**4.1 Study area**

The study area is located in the north-west of Calvados. The catchment called the Lingèvre covers an area of 15 km². It is part of the Seulles, a larger catchment covering an area of 450 km² in the western part of the French department. The Lingèvres is located on a transition zone between the Armorican block upstream and the Paris basin downstream. At the periphery of the catchment, more particularly upstream, some thick patches of aeolian silt (loess) over clay and limestone formations from Secondary and Tertiary.

Fig. 11. Maps of soil erosion hazard at various temporal scales.

Slopes are generally gentle, especially on the higher parts reaching 130 meters high. The difference of height with the outlet is about 80 meters at the north of the basin. Slopes are increasing downstream of the Lingèvres.

Soils are predominantly hydromorphic. At the basin's periphery, on the higher slopes, we notice the presence of moderately to strongly redoxic silty luvic cambisols which thickness exceeds 1 meter. 70% of the Lingèvre's slopes are made of thin (40 cm) clayey redoxic soils. Umbric an rendzic leptosols less than 40 cm thick are sporadically localized. Gleysols are located in valley bottoms.

conditions, it is not possible to carry out a monthly mapping of the hazard erosion for territories that exceed several hundred or thousand of km². This work must be limited to areas recognized as sensitive through the initial model's representation of the hazard or by

**4. SCALES, a model to consider the climate change impact on soil erosion by** 

The structure and modularity of SCALES allows us to plan its use at long-term scale. This approach has been set as part of study of the impact of the climate change on the soil erosion hazard. We tried to compare at a monthly scale the present levels of hazard with those

The study area is located in the north-west of Calvados. The catchment called the Lingèvre covers an area of 15 km². It is part of the Seulles, a larger catchment covering an area of 450 km² in the western part of the French department. The Lingèvres is located on a transition zone between the Armorican block upstream and the Paris basin downstream. At the periphery of the catchment, more particularly upstream, some thick patches of aeolian silt

Slopes are generally gentle, especially on the higher parts reaching 130 meters high. The difference of height with the outlet is about 80 meters at the north of the basin. Slopes are

Soils are predominantly hydromorphic. At the basin's periphery, on the higher slopes, we notice the presence of moderately to strongly redoxic silty luvic cambisols which thickness exceeds 1 meter. 70% of the Lingèvre's slopes are made of thin (40 cm) clayey redoxic soils. Umbric an rendzic leptosols less than 40 cm thick are sporadically localized. Gleysols are

forecasted for the year 2100 based on a case study carried out in Normandy (Fig. 1B).

(loess) over clay and limestone formations from Secondary and Tertiary.

Fig. 11. Maps of soil erosion hazard at various temporal scales.

increasing downstream of the Lingèvres.

located in valley bottoms.

the intermediary of the land managers' knowledge.

**water** 

**4.1 Study area** 

The climatic context is similar to the one described in the previous case study. Rainfall is quite constant all year long with an increase in autumn and winter. The annual accumulation of rain is around 950 mm.

Agriculture combines cereal crops, fodder crops, and bovine breeding gathered in huge farms intensively exploited. Grassland cover half of the agricultural land of the catchment. These are almost always permanent grassland. Crops are covering an area equivalent to the one of the grassland. Arable lands are fairly divided between spring crops (maize silage) and winter crops (wheat).

## **4.2 SCALES data for the current period and for 2100 4.2.1 Data for the current period**

The digital elevation model of Calvados at 20 m scale was used to estimate the slopes of the Lingèvres. The local climatic data comes from the same weather station than the one mentioned in the case study of the Branche catchment. This weather station is located 5 km from the Lingèvres. The identification of the agricultural parcel network and agricultural practices was based on field work. The data collected covers the period from September 2009 to august 2010. The soil data used for calculation of available water content and hydrous budget were extracted from the database related to the 1/50000 map of Calvados soils described in the first part of this document. Additional survey with soil boreholes also allowed refining the spatial resolution of pedological characteristics of the Lingèvres. Therefore the structural instability of the catchment's soils was deducted from already existing administrative data and from 18 additional analysis on representative of the soils and agricultural practices diversity. Input data of the model and their treatment at monthly and seasonal scale for an average climatic year had been integrated in elementary spatial units represented by agricultural parcels.
