High resolution climate spatial analysis of European winegrowing regions

Climate strongly affects the geographical distribution of grape varieties, grapevine cultivation techniques and wine organoleptic properties. The current study aims at comparing the climatic features of European winegrowing regions. A geodatabase of 260 wine producing areas within 18 countries of the European Community was first established by means of maps collected from various sources (e.g. atlases and national wine and vine services). Within the 247 of the 260 initially delimited regions, areas actually planted with vine were identified by means of the Corine Land Cover database, for a total of 6 million of hectares. Each of the 1 km resolution pixels of the WorldClim 1950-2000 monthly climatic database located within these planted areas were used to calculate agroclimatic indices. The Huglin index, the Cool night index and the Dryness index, as described by the Multicriteria Climatic Classification system, as well as a winter freeze risk index, a spring frost risk index and a heat stress index were calculated. The use of a clustering algorithm (CLARA) with each of these 1 km resolution gridded indices resulted in the identification of six climate types: (1) sub-humid temperate, (2) sub-humid cool with very cool nights and high spring frost risk, (3) moderately dry and temperate with cool nights, (4) dry and temperate warm with temperate nights, (5) sub-humid temperate with strong frost risks, and (6) very dry and hot, with cool nights climates. Each of the 247 winegrowing regions was classified according to the type of climate that covers the largest part of its territory. Despite the clustering, the type 4 climate still exhibits a large diversity of climatic characteristics. It is located mainly within winegrowing regions located close to the Mediterranean Sea. To our knowledge the current work is the largest spatial climate analysis of winegrowing regions that have been performed so far.