There's a debate going on here and there about what is included in the concept of terroir : we know that it includes the progressive adaptation of a particular variety to a region and to its soil along the ages and we know that human intervention on the slopes and soils played a role with the selection of climats and building of walls and of drains. But how far should it go, is there some antinomy between massive bulldozer landscaping and the respect of terroir and its soil ? Many wineries are tempted to resort to some sort of vineyard landscaping in order to maximize available room (which is often in dire shortage in the sought-after Appellations) or get the best orientation for a given vineyard. Some wineries have powerful financial backing and anyway, an increased (or optimized) surface will pay back the expenses through a sizeable increase in revenues.
The bulldozer-made amphitheater at Pibarnon (known as théatre d'épidaure) in Bandol exemplifies what can be made in modern times : what our ancestors made in a lifetime, building terraces (called restanques in provence) with walls to hold the earth for cultivation, olive trees and viticulture, modern machines and daring investors can do in a year. If we did it painstakingly by hand in the past, why not do it machines today, then ? The answer is not simple. Of course, there's this shortage of available (and affordable) surface in expensive Appellations, and some droits de plantations (plantation rights, something that is stricly controlled by the Appellation bodies) are sometimes tied to potential plots too steep, too stony or too uneven for exploitation.
The deep restructuring of vineyards is also something that the estates conduct without much publicity, preferring usually to entertain the customers with the concept of a terroir built step by step along the millenaries rather than having to tell the unpoetic story of bulldozers flattening the irregularities of a block...
On this particular case, Eric Vincent says that this plot was a former medieval quarry which had been entirely covered with earth along the ages. There were curves on the surface on the border and the owner wanted to regulate the surface. For this, he needed to take all the surface earth out, regulate the bumps and the hollows and pull the earth back (which is the stage on the picture I guess). This block was still planted and exploited before this landscaping but the irregular surface was bringing problems with the use of machines and tractors according to the grower, so the landscaping work was given the green light. That's something (the accident risks) that the INAO takes into account when auditing the planned terrain modifications.
Eric Vincent knows this particular vineyard work too : there is actually a former quarry in the middle of it (the region had plenty of these small quarries). The landscaping company dug into the hill on the lower part to get some thing more flat and manageable (there were redants in the middle) but he says that the original topography has been maintained overall. On the upper slope, a large rock bench has also been erased. He says that he had always seen these plots before covered with woods and bushes and the vineyards that were planted long time ago there are supposed to have been abandonned before WWI [maybe following the Phyloxerra disaster]. The vigneron who had this landscaping done spent years to buy one by one the many, intertwinned tiny plots around this former quarry (the existence of many different plots is an other indication that there was cultivation before). He says that the whole surface given back to viticulture here is a bit more than 2 hectares.
Eric Vincent says that they take into account the necessity to adapt the size of such remodeled plots to trellising (which is needed for modern viticulture) but at the same time avoid as possible the erosion (which means avoid having long rows), build embankments and the likes. He says that in some instances the correction of a slope will diminish the risk of tractor accidents (there are many cases of vineyard tractors turning over its driver on difficult terrain, and he added that there has been such a fatal accident in Saint Romain not long ago, by the way).
Looking back to this major work in Saint Romain, it has been considered locally as a very nice and successful job. Eric Vincent says that in the matter of 4 to 5 years when the vines and bushes will have grown back, it will be more obvious for the visitor and for the grower of course.
Eric Vincent says that if before there was no clear written obligation for the vigneron to signal his desire to conduct work on his soil and terrain, now a rule has been added in the new workbooks related to the Appellations (which will replace the Décrets de Définition des Appellations) : it's now clearly said that the grower planning any substantial modification of his soil or terrain has to make a formal demand at the Organisme de Defense et de Gestion de l'Appellation (ODG) tied to his vineyard.
Eric Vincents says that in terms of erosion risks, the recent evolution in the viticulture practices had a big impact : the changes observed around the region for a stark diminution in the use of pesticides and weedkillers had very positive consequences on the soil life, allowing it to better stand and absorb the rains and storms.