What is the term for the daily changes in water demand?

The term "diurnal variation" specifically refers to the fluctuations in water demand that occur within a 24-hour period. This daily cycle is typically driven by factors such as human activity patterns, weather conditions, and operational schedules. For instance, residential water use tends to peak in the morning when households are starting their day, and again in the evening when residents return home. Understanding diurnal variation is crucial for water distribution planning, as it helps utilities manage supply and demand effectively, ensuring that adequate resources are available during peak usage times. This knowledge assists in designing infrastructure that can handle these daily changes without causing shortages or excess capacity.