Are floods caused by geologic factors or by humans?

Answer 1

In some ways both, and in some ways niether. Floods are primarily a weather phenomenon, as the ultimate deciding factor is usually heavy rain or melting snow. However, the geology of an area can affect the risk of flooding. Low lying areas, especially valleys, are usually the most vulnerable. Human acitivty can also increase flooding risk, such as by removing vegetation and by building impermeable surfaces such as roads.

Answer 2

Floods can be caused by both geologic factors, such as heavy rainfall or snowmelt, as well as human activities like deforestation, urbanization, and improper land use practices that contribute to increased runoff and erosion. Human-induced factors can exacerbate flood risk and intensity.