Ground Flash Density Mapping in Nepal: Enhancing Lightning Performance and Resilience of Distribution Lines

This paper presents the first comprehensive Ground Flash Density (GFD) map of Nepal, an essential tool for addressing the high incidence of lightning strikes that significantly threaten the country’s power infrastructure. Analyzing data from the GLD360 network over 2015-2019, the study maps lightning activity across Nepal, highlighting its year-round occurrence with a peak during the pre-monsoon season. The findings show the highest frequency of lightning strikes in the Terai region, decreasing with elevation. The GFD map specifically identifies a critical 30 km segment of a $33 \mathbf{~ k V}$ distribution line, which recorded an extraordinary 10,751 flashes, peaking at a density of 25.31 strokes $/ \mathbf{k m}^{2}$. Additionally, the study advocates for ongoing monitoring to assess the efficacy of implemented mitigation strategies. This includes tracking arrester currents and deploying high-speed cameras for detailed lightning strike analysis, which will contribute to a deeper understanding of lightning behavior and further improve protective measures for Nepal’s power systems.