Table 3.

Definition of exposure levels used in Adjustment A1.

ShelteredFor example, a two-lane highway with excavated rockslopes on each side, notwithstanding any other extremes of altitude or climatic conditions. Alternatively, a continuous, multiple-layered belt of evergreen trees located opposite the rockslope, reaching to at least the height of the slope and densely underplanted with evergreen shrubs. The distance between the shelterbelt and the slope would need to be less than twice the height of the slope. A discontinuous, or single-layered, or deciduous tree belt provides less shelter. A slot-like quarry location or surrounding higher relief in close proximity also provides considerable shelter
Slightly exposedFor example, a medium-sized quarry enclosed on all sides. ‘Medium-sized’ depends on the length and breadth of the quarry, and also on the relationship of these dimensions to its depth. A dual carriageway with cuttings on either side is another example
Moderately exposedFor example, a very large quarry with no shelter provided by its basin-like form. A motorway crossing open land that passes through cuttings would be another example, as are slopes that face onto land that is open for up to 1 km away
Very exposedFor example, slopes situated on topographic highs at higher altitudes overlooking land that falls away into the distance, with no shelter provided and completely exposed to the elements. Individual units of a such slopes that were locally protected by close proximity vegetation, structures or other slopes might be classed only as moderately exposed