Flood Risk Assessment at Electrical Substations Using a Risk Matrix Coupled with a Hydrodynamic Model

With the rapid development of urban expansion, as well as the frequent occurrence of extreme weather conditions such as extreme rainfall, flooding disasters at substations are becoming severe. Such flooding events can interrupt the power supply of residents and effect large areas. This paper presents a methodological framework for assessing the flood risk of substations based on the risk matrix coupled with a hydrodynamic model in the Dashi River Basin. Two factors of the risk matrix of substations are considered to determine the flooding risk level. One factor is the possibility of flood risk, and the other factor is the severity of the consequences of substation inundation. The hydrodynamic model is used to quantify the possibility of the flood risk, which is validated using the inundation process during the 23.7 catastrophic flood event. Additionally, the analytic hierarchy process (AHP) is applied to analyze the severity of the inundation consequences. Moreover, we identify four flood risk levels: general, high, higher, and particularly significant. For demonstration, the proposed framework is applied to 12 substations in the Dashi River Basin. The findings indicate that more than half of the substations in the Dashi River Basin are at risk of flooding, and the risk levels of substations D9 and D12 are particularly significant, indicating a very high risk. These results emphasize the need to improve the flood risk management ability for the power grid so as to enable the application of accurate and effective measures to reduce the substation flood disaster risk. Moreover, the framework developed in this study has good universality and can provide a systematic solution for flood risk analysis of similar substations.