# Review of Power System Resilience Concept, Assessment, and Enhancement Measures
## 2 Impacts of Extreme Events on Power Systems
### Heavy Precipitation and Floods  
Heavy precipitation and floods can directly impact hydroelectric and thermal power stations. Heavy precipitation increases river flow, leading to higher water levels in reservoirs. Floods carry a large amount of sediment, causing the spillways of dams to become blocked. Low-lying areas where thermal power plants are located are also susceptible to direct flooding impacts [13; 31]. In January 2013, severe flooding on the northern coast of Jakarta resulted in a 909 MW power plant being shut down for 12 days [32]. In the summer of 2010, Queensland, Australia, was affected by massive floods, resulting in severe damage to multiple infrastructure systems and approximately 150,000 users experiencing  
\begin{table}
\begin{tabular}{c l c} \hline \hline
**Events** & **Quantification** & **References** \\ \hline \multirow{8}{*}{Hurricane} & The annual probability of hurricanes can be expressed as follows. & \multirow{2}{*}{[19]} \\  & \(P=\frac{exp(-\lambda)\times k}{\mu^{\prime}}\) & \\  & where \(\lambda\) and \(h\) are the average number of hurricanes and number of hurricanes per year, respectively. & \\  & The probability of damage for substations can be expressed as follows. & \\  & \(P=\Phi\left[\frac{\ln(v)-\mu}{\phi}\right]\) & \\  & where \(\Phi[.]\) is the normal cumulative distribution function, \(v\) is the wind speed, \(\mu\) is the logarithmic mean, and \(\sigma\) is the standard deviation. & \\ \hline \multirow{4}{*}{Flood} & Failure probability of substation can be expressed as follows. & \multirow{4}{*}{[22]} \\  & \(\pi_{k}=\sum\pi_{kj}\cdot\pi_{kj}^{\prime}\) & \\  & where \(\pi_{kj}\) is the failure probability of substation \(k\) due to flood scenario \(j\), and \(\pi_{kj}^{\prime}\) is the probability of flood scenario \(j\) at substation \(k\). & \\ \hline \multirow{4}{*}{Earthquake} & The probability of damage can be expressed as follows. & \multirow{4}{*}{[23]} \\  & \(P=\Phi\left[\frac{1}{B}\ln\left(\frac{S_{d}}{S_{d_{s}}}\right)\right]\) & \\  & where \(\Phi[.]\) is the standard cumulative normal distribution function, \(\beta\) is the parameter related to the earthquake, \(S_{d}\) is spectral displacement, and \(S_{d,s}\) is the median value. & \\ \hline \multirow{4}{*}{Ice} & The failure probability of components can be expressed as ice thickness, as shown below. & \multirow{4}{*}{[24; 25]} \\  & \(R_{it}=\frac{H}{\mu^{\prime}n}\sqrt{\left(P\rho_{\omega}\right)^{2}+\left(3.6V \right)^{2}}\) & \\  & where \(R_{it}\) is the ice thickness, \(H\) is the hours of freezing, \(\rho_{i}\) and \(\rho_{\omega}\) are the density of ice and water, respectively. \(P\) is the precipitation rate, \(V\) is the wind speed, and \(L\) the liquid water content. & \\ \hline \multirow{4}{*}{Wildfire} & The rate of fire spread can be calculated as a wind-dependent function, as follows & \\  & \(v_{f}=\frac{k(1+v_{\omega})}{\rho_{b}}\) & \\  & where \(k\) is a factor, \(v_{w}\) is the wind speed, and \(\rho_{b}\) is the fuel bulk density. & \\ \cline{1-1}  & The change in conductor temperature can be expressed as follows. & \\ \cline{1-1}  & \(\Delta T=\frac{\Delta t}{m\
abla_{\sigma}}\left(q_{l}+q_{s}+q_{f}-q_{c}-q_{r}\right)\) & \\ \cline{1-1}  & where \(\Delta t\) is the duration of time intervals, \(m\
abla_{\sigma}\) is the total heat capacity of conductor, \(q_{l}\) is the resistive heat gain rate, \(q_{s}\) is the heat gain rate from sun, \(q_{f}\) is the heat gain rate from fire, \(q_{c}\) is the convection heat loss rate, and \(q_{r}\) is the radiated heat loss rate. & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Quantification of the impacts of natural disasters.  
power outages [11]. In July 2021, Zhengzhou, China was hit by floods, causing multiple distribution lines to fail and leaving 1.2 million residents without electricity [33]. In May 2022, northeastern Bangladesh was affected by devastating floods, impacting more than 7 million people [34].