Hydrologic Oddities: Where Two Rivers Become a Creek

Scott Bridle's photo of river channels in the outback

Bureau of Meteorology forecaster Chris Leahy told me about an interesting hydrologic oddity in Australia. Cooper's Creek is the only place where "Two rivers meet to form a creek." Wikipedia describes Cooper's Creek as "One of the most famous, yet least visited rivers in Australia". 

A map of Australia's outback rivers

According to Red Nomad OZ

When he discovered it in a dry year, misguided explorer Charles Sturt named it 'Cooper's' after Charles Cooper (then [South Australia's] Chief Justice) and 'Creek' because he didn't think anything that small was actually a river!

Scott Bridle's aerial photo of flood patterns. His website has many more good photos of Australian landscapes taken from above.

Often the interior of Australia is completely dry and there is no surface flow. But when it flows, it flows everywhere. There is not so much a river channel as there is the "channel lands". 

A satellite image of where the rivers come together to form a "creek"

There's many words for water flowing in channels and there's no standard definitions. Here are some of the ones I have known, roughly from my notion of largest to smallest:

River

Stream

Run

Creek
Brook

Rivulet
Wash...

There's similar debates about how to describe the land surface area that drains into a channel. 

Basin

Watershed

Catchment

Area

Drainage

Hillslope

Many people also use sub-catchment, sub-area and so on, adding another layer of complexity (e.g. which is bigger, a sub-watershed or catchment?)

My rule of thumb when living in Arizona was that a river was anything you couldn't jump across. I learned this by unsuccessfully trying to jump across the Gila River.