Abstract
A physical and mathematical formulation of the problem to simulate ignition of a deciduous tree in the approximation of large vessels is presented. The problem is considered in a flat formulation in polar coordinates. A parametric analysis of the current-voltage characteristics of cloud-to-ground lightning discharges on the process of heating the wood of a deciduous tree trunk is carried out. The conditions for the ignition of a tree trunk in the typical range of the parameters for discharge effect are established. Variants without and taking into account the surface layer of water are considered.