# Map API-Based Evacuation Route Guidance System for Floods
## 2 Research Methodology
### Flood Evacuation Analysis  
In August 2022, heavy rain occurred nationwide, primarily in the central region, which resulted in human fatality and property damage. Densely populated large cities are flooded by heavy rains; and apartments, houses, shops, and roads are submerged, thus causing traffic disruptions, power outages, and significant damage. In addition, many disasters occur due to floods caused by bank collapse arising from heavy rains and typhoons as a result of climate change [31,32]. The Ministry of Public Administration and Security of Korea collects and analyzes information related to flood risk areas, weather forecast, and water level, such as observational data, to assess the degree of risk. This evaluation is performed considering the possibility of flooding, the scope of impact, and the degree of damage. This determines which regions or infrastructures are most at risk. In modern society, as cities develop, urbanization intensifies in many areas; these cities become larger and forests are diminished, thus resulting in a high risk of flood damage. Korea is actively conducting research pertaining to flood damage while considering climate change and have implemented various countermeasures. Table 3 shows the state of loss and restoration costs over the past 10 years, and Table 4 shows the state of human damage over the past 10 years. \begin{table}
\begin{tabular}{l c c c c c c c c c c} \hline \hline
**Division** & **2012** & **2013** & **2014** & **2015** & **2016** & **2017** & **2018** & **2019** & **2020** & **2021** & **Sum** & **Average** \\ \hline heavy rain & 2 & 4 & 2 & 1 & 7 & 2 & & 44 & 3 & 65 & 6.5 \\ \hline typhoon & 14 & & & 6 & & 2 & 18 & 2 & & 42 & 4.2 \\ \hline typhoon, heavy rain & & & & & 1 & & & & 1 & 0.1 \\ \hline heavy snow & & & & & & & & & & \\ \hline heat wave & & & & & & 48 & 30 & 29 & 39 & 146 & 36.5 \\ \hline sum & 16 & 4 & 2 & 7 & 7 & 53 & 48 & 75 & 42 & 254 & 25.4 \\ \hline \hline \end{tabular}  
* The current status of casualties for the rainy season of 2019–2021 was prepared based on the statistics on the causes of death from the National Statistical Office [31].  
\end{table} 
Table 4: Status of casualties by cause for the past 10 years [31,32]. Figure 2: Total population and population density by state/province in South Korea in 2020 [32]. Statistics compiled by the Ministry of Public Administration and Security show the status of damage, restoration costs, and casualties over the past 10 years (2012-2021) [31]. Property damage amounted to KRW 3691.3 billion, accounting for most of the total damage. Although these studies are conducted annually, heavy rain and flood damage during the monsoon season increase annually. The course of a flash flood depends on the intensity, duration, and local characteristics of the heavy rainfall. Urban flooding is directly caused by heavy rainfall during the monsoon season. Water can enter a house, such as a semi-basement, during the rainy season, resulting in loss of life and property damage. However, in forested areas, large amounts of rain are absorbed by soil. The absorbed rainfall is not visible to the naked eye until the groundwater coincides with the underground surfaces. As this is not direct urban flooding, the flooding in forested areas is delayed; however, the delay does not imply that there is no damage. To solve this problem, the government is attempting to establish flood control measures to safely evaluate nearby people during flooding. Therefore, in this study, we propose a route-search system using an API map for flash floods, based on the flood discrimination model used in a previous study. In the water level prediction model [33] conducted as a preliminary study, the water levels resulting from rain at the upper and lower valley locations in the testbed area were overturned, and the occurrence of floods was predicted. The user's current location inside the testbed was identified and guided.