What are some key factors affecting water pressure in distribution systems?

The correct choice highlights essential factors that directly influence water pressure in distribution systems.

Pipe diameter plays a crucial role because larger pipes typically allow for greater flow rates with less resistance, resulting in more stable pressure. Conversely, smaller diameters can restrict flow, leading to pressure drops, especially when there is high water demand or during peak usage times.

Elevation changes also significantly impact water pressure. Water pressure increases when moving downward from a higher elevation (due to gravity) and decreases when moving upward. This principle is crucial in designing systems that must service varying terrains, where pressure adjustments may be necessary to maintain adequate supply.

Flow rates affect the system's ability to deliver water consistently. A high flow rate can lead to pressure drops if the system is not designed to accommodate the demand, especially in areas where pipe sizes or other adaptations might be inadequate.

Friction loss occurs as water moves through pipes; it is caused by the interaction between the water and the pipe walls. The roughness of the pipe material, length of the pipe, and the speed of the water contribute to this loss. Systems must be designed to minimize friction loss to maintain adequate pressure.

The other options refer to factors that do not directly influence water pressure within distribution systems. Temperature and humidity, while they