Terroir 1996 banner
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

Contact the author

Keywords

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

Tags

IVES Conference Series | Terroir 2002

Citation

Related articles…

How can historical cultivars mitigate the effects of climate change?

IFV, INRAe and the national network “Partenaires de la Sélection Vigne” representing 37 organizations from the different wine regions, have been working increasingly closely over the last 2 decades towards the preservation of the French varietal patrimony. There are approximately 600 patrimonial varieties according to INRAe and SupAgro Montpellier experts, including ancient cultivars (400) and intravarietal crossbreeds obtained since the 19th century. In the context of a drastic reduction in such varieties from the mid 1980’s in favor of mainstream varieties, it was essential to carry out an inventory of old vines and vineyards. INRAe Vassal collection plays a key role here as it holds the largest diversity available, along with a rich bibliography and herbariums, offering us the opportunity to document and double check the identity of a cultivar, consolidating the expertise of ampelographers. The work is carried out in several stages, from verifying the existence of a variety in a small region, through to rehabilitation. During this session, the authors present the process that leads to the official registration of a variety. After this, IFV selection center takes over to initiate the process of selection and propagation. A specific focus within regions such as the Alps, Champagne and the South-West will provide details of the full procedure. Bia, Bouysselet, Chardonnay rose, Mecle and the aptly named Tardif, are some of the cultivars that have followed this procedure. Furthermore, a recent regulation established by INAO on “varieties of interest for adaptation purposes” might boost uptake by growers. Since 2006, 36 historical cultivars have been registered. Most of these have been neglected in the past due to late maturity, lack of sugar and high titratable acidity at harvest time. Such characteristics are today considered as positive qualities, not only in mitigation of the effects of climate change, but also as an opportunity for restoring diversity…

Impact of geographical location on the phenolic profile of minority varieties grown in Spain. II: red grapevines

Because terroir and cultivar are drivers of wine quality, is essential to investigate theirs effects on polyphenolic profile before promoting the implantation of a red minority variety in a specific area. This work, included in MINORVIN project, focuses in the polyphenolic profile of 7 red grapevines minority varieties of Vitis vinifera L. (Morate, Sanguina, Santafe, Terriza Tinta Jeromo Tortozona Tinta) and Tempranillo) from six typical viticulture Spanish areas: Aragón (A1), Cataluña (A2), Castilla la Mancha (A3), Castilla –León (A4), Madrid (A5) and Navarra (A6) of 2020 season. Polyphenolic substances were extracted from grapes. 35 compounds were identified and quantified (mg subtance/kg fresh berry) by HPLC and grouped in anthocyanins (ANT) flavanols (FLAVA), flavonols (FLAVO), hydroxycinnamic (AH), benzoic (BA) acids and stilbenes (ST). Antioxidant activity (AA, mmol TE /g fresh berry) was determined by DPPH method. The results were submitted to a two-way ANOVA to investigate the influence of variety, area and their interaction for each polyphenolic family and cluster analysis was used to construct hierarchical dendrograms, searching the natural groupings among the samples. Sanguina (A3) had the most of total polyphenols while Tempranillo (A5) those of ANT. Sanguina (A2) and (A3) reached the highest values of FLAVO, FLAVA and AA. These two last samples had also the maximum of AA. The effect cultivar and area were significant for all polyphenolic families analyzed. A high variability due to variety (>50%) was observed in FLAVA and the maximum value of variability due to growing area was detected in AA (86.41%), ANT and FLAVO (51%); the interaction variety*zone was significant only for ANT, FLAVO, EST and AA. Finally, dendrograms presented five cluster: i) Sanguina (A2); ii) Sanguina (A3); iii) Tempranillo (A5); iv) Tempranillo (A3); Terriza (A3,A5), Morate (A5,A6); v) Santafé (A1,A6); Tortozona tinta (A1,A3,A6); Tinta Jeromo (A3,A4).

Co-design and evaluation of spatially explicit strategies of adaptation to climate change in a Mediterranean watershed

Climate change challenges differently wine growing systems, depending on their biophysical, sociological and economic features. Therefore, there is a need to locally design and evaluate adaptation strategies combining several technical options, and considering the local opportunities and constraints (e.g. water access, wine typicity). The case study took place in a typical and heterogeneous Mediterranean vineyard of 1,500 ha in the South of France. We developed a participatory modeling approach to (1) conceptualize local climate change issues and design spatially explicit adaptation strategies with stakeholders, (2) numerically evaluate their effects on phenology, yield and irrigation needs under the high-emissions climate change scenario RCP 8.5, and (3) collectively discuss simulation results. We organized five sets of workshops, with in-between modeling phases. A process-based model was developed that allowed to evaluate the effects of six technical options (late varieties, irrigation, water saving by reducing canopy size, adjusting cover cropping, reducing density, and shading) with various distributions in the watershed, as well as vineyard relocation. Overall, we co-designed three adaptation strategies. Delay harvest strategy with late varieties showed little effects on decreasing air temperature during ripening. Water constraint limitation strategy would compensate for production losses if disruptive adaptations (e.g. reduced density) were adopted, and more land got access to irrigation. Relocation strategy would foster high premium wine production in the constrained mountainous areas where grapevine is less impacted by climate change. This research shows that a spatial distribution of technical changes gives room for adaptation to climate change, and that the collaboration with local stakeholders is a key to the identification of relevant adaptation. Further research should explore the potential of adaptation strategies based on soil quality improvement and on water stress tolerant varieties.

Effect of vigour and number of clusters on eonological parameters and metabolic profile of Cabernet Sauvignon red wines

Vegetative growth and yield are reported to affect grape and wine quality. They can be controlled through different techniques linked to vine management. The objective of this research was to determine the effect of vine vigour and number of clusters per vine on physicochemical composition and phenolic profile of red wines. The experiment was carried out during two vegetative cycles, with cv. Cabernet Sauvignon grafted onto Paulsen 1103. Three vine vigour were defined, according to shoot weight at previous harvests, being low, medium and high. Five treatments of number of clusters were used for each vigour, with 15, 22, 29, 36, and 45 clusters per vine. Grapes from all treatments were harvested in the same day from Brix and total acidity criteria. Thirty days after bottling, classical analyzes and phenolic compounds were performed. As results, different responses were obtained from each vintage. In 2020, a dry season from veraison to harvest, grapes and wines obtained from low vigour treatment and 45 clusters per vine was the highest in sugar and alcohol content respectively, while grapes and wines from high vigour and 15 clusters presented the lowest sugar and alcohol content. Total anthocyanins were higher in treatment with low vigour and 15 clusters, while the lowest amounts were found in low vigour with 45 clusters, as well as medium and high vigour with 36 clusters per vine. Total tannins were higher in high vigour with 22 clusters and medium vigour with 29 clusters, while were lower in low vigour with 36 clusters. In 2021, a wet season at harvest, responses were different, and great variations were observed between treatments. As conclusions, yield and vine vigour had strong influence on grape and wine quality, promoting different enological potentials on which can be indicated/used for aging strategies of red and even rosé wines.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares