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Examples of threshold criteria used by practitioners

Example 1 Based on criteria of Terence O’Rourke plc Definition of magnitude/Degrees of effects on visual amenity

The following is based on six classifications of the degree of impact. None No part of the development, or work or activity associated with it, is discernible. Negligible Only a very small part of the proposals is discernible and/or they are at such a distance that they are scarcely appreciated. Consequently they have very little effect on the scene. Slight The proposals constitute only a minor component of the wider view, which might be missed by the casual observer or receptor. Awareness of the proposals would not have a marked effect on the overall quality of the scene. Moderate The proposals may form a visible and recognisable new element within the overall scene and may be readily noticed by the observer or receptor. Substantial The proposals form a significant and immediately apparent part of the scene that affects and changes its overall character. Severe The proposals become the dominant feature of the scene to which other elements become subordinate and they significantly affect and change its character. It should be noted that these definitions can apply to either existing or proposed situations and that impacts need not necessarily be detrimental. For example, a proposed prominent group of trees might have a ‘substantial’ impact, but the effect on the landscape and views would be beneficial.