Nondestructive evaluation of trees in urban environment through electroresistivity and Ground Penetrating Radar methods combination

• Grant number: 19/09483-0
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: July 01, 2020
• End date: June 30, 2022
• Field of knowledge: Biological Sciences - Botany - Applied Botany
• Principal Investigator: Vinicius Rafael Neris dos Santos
• Grantee: Vinicius Rafael Neris dos Santos
• Company: Kerno Geo Soluções Ltda
• CNAE: Serviços de engenharia ; Pesquisa e desenvolvimento experimental em ciências físicas e naturais
• City: São Paulo
• Pesquisadores principais: Marcelo Farias Caetano ; Marcelo Martinatti
• Associated research grant: 17/22855-9 - Nondestructive evaluation of trees in urban environment through electroresistivity and ground penetrating radar methods combination, AP.PIPE
• Associated scholarship(s): 20/11873-9 - Analysis of geophysical data and its application for understanding the physiology and phytosanitary status of trees, BP.TT; 20/12750-8 - Application development for risk mapping and tree fall prevention and software for information management, BP.TT; 20/09315-8 - Combination of electroresistivity and GPR methods to assess the risk of falling trees, BP.PIPE; 20/09318-7 - The use of electro resistivity in the evaluation of risk of falling trees, BP.PIPE

Abstract

Urban trees brings several benefits, both aesthetic and functional, to the population and the environment. However, the lack of planning from the choice of the appropriate species to the management of the plant implies in disorders, including accidents resulting from the trees fall. Currently in Brazil, there are gaps for the correct diagnosis of the health condition or risk of falling of a tree, mainly regarding the roots. Many analyzes depart from invasive (penetrograph) or visual-only assessments, resulting in mistaken decisions about tree management. The continuation of the Phase 2 project focuses on root analysis, combining the geophysical methods of electroresistivity (ER) and GPR (Ground Penetrating Radar). The first methodology measures the variation of electrical resistivity, by directly current injection into the trunk or soil. The GPR method uses the principle of electromagnetic waves reflection in high frequency, allowing the obtaining of a high resolution image of the interior of the trunk and the roots. The urban environment requires that the analyzes be carried out in an efficient way, that is, that it does not hamper road traffic and that it provides a quick response so that the necessary actions are put into practice. Both geophysical methods are able to indicate cavities and other defects, as well as the root system at different depths, by imaging the condition and spatial distribution of the roots under the soil, through variations in the physical properties involved. Soil parameters, such as porosity, compaction and water content, will be obtained from the geophysical data, which relate the physical magnitudes of apparent resistivity and dielectric permittivity to soil petrophysics. For the GPR data, the amplitude spectrum of the electromagnetic signal will also be analyzed using the short-time Fourier transform (STFT), in order to establish the relation of this spectrum with the sanity (water content) of the roots in subsurface. From the monitoring of the trees, a participatory population appraisal will be developed to generate a risk map that can help in the determination of fall regions. In the context presented, ER and GPR show potential to be practical tools that can and should be integrated with other types of analysis already well established, aiming at the correct monitoring of trees in urban environment. (AU)