The Indre Valley

Dissymmetrical and steep-sided (30 to 40 metres deep), the valley of the River Indre widens as it approaches the site of its former confluence with the Cher. The Indre then splits into numerous branches which eventually meet up and join the Vieux Cher. As it enters the Loire valley, the Indre changes direction and flows parallel to the Loire.

Upstream, there is a marked contrast between the concave valley sides with their steep rocky walls and the convex, gently rounded valley sides with their vast strips of low terraces. The whole of the Indre's catchment area (3,200 km²) is a sedimentary basin: therefore, pluviometry is the key factor in its hydrological operations (suddenness and intensity of flooding).
Nevertheless a certain degree of regularity can be observed in the Indre's low water flow, as it is fed by numerous exsurgences of ground water. The flows are therefore low at 9.5 m3/second, and close to those of the low water level. Flooding, on the other hand, can be devastating.

 

The Loire Valley

The Loire, France's longest river, constitutes a natural and environmental legacy of exceptional importance at the European level. However, the variations in its levels, both sudden and potentially devastating, represent a serious problem for the residents of the communes that line its banks. Consequently, its management and development are crucial issues for both local residents and the nation as a whole.
The river's islands and alluviations are constantly changing and bear witness to the strength of the currents during flooding, which often occurs in spring or summer.

Some facts and figures about the Loire :
- Its average width is 375 metres
- Under normal conditions, it has a flow of 215 m3/second
- Its low water flow is 52 m3/sec

In November 2000, UNESCO placed the Loire Valley on its list of World Heritage Sites for cultural landscapes, thus acknowledging both the quality of the site and the efforts involved in its preservation and promotion.
The Loire valley is the largest single site ever listed in France (280 kilometres long, with 160 communes included in its 800 square kilometres of area). Its boundaries include the strip of land running both sides of the Loire, along with the city centres and valley slopes wherever possible. The boundaries are sometimes extended in order to accommodate areas considered to be part of the Loire valley landscape.

The plateau of Sainte-Maure

 This is a tabular plateau varying between 110 and 120 metres in height. The northerly limit of this area is defined by the Indre valley which bisects the landscape. To the west, the landscapes (woodlands and moorlands) and soils (changing to bleached, degraded soils) hint at the proximity of the forests and moorlands of Chinon.
Belonging to our area, the communes of Thilouze and Villaines-les-Rochers are situated on this plateau.

 

The forests of Villandry and Chinon

The northeastern section of the crown forest of Chinon stretches over the loamy soils of the plateau. This consists of a vast, degraded and podzolised sector, a large part of which has been planted with conifers in the framework of its development by a forestry unit. The majority of these units are located on vast tabular plateaux at altitudes of between 110 and 120 metres.
The pedological characteristics show the extent of the degradation of certain sites, which also applies to the moorland areas. Particularly intensive agricultural "improvement" methods, some of which date back to early history, are partly responsible for these phenomena: deforestation followed by the acidification of soils, the rising of ground water during winter and colonisation by secondary vegetation typical to these areas (ericaceous moorland).
Moorland and woodlands occupy the greater part of the plateau, thus enclosing the landscapes. The Forest of Chinon is a mixed broadleaf-coniferous woodland that owes its existence to unfavourable pedological conditions which have resisted any attempts at agricultural development. The "natural" vegetation is quick to return as soon as any plot of land is left untended. The proliferation of scrubland invaded by conifers and oaks at the edge of the Forest of Chinon is the main evidence of this phenomenon.