Reduction of electric field strength by two species of trees under power transmission lines

Electrical pollution is a worldwide concern, because it is potentially harmful to human health. Trees not only play a significant role in moderating the climate, but also can be used as shields against electrical pollution. Shielding effects on the electric field strength under transmission lines by two tree species, Populus alba and Larix gmelinii, were examined in this study. The electrical resistivity at different heights of trees was measured using a PiCUS sonic tomograph, which can image the electrical impedance for trees. The electric field strength around the trees was measured with an elf field strength measurement system, HI-3604, and combined with tree resistivity to develop a model for calculating the electric field intensity around trees using the finite element method. In addition, the feasibility of the finite element method was confirmed by comparing the calculated results and experimental data. The results showed that the trees did reduce the electric field strength. The electric field intensity was reduced by 95.6%, and P. alba was better than L. gmelinii at shielding.