That's a good point. One of the many things I am not is an architect (or, make it two, an engineer). However I would guess that if the water is shallow enough that you can easily plant as many spans' pillars (or whatever they are called) as you want, than a bridge could technically be any length (elevated portions of roman aqueducts were in fact bridge over land, and they could be very long). However, would that (plausibly) be the case for such a big river? Not sure.
Edit: This is the bridge. The river looks quite shallow, and besides the given length seems to be for the entire bridge; but it touches the island in-between, so the actual width of the longer uninterrupted tract of river is less.
A river is (typically) going to be much shallower near any islands, though... just as it's shallower near the shoreline on either side, it's shallower near the shoreline of the island.
The *height* of the river water doesn't change, but the height of the *land* beneath it does.
The land doesn't just drop off and disappear, giving you a floating pile of earth. TECTONICS don't form river islands. It's not the ocean. EROSION and LAND HEIGHT forms river islands.
So *every* island, especially the ones that are closer together, are going to help with crossing that river ... and I'm sure that includes bridging it. :)
@ Jalyha - not always true. In the section of the Illinois River, where I live (in north central Illinois) are featured with large sandstone bluffs formed from ancient sea sand turned to stone, then about 10,000 years ago a huge ice dammed lake formed as the glaciers melted back broke open and millions of gallons of water poured out forming the channels and cut sandstone bluffs of the Illinois River valley over the course of 3 days - not millions of years like most erosion. Many of the islands here are kind of mushroom in shape, where the portions under the rivers surface actually cut under the islands above the water, as in the illustration below. Granted it was fairly unusual geologic formation due to catastrophic erosion event, but this happened at many places around the world at the end of the ice age.
YES! GOOD! You're right and I like that. Don't ever let me generalize :)
BUT you're still illustrating (with a better illustration) my key point. The slope is gentler near the edge of the land. :)
That's sediment build up, right there. Good 'ole homegrown dirt.
If you look at the same size/scale cutaway of a part of the river with no islands, you'll see a deeper river... cause the river bottom keeps sloping underneath.
My AMAZING illustration:
The section you showed would still be easier to ford (or swim, or bridge) than a section with no island, yes? :)
Oh, I wasn't arguing one couldn't cross a river with such formations, only that not all islands have sloping edges.
Yeah, I know that's what I meant about me generalizing - I was being lazy :)
OH I guess I should add, since laziness isn't allowed, that some river islands are *entirely* deposits of rock/sediment.
They still have the same effect, but instead of being part of the land, they're formed by, basically, large amounts of rocks piling up over time :)
Usually the weight of the water compresses the rocks and makes it really solid, but sometimes there's holes and gaps and (I forget which river it was) but one time this whole ISLAND collapsed, cause the rocks over a really big gap just fell in o.o.
I was like whoa. :D
I hope to have finally reached a definitive shape for the river.
Meanwhile, the second step in the history of the great city.
I see you widened it? :)
I think everything looks pretty good (was afraid you'd been scared off!)"
I waas going to say something about there being so many villages in such a small area, usually they'd be much more scattered... but then, your area is bigger than it looks, AND if they were competing for this area, I can see it happening easily :)
(And I hope Elinore is the one that builds the ginormous bridge! :D )
I like the river much more now. Also, at the risk of starting another furious discussion, I disagree with Jalyha about the villages. Dense settlement was the norm in many parts of Europe (as GoogleEarth reveals) and more often a rarity in Australia and USA (where I assume you are from, Jalyha?).
Point being, I don't think there's a problem with your (i.e. feanaaro's) update.
EDIT: I do have one comment to provide: medieval farming rarely involved large rectangular or square farming plots. More commonly, fields would be divided into long strips, each worked by a different family. These plots of land were the main way people got food for the table, so only in large towns and cities, where sufficient wealth exists to import food, would you not find this arrangement of fields (which are called burgages, by the way). Thus even the inhabitants of your villages should have burgage plots (which could be outside your back door, or could be a five minute walk away). Just thought I'd mention it.
Europe is little :P
I meant overall... not in any specific area and dense settlements happened, even in Europe, around resources, or large cities... points of interest, let's say. Tiny villages (like those depicted) were mostly scattered, without those points of interest.
Since the river (the only bridgeable area of the river) is one of these points, I was actually saying the settlement *does* make sense :)
And yes, I'm from the USA, but I try not to let that bother me :P
Also: THANK you, about the farms. No one ever believes me about the big ole' perfectly even rectangles >.<