Nature

===Streams===
[[File:Hawaii Creek.jpg|thumb|A rocky stream in [[Hawaii]]]]
{{Main|Stream}}
A stream is a flowing body of water with a [[Current (stream)|current]], confined within a [[stream bed|bed]] and [[stream bank]]s. In the United States, a stream is classified as a watercourse less than {{convert|60|ft|m|abbr=off}} wide. Streams are important as conduits in the [[water cycle]], instruments in [[groundwater recharge]], and they serve as corridors for fish and [[wildlife]] migration. The biological [[habitat]] in the immediate vicinity of a stream is called a [[riparian zone]]. Given the status of the ongoing [[Holocene extinction]], streams play an important [[wildlife corridor|corridor]] role in connecting [[Habitat fragmentation|fragmented habitats]] and thus in conserving [[biodiversity]]. The study of streams and waterways in general involves many branches of inter-disciplinary natural science and engineering, including [[hydrology]], [[geomorphology|fluvial geomorphology]], [[aquatic ecology]], [[Freshwater fish|fish biology]], [[riparian|riparian ecology]], and others.