Extreme rainfall and flooding in Korea has been occurring more frequently as a result of climate change and President Yoon Suk-yeol has said that they must prepare for more extreme forms of weather in the future because of this. In fact Korea is dealing with the worst flood in the last 80 years and three days of recorded rainfall have left at least nine people dead and seven missing around South Koreas capital. After a record of 15 inches of rain were let loose in less than 24 hours in Seoul at least eight are dead, the Korea Meteorological Administration warned that the unprecedented rate of rain would reach 2 to 4 inches per hour and that roads would be turned into rivers and lakes, subway systems would be knocked out of service, and entire neighborhoods would be submerged. 

Some ways Korea can use to help mitigate extreme flooding and rainfall is to maintain proper water runoff and drainage. This way the rain has a way to leave the city and not get clogged thereby causing a flood. They can also install flood vents inside homes, this allows water to flow freely through an enclosed space such as a garage. This helps prevent the build up of pressure that is capable of destroying walls and foundations, as long as the vent is clear of debris and unclogged it can save people and prevent homes from being destroyed. 

References

https://www.npr.org/2022/08/10/1116689027/southkorea-is-dealing-with-the-worst-flooding-in-80-years

https://news.yahoo.com/south-korea-hit-with-deadly-flooding-as-climate-change-makes-extreme-rainfall-events-more-frequent-190255330.html

https://www.fema.gov/sites/default/files/documents/fema_protect-your-home-from-flooding-brochure_2020.pdf

Landslides in Korea are one of the most common natural disasters because it doesn't need anything to trigger it except for gravity which is pretty common all around the planet. A landslide is when a big mass of rocks, debris, or earth is pulled down a slope by gravity. These are also called Mass wasting events, not to confused with wasting as in trash. These mass wasting events also include mudslides, rockslides, etc. in addition to landslides. 

The most recent landslide in Korea seems to have happened on July 7th 2021. Heavy rain in  the city of Gwangyang caused a landslide that destroyed several houses and killed one person. The deadliest landslide so far happened in 2011 on Jul 27th. Heavy rain in Seoul, South Korea's capital, alongside a northern town triggered a landslide killing 32 people and causing one child to go missing. About 800 houses were flooded and 23 roads had to be closed. To help prevent landslides Korea has taken to planting trees, controlling erosion, and doing inspections to vulnerable areas. They also have enforced piling sandbags and established retaining walls to help prevent landslides in urban and areas with a high population. 

Refrences: 

https://www.theguardian.com/world/2011/jul/27/south-korea-landslides-kill-17

https://floodlist.com/asia/south-korea-floods-landslides-july-2021

https://www.adrc.asia/management/KOR/Natural_Disaster_Countermeasures_in_Korea.html