D. Viscosity of a fluid and pressure exerted on the fluid influence the motion of the fluid. Conversely, a moving fluid can interact with objects to exert forces on the objects. Pressure differences cause water to flow in restricted spaces. Flow patterns of surface waters are determined by the interactions of the moving water with the surrounding materials. Flowing water will interact with surroundings in a way that transfers energy to the surroundings until the water has reached a state of minimum potential energy.
Human activities can influence changes in the watershed.