the risks and threats facing agricultural territories, (2) the co-construction with stakeholders of possible and acceptable solutions to deal with these risks and threats, and (3) the ex-post analysis of previous work to rethink the contribution of research in response to the needs of the actors. These actions are carried out in connection with the axes, for example at the level of axis 3 which calls on the skills of axis 2 in numerical simulations to evaluate the functionalities induced by the evolution scenarios (innovative management methods).

Vulnerability of agriculture to climate change.

On the one hand, it will be a question of finalizing the work carried out during NAÏLA 1: (1) consolidating / spatializing temporal chronicles from sparse meteorological networks, (2) jointly using these chronicles with thermal infrared satellite data to constrain a surface energy balance model (i.e., SPARSE), and (3) establish from this model water stress chronicles on a past - present - future continuum of several decades.
On the other hand, we will deepen the joint use of various observations to establish chronicles of water stress, including satellite data on the optical and microwave domains, based on the cross-analysis of different chronicles.
Finally, we will deepen knowledge on the functioning of vegetation, by conducting experimentation / modeling work, with a focus on the response of the olive tree to drought. We will rely on 3D tools for modeling water exchanges, constrained by eco physiological measurements by proximity detection (fluorescence, temperature).

The co-construction of possible and acceptable solutions, in connection with the design of water resource management methods, our approach is dual. On the one hand, we explore the possible innovations, in connection with the compositions and the spatial layouts, from the plot to the territory, and this by considering “social-eco-agro-hydrological” elements alone (e.g., associated crops) or combined (e.g., land use and hill lake networks). On the other hand, we study the biophysical and socio-economic consequences of these innovations, including the recharge of reservoirs (aquifers, lakes, dams), agricultural production, and the minimization of erosion.

Study the combined effects of land use and climate forcing on water efficiency in rain fed agriculture, considering mechanistic modeling on a small watershed. Based on climate scenarios and land use scenarios established during NAÏLA 1, the aim is to combine detailed hydrological modeling (e.g., MHYDAS) and modeling of the functioning of cultivated vegetation (e.g., AquaCrop or CropSyst), to simulate the water consumption of crops at the scale of the agricultural plot. The originality is to explain the intra-plot hydrological connections that induce an uneven distribution of precipitation in the root zone.

Still in the continuity of NAILA 1, studies the combined effects of land use and climate forcing on three ecosystem services in rain fed agriculture (water production in dams, agricultural production and minimization of erosion), by considering a semi - empirical on an agricultural territory. For this, we rely on the integrated SWAT model, which constitutes a basic reference compared to the mechanistic modeling proposed in the previous action, but which provides a less explicit description of intra-plot hydrological connectivity.

Capitalizes on the results of two other cross-cutting actions to study the impact of upstream land use on the recharge of the aquifer underlying the downstream dam. On the one hand, an ongoing transversal action characterizes the hydrological functioning of the downstream dam and the infiltrations towards the underlying aquifer (see report, § 7, action 2). On the other hand, the second action discussed above proposes to study the cross impacts of land use and climate forcing on the recharge of the downstream dam. The combination of these two actions will make it possible to study the evolution of upstream (rain fed agriculture) - downstream (dam and underlying aquifer) interactions under the influence of global change.

Explores the combined influences of land use and hydro-agricultural developments on reservoir recharge (lakes, dams) and agricultural production. This involves coupling different modeling tools (surface hydrology with runoff, hydrology of hill lakes and dams, functioning of cultivated vegetation) within an integrated modeling platform (e.g., OpenFLUID, ,, in order to simulate the biophysical functionalities induced by the combination of these two "socio-eco-agro-hydro logical" elements, the idea being to explore new innovations that the stakeholders do not have in mind.