Terroir 2004 banner
IVES 9 IVES Conference Series 9 Method for the evaluation of climatic changes envisaging the protection of grape-growing terroirs: the Géoviticulture MCC system in the evaluation of the potential impact of the construction of hydroelectric power plants on viticulture

Method for the evaluation of climatic changes envisaging the protection of grape-growing terroirs: the Géoviticulture MCC system in the evaluation of the potential impact of the construction of hydroelectric power plants on viticulture

Abstract

[English version below]

La recherche, conduite en 2002, a envisagé l’estimation, a priori, de l’effet du changement mesoclimatique sur le potentiel qualitatif de la région viticole de la Serra Gaúcha (Vallée du Rio das Antas) – Brésil, en fonction de la construction de 3 usines hydroélectriques. Avec une puissance totale de 360 MW, les usines seront opérationnelles entre 2004-2007. La superficie totale d’inondation est de 11,4 km2. La demande des viticulteurs était d’avoir une évaluation des effets d’un éventuel changement climatique en fonction de cette action humaine sur le potentiel viticole de la région. Elle présente climat IS-2 IH+1 IF-1 (humide, tempéré chaud, à nuits tempérées) selon le Système de Classification Climatique Multicritères Géoviticole (Système CCM Géoviticole). Le Système, qui offre plusieurs outils d’aide aux études de zonage vitivinicole à différents échelles, utilise 3 indices climatiques viticoles de référence (Indice de Sécheresse – IS, Indice Héliothermique – IH et Indice de Fraîcheur des Nuits – IF). Ces indices sont représentatifs de la variabilité du climat viticole liée aux exigences des cépages, à la qualité de la vendange (sucre, couleur, arôme) et à la typicité des vins. Dans une première étape, l’étude a été développée en utilisant la modélisation climatique numérique avec le modèle RAMS (Regional Atmospheric Modeling System), version 4.3, au niveau meso et macroclimatique dans la région des usines. Quatre situations ont été simulées : vigne au Fond de la Vallée – FV (situation juste à coté de la rivière) – (1) Climat Actuel (CA-FV) et (2) Climat Futur (CF-FV) ; Haut de la Vallée – HV (416 m supérieure en altitude et à une distance horizontale de 102 m para rapport à FV) – (3) Climat Actuel (CA-HV) et (4) Climat Futur (CF-HV). Le CF représente la situation de plus fort impact potentiel, où la superficie a être inondée sera la plus grande. Egalement, une étude de l’évolution du changement climatique à partir de la rivière jusqu’à la disparition de ces effets dans la région a été conduite. Les variables climatiques concernent les températures (minimale, maximale et moyenne), pluie, Rg, insolation, humidité de l’air e vitesse du vent ont été modélisées au pas de temps mensuel. L’évapotranspiration potentielle (ETP Penman) a été calculée. Par la suite, les indices IH, IF et IS ont été calculés, avec l’utilisation des fonctionnalités du Système, soit pour CA, soit pour CF dans les situations FV et HV. Les résultats ont montré que le climat viticole ne change pas de classe dans le climat futur. Pour l’IH au fond de la vallée, la valeur de 2.488 (CA-FV) passe à 2.483 dans le scénario futur (CF-FV). En haut de la Vallée, l’IH passe de 2.451 (CA) à 2.443 dans CF. Pour l’IF on ne constate pas un changement climatique pour la période de référence de l’indice (moi de mars), sauf pour la période de décembre à février, avec une augmentation de 0,1 à 0,2 ºC dans le climat futur pour les deux situations (FV et HV). L’IS présente des valeurs entre 4 à 6 mm supérieurs dans le climat futur en comparaison avec CA, soit pour FV ou HV. Le résultat est fonction surtout d’une précipitation un peut plus élevé et d’une ETP un peut plus faible dans le climat futur. L’étude a permis d’estimer que la construction des 3 usines hydroélectriques ne changera pas le macroclimat, mais devra causer un changement au niveau du climat local (topoclimat), en fonction d’une augmentation de l’IS et de la réduction de l’IF, restreint aux zones internes (coteaux de la Vallée du Rio das Antas). Le changement tend à zéro quand on s’éloigne de la vallée (plus de 1000 m de distance la rivière). Ce changement est potentiellement négatif vis-à-vis des caractéristiques qualitatives du raisin. Par contre, il est de très faible intensité. Une cartographie en 3D de la région des usines, avec la superficie a être inondé, a été saisie. Une suivie des conditions climatiques de longe terme est en cours envisageant l’évaluation du changement climatique réel et son influence sur la viticulture.

The research, conducted in 2002, has aimed at estimating, a priori, how the mesoclimatic change, conditioned by the construction of 3 hydroelectric power plants, will affect the qualitative potential of the grape-growing region of the Serra Gaúcha (Rio das Antas Valley), Brazil. The power plants will begin to operate between 2004 and 2007, and their total capacity will amount to 360 MW. The total inundation surface will be 11,4 km2. The vine growers requested to get an idea about how a possible climatic change, caused by this man-made action, could affect the vineyard potential of this region. According to the Géoviticulture Multicriteria Climate Classification System (Géoviticulture MCC System), the region has the climate IS-2 IH+1 IF-1 (“humid, temperate warm, with temperate nights”). The system, which offers several tools for viticultural zoning studies on different scales, employs 3 viticultural climatic indices of reference (Dryness Index – IS, Heliothermal Index – IH, and Cool Night Index – IF). These indices are representative of the variability of the viticultural climate related to the requirements of the grape varieties, the quality of the grapes (sugar, color, flavor) and the characteristics of the wines. In a first stage of the study, numerical climatic modeling with the RAMS (Regional Atmospheric Modeling System), version 4.3, was employed at the meso- and macroclimatic level in the region of the power plants. Four situations were simulated: vineyard at the foot of the valley – FV – (location right at the riverbanks) – (1) Current Climate (CA-FV) and (2) Future Climate (FC-FV); at the top of the valley – HV – (416m higher and at a horizontal distance of 102m in relation to FV) – (3) Current Climate (CA-HV) and (4) Future Climate (CF-HV). The CF demonstrates the situation with the strongest potential impact where the surface to be flooded is the largest. Equally, a study on the evolution of the climatic change was conducted starting from the river up to the disappearance of these effects in the region. The climatic variables, concerning the temperatures (minimum, maximum and average), rain, Rg, insolation, air humidity and speed of the wind were modeled at a monthly rate. The potential evapotranspiration was calculated. In the following, the indices IH, IS and IF were calculated, using the functions of the System, for CA as well as for CF in the situations FV and HV. The results have shown that the viticultural climate does not change class in the future climate. For IH at the foot of the valley, the value 2.488 (CA-FV) changes to 2.483 in the future climate (CF-FV). At the top of the valley the IH changes from 2.451 (CA) to 2.433 for CF. In this way, no significative influence on IH was observed. For IF it is not possible to observe a climatic change in the period of reference of the index (March) except for the period from December to February, with an increase of 0,1 to 0,2ºC in the future climate for the two situations (FV and HV). The IS shows values between 4 and 6 mm higher in the future climate when compared with CA, be it for FV or HV. The result is above all a consequence of a slightly higher precipitation and of a slightly weaker ETP in the future climate. The study has allowed to estimate that the construction of the three hydroelectric power plants will not change the macroclimate, but should cause a change at the level of the local climate (topoclimate), as an effect of an increase of the IS and of the reduction of the IF, restricted to internal areas (slopes of the Rio das Antas Valley). The change tends towards zero at a certain distance from the valley (more than 1000m distance from the river). This change is potentially negative for the qualitative characteristics of the grapes. However, it is of very weak intensity. A 3D chart of the power plants region with the surface to be flooded has been produced. A study on the long-term climatic conditions is currently being performed aiming at the evaluation of the real climatic change and its influence on the viticulture.

Download the PDF

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

J. Tonietto (1), O.L.L. de Moraes (2) et H. Hasenack (3)

(1) Embrapa – Centre National de Recherche de la Vigne et du Vin ; Rua Livramento, 515 ; 95700-000 –
Bento Gonçalves, Brésil
(2) Département de Climatologie, Université Fédérale de Santa Maria – UFSM
(3) Centre d’Ecologie, Université Fédérale du Rio Grande do Sul – UFRGS

Contact the author

Keywords

Qualité, changement climatique, impact climatique, Système CCM Géoviticole, protection des terroirs viticoles

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Assessing the relationship between cordon strangulation, dieback, and fungal trunk disease symptom expression

Grapevine trunk diseases including Eutypa dieback are a major factor in the decline of vineyards and may lead to loss of productivity, reduced income, and premature reworking or replanting. Several studies have yielded results indicating that vines may be more likely to express symptoms of vascular disease if their health is already compromised by stress. In Australia and many other wine-growing regions it is a common practice for canes to be wrapped tightly around the cordon wire during the establishment of permanent cordon arms. It is likely that this practice may have a negative effect on health and longevity, as older cordons that have been trained in this manner often display signs of decay and dieback, with the wire often visibly embedded within the wood of the cordon. It is possible that adopting a training method which avoids constriction of the vasculature of the cordon may help to limit the onset of vascular disease symptom expression. A survey was conducted during the spring of two consecutive growing seasons on vineyards in South Australia displaying symptoms of Eutypa lata infection when symptomless shoots were 50–100 cm long. Vines were assessed as follows: (i) the proportion of cordon exhibiting dieback was rated using a 0–100% scale; (ii) the proportion of canopy exhibiting foliar symptoms of Eutypa dieback was rated using a 0–100% scale; (iii) the severity of strangulation was rated using a 0–4 point scale. Images were also taken of each vine for the purpose of measuring plant area index (PAI) using the VitiCanopy App. The goal of the survey was to determine if and to what extent any correlation exists between severity of strangulation and cordon dieback, in addition to Eutypa dieback foliar symptom expression.

Read More

The plantation frame as a measure of adaptation to climate change

The mechanization of vineyard work originally led to a reduction in planting densities due to the lack of machinery adapted to the vineyard. The current availability of specific machinery makes it possible to establish higher planting densities. In this work, three planting densities (1.40×0.80 m, 1.80×1 m and 2.20×1.20 m, corresponding to 8928, 5555 and 3787 plants/ha respectively) were studied with four varieties autochthonous of Galicia (northwestern Spain): Albariño and Treixadura (white), Sousón and Mencía (red). The vines were trained in a vertical shoot positioning system using a single Royat cordon, and pruned to spurs with two buds each. Agronomic data (yield, pruning wood weight, Ravaz index) and oenological data in must were collected. The higher planting density (1.40×0.80 m) had no significant effect on grape yield per vine in white varieties, although production per hectare was much higher due to the greater number of plants. In red varieties, this planting density resulted in a significantly lower production per vine, compensated by the greater number of plants. In addition, it significantly reduced the Brix degree in the must of the Albariño, Treixadura and Sousón varieties, and increased the total acidity in the latter two and Mencía. It also caused an increase in extractable and total anthocyanins and IPT in red grapes. The effects of high planting density on grapes are of great interest for the adaptation of varieties in the context of climate change. In the future, it could be advisable to modify the limits imposed by the appellations of origin on the planting density of these varieties in order to obtain more balanced wines.

Read More

Local adaptation tools to ensure the viticultural sustainability in a changing climate

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...
Read More

Impact of yeast derivatives to increase the phenolic maturity and aroma intensity of wine

Using viticultural and enological techniques to increase aromatics in white wine is a prized yet challenging technique for commercial wine producers. Equally difficult are challenges encountered in hastening phenolic maturity and thereby increasing color intensity in red wines. The ability to alter organoleptic and visual properties of wines plays a decisive role in vintages in which grapes are not able to reach full maturity, which is seen increasingly more often as a result of climate change. A new, yeast-based product on the viticultural market may give the opportunity to increase sensory properties of finished wines. Manufacturer packaging claims these yeast derivatives intensify wine aromas of white grape varieties, as well as improve phenolic ripeness of red varieties, but the effects of this application have been little researched until now. The current study applied the yeast derivative, according to the manufacture’s instructions, to the leaves of both neutral and aromatic white wine varieties, as well as on structured red wine varieties. Chemical parameters and volatile aromatics were analyzed in grape musts and finished wines, and all wines were subjected to sensory analysis by a tasting panel. Collective results of all analyses showed that the application of the yeast derivative in the vineyard showed no effect across all varieties examined, and did not intensify white wine aromatics, nor improve phenolic ripeness and color intensity in red wine.

Read More

An analytical framework to site-specifically study climate influence on grapevine involving the functional and Bayesian exploration of farm data time series synchronized using an eGDD thermal index

Climate influence on grapevine physiology is prevalent and this influence is only expected to increase with climate change. Although governed by a general determinism, climate influence on grapevine physiology may present variations according to the terroir. In addition, these site-specific differences are likely to be enhanced when climate influence is studied using farm data. Indeed, farm data integrate additional sources of variation such as a varying representativity of the conditions actually experienced in the field. Nevertheless, there is a real challenge in valuing farm data to enable grape growers to understand their own terroir and consequently adapt their practices to the local conditions. In such a context, this article proposes a framework to site-specifically study climate influence on grapevine physiology using farm data. It focuses on improving the analysis of time series of weather data. The analytical framework includes the synchronization of time series using site-specific thermal indices computed with an original method called Extended Growing Degree Days (eGDD). Synchronized time series are then analyzed using a Bayesian functional Linear regression with Sparse Steps functions (BLiSS) in order to detect site-specific periods of strong climate influence on yield development. The article focuses on temperature and rain influence on grape yield development as a case study. It uses data from three commercial vineyards respectively situated in the Bordeaux region (France), California (USA) and Israel. For all vineyards, common periods of climate influence on yield development were found. They corresponded to already known periods, for example around veraison of the year before harvest. However, the periods differed in their precise timing (e.g. before, around or after veraison), duration and correlation direction with yield. Other periods were found for only one or two vineyards and/or were not referred to in literature, for example during the winter before harvest.

Read More