# Main > General Discussion >  A tasty RIVER oddity in the real world

## XCali

Huehuehue,  :Razz: 

So, mostly we are aware that rivers don't split, well apart from very rare rivers like the one in the states that splits to go to both oceans. Strange, but true. Or the fact that we get deltas at the sea.  BUT today something came to my attention, one I've heard about over the years in talking, yet never realized the significance until, I heard the Okavango *Delta* in Botswana, but Botswana does not border on the ocean at all. So, how can it it be a delta? 

Well, as I looked to the satellite photos, it became clear, it is indeed an inland delta. To be honest, I didn't really know about inland deltas until today. One can always learn more things! Yays  :Very Happy: 

A bit of info: 
"The Okavango Delta in Botswana is one of the world's largest inland deltas. While most river deltas usually lead to an ocean, the Okavango River empties onto open land, flooding the savanna and creating a unique and ever-changing inland delta"

And for a little bit of extra strangeness, its end point is in the lake Ngami. So, to my knowledge the water from the delta never goes on to an ocean. 

My whole point of this discussion is the fact that rivers do indeed do some strange things in the real world. It's quite cool actually. There is a general rule, sure, but it doesn't mean stuff like this doesn't happen. So our river police guidelines should add this tidbit when we instruct newer cartographers. 

Some of you might already know all of this, but it is still an interesting fact of our little blue planet.  :Wink: 

Cheers,
Omri

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## Jaxilon

As far as I know, the River Police are just there to remind us that when we do something odd, such as create a bunch of deltas or split a river, we need to have some kind of reason for it. Maybe it was intelligence placing it's force upon the land or maybe it was a fluke of nature.
I'm pretty sure the River Police do know there are exceptions and that is one of the beautiful things about our planet. In fact, the proof is that so many of us WANT to use these exceptions in our maps because they are cool and they draw attention to themselves and they make the viewer wonder what the story is behind the feature.
However, when we have splitting rivers all over the place and/or every river to ocean connection is a delta, well....now we are just getting crazy.

Unless of course, the planet is sentient and doing it on purpose  :Very Happy:  

And now you make me want to go watch one of those nature shows about the Okavango again. I love the Elephants create the pathways. It's sad we don't do a better job of caring for the planet but tend to rape and pillage it for greedy reasons. It's no wonder we suffer for it...man as a whole is so ignorant and arrogant.

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## XCali

We were(are) meant to be its care takers. I guess the problems come when nobody cares and the greedy seek to overly exploit instead of doing it in a sustainable way. That in turn create scenarios where the planet looks and feel sick. I guess if you think about it, if people would love one another instead of seeking to manipulate and or exploit each other, it would transfer over to how we see the nature too, something to nurture so that we can enjoy it together.

A bit of thinking.  :Razz: 

Anyway, the reason why I mentioned the river police really is that when we talk to newer cartographers, yes we need to teach the rule of thumb, but it would also be nice if we mention some of the rare oddities on our own planet to maybe create the space for them to craft more unique maps. To experiment really.

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## Gamerprinter

We do all the time. Practically every "river police" incident I've ever been involved in, I include the exceptions, along with geologic explanations of the exceptions. But haven't made any "river police" posts in more than 5 years, as my presence in the community is much less than it used to be.

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## Falconius

That's a pretty interesting phenomenon.

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## waldronate

There are a great many hydrographic oddities that happen all over the world. There are rivers that reverse direction with the tide, rivers that split, lakes that have multiple outflows, land below sea level, lava so cold that it doesn't glow, rivers that appear and disappear, and so on. However, they are generally very localized and/or very unstable in a geologic sense. The Okavongo delta is a delta for the same reason that the Nile delta is a delta: the river enters an area that's effectively perfectly flat, causing the river to drop all of its sediment, which forces the river to split as its bed level rises to the point where the channel can't contain the flow (eventually, those splits themselves split and/or force the channels to wander back and forth across the area). A river that splits in the middle of nowhere or a lake with two outflows isn't going to stay that way for long, because of the first rule of hydrography: water flows downhill. Sure, there are cases where it's possible to get water to flow uphill, but that is the case of something called a hydraulic jump and is usually at most on the order of a couple of feet and generally results in a hugely turbulent area of flow that eventually destroys the conditions that allow for the hydraulic jump in the first place.
The river police actions usually revolve around maps with river networks that look like fishing nets with splits everywhere, with rivers that flow up and over mountains, or with lakes that have multiple outflows. These things all violate the first rule and are usually done by people who have not looked at maps before or who didn't pay much attention during their geography lessons at school. I've seen maps that are obviously implausible but that have solid reasons for that implausibility (most of which area supernatural, btw).
In case you're wondering, the two major rules of hydrography are: (1) water flows downhill and (2) rivers erode their channel. These two rules are responsible for all of the normal rivers and exceptional rivers that we see and are also why exceptional rivers eventually revert to normal rivers. Yes, a river in granite mountains looks very different from a river flowing across a nearly-flat plain, but they follow the same rules.

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## Redrobes

I wrote this thread about rivers:
https://www.cartographersguild.com/s...ead.php?t=3822
to summarize a lot of discussion about rivers that we were having at the time. Its not for me to say whether its the guidelines for the river police tho.

But in the initial post I said that there are 3 ways that a river terminates and number 3 mentions the rare but occasional phenomenon of a river evaporating into nothing which is an Endorheic Basin of which the Okavango Delta is one. It does indeed make for a very unusual spectacle that this river forms a delta at one of these basins too. Within that thread there are several more posts about Enhorheic basins so its worth going through some of them if your interested.

But as Waldronate says, we see many maps where this is clearly not the case and the map is showing rivers with wild and impossible structure mainly due to the person who made the map not really studying rivers in depth or having a false metal model of how rivers look. Now were mostly a fantasy mapping site and many wild and impossible maps are made deliberately so the post about rivers is a guide to help, but you may ultimately want to break some of the "rules" for your own place if you want to justify it to yourself with magical effects etc.

But an Endorheic Baisin on your map should not cause a river police violation if its in a dry place similar to Botswana.

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## Falconius

Also we do have a contest specifically where "impossible" rivers are the entire point.  In any case the "rules" are there to increase the verisimilitude of the place depicted. They exists to make things better, and they make things better by providing a strong foundation on which to build something amazing.  As the Okavango Delta is amazing.  If such oddities occurred all the time it wouldn't be all that fantastic, and wouldn't be odd, or all that spectacular.  I think the best case to argue in favour of haveing a base set of rules that inform one's understanding is actually modern movies, thanks to CGI they can make all sorts of visually stunning and amazing things, places, movements, weird effects etc.  And when they chock every scene of the movie full of these things it all feels flat and boring.  If you sat in a trench listening to explosions for hours or days on end you become inured, same thing.

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