Terroir 2008 banner
IVES 9 IVES Conference Series 9 Contribution of Electrical Resistivity Tomography (ERT) measurements for characterizing hydrological behaviour of an experimental plot in relation to pedo-geological factors (AOC Gaillac, SW France)

Contribution of Electrical Resistivity Tomography (ERT) measurements for characterizing hydrological behaviour of an experimental plot in relation to pedo-geological factors (AOC Gaillac, SW France)

Abstract

Electrical Resistivity Tomography (ERT) measurements have been performed by the Wenner method on an experimental plot situated in Gaillac region. They have been carried out during two highly contrasted hydric periods: (i) dry (spring 2006), (ii) humid (spring 2007) with soils close to field capacity. Results are compared to evaluate the hydrological behavior of the plot in relation with its main pedo-geological characteristics. The three reiterated transects (North-Median-South) give a general view of the plot configuration in agreement with the pedo-geologic observation trenches data. All the resistivity profiles show the superposition of two highly contrasted sequences. The first sequence, at the bottom, is a very low resistivity values sequence (up to 40 Ω.m) which coincides with the argillaceous-dominated molassic bed-rock. The second is a high to very high resistivity values sequence (from 300 Ω.m to more than 1500 Ω.m at the very top) which coincides with a silty-sandy and gravels soil complex of about 2 m thick. Resistivity of the molassic clayed-dominated geological basement does not depend on climatic conditions and stays at a very low value independently of dry or humid periods. Resistivity values of the silty-sandy/gravels horizons vary with a factor 2, from 300 to 750 Ω.m in humid conditions and from 750 Ω.m to 1500 Ω.m under dry conditions. Furthermore, the invariant location in the resistivity profiles of the two sequences, implies that the water runoff at the molassic bed rock/gravels interface is short-lived and most probably of low amplitude.
The hydric behavior of the experimental plot evidences a high risk of drought stress during summer. The choice of a rootstock with a hemi-plunging habit (Gravesac) will allow roots to attain the moisture at the molasse/gravels boundary and protect them from excess of drought.

DOI:

Publication date: December 8, 2021

Issue: Terroir 2008

Type : Article

Authors

Pierre COURJAULT-RADÉ (1), José DARROZES (1), Muriel LLUBES (2), Eric MAIRE (1), Marguerite MUNOZ (1) and Nicolas HIRISSOU (3)

(1) Laboratoire des Mécanismes de Transfert en Géologie (LMTG) – Université de Toulouse – UMR 5563 – CNRS – 14, Avenue E. Belin 31400 Toulouse (France)
(2) Laboratoire d’Etudes en Géophysique et Océanographie Spatiales (LEGOS)- Université de Toulouse – 14, Avenue E. Belin 31400 Toulouse (France)
(3) Domaine du Moulin, Chemin de Bastié, 81600 Gaillac (France)

Contact the author

Keywords

AOC Gaillac, Fonctionnement hydrique, Pédo-géologie, Résistivité, Sud-Ouest France

Tags

IVES Conference Series | Terroir 2008

Citation

Related articles…

The adaptative capacity of a viticultural area (Valle Telesina, Southern Italy) to climate changes

The viticulture aiming at the production of high quality wine is very important for the landscape conservation, because it allows to combine high farmer income with soil conservation

MODELLING THE AGEING POTENTIAL OF SYRAH RED WINES BY ACCELERATED AGEING TESTS: INFLUENCE OF ANTIOXIDANT ASSAYS AND PHENOLIC COMPOSITION

Red wine ageing is an important step in the red wine evolution and impacts its chemical and sensory characteristics through many chemicals and physico-chemical reactions. The kinetics of these evolutions depend on the wine studied and influence the wine ageing potential. Generally, high quality red wines require a longer period of bottle ageing before consumption¹. The ageing potential is an impor-tant parameter for wine quality and is related to the capacity of a wine to undergo oxidation over time². Phenolic compounds which are ones of the main substrates for oxidation can then potentially modulate ageing potential³.

Une procédure de mise à jour des zones AOC

In France, one of INAO missions is to delimit the production area of the « Appellations d’origine contrôlées » (AOC). For wine AOC, the delimitation of plots allows for identifying plots of land that respond to technical criteria of the vine location, criteria adapted in every appellation. Some old delimitations AOC are not in adequacy with their territory. Indeed, in spite the existence of a politic aiming to protect production areas AOC, urbanization, road infrastructure or quarries occupy surfaces classified in AOC today.

Mapping terroirs at the reconnaissance level, by matching soil, geology, morphology, land cover and climate databases with viticultural and oenological results from experimental vineyards

This work was aimed at setting up a methodology to define and map the «Unités Terroir de Reconnaissance» (UTR), combining environmental information stored in a Soil Information System with experimental data coming from benchmark vineyards of Sangiovese vine.

DNA and type of grain: which factor does better explain sensory differences of sessile and pedunculate oaks?

Sessile oak and pedunculate oak have shown several differences of interest for enological purposes. Tannic and aromatic composition among sessile oak or pedonculate oak has been well studied. Sessile oak is generally more aromatic than pedunculated, while the later is more tannic. This scientific point of view is rarely applied to classify oak in cooperages. Most coopers use the type of grain to distinguish wide and thin grain.