Atlas Integral de las Características Naturales en los Paisajes Protegidos de Perú

A river is a substantial natural watercourse that flows through a defined channel toward another river, lake, wetland, sea, or inland basin. Its system may include tributaries, distributaries, floodplains, seasonal reaches, gorges, waterfalls, and deltas far beyond any single mapped park relationship. The distinction from a stream depends on local convention, scale, and source usage rather than one universal rule.

A stream is a natural flowing watercourse contained within a channel, generally smaller than a river but defined primarily by local naming and hydrological context. Streams may be perennial, seasonal, intermittent, spring-fed, glacial, or ephemeral and often form tributaries within larger drainage networks. No universal width or discharge threshold cleanly separates a stream from a river.

A lake is an inland body of standing water occupying a natural or substantially natural basin and supplied by precipitation, groundwater, streams, rivers, meltwater, or combinations of these sources. Lakes can form through tectonic, volcanic, glacial, karst, fluvial, coastal, or impact processes and may drain externally or remain closed. Size alone does not consistently separate lakes from ponds, so the established entity name should be respected.

A glacier is a persistent body of land ice formed through the long-term accumulation and compaction of snow and capable of deforming or flowing under its own weight. Glaciers occupy mountain valleys, icefields, plateaus, or polar terrain and shape landscapes through erosion, transport, deposition, and meltwater. The category excludes seasonal snowfields and sea ice unless a source explicitly identifies a true glacier.