Integrated approach to assess tree stability in storms and risk assessment

Academic Institution: University of Dundee

Academic Supervisor: Dr Matteo Oryem Ciantia

Industry Partner: Agroservice s.r.l.

PhD Student: Andrea Marsiglia

Start Date: 3rd May 2020

Abstract

More frequent intense storm events, associated with climate change, increase the likelihood of tree collapse adjacent to transport corridors that lead to costly disruption of road and rail journeys. Tree stability in windstorms and tree failures raise additional concern in urban areas where the risks of damage to people and property is higher. The 2014 winter storms in the UK caused the 'greatest loss of trees in a generation' (Guardian newspaper, 7/03/2014), with the National Trust survey reporting that up to 500 trees were lost at the Killerton Estate in Devon.

Current methods of managing urban trees, such as pruning and assessing mechanical strength, are mainly based on the study of a single tree. These are based on visual tree assessment (VTA) by trained arborists and sometimes by means of expensive static pull tests. Despite both of these methods suffering significant limitations, they are still the most common techniques used as the regional authorities are responsible for thousands of trees and there is as yet no simple, detailed and affordable method of assessing many trees which would be necessary to accurately quantify risk.

In this project, a cheap novel approach to assess tree stability at the regional scale aimed at addressing the current limitations listed above will be developed. This will utilise advanced and rigorous numerical modelling, informed by small scale (laboratory) testing and available wind data, combined with wireless real time monitoring of tree arrays using low-cost sensors. Tree behaviour will be up-scaled to the regional scale by means of mathematical and statistical methods. The approach will be validated against field scale experimental testing, with a view to developing future urban risk maps. To achieve these goals a multiscale and multidisciplinary approach will be adopted, involving geotechnical engineers, fluid dynamicists and plant scientists.