Évaluation de l'impact d'un futur remblai de la ligne à grande vitesse Est Européenne sur le risque de gel dans le vignoble de Champagne

Abstract

In order to evaluate for the vineyard, the additional risk of freezing, which could be generated by a railway embankment of the High Speed Line (TGV «Paris-Strasbourg») a canvas cover of the future embankment (length 480 m, height 3 m maxi) was drawn up in the bottom of a wineyard slope. Measurements of Actinothermal Index (AI) Temperatures, at the height of the bud (at 50 cm of the surface) and measurements of of cold air windslopes, were carried out on a microclimatic scale. We recorded 19 points of measurements, without then with the presence of the canvas cover, for the nights characterized by a radiative cooling (wind £ 2m.s-2, clear sky) during spring 2001. The possible incidence of the embankment was also evaluated with the IA temperatures of an automatic meteorological station set in 1998 to 600 m of the future line in prevision of this study. The meteorological data were estimated by simple regression with data equivalent provided by a neighbouring station. During spring 2001 (5 nights of measurements including 3 nights with the embankment), the results of microclimatic measurements and the statistical analysis of the automatic meteorological station show that there was not, on the studied area, significant incidences of the embankment on the spring frost intensity. The accumulation of cold air upstream the canvas cover does not affect the vineyard of this area, but the short temporal sampling imposes to be carefull with this interpretation.