# UAV Application for Typhoon Damage Assessment in Construction Sites
## 2 Construction Sites and Natural Disasters
\begin{table}
\begin{tabular}{c c c} \hline
**Target Layer** & **Criterion Layer** & **Factor Layer** \\ \hline  & & Typhoon intensity (C1) \\  & & Annual frequency of typhoons(C2) \\  & & Maximum daily precipitation (C3) \\ The degree of risk related to & & Mean annual precipitation (C4) \\ construction sites under typhoon & (B1) & Regional elevation (C5) \\ (A) & & Regional vegetation coverage rate (C6) \\  & & Width of drainage channels in respective districts (C7) \\  & & The integrity of drainage channels in respective districts (C8) \\ \hline  & & Number of on-site construction management personnel (C9) \\  & & Number of workers in each construction team (C10) \\  & & Construction materials (C11) \\ The degree of risk related to & & Mechanical equipment matching (C12) \\ construction sites under typhoon & (B2) & Tower crane (C13) \\ (A) & & Scaffold (C14) \\  & & traffic conveyance (C15) \\  & & Staff office accommodation (C16) \\ \hline The degree of risk related to & & Vulnerability of construction in progress (C17) \\ construction sites under typhoon & Vulnerability (B3) & Vulnerability of large mechanism(C18) \\ (A) & & Vulnerability of construction materials (C19) \\  & & Worker vulnerability index (C20) \\ \hline  & & Predictive accuracy of Met Office (C21) \\  & & Number of monitoring sites (C22) \\  & & Number of site investigations (C23) \\  & & Speed of communication (C24) \\ construction sites under typhoon & Capability of disaster & Number of emergency personnel (C25) \\ (A) & prevention (B4) & Level of emergency equipment(C26) \\  & & Evaluation index of emergency management (C27) \\  & & Medical professional (C28) \\  & & Rationality of organizational structure(C29) \\  & & Level of the project manager (C30) \\ \hline  & & Share of project investment devoted to security risk (C31) \\ The degree of risk related to & & The capability of disaster \\ construction sites under typhoon & mitigation (B5) & The capability of site personnel (C32) \\ (A) & & mitigation (B5) \\ (A) & & Level of the project manager (C34) \\  & & Requirements for goal achievement (C35) \\ \hline \end{tabular}
\end{table} 
Table 1: Risk index decomposition for construction sites under typhoon. and mitigation strategies. The authors of [29] used the Analytic Hierarchy Process method and k-means Clustering Algorithm to identify the factors, including natural and human activities, landslide-debris flow hazards, environmental susceptibility, and exposure. Researchers pay attention to the disaster-forming factors, environmental susceptibility, and exposure to assess the risks of natural disasters. In recent years, construction site safety accidents frequently resulted in heavy losses to construction personnel, the economy, and buildings. The construction industry is susceptible to extreme weather events due to most of its activities being conducted by construction workers outdoors [35]. Ref. [36] revealed that the type of accident with the highest risk score is \"falling objects\", while the leading cause is excessive winds on the project site. Natural disasters such as typhoons and rainstorms can produce strong winds and cause damage to incomplete construction. A super typhoon can blow down under-construction buildings or even cause accidents when a construction site is not well protected. The destructive power of natural disasters on buildings has drawn wide attention from researchers. Ref. [37] developed a conceptual weather environmental forecasting system (CWEFS) that can be used to identify potential safety risks of structures under construction through a typhoon wind velocity model and structure reference load simulation. Ref. [38] investigated wind pressure characteristics on the roof of a low-rise building during typhoon landfalls to reduce windstorm damage to residential buildings. Ref. [39] researched wind effects on a 420 m-tall building during typhoons by investigating wind effects by field measurements and wind tunnel testing. Ref.