Vulnerability and risk assessment of power distribution networks under typhoon compound hazards: a case study of Fujian Province China

Abstract Typhoon compound wind-precipitation disasters (TCWPD) pose a significant threat to distribution network infrastructure, triggering cascading socioeconomic impacts through widespread power outages. We developed a vulnerability-informed risk assessment framework to quantify the impacts of TCWPD on distribution networks. By integrating hourly meteorological data from seven typhoons affecting Fujian Province and feeder fault rates at the grid jurisdiction level, we established a logistic-based vulnerability model, with most model fits achieving an R 2 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo>&gt;</mml:mo> </mml:mrow> </mml:math> 0.65 and RMSE <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo>&lt;</mml:mo> </mml:mrow> </mml:math> 0.01. This model characterizes the nonlinear relationship between a hazard index (HI) and feeder fault rate, deriving three critical vulnerability factors: the disaster resistance threshold, system resilience, and potential loss scale. These factors are confirmed to have physical meanings through their significant correlations with 13 socioeconomic and power grid indicators. A risk assessment model was then constructed by incorporating these three parameters with HI, enabling the spatial categorization of risk levels across 67 grid jurisdictions in Fujian. Results reveal distinct spatial patterns in vulnerability, with central and northern Fujian exhibiting lower resistance thresholds (with the highest threshold being 2.9 times the lowest) and western/central-southern areas showing higher sensitivity to hazard changes. Moreover, the distribution networks in core urban areas of coastal developed cities exhibit a low-frequency, high-consequence risk profile. The model identifies the top 20% (14 out of 67) as high-risk jurisdictions, for which the key contributing risk factors are quantified. This study provides a scientifically grounded methodology to support utility companies in pre-disaster prevention, emergency response, and post-disaster recovery planning, thereby enhancing the resilience of urban power systems to escalating typhoon hazards.