Jeremy Barrell’s Arboricultural Association's Arb Magazine version of his journal article has had some Duty Holders and Arborists ask us about where his binary, ‘High’ or ‘Low’ likelihood of occupancy approach sits with VALID.
To recap. The heart of the article is three legal cases cherry-picked by Jeremy, where Jeremy acted as an expert, and are Jeremy’s interpretations of these cases where Jeremy’s evidence was a key factor.
When we first went through the article, we were disappointed to find it appeared to be less about reasonable, proportionate, and reasonably practicable tree risk-benefit management (which is what the Courts and Coroners want) and more about setting out what Jeremy expects to contest as an ‘expert’.Jeremy Barrell Tree Risk Management Article
Back to the binary ‘High’ v ‘Low’ likelihood of occupancy.
VALID’s likelihood of occupancy categories are based on log base 10, like the Richter scale uses to measure earthquakes. If we show the likelihood of occupancy to scale as 10 x 10 canvases, and set High at the centre, we can compare VALID’s and Jeremy’s likelihood of occupancy categories.
Jeremy’s High occupancy spans 4 orders of magnitude. Or, another way of looking at it. A Richter scale 4 earthquake is categorised the same as a Richter scale 7 earthquake.