scour

Scour is a term with several related senses. As a verb, it means to clean or rub away dirt with an abrasive, and it also means to search thoroughly or examine something in detail. As a noun, it can refer to the act of scouring or to material removed in the cleaning or erosion process. In hydrology and civil engineering, scour denotes erosion of sediment around submerged objects caused by flowing water.

Scouring for cleaning involves the mechanical removal of dirt from surfaces using abrasive materials, often with detergent. Common tools include scrubbing pads, brushes, and powders. It is used on cookware, metalwork, ceramics, and other durable surfaces, and its effectiveness depends on the material, type of dirt, and abrasive used.

In hydraulics and geomorphology, scour describes the removal of sediment around structures such as bridge piers, abutments, and pilings caused by flowing water. Erosion can form scour holes and undermine foundations if not mitigated. Scour depth depends on flow velocity, sediment size, depth of flow, and the geometry of the obstruction. Engineers assess potential scour with models or empirical methods and design for safety margins.

Countermeasures to reduce scour include protective linings and materials such as riprap (loose rock), gabions, concrete aprons, and scour collars. In some cases, structural changes, deeper foundations, or relocating a structure may be required to prevent failure due to scour.

The term scour also appears in non-engineering contexts, notably the verb phrase to scour for information, meaning to conduct a thorough search of data, records, or locations.