Climate Change impact on cereals production by using agroclimatic indices.

One of the main challenge for the next decades will be the resilience of the food supply chain. The first element of this system is the agricultural productivity like cereals.
We propose here an example of the application of our methodology for estimating the impact of climate change on maize (Zea mais) in a municipality of Archèche (France). This methodology is based on the two following steps:

• The use of our model of downscaling on climate scenarios (current period, 2050 RCP2.6 and RCP4.5) at Very High Spatial Resolution (5m). This model allows providing climatic variables (Tmin, Tmax, P etc.) for each month at a very accurate geographical scale;
• The application of downscaled climatic data into agroclimatic indices. Here we propose to use the well known GDD (Growing Degree Days) index defined for the cultivation of maize.

The cultivation cycle ends in September.
The blue cluster indicates the areas where the flowering period will be exceeded. The brown cluster represents areas that won’t have enough Growing Degree Days (GDD) for joining the maturity condition. The green cluster shows areas that will join the maturity stage.
In this territory, the current period is not suitable for cultivating maize, apart in the West side of the municipality. In the future, the territory should be more suitable for the cultivation of maize in almost all areas of the municipality.

The application of the Martone Aridity Index indicates similar results and the general suitability of the territory for cultivating cereals in the future.