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IVES 9 IVES Conference Series 9 Modelisation of the microclimatical parameters for the viticultural ”terroirs”characterization of “Canton de Vaud” (Switzerland)

Modelisation of the microclimatical parameters for the viticultural ”terroirs”characterization of “Canton de Vaud” (Switzerland)

Abstract

Dans le cadre d’une recherche sur les terroirs viticoles du canton de Vaud – Suisse, un modèle du microclimat intégrant température, relief, éclairement et pluviométrie a été conçu. L’objectif est d’établir un zonage du microclimat pour mieux comprendre les corrélations existantes entre le comportement agronomique de la vigne, les caractéristiques des sols et les variables microclimatiques. L’approche adoptée utilise notamment un modèle numérique d’altitude de 25m de résolution, le MNA 25 de l’Office fédéral de topographie.
Le gradient thermique est déduit de l’éclairement, de l’estimation de l’effet du vent et d’un modèle empirique de la répartition thermique altitudinale. L’ensoleillement est calculé à l’aide d’un modèle de rayonnement intégrant l’effet du relief environnant et la hauteur du soleil sur l’horizon durant la période considérée. Quant à l’effet du vent, il est estimé par la configuration du relief et les directions principales fournies par une cartographie régionale.
La comparaison finale avec la carte de niveaux thermiques du canton de Vaud, établie sur la base de relevés phénologiques de cultures représentatives [SCHREIBER, 1968], permet d’ajuster le modèle du microclimat. La répartition pluviométrique provient d’une régionalisation des informations collectées dans les stations de mesure du réseau Météosuisse.
Le zonage microclimatique définitif est une combinaison pondérée des variables citées. Sa valeur est davantage d’ordre qualitatif que quantitatif. ‘Il offre, cependant, une base comparative entre les différentes régions concernées. Finalement, la caractérisation des terroirs réunit le zonage microclimatique, les unités pédologiques et les résultats de l’étude agronolllique.

As part of a research on the viticultural terroirs of “Canton de Vaud” – Switzerland, a microclimatic model integrating temperature, relief, illumination and pluviometry was built. The objective is to make microclimate zoning in order to better understand the correlations between the agronomical behaviour of the vineyard, the soils characterization and the microclimatic variables. The adopted approach uses a digital elevation model with a resolution of 25 meters, the DEM25 of the Federal Office of Topography.

The thermical gradient is deduced from illumination, wind effect estimations and an empirical model of thermical altitudinal distribution. The illumination is calculated with a radiation model that integrates the effects of the surrounding relief (slope, aspect and casted shadow) and the sun height above the horizon during a specific period. The relief shape and the principal wind directions based on a regional cartography allowed to estimate the wind effect.
The achieved results are adapted to measurement stations data. Finally, a comparison with the map of thermical levels of “canton de Vaud”, determined on the basis of a phenological survey of representative cultures [SCHREIBER, 1968], allows to adjust the microclimate model. The rainfall distribution is the result of a data regionalization coming from the Meteosuisse station networks.
The final microclimatic zoning is a weighting of the above mentioned variables. lts value is more qualitative than quantitative. It offers however a comparison basis between the different regions concerned by the study. Finally, terroirs characterization combines microclimatic zoning, pedological unities and agronomical study results.

 

 

 

DOI:

Publication date: February 15, 2022

Issue: Terroir 2002

Type: Article

Authors

K. PYTHOUD and R. CALOZ

Faculté de l’Environnement naturel, architectural et construit
Laboratoire de Systèmes d’information géographique (LASIG)
Ecole polytechnique fédérale de Lausanne
CH – 1015 Lausanne

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Keywords

Modélisation, microclimat, terroirs, gradient thermique, pluviométrie
Modelisation, microclimate, terroirs, thermical gradient, pluviometry

Tags

IVES Conference Series | Terroir 2002

Citation

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