Which of the following factors does NOT influence pressure in an irrigation system?

The correct choice indicates that water temperature does not influence pressure in an irrigation system. Pressure in an irrigation system is primarily determined by the physical characteristics of the water and system configuration, rather than the water's temperature.

When considering the height of the water column, gravity plays a vital role. The greater the height of the water column, the more pressure is exerted at the base due to the weight of the water above. This is known as hydrostatic pressure, which is a direct consequence of gravity acting on the water.

The density of water is also significant because pressure is influenced by how much mass is contained within a given volume. The denser the water, the more a given height of water contributes to the overall pressure at the system's outlet.

While temperature might affect the properties of water, such as viscosity, it does not directly factor into the calculation of static pressure under normal operating conditions in irrigation systems. Pressure calculations are typically based on height, gravity, and density, which directly relate to how pressure is exerted throughout the system.