Which term describes the process when a river's water level exceeds its bank, causing overflow?

The term that describes the situation when a river's water level exceeds its banks and causes overflow is flooding. This occurs when there is an excess of water in the river due to various factors such as heavy rainfall, melting snow, or upstream runoff, leading the river to overflow its banks and inundate the surrounding areas. Flooding can have significant impacts on the environment, infrastructure, and communities, often resulting in damage and potential loss of life.

Other terms like drought refer to prolonged periods of below-average rainfall, leading to water shortages. Drainage pertains to the removal of excess water from a certain area, and consolidation refers to the process of solidifying or compacting material. Thus, flooding is the correct choice as it specifically addresses the scenario of a river overflowing its banks.