Bay 12 Games Forum

The Z-1 tile 'volume' beneath the 'brook' floor would ground be as solid as if no watercourse were there.  Except that tunnelling underneath might be expected to wreak the vengeance of Flooding (after a 'wetness warning'?)  Albeit a 1/7th quantity of flooding(properly 1/8th, although the missing 'floor' level doesn't get counted in normal multi-Z flooding, of course... maybe it should!!!).  Aand depriving the downstream channel of water, to become "a dry rhyolite stream bed", like a murky pool, or just a standard rhyolite floor tile with a hidden tag, if that's the preference of the coder.  But essentially the same as if a channel had been dug in the path of a minor spillage.

Of course, implementing it as a floor tile might mean that one could have the Dwarfs change the course.  Possibly by assigning a labortype-free job of "divert brook" to suitable tiles adjacent to current brook tiles, which may or may not "de-brook" the opposing bank unless you allow leets (a.k.a. mill-race) to provide brook-quality water supply to another location (power from a brook should be tweeked to be less than power from a channel-filling river or full artificial water-channel, but this could be allied to undershot, breastshot, backshot and overshot modification to waterwheel application and power availability).

But what I would find most interesting is the possibility of natural evolution of a watercourse, independant of (despite!) Dwarf or player intervention.  A trivial cell-automata algorithm could (slowly, but inexorably) cause a brook to divert itself across whatever floodplain it exists in, which may call for a little extra engineering on behalf of the fortress design, especially if Z-1 tunnels can get threatened by such drift (perhaps this is a use for a Support, preventing such effects by providing a brook-proof artificial ceiling, at least until any connected lever was assigned to pulled .

Of course, if we have brook drift, then river drift and more active hydrodynamics applied to the Fortress Mode simulation (as opposed merely to the worldgen one) might become a logical progression.  River Drift coming with channel movement (and deposition of sedimentary replacement on the opposite bank), and potentially causing its own problems (a not just 1/7th-worth of water) unless stimied by specific construction, or increasingly slowed by appropriate soil/rock-hardness levels.  Aided/mitigated by pre-smoothing the latter?  Not at a tremendous rate, but certainly enough to make one cautious alongside with any river not frozen.  But deposition of loose sedimentary gravels/whatever could make riverside deposits available (without pump support in their removal), as much as they could sweep through an extant deposit and erode it (for non-zero chance of redeposition within the remaining downstream length of the channel).  I'm sure panning has been suggested, in the extensive history of these forums...  An analogue to fishing (zoned or 'freeform'; same danger of carp, if applicable; muddying the water though, which may interfere with the viability of vermin fish in that stretch (not sure if that's already implemented).

And don't forget seasonal variations.  If glacial meltwaters (not to mention the seasonal advance and retreat of the glaciers themselves and the associated morraines, all of which would be interesting aspects of the hydrology aspect) increase and decrease flows, then waterways could be in spate (slowly flooding, or expanding widthwise) or reduce to a trickle (eventually a "brook" floor-tile at the bottom of the original river channel, if not a completely dry river bed).

But to properly implement, the level-finding nature of water should include the ability to dam valleys without artificually enclosing the arena-edge and pumping the water artificially high above the level of the watercourse, or whatever methods people currently use.  But I quite like the idea, now that I have raised active in-game erosion as a concept, that an unwisely dammed river that finds itself overflowing a constrainign hillside (not having implemented a sufficiently strong spillway) could (after the first little bit of erosion in whatever soft rock it consists of) start to cut itself down and produce a ceritable deluge of floodwater across the landscape/through the mineworkings emplaced within the now eroded landscape...


This may or may not be in the hydrodynamics development cycle.  Again, I regret to say that I'm while feeling free to speculate methods that the game might embrace, tend not to go looking for the developmental spoilers that are already extant.

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