Towards understanding the DOQ Priorat terroirs: A multivariate GIS analysis

Abstract

The notion of terroir covers the interaction between the natural, the cultural conditions and the grape vine itself relative to the character of the final wine product. It is about a dynamic chain whose factors get different weights in each wine region and this results in the typicality of the different terroir wine products. The Old World wine regions have been for many years occupied with the terroir research in order to explain the uniqueness and the specificities of their wine products. Nowadays, more and more wine regions are interested in such kind of investigations in order to highlight their distinct products, expose their originality and get a place in the wine market. DOQ Priorat is located in South Catalonia in Spain and is a wine region that has recently been nominated a label of originality for its products. Such a denomination made the region’s cultivators interested to learn more about the natural conditions of the area in a try to explain the success of their products and with the prospect to preserve the quality of their wines. In these terms, Geographical Information Systems (GIS), providing the ability for spatial, statistical analysis and visualisation, have been considered important tools for the DOQ Priorat’s natural conditions’ analysis and diverse terroir investigation. Previous research has indicated topography, the soil properties and the climate of a region to define the natural conditions of a region and therefore being the factors of interest/effect in the wine terroir. These three factors can be described by specific attributes. For instance, elevation and ground inclination for topography, PH and texture for soil, temperature and precipitation for climate. The distribution of such attributes and many others that characterize the aforementioned natural conditions, has been studied in the DOQ Priorat territory in order to examine the resemblance of the DOQ Priorat vine growing conditions to the conditions that are considered beneficial from international research. The correspondence of the DOQ Priorat conditions to the standards for vine growing has been treated by means of a multivariate GIS analysis. The DOQ Priorat topographic and soil attributes have been evaluated relative to their suitability for vine growing and different suitability classes have been defined. Moreover, the growing season temperature distribution and its capability to define conditions of viability for specific grape varieties, has been used to define two major terroir units in DOQ Priorat. The suitability of the DOQ Priorat land for cultivation of specific varieties has been assessed through the topographic-soil composite suitability in relation to the teroir units defined. DOQ Priorat’s greatest extend has been classified in intermediate and intermediate to high vine growing suitability classes relative to its topography and soil conditions. The shallow and dry soils as well as the steep slopes visited in the area seem to contradict to what is considered beneficial for vine growing. In terms of climate however, the whole area presents ideal conditions for a wide variety of grape cultivations whereas most of these varieties proposed to fit the area are already cultivated today. Even though the current vineyard cultivations still present conditions of intermediate and intermediate-high suitability relative to what is considered beneficial from international vine growing research, the quality of the wines produced in DOQ Priorat is indisputable; there are therefore some unique features in the DOQ Priorat terroirs. The DOQ Priorat vines are cultivated in higher elevations and in soils shallower and less fine textured than what is considered to fit for vine growing internationally. That is what gives the DOQ Priorat wines their unique character and these are finally the conditions that are considered ideal for Priorat wines. Such a conclusion, leads to the confirmation of the dynamic nature of terroir, whose factors and attributes cannot be strictly defined and quantified for every wine region. New vine growing standards could be defined for several wine regions relative to their specificities whereas it is mostly the try, the result and the experience that define good and bad terroirs. The DOQ Priorat case has been a very nice example of a region going against the vine cultivation pattern whereas obtaining high quality and recognised wine products.GeomaticsGIS technologyOTB Research Institute for the Built Environmen