# UAV Application for Typhoon Damage Assessment in Construction Sites
## 5 Discussion
\begin{table}
\begin{tabular}{c c c} \hline \hline  & \multicolumn{2}{c}{**Natural Disaster Forecast and Warning Level**} \\ \hline
**Level** & **Standard** & **Solutions** \\ \hline \multirow{3}{*}{IV} & \multirow{3}{*}{Low probability happens within 24 h, and low disaster intensity} & 1. Spot and inspect hidden dangers (no UAV). \\  & & 2. Stop outdoor operation at the construction site, especially the operation \\  & & 2 above the tower crane. \\  & & 3. Transfer essential construction materials and large machinery to protect \\  & & & related structures. \\ \hline \multirow{3}{*}{III} & \multirow{3}{*}{Medium probability happens within 24 h, and low disaster intensity} & 1. Make inspections on hidden dangers with UAVs and collect relevant data. \\  & & 2. Stop any operation, especially the operation above the tower crane at the site. \\  & & 24 h, and low disaster intensity & 3. Transfer important construction materials and large machinery and protect \\  & & & temporary structures. \\ \hline \multirow{3}{*}{II} & \multirow{3}{*}{High probability happens in 24 h, and disaster intensity increases rapidly} & 1. The whole site will be inspected by UAV, and data collection will \\  & & & be conducted. \\  & & & between tower cranes. \\  & & & reduction working group will be set up immediately to deal with it. \\ \hline \multirow{3}{*}{I} & \multirow{3}{*}{Must happen within 24 h, and the largest disaster intensity} & 1. The whole site will be inspected by UAV, and data collection will \\  & & & be conducted. \\ \cline{1-1}  & & 2. Make use of UAVs to inspect large machinery, especially the connection \\ \cline{1-1}  & & & between tower cranes and temporary structures. \\ \cline{1-1}  & & 3. According to the results of the UAV inspection, the disaster prevention and \\ \cline{1-1}  & & & reduction working group will be set up immediately to deal with it. \\ \hline \hline \end{tabular}
\end{table} 
Table 11: The measures of disaster prevention and mitigation. also be formed. At the same time, it can also analyze which places are most vulnerable to losses, providing valuable experience for the follow-up prevention of similar disasters. Thirdly, through the powerful image processing technology of Matlab software, the high-definition pictures obtained by the drone can be used. For example, the use of drones to inspect large machinery, especially tower cranes, is easy to collapse under typhoon disasters, causing a series of disaster losses. The survey found that most of the tower cranes that collapsed under the typhoon collapsed because of problems in the connection between the tower cranes. Drones can be used to collect photos, and then image processing technology such as denoising, enhancement, transformation measurement, sharpening, and other technologies can be used to effectively identify the location of the tower crane with potential safety hazards and carry out timely protection processing. In a word, UAV photography technology and point cloud processing technology provide strong technical support for the risk control of construction sites under natural disasters, and it is expected to have greater expansion in the automatic detection of construction site risks.