cauces

Cauces is the plural of the Spanish noun cauce, which in geography refers to the channel or bed of a river or other watercourse. In English-language hydrology, cauce is rarely used directly; the concept is described with terms such as river channel, riverbed, or drainage channel. A cauce encompasses the path along which water regularly flows, its banks, and the adjacent floodplain when water levels are high. It reflects the channel’s geometry and its relationship to flow, sediment transport, and ecological functions.

Channels can be categorized by formation and characteristics. Alluvial channels form in unconsolidated sediments and are common in plains and deltas; bedrock channels cut into solid rock and often appear steep and narrow. Braided channels consist of multiple interwoven strands with abundant sediment, while meandering channels show a single, winding path with curving bends. Straight channels have relatively low sinuosity and occur in stable, uniform environments. The shape and size of a cauce are influenced by discharge, sediment supply, gradient, substrate, and vegetation.

Dynamic processes continually modify cauces. Erosion removes material from banks and bed, while deposition builds up point bars and levees. Lateral migration and avulsion can alter the main flow path, especially during floods or changes in sediment load. Human activity commonly alters cauces through damming, dredging, channelization, and urban development, impacting flood risk, navigation, water supply, and ecological connectivity.

Ecologically, cauces support aquatic habitats, species movement, and nutrient transport. Their management often aims to balance flood control, water extraction, habitat restoration, and sediment management within river basins.