PrintDriving Forces for Groundwater Flow
The driving forces that control groundwater flow are a bit more complicated than those controlling flow in rivers and streams. As you learned in Module 3, surface water flows downhill due to gravity, and the flow direction is defined by the topography. Water flows downhill because gravity is a form of potential energy – and the water, or anything that falls or rolls downward – flows in response to differences in potential energy (from high to low).
In contrast to surface water, groundwater is separated from the atmosphere, and as a result, it can be under considerable pressure. Therefore, the potential energy that drives groundwater movement includes both pressure and gravity. In this section, you will learn about these driving forces, how we define them, and how they translate to the direction and rate of groundwater movement in the subsurface.