Carving rivers - help required

[EthanZak]

I've just started working on a map based on my RL location, and am having trouble replicating a river correctly.

The river winds it's way across a broadly flat plain; I've tried to ensure the gradient drops regularly, but I can't seem to avoid the water separating into dinstinct blobs as it proceeds downriver. I've tried adjusting flow-rates/depth/width but I can't seem to find a good balance.

I've had to resort to installing extra water sources halfway down the length of the river to maintain the water level, but the split in water still occurs in certain places. Any ideas on what I'm doing wrong?

 

[Promethian]

Been a while since I looked but isn't there a slider when a water source is selected to adjust for its power?

 

[Torakka]

I don't know really well how the game handles water physics, but from my personal experience that kind of behaviour starts to emerge when the water can continuously accelerate down a slope. Having small enough gradients, "buffer areas" such as small lakes or otherwise limiting the potential acceleration of the water seems to mitigate this issue.

 

[EthanZak]

Prom: There is, and I've been varying the flow rates but I'm still getting these 'pulses' - I'm playing around with it now and I think it's something to do with the varying capacity of the river as it goes downstream, but I'm struggling to get any kind of uniformity to it's size with the standard brushes available.

Torakka: thanks for that, I've just noticed one of the areas that seems to generate these blobs has a faster gradient than the rest - I'll see if I can fiddle the levels with a nearby lake and see if it makes any difference.

 

[Turjan]

The easiest way to force direction is to close up the river at the map edge. That prevents ships from going through though.

Multiple spawners are a two-edged sword. They function as drains when they are lower than the original one and may produce weird effects with the overall flow if the slope is not large enough.

Edit: There's nothing on your pic to gauge the size of that river, but is it correct that it is rather narrow? The game water is rather viscous compared to real water, and I know it doesn't flow correctly in narrow places, except when forced by a large grade.

You could try and make it much deeper, which would allow you to use a larger spawner.

 

[EthanZak]

Hm, hadn't thought of that effect with multiple water sources - I'll see if that's having an effect.

With regards size of river, yes it's quite narrow - I'm trying to model the river Derwent in N. Yorkshire as it meanders across a flood plain, it's usually a benign little thing that suddenly submerges all the nearby farmland when it floods. It does seem like the water is getting particularly 'blobby' at narrow points, I may just have to fudge my map to make for a wider river.

 

[Fox_NS_CAN]

I can't see your image, so not sure exactly what you mean, but wondering if it is anything like this:

I was getting this from time to time on a CO map. Not sure the map name, but the city was "Pepper Lake". It's the one from the "Tornado Country" scenario.

 

[EthanZak]

Fox: Yeah, it's a more extreme version of that - the water bulks up and then all comes tumbling down in a blob. I've grabbed some video so you know what I'm prattling on about (apologies for shonky camera-work):

 

[Fox_NS_CAN]

Yeah, similar, but definitely more extreme in your case.

 

[Turjan]

Okay, that video is helpful. Put the river source further out right next to the map edge so it won't be visible from the city. Then widen the origin where you put the water source to something like a bulb (see center or right of this image):

Spoiler

The purpose of the bulb is that you can place a large water spawner and pull it higher up into the air. It doesn't matter if it spills a bit in the beginning, you have to see at what water level it ends up after a while. You can pull the ground at three sides around that spawner bulb up a bit if you need that. You can always hide it with some trees.

You want to have the spawner high enough so that it never gets flooded (this is the one from the center source in the last image):

Spoiler

 

[EthanZak]

It seems most of the problems were being generated by the drops in gradient - I've eliminated virtually all the gradual gradient drops, and opted instead for a couple of steep drops, each fed by a narrowed fissure to regulate flow. Combined with a secondary spring and a feeder lake, my river is now flowing smoothly (mostly) :

Thanks to all of you for the advice, I'd have given up in frustration without it - this is my first go at map editing so I'll probably be looking for more help very soon!

 

[Kedryn]

Some days later but it looks like your river gradually gets wider. There are actually a few ways to help with the blobbing as a river widens now. Making the place where it gets wider more flat and shallow can help, rocks can help and a smaller stream entering where it gets wider can help as well.

 

[EthanZak]

Some days later but it looks like your river gradually gets wider. There are actually a few ways to help with the blobbing as a river widens now. Making the place where it gets wider more flat and shallow can help, rocks can help and a smaller stream entering where it gets wider can help as well.

Cheers, I'm gradually getting the width more uniform now, and have balanced out the flow on the other river (not pictured above, more of a canal) with multiple small springs to keep it even, and it seems to be working. I hadn't thought of rocks, though - I shall have to have a play around with that, ta