The hydraulic gradient is a measure of the change in hydraulic head per unit distance in a fluid flow system. It indicates how steeply water moves through soil or rock, influencing groundwater flow and surface water movement. The hydraulic gradient is calculated by dividing the difference in hydraulic head between two points by the distance between them. In practical terms, a higher hydraulic gradient means water flows more quickly, while a lower gradient indicates slower movement. This concept is essential in fields like hydrology, civil engineering, and environmental science, as it helps in understanding water resources and managing groundwater systems effectively.