So, first post, etc. I'm pretty new to DF, but have a good handle on the mechanics and controls, I think.
I've been trying to build a glass tower on/in a lake, which is damn near impossible insofar as starting locations are concerned. So I gave that idea up and decided to make a tower, then flood the area, which leads me to my current fortress. My embark gave me a volcano in the NW end, and a river in the SW, on a totally flat map. Now, as we all know, the only thing more awesome than a gnarly flood, is a flood of liquid hot magma.
But the position of these features made me wonder about doing both, i.e. flooding the north half with magma and the south with water. And lo, it was good. But after starting on this project, I've run into a couple snags.
First, is there a way to get rid of the tiles on the very edge of the map? I'd hate to have to build a wall all the way to the top of the map to keep the river/volcano from flooding my compound.
Second, will immigrants/invasions start on those edge tiles?
Third, I plan to make the pools by channeling out the areas outside the compound 2 z-levels, then unleashing the fury. Any tips on flood control that would allow me to completely remove the edges of the river and the volcano for both levels?
Finally, the point of all this is that once I get the above sorted out, the pools are going to be separated by a glass walled channel, about 5x50, with floodgates built at intervals to release the fluids. The idea being that I have a bridge or bridges setup over the channel to drop opposing invasions in, then releasing the flood, (hopefully) encasing their force in car... I mean, obsidian, and at the least killing them horribly. Fail plan, or awesome?