Which factor does NOT affect the movement of groundwater?

The correct answer is determined by recognizing that temperature, although it can influence various physical processes, does not play a direct role in the movement of groundwater itself. The movement of groundwater primarily depends on other physical characteristics and conditions of the aquifer system.

Porosity is critical because it measures the volume of void spaces in a material, which affects the amount of water that can be stored in the ground. A high porosity means more water can be retained, thus influencing its movement through the groundwater system.

The hydraulic gradient, or the slope of the water table, is a key factor that drives groundwater flow. Water moves from areas of high hydraulic pressure to areas of low hydraulic pressure, and the steepness of the hydraulic gradient will determine the velocity of this movement.

Groundwater discharge refers to the process by which groundwater exits the subsurface to surface water bodies, such as rivers or lakes, and this can be driven by factors like pressure and elevation differences. It is intrinsically linked to the movement of groundwater as it defines how and where groundwater travels towards discharge points.

In contrast, temperature mainly affects the viscosity of water and can influence rates of chemical and biological reactions within the groundwater, but it does not directly dictate the flow or movement through the geological layers. Thus