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Gamerprinter
09-10-2009, 01:38 PM
I joined ConceptArt.org last week to make my comment on their forum regarding the map Torstan linked in his General Forums thread "map that needs some love".

So I decided to upload my portfolio onto their site and three days later I received a commission from one of the other artists there. They don't want me to map per se, rather they want me to colorize an existing B/W map he is using for an online game site.

Problem is, its the most River Violation riddled map I have ever seen. Although I'll do what he asks in coloring it in, I had to tell him all the river violations on his map. To the point that I want paid for the commission, but I really don't want credit for doing the work, as I do not want to be associated with such a violated map.

I had to laugh, at how bad the river violations are! "Cringe"

GP

AslanC
09-10-2009, 01:47 PM
Wow that's just ... wow.

torstan
09-10-2009, 02:09 PM
Perhaps try thinking of them less as rivers, and more as very thin bits of sea between very close together land masses?

That is pretty shocking.

Steel General
09-10-2009, 03:19 PM
Looks like one of my early maps before my time at the River Police Academy :D

Lucas_Adorn
09-10-2009, 04:54 PM
its like.. all upside down. or sideways...:?

su_liam
09-10-2009, 05:01 PM
Have to agree with Torstan. Those aren't rivers, that's just a really closely-spaced archipelago. :)

Ascension
09-10-2009, 05:10 PM
We should require these so-called artists to do an internship here. Interesting concept, too bad the natural laws of geology prohibit something like this from ever actually happening. I'm with ya GP, I'd do the same thing. I might even go so far as to make a nice big cartouche and fancy title with the original artist's name on it instead of mine...or yours in this case, you know what I mean :)

NeonKnight
09-10-2009, 08:04 PM
Ok, the river riddled swamp I can see...kinda. But the others are just WOW!

RobA
09-10-2009, 11:08 PM
All a question of scale...

check out this insanity:
http://maps.google.com/maps?&split=0&gl=us&ei=kL6pSsm1FIeSlAfEtdXlBg&ll=38.067014,-121.735382&spn=0.400036,0.699692&z=11

-Rob A>

Korash
09-11-2009, 12:22 AM
Yeah, but that is just a flood plain that hasn't finished draining yet :) GP's example is just WRONG :D

RobA
09-11-2009, 12:34 AM
...maybe the whole island rose from the sea so it is a still draining sea bed...or, as maybe as you said, it is just wrong...

-Rob A>

Lwaxana
09-17-2009, 07:39 PM
Oy Vey... the gods must have been drunk when they made this continent.

zenram
09-18-2009, 12:45 PM
Well, i would like to go to the "River School, could you enlighten us?, please?

A list of mistakes or something, besides the scale, of course.

NeonKnight
09-18-2009, 03:37 PM
Well, i would like to go to the "River School, could you enlighten us?, please?

A list of mistakes or something, besides the scale, of course.

Rivers flow down hill and follow the path of least resistance. As a result, using the map above as a example, a river can not flow from one sea to another sea (this would require the river to flow uphill at some point).


Another example is a river splitting as it flows. Rivers simple do not do this. Now, river can certainly have islands in them, so a river can 'split' around an island but it will rejoin itself downsteam. And these islands will not be more a few miles in length.

The only times a river will 'split' will be in the case of either a River Delta (The Largest real world example being the Nile Delta (http://www.specialtyinterests.net/map_nile2nubia.JPG)), or during a time of flooding as a river is gorged with excess water and can split and flow down new paths as it overflows, but this will be temporary at a best as as soon as the excess water has flowed out, it will return to a single channel.

This is the same reason a lake can have many incoming rivers but only a single out flow. If it had more that one out flow it would drain to the point where the level would fall to only one outflow.

zenram
09-18-2009, 03:46 PM
Woooww, thanks, Are there some post with the river rules?
Or this are all? XD

Gamerprinter
09-18-2009, 04:46 PM
There is somewhere on this site, either the tutorials forum or the reference forum, I did a search for it this morning, but couldn't find that page - I know its there, but I didn't respond to your post here, as I couldn't find. I expected one of the CLs to point it out, but so far only SG has posted, and basically gave you the "watered down" version. If I or someone else finds that list of river violations, we will certainly post a link here. Like I said, I did a quick search and couldn't find it??!!!

Go look yourself, you might find it, in case its deep in the forum somewhere...

GP

waldronate
09-18-2009, 05:19 PM
Rivers flow down hill and follow the path of least resistance.


I think that it would be clearer if "least resistance" was "steepest descent" instead. That way people don't have to understand how water is supposed to behave. Most people I know of think of going down steep hills as a back and forth process, while most water parcels I know prefer the "jump over the edge" philosophy. It's a misapplication of experience on the part of people.

An an aside for bizarre river behavior, it's possible for a "river" to flow from the sea inland if there is a large dry inland basin lower than sea level that can sustain a higher evaporation rate than the inflow amount. In the Afar Basin in Africa there are small streams that are being forced through the rock from the ocean. Soon (geologically speaking) there will be a river and soon after that an inlet like the Red Sea. Consider also the the Mediterranean Sea. It has a net influx of water from the oceans because of its high evaporation rate. Choke off the Straits of Gibraltar and there would be a "river" flowing from the Red Sea through the Suez canal (plus all of those regular rivers that would be wandering off into a desolate wasteland).

NeonKnight
09-18-2009, 06:43 PM
I think that it would be clearer if "least resistance" was "steepest descent" instead. That way people don't have to understand how water is supposed to behave. Most people I know of think of going down steep hills as a back and forth process, while most water parcels I know prefer the "jump over the edge" philosophy. It's a misapplication of experience on the part of people.

An an aside for bizarre river behavior, it's possible for a "river" to flow from the sea inland if there is a large dry inland basin lower than sea level that can sustain a higher evaporation rate than the inflow amount. In the Afar Basin in Africa there are small streams that are being forced through the rock from the ocean. Soon (geologically speaking) there will be a river and soon after that an inlet like the Red Sea. Consider also the the Mediterranean Sea. It has a net influx of water from the oceans because of its high evaporation rate. Choke off the Straits of Gibraltar and there would be a "river" flowing from the Red Sea through the Suez canal (plus all of those regular rivers that would be wandering off into a desolate wasteland).

True steepest descent normally wins over least resistance, but even a granite cliff will lose eventually to the sandstone plains it abuts next too ;)

waldronate
09-18-2009, 07:11 PM
True steepest descent normally wins over least resistance, but even a granite cliff will lose eventually to the sandstone plains it abuts next too ;)

Not until the sandstone wears away enough to become the path of steepest descent.

Ascension
09-18-2009, 07:43 PM
There's a thread by Redrobes in the Tutorial section. I went ahead and stickied it because of it's usefulness. It is here (http://www.cartographersguild.com/showthread.php?t=3822).

Juggernaut1981
09-18-2009, 11:31 PM
I'm sure the other post is comprehensive, I haven't read it for its physics/hydrology/chemistry content.

**Puts on his Chemistry/Physics Hat**

All liquids move towards a point of "lowest energy" (i.e. closest to the centre of the relevant planet) by the path with the "least resistance".

Least resistance has two parts: descent rate and the ability for the water to alter its surrounds. Given the options of trying to make a gully in granite or in nice loose black soil... the river will move to the soil and then take the path which maximises the descent and takes the path through the most "movable" material.


Take an example with a big mountain range. The river will move fairly straight through natural cracks in the rocks (opening them up further... see The Grand Canyon) and take very few sharp turns, rarely double up on itself or anything similar without a VERY VERY good reason.

Once it leaves the mountains it entirely depends on the slope to the ocean. If the land is basically flat (barely ANY slope at all) the river will wander all over the place until it finds the path with the most easily moved material.

My advice: Use Google Maps to look at China. Plenty of rivers. They all start in mountainous areas, flow straight for a long-ish period of time and then start straying when they hit the wide flat lands across most of central and coastal China.

Deltas = wierd places where rivers get confused and hedge their bets by splitting and taking as many paths as they can push water through. Nile River Delta, end of the Mississippi river...

Australian Rivers = we have a near monopoly on the concept of a "sand river". There is a river flowing, but it's underneath/through 5m depth of sand and only really flows above-land when you've REALLY got water flowing.



As an explorer, if you ever got lost, the solution to getting to somewhere nice and hospitable was find a river and follow it. Eventually you will hit the coast. Don't try this trick in Australia... it doesn't work quite right and we have the dead 1800s-era explorers to prove it.

Gamerprinter
09-19-2009, 02:25 AM
OK, Juggernaut, have some REP for that bit science on rivers!

My curious question now regards the Yucatan Peninsula, and the Island of Cozomel. I've been to Cancun, Mexico, on vacation a few years ago, having recently (at the time) learning about the propensity of underwater rivers in southern Mexico. The island of Cozomel (largest island off Mexican coast, very near Cancun.

Most of the Yucatan is extremely flat, but there are almost no surface rivers there. Sinkholes everywhere. Underground rivers everywhere.

I visited a "park" that contained a sinkhole right near the coast, about a half mile away from the sea. Fresh water rose from the sinkhole and formed a short surface river called a "Ria" that reached the sea.

Cozomel is really not that big, yet underground rivers course meandering around the reaching the sea.about 5 meters under the surface.

I've always wondered about the science regarding that... Can anyone answer, Juggie or Waldronate?? It seems almost bizzare.

GP

Coyotemax
09-19-2009, 02:41 AM
Cenotes! (underground caverns/sinkholes with pools or rivers running through them)

wonderful places from what I understand. I'm going to the yucatan for our 10th anniversary, I'll b taking lots of pictures so you can marvel over those. if I learn something neat about them while I'm there I'll let you know :) (i suppose I could google-fu, but i think it'll be more fun to find out while I'm there)

NeonKnight
09-19-2009, 11:35 AM
OK, Juggernaut, have some REP for that bit science on rivers!

My curious question now regards the Yucatan Peninsula, and the Island of Cozomel. I've been to Cancun, Mexico, on vacation a few years ago, having recently (at the time) learning about the propensity of underwater rivers in southern Mexico. The island of Cozomel (largest island off Mexican coast, very near Cancun.

Most of the Yucatan is extremely flat, but there are almost no surface rivers there. Sinkholes everywhere. Underground rivers everywhere.

I visited a "park" that contained a sinkhole right near the coast, about a half mile away from the sea. Fresh water rose from the sinkhole and formed a short surface river called a "Ria" that reached the sea.

Cozomel is really not that big, yet underground rivers course meandering around the reaching the sea.about 5 meters under the surface.

I've always wondered about the science regarding that... Can anyone answer, Juggie or Waldronate?? It seems almost bizzare.

GP

Could be the Yucatan Peninsula is the remnants of that GINORMOUS Meteor Impact that spelled the end for our favorite dinosaurian friends ;)

Gamerprinter
09-20-2009, 05:52 AM
The Yucatan is mostly liimestone. Tropical rainforest or at least jungle at the surface, thus rainfall becomes acidic and "melts" holes into the surface and carves channels underneath. Holes enlargen and become sinkholes (cenotes) and dozens if not hundreds of unexplored rivers carve the underground of the Yucatan. Underground rivers join, eventually reaching the sea. Many rivers reaching the sea separately. Some as the "rias" mentioned in the above post, some as partially submerged tunnels reaching the sea.

Of course, closer to the sea, the upper portion is fresh water, while the lower portion is salt water. Most life, live in the salt water. Unsure of the technical name, but like a thermoclyne, there is a defined separation layer between the salt and fresh water. Salt water is blurry, while fresh water is clear. If swimming in the fresh water portion, crossing into the salt water causes the waters to mix and vision to become cloudy. Due to large and small hole, almost invisible sinkholes many chambers have that rise above the water level.

From discussion with friends and some google-fu.

Could make an interesting subterranean river system map with exposed sinkholes and of course Mayan ruins/zigurrat pyramids hidden in jungle at various cenotes...

GP

RobA
09-20-2009, 10:19 AM
Unsure of the technical name, but like a thermoclyne, there is a defined separation layer between the salt and fresh water.

Think it is a Halocline.

[EDIT: checked at wikipedia: http://en.wikipedia.org/wiki/Halocline]

-Rob A>

waldronate
09-20-2009, 06:31 PM
Karst terrain is fun. Sinkholes, rivers that disappear underground, and rivers that appear full-blown out of a cliffside are all examples of the fun things that happen there. Turkey and Greece are examples of karst terrains where those features have played a major role in history. The Kentucky area with its famous caves is another example. Maturing limestone terrains are always full of surprises.

Gamerprinter
09-20-2009, 06:42 PM
Thanks for the proper vocabulary, Waldronate (haven't REPped you in awhile, so I'll do so now!)

I know that Japan has several extensive limestone cavern systems as well, though I hadn't heard of any until a quick google-fu said there was...

So, I think (agreeing with Waldronate) Karst terrain is fun. So I think I'll work on a Karst terrain map with above above ground view of map area and underground reveal of map area showing underground river systems - eventually reaching the sea, then developing a complex adventure module to utilize that terrain effectively for more Kaidan fun.

I was thinking of working on a Karst terrain as a side project, but since I am deep in Kaidan development, why not continue and try a Karst terrain with my current project and make it fun, useful and profitable!

That's my next project I think. (I do eventually want to involve my undersea map, and may be able to connect the two - Karst + Ryukyo.)

GP

zenram
09-21-2009, 10:11 AM
Wow, that's something, i think it's the part that keep me away of drawing an area or world maps, there are so much research to do. The other day i was thinking in to draw a continent map and was so surprised about all the thing to take into account....

Well, this will help me a little more. Thanks XD
__________________

Lwaxana
09-21-2009, 04:39 PM
Most important things to remember I think is that rivers run downwards and go from smaller ones to forming wider ones and there are usually at least 2 large rivers on a continent. Up to now no one complained about my rivers but i had a few people pointing out my weird continent design once :)

The info above is very interesting though and might help me in my plan for an underground city.

Juggernaut1981
10-11-2009, 09:01 PM
OK, Juggernaut, have some REP for that bit science on rivers!

My curious question now regards the Yucatan Peninsula, and the Island of Cozomel. I've been to Cancun, Mexico, on vacation a few years ago, having recently (at the time) learning about the propensity of underwater rivers in southern Mexico. The island of Cozomel (largest island off Mexican coast, very near Cancun.

Most of the Yucatan is extremely flat, but there are almost no surface rivers there. Sinkholes everywhere. Underground rivers everywhere.

I visited a "park" that contained a sinkhole right near the coast, about a half mile away from the sea. Fresh water rose from the sinkhole and formed a short surface river called a "Ria" that reached the sea.

Cozomel is really not that big, yet underground rivers course meandering around the reaching the sea.about 5 meters under the surface.

I've always wondered about the science regarding that... Can anyone answer, Juggie or Waldronate?? It seems almost bizzare.

GP

GP> Thinking about this one... trying to nut the sucker out and I keep coming back to some stuff that is hard to explain but easy to demonstrate.

Everything has a property called "surface energy" (it's basically the energy required to make surface area)...

If you drop a liquid on a surface (i.e. glass, the kitchen bench, a sink) it reshapes itself to minimise its surface (because more surface = more energy) and the universe likes to minimise energy.

Why does this matter?
Experiment: Get a glass of water, stick a dishcloth in it, drape the dishcloth over the edge of the glass and into the sink. Do the same with another glass but use a NORMAL cloth (any old boring bit of tight-weave fabric)

Expected results: Water climbs the cloth, over the edge of the glass and down the sink. (Note: if you use hot water, it should do it faster). The dishcloth glass should be more empty than the "normal cloth" after say 1 hour.

How the cheese does this relate to sinkholes and the Yucatan?
The ocean is your "sink". The water source is your glass. The two cloths represent the different kinds of land.

Water likes touching water, but it also hates having lots of surface. In the tight-weave cloth you reduce the surface (by making it touch the cloth) BUT more water is touching cloth which it doesn't like much. There is also no nice smooth "water highway" through the cloth. Any water has to move around in a lot of directions to get around the threads.

In the dishcloth, there are lots of nice holes and spaces. Holes = water touching water which is good. Cloth = less surface which is good. Loose weave = clear paths to the other end of the cloth. Hence the water should move faster.

SO back to the Yucatan. Given the options: make a river versus "flow through this swiss-cheese rock stuff" the one that has the least energy involved is the "swiss-cheese rock" AND because there is less energy spent on surfaces, more energy can be spent on moving and hence it is a faster path making sure it meets the requirements of the river police.

Tiana
10-13-2009, 11:14 PM
Wow. Just... wow. I admit I cracked up a bit on the original posted map but the thread was a great read, full of awesome information on rivers and really helps me with my issues with them.

I do like the cloth/glass explanation, it does help make sense of that theory.

rdanhenry
10-14-2009, 05:51 AM
Does anyone know why these kind of errors are so common? I look back over my old maps, some done as a child (ten, if not earlier) and even when my spelling is terrible and my drawing crude(r than now), the worst things I kind find are an inland lake with no outflow that I think I hadn't planned on being salt water and perhaps a tendency (that has not left) to somewhat exaggerate the meandering of my rivers. Is it just people trying to make maps without any real familiarity with them or something else? I'm inclined to think there is more involved, since these errors seem so common, while I am not seeing such frequent, obvious errors in other factors.

Ascension
10-14-2009, 07:07 AM
My thought is that people just draw maps from old memories and don't really think about it. Memory is often wrong, ask anyone in law enforcement. They get the idea of squiggly meandering rivers with branches but don't even think about rivers joining up to form bigger rivers so they split 'em. They get the idea of a river delta but don't think about it being close to the coast so they start their deltas about 1000 miles upstream. They get the idea of rivers going into lakes but don't think about the lake having to drain...they know about the Great Lakes but forget about the St. Lawrence seaway. When they do think about drain they don't know about one outflow so they put in a bunch...so this is more technical and less common-sense. By and large, people just do and don't bother with the thinking part...that seems to require too much effort, and while that is good for some things (being instinctual is a great boon for say an athlete or a lothario) it is not so good for other things (like physics and medicine). But, that's why we're here...people who want to learn do so and they come here to do it.

Amazon_warrior
10-15-2009, 02:27 AM
Maybe they just didn't pay attention in Geography? :D


(I'm pleased to say that my GCSE Geography project was all about a river - nothing like actually studying the real thing!)

Juggernaut1981
10-15-2009, 05:46 PM
Expected results: Water climbs the cloth, over the edge of the glass and down the sink. (Note: if you use hot water, it should do it faster). The dishcloth glass should be more empty than the "normal cloth" after say 1 hour.



Just a side-note for the science inclined amongst us... the REAL fun is observing the water "climbing" the glass when the surface tension/energy minimisation makes it better for the water to climb to the cloth when the cloth isn't touching the water directly than it is to stay where it is.

This is similar to the phenomenon of "super-fluidity" found when you get liquid helium. The end result is the liquid helium running up the sides of a container to drop onto the floor of the cooling-chamber. I've forgotten how far it will climb, but for <5mL of liquid more than about 10cm is HUUUGE. (Points further questions on super-cooled super-fluid helium to our resident CERN-Nerd)

Meridius
10-25-2009, 09:12 AM
Hopefully I can add to some understanding of rivers for the downstream part. My knowledge mostly comes from the Dutch situation.

The most important words for rivers in mountain-like terrain is erosion. Most people know that. Sedimentation is however the word for low-land rivers. Sediment (=soil and tiny rock fragments) is being eroded away by large rivers. However, not all that sediment disappears into the sea.

In low-land, rivers start to slow down, they get a bit lazy. And because this slower flow-rate (less relief) the heaviest sediments start to sink. Particularly when a river overflows it's banks and retreats again. This water on the banks comes to a complete stop. ALL sediment starts to sink down, and the water eventually drains. The banks become 'higher ground'. If this happens enough times, the rivers main stream will get choked off, and the main stream will bend off around the 'tight spot'. The water in the 'old' river will slow down, and drop more sediment. Eventually the old river will dry up completely.

Now, even though all this sediment rained down on the upstream part of the low-lands, once the river drains into the sea, there's still a lot of sediment in it. This tends to fall down close to the river. Basically the same thing happens close to shore as it did inland. The river throws down sediment, and land starts to rise. Once formed, the river will flow around here. Eventually, delta's come into being. Because of this process, as long as the river flows the delta will keep moving into the sea (SLOWLY), and branches on the main river in the OLD part of the delta will appear as major rivers branching off.

Everything in geology is dynamic, it only moves slower than our lives. For things like geology you need to put away your human time-perception, and switch to one where 500 years is 'a short time'.

Now, all this would be fairly simple if we didn't exist. Rivers follow their own rules, but humans can use those rules. By carving out a channel, a river is easily persuaded to flow into another river. This happens mostly around Delta's I guess, but it makes the situation a bit more complicated. Man, likes having a boat. But man also likes his home. He would also like to have his boat close by his home. Now this is fine, if only the damned river didn't move off... So man will ensure his access to the river by either guiding the river, or by digging channels. This will make us cartographers completely confused about what part of a river is man-made (or man influenced) and what part not. Since our ancestors didn't really care about perfectly straight waterways. Some waterways follow already existing low points in the landscape. Making them look quite natural.

To name a few rules:
- GENERALLY rivers only join. They don't separate (delta's are the exception).
- Rivers flow to somewhere, this may be a lake (which may, or may not drain into another (or the same) river, but this is usually the sea.
- Rivers flow faster upstream than downstream.
- In delta's weird stuff can happen, like rivers branching off into two smaller rivers, only to flow into another river, or another earlier branch. As a rule of thumb, delta's are quite big if they extend about 100 km (about 60 miles) inland. Generally the bigger the river, the bigger the delta.
- Meandering (squigglyness) takes place DOWNSTREAM rather than upstream. The slower a river flows, the more it meanders. Upstream where it flows faster, it usually is much more 'straight'. To get a good feel, go to Google earth/maps, and follow some different rivers in their flow. You'll get a good feel eventually. It isn't really straight what I mean, but you'll see the difference.
- Don't forget, unless you build a planet without intelligent life, a river will be influenced by intelligent species. As a rule of thumb, if a civilization has bigger ships, it will more actively influence it's rivers. And with 'bigger ships' I mean bigger than a canoe. Draft-ships (ships being pulled by horses) for example. In 'modern' societies (industrial revolution and later) this process only expands. There however will always be people who leave the river as is. Once again, I'm basing this mainly off the Rhine.
- Two or more rivers can share a single delta.
- In more local maps depicting a river delta, rivers CAN and WILL branch off and join together again.
- River islands can be natural, or man-made (channelized river).
- Rivers don't flow from one ocean to another.

Basically, the mentioned map is a fine example of how it's done wrong. I doubt it was made this way for this purpose, but showing how it's not supposed to be done is a good way of teaching people :)

delgondahntelius
11-01-2009, 06:25 AM
As to the question on in-house posts referring to river violations and general guidelines on how to map rivers, I thought I'd point to my own tutorial (http://www.cartographersguild.com/showpost.php?p=34253&postcount=38)where I touch the subject briefly

su_liam
11-02-2009, 01:25 AM
In reality, rivers flow faster downstream than upstream. Try standing in the Mississippi in northern Louisiana. The land is flat and has been for some time, but that water is hauling ass. And it will haul yours out to sea if you're not careful. It's so deep that it looks sedate. That's just because it isn't AS turbulent. I almost said, "it isn't turbulent," but my fluvial geomorphology teacher would have knocked my block off if she knew I had said that.

Give a river a bit of time(and in geological terms, rivers are quick actors: a few centuries can bring big changes, a millennium or two can change the whole gorram river) and it will build a floodplain way up in the mountains and start meandering across it.

As to time scale, let's just say that using rivers to define borders can lead to headaches. While geologically 500 years is a terribly short time, for a lot of fluvial processes it can be quite awhile. There are borders between my home county and neighboring counties that have been complicated by river movements since reliable maps have been in place. In Oregon. There are significant pieces of Lane county that were on the west side of the Willamette River less than two centuries ago that are now high and dry and on the opposite bank! Mostly folks in Lane county aren't shooting at people in Linn county over border disputes. Now look

All deltas don't empty into the ocean. Rivers sometimes split into deltas leading into lakes, and rivers often form deltas at confluence points.

Intelligent life is a huge wildcard. Rivers are sensitive beasts: they connect everything and everything is connected to them. My current watersheds teacher just published a paper about the effects of roads on the evolution of rivers. Dams are huge. Not just in the big flooded area upstream, but by interfering with the natural flood/drought cycle of the downstream reach.

People like having homes near their boats. True, they don't like the river moving away, but they cry like babies if the river moves into their living rooms. They also tend to do things that make life lucrative for lawyers.

Don't get me started on irrigation. Look at the mouth of the Colorado... if you have a strong stomach.

A personal fascination of mine is anastomosing rivers. Look them up. They kind of look like braided streams, but with some significant differences. Braided streams tend to occur on fairly steep slopes(usually with steeper slopes close upstream), anastomosing streams occur in really flat low-energy areas. The bars and islands generated by braided streams usually have fairly low non-climax vegetation, and they are ephemeral things, typically inundated and removed by the annual flood cycle to be replaced by new and different bars. They are below bankful elevation, being basically high points in the streambed. The islands between the branches of an anastomosing reach are usually covered with mature climax vegetation, often forests. The islands in the floodplain of an anastomosing stream are fairly permanent affairs, typically only being flooded on multiyear frequencies and usually surviving several floods with only relatively minor modifications to their size and shape. The islands associated with an anastomosing reach are above bankful elevation and should be considered as part of a segmented floodplain. Also the braided stream has a shallow and wide profile with fairly weak bank material(often pretty similar to the bed material). The anastomosing stream has deep-narrow channels and resistant banks. Okay these are a bit of an obsession with me.

Oh yeah, sometimes rivers flow nowhere in particular and just dry up. Clearly more of a deserty thing and usually seen more with intermittent or occasional streams. Also... looks nasty on a map.

Meridius
11-02-2009, 11:20 AM
Guess I took in a bit too much of the home-situation. The rivers here really don't 'haul ass'. It's perfectly fine to go against the flow in a rowing boat. Try that upstream... But I guess turbulence was more of the word I should have used.

I should have added that MOST of my knowledge stems from living in a country that was CREATED by rivers. Without rivers, no Netherlands. WHERE a river flows makes major difference.

Another thing to remember is that you probably tend to look at a much larger portion of the 'downstream' portion of the river. The US, and most other countries, are HUGE compared to the Netherlands. The Rhine delta IS the Netherlands. So if I'm talking about a river, I'm basically talking about it's delta.

But I definitely wouldn't say rivers flow faster downstream than upstream. I personally never heard of the opposite, I guess it depends on the river, and that also makes me at fault for stating the opposite. In any case, good point! It proves rivers do different stuff depending on where they flow.

It also makes perfectly clear why rivers are so tough to understand. Einstein once said sedimentation of rivers is so complex that he couldn't understand his son would even try... I think rivers are pretty complex as a whole.

About intelligent life. Yes, people cry foul when the river flows in... but it happens. And people still live there. And will stay living there... the same with volcanoes and tidal marshes.

LS-Jebus
11-06-2009, 07:35 PM
Sometimes people call the river police when they don't need to.

I'm not saying the example on the first page isn't a crime, or else a very unique place that needs a bit of explaining.

If I have an area just full of lakes everywhere and no rivers, people would go crazy. But its not a violation at all. In the Canadian Shield area, that's what I see all the time. Small lakes that don't drain anywhere, and don't even have a discernible river to support it - the water either goes directly from the surface to the lake, or it is fueled by groundwater coming from higher terrain. So many rivers are below the ground.

Then there's rivers that split - depending on the situation, it may or may not make sense. We all know about deltas, but in areas where the bedrock is exposed with a thin layer of soil, a large "island" of rock can divide a river in two before it drains into a sea or large lake. Normally, the river would eventually find one path easier, and the other would slowly cease to flow. But in areas full of lakes and rivers fueled by immense storages of groundwater or mountain glaciers, the split river continues to flow for a long time.

I've made landscapes where two oceans are joined by a thin stretch of water, but I ensure that it is large enough to be obviously a channel, and not a river.

I've never had a situation with crazy rivers joining up and splitting constantly on a wide scale, but its another time when most people would needlessly call foul. "Anastomosis" seems the right word. A good example is in the northern territories of Canada - lowlands with more water than the population of China would need, flowing through an insane network of rivers and swamps.

There really needs to be a detailed height map to analyze before one can fully justify the report to the river police.

Rivers are very complex, and you could easily write a large book in several volumes to cover all the different possibilities with explanations and examples.

NeonKnight
11-06-2009, 07:50 PM
True. True. Most of the times we call the River Police is when we see not so much tons of lakes with no ingress or egress, but when we see rivers join split, etc, or lakes drain vi more than one outlet. Things that normally just don't do that.

Of, course, things being as they are, we can point to MANY things in the real world that just breaks the rules. The Dead Sea for example being a body of water that does not drain to the sea/ocean. The Nile River Delta, being an hundred+ miles of splitting river as it flows to the sea, etc.

vernontwinkie
11-06-2009, 08:44 PM
We should require these so-called artists to do an internship here. Interesting concept, too bad the natural laws of geology prohibit something like this from ever actually happening. I'm with ya GP, I'd do the same thing. I might even go so far as to make a nice big cartouche and fancy title with the original artist's name on it instead of mine...or yours in this case, you know what I mean :)


Where can I sign up to be an intern? I'd love the chance to have exercises assigned to me so I can draw maps effectively!