QTRA - I'm sorry i don't agree with it!

[RobArb]

Look at it in context. What are the options for assessing a tree? You can go to it, poke around a bit, find a problem, follow VTA and if neccessary come up with a spec that will reduce the risk associated with the problem.

 

Great but is that tree worth doing more than its neighbour? Is it worth doing at all? What do you compare it with? How can you show that you assessed both it and its neighbour on as equal a footing as possible? How can you show that the work you specified reduces the risk? How do you ensure there is a paper trail of your decisions?

 

 

I think the word "risk" has a lot to answer for on the human psyche, what happened to just being in the wrong place at the wrong time? Why quantify something that isn't a constant? I suppose you could argue (as you did) on how to reduce this "risk" but surely in this day and age we take a risk by getting out of bed in a morning!

 

Risk is a fact of life and not something that IMO needs quantifying

[Amelanchier]

I hate it when the doctor says 'how much does it hurt...on a scale of 1-10'. I always want to argue with him on the parameters or basis of his scale:001_smile:

 

Good example - the scale is relative to you. He doesn't care if you claim six for something someone else said was a two. He wants to know whether your experience is worse now than it was yesterday and by how much.

[RobArb]

Clearly Mr Lonsdale is entitled to his opinions (well that is to say, they are certainly his to have).

 

I don't know that I would agree that every tree different in respect to hazard assessment. There are certainly a great number of trees that are much the same (i.e., plantations / shelter belts) and even more trees that are just too young, small or remote to be a hazard. Of those that remain gravity ensures that there are only so many ways that a tree can fail and those failure modes affect a predictable area around the tree. Very few explode; even fewer implode.

 

It is within that small set of possibilities that we are expected to differentiate probability with a liberal smattering of precaution and I am personally of the opinion that it is reasonable to set out a system for doing so. Quite often, I use QTRA for doing so - especially when there are a lot of trees to compare and prioritise for a client.

 

I am not dispelling your opinions as we all are clearly entitled to have them, i just like to debate:biggrin:

 

 

 

PS this tree exploded, albeit with the help of a lightning bolt!

 

[ame]http://www.youtube.com/watch?v=f6PJdAee7qY[/ame]

 

Don't know why it won't embed?

Edited November 27, 2012 by Amelanchier

[Amelanchier]

I think the word "risk" has a lot to answer for on the human psyche, what happened to just being in the wrong place at the wrong time? Why quantify something that isn't a constant? I suppose you could argue (as you did) on how to reduce this "risk" but surely in this day and age we take a risk by getting out of bed in a morning!

 

Risk is a fact of life and not something that IMO needs quantifying

 

I would agree about the use (misuse?) of the word risk. But I disagree about the need to quantify it. We need to quantify it to compare it against other things. If we don't compare it properly, we can make some pretty bad decisions!

[Albedo]

Good example - the scale is relative to you. He doesn't care if you claim six for something someone else said was a two. He wants to know whether your experience is worse now than it was yesterday and by how much.

 

Half an hour ago my head didn't hurt at all, now I'd give it about a 7:001_smile:

[Amelanchier]

I am not dispelling your opinions as we all are clearly entitled to have them, i just like to debate:biggrin:

 

Nothing wrong with that at all. I have always taken the view that an idea, if it is to be worth anything at all, should be dragged out into the open and given a good kicking. Those that don't get back up should be left to expire... A cheery image but the best I can think of.

 

 

 

PS this tree exploded, albeit with the help of a lightning bolt!

 

Lightning Strike Turns Tree into Bomb - YouTube

 

Don't know why it won't embed?

 

Your browser decided to secure Youtube and encrypt the link - I took the 's' out of https://... Mine does that sometimes - I haven't worked out why yet.

[Amelanchier]

Half an hour ago my head didn't hurt at all, now I'd give it about a 7:001_smile:

 

I'll ask you in an hour

[showoffsummer]

I was reading about QTRA for the first time today! i'm sure you would of read about it as its quite a big case, but the Mullinger & Others v The National Trust case study is very interesting, with David Lonsdale arguing QTRA is a accurate formula to inspect trees and

Forbes- Laird arguing his THREAT inspection is better.

 

https://docs.google.com/viewer?a=v&q=cache:Mcw3rBfHgv0J:www.qtra.co.uk/cms/index.php?action%3Ddownload%26id%3D205%26module%3Ddownloadmodule%26src%3D%2540random4ecbc721b3d91+2007+national+trust+V&hl=en&gl=uk&pid=bl&srcid=ADGEESjppDK88AiIqsCVjrpC4T6GXe_9_EcOpAGh6eZZuYNEP3I-kGVV5SYweMUbaoyepgTcu_h3MOsbqHBjYjH3pXQM3tS2mmHs-PuxuhgGtqgma8GCcgLgFQehoAYK7goNQWFCErxK&sig=AHIEtbSXfbXJTesdwLTVTr3s5BSlIlTh_A

 

Got more info on it if you want it but its on my college computer!

[HCR]

Surely QTRA is numerical rather than statistical

 

As a system I don't think it's any better or any worse than any other. Or any more or less necessary than any other...

 

Any system will come down to a subjective view, which must be reasonable. To complicate things, this would be an objective test in a court - the view must be reasonable when compared that of the reasonable tree inspector, not the reasonable person (i.e. juror).

 

We can't really 'test' trees, however much we might think we can. We can spot something as dangerous at the extreme end of the scale, but it just gets woolier as we move towards the safe end of the spectrum. We apply opinion and hope that we don't get caught out. Having a system, whatever that is, reduces the likelihood of being caught out if only for introducing repeatability.

[RobArb]

we shouldn't be wary of "getting caught out", societies "blame" culture has enforced people to create these systems.

 

Sometimes things just happen as Forrest Gump once eloquently put it, but, in retrospect of trees and QTRA surely there must be a better system to cope with today's expectations of our so called perceived state of "risk":biggrin: