# Effect of Tree Quantity and Distribution on the Electric Field under Transmission Lines
## 1 Introduction  
With the rapid development of the world economy, the construction scale of ultra-high voltage transmission lines continues to increase, but their power frequency electric fields have also had serious negative impacts on residents' production and life. At the same time, dense ultra-high voltage transmission lines span vast land, greatly affecting the natural landscape and environment. By planting trees to form green belts, not only can the width of power transmission corridors be reduced, but the impact of power transmission lines on the surrounding environment can also be minimized. Therefore, studying the influence of tree electromagnetic parameters on the power frequency electric field of transmission lines is of great significance for line design and cost savings. According to relevant research, the electromagnetic interference of transmission lines can have a certain negative impact on the human body. [PERSON] et al. [1] confirmed that ionizing radiation is one of the few known risk factors for acoustic neuromora through radiation therapy and dental X-ray studies. [PERSON] et al. [2] discussed that radiation in residential areas is one of the main reasons for the increase in the incidence rate of childhood leukemia. [PERSON] [3] proposed that the electrical stimulation generated by low-frequency electric fields can slightly affect visual processes and motor coordination. Therefore, since 1996, the World Health Organization (WHO) has organized over 60 countries and multiple international organizations to conduct global research on the \"International Electromagnetic Field Program\". In addition, in order to ensure the safety and efficiency of power transmission,corridors need to be opened up along the path of high-voltage transmission line construction. However, the high-voltage transmission corridor requires a large amount of land to be requisitioned, and the width of the ultra-high voltage corridor is over 100 m. Economically developed areas have high electricity consumption, while land resources are scarce. Therefore, the contradiction between high-voltage transmission corridors and local land tension has become very prominent, and as the width of transmission corridors increases, the cost also increases sharply. For example, the cost of land occupation and demolition for the Xiangjiaba to Shanghai ultra-high voltage transmission line is far greater than the cost of the project construction itself [4]. Due to the above reasons, complaints and disputes about long-distance and high-capacity ultra-high voltage transmission line corridors are gradually increasing. According to statistics, since 2010, the number of complaints and petitions regarding the electromagnetic environmental impact of high-voltage transmission and transformation projects in China has been increasing at a rate of 10% per year. With the widespread construction of ultra-high voltage, the annual growth rate has exceeded 15% in the past three years [5]. Therefore, it is crucial to predict the power frequency electric field of transmission lines, reduce the electric field strength, and minimize the area of transmission corridors. At present, the prediction of the power frequency electric field in transmission lines often adopts calculation methods such as the charge simulation method (CSM), finite difference method, moment method, and finite element method. Among them, the simulated charge method is based on the uniqueness principle of electrostatic fields, with high computational efficiency and strong real-time performance, and has been widely applied. The principle of CSM is to replace the free charges continuously distributed on the electrode surface or the bound charges continuously distributed on the dielectric interface with a set of discretized simulated charges and then use the superposition principle to superimpose the field generated by the discrete simulated charges in space, thereby obtaining the spatial electric field distribution equivalent to the original continuous distributed charges [6; 7; 8].