氾濫

洪水 is the general term for a flood, while 氾濫 is the act of overflowing.

溢れる is a general verb for 'overflowing,' whereas 氾濫 is specific to water exceeding its boundaries.

浸水 means 'to be submerged in water,' often a consequence of 氾濫 (overflowing).

Both 氾濫 and 洪水 refer to flooding. Learners might struggle to differentiate between the nuances.

洪水 (kōzui) is the general term for a flood, an inundation of water. It can be caused by heavy rain, overflowing rivers, etc. 氾濫 (hanran) specifically describes the act of water overflowing its banks or usual boundaries.

大雨で川が洪水になった。 (Ōame de kawa ga kōzui ni natta.) The river flooded due to heavy rain. / 川が氾濫した。 (Kawa ga hanran shita.) The river overflowed.

Both words involve something overflowing. Learners might use 溢れる where 氾濫 is more appropriate for water.

溢れる (afureru) is a more general verb meaning 'to overflow' or 'to spill out.' It can be used for liquids, emotions, or even people. 氾濫 is specifically for water overflowing its boundaries.

コップから水が溢れた。 (Koppu kara mizu ga afureta.) Water spilled from the cup. / 川が氾濫して、街が水浸しになった。 (Kawa ga hanran shite, machi ga mizubitashi ni natta.) The river overflowed, and the town was submerged.

Both terms relate to water and damage. Learners might mix up the cause and effect.

浸水 (shinsui) refers to inundation or being submerged in water, often implying damage or an area being underwater. 氾濫 describes the act of water overflowing, which can lead to 浸水.

地下室が浸水した。 (Chikashitsu ga shinsui shita.) The basement was flooded. / 氾濫により、多くの家屋が浸水した。 (Hanran ni yori, ooku no kaoku ga shinsui shita.) Due to the overflow, many houses were flooded.

Similar to 浸水, both indicate an area covered in water. The distinction can be subtle.

冠水 (kansui) means 'to be submerged' or 'to be under water,' often used for roads, fields, or other open areas. While 氾濫 describes the overflow, 冠水 describes the state of being covered by water as a result.

道路が冠水している。 (Douro ga kansui shite iru.) The road is submerged. / 川の氾濫で、田んぼが冠水した。 (Kawa no hanran de, tanbo ga kansui shita.) The rice fields were submerged due to the river's overflow.

Both involve large amounts of water causing damage, but they are very different phenomena.

津波 (tsunami) is a seismic sea wave, typically caused by underwater earthquakes or volcanic eruptions. 氾濫 is the overflowing of a river or body of water due to heavy rainfall or other factors within its normal course.

津波警報が発令された。 (Tsunami keihō ga hatsurei sareta.) A tsunami warning was issued. / 大雨で川が氾濫した。 (Ōame de kawa ga hanran shita.) The river overflowed due to heavy rain.