Which physical method of confinement involves building barriers to prevent liquid flow into the environment?

The correct choice is damming, as this method specifically refers to creating barriers to contain and redirect the flow of liquids, especially in scenarios where hazardous materials may be involved. Damming typically involves constructing a barrier across a waterway or at a specific area to stop or mitigate fluid movement, preventing contaminants from spreading into the surrounding environment.

Building such barriers is crucial during hazardous materials incidents to protect the ecosystem, water sources, and public health. While other methods, such as diking, also involve creating barriers, they are generally used in different contexts. Diking is more about controlling surface runoff in an area, whereas damming focuses on directing the flow of liquid in a specific way across a larger body of water or flow path. Therefore, understanding the distinct focus of damming on stopping liquid flow helps to identify it as the correct answer.