Hydrograph

A hydrograph is a fancy way of saying a chart that shows how quickly water flows in a river or stream during and after a rainstorm. Think of it like a graph that shows how fast you run during a race, but instead of speed, it shows how high the water is and how fast it moves.

When it rains, water gets into the river or stream and makes the water level go up. That's called a "rise" in the hydrograph. As the rain stops and the water slowly flows downstream, the river level goes down. That's called a "fall" in the hydrograph.

Hydrographs are important because they help scientists and engineers understand how much water can flow in a river or stream and how much space it needs. This can help them prevent floods, which happen when there's too much water and it spills over the banks of the river or stream. By looking at hydrographs, they can figure out how to build dams and levees to keep the water in the river or stream and prevent it from causing damage.