Constraints related to the risk of rock-wall landslides - Series

This series of data layers identifies the risk perimeter of rock wall collapse or boulder fall and slopes with a slope greater than 30 degrees.

This series consists of two layers of data:
- Physical constraints related to landslides
- Slopes greater than 30 degrees

Areas of major stress define a space on which the risk resulting from a rock wall collapse or block falls is significant and which results in a geotechnical stress important for urbanisation within the meaning of the CoDT.

Slopes where the inclination of the slope is greater than 30 degrees are categorised according to the degree of urban constraints they generate. They constitute a ‘simple’ geotechnical constraint They do not, in themselves, constitute a major geotechnical constraint for urbanisation within the meaning of the CoDT.

This mapping of the risk of rock wall collapse or falling blocks, including wall removal, is mentioned in former Article 136 of the CWATUP, now D.IV.57 of the CoDT (legal definition of natural risks and/or major geotechnical constraints in terms of spatial planning and town planning).

82 municipalities are affected by the major localised rockfall constraint along 127 km of walls over an area of 345 ha (projected).

The areas of the risk perimeters vary from 20 square meters for the smallest area, to 124,000 square meters or 12.4 ha for the largest.