The Fluidity of Rivers

[johndmuller]

Recently I built a borehole inland on a river, mostly because the river flowed in the low spots, but the extra energy was also nice. Several turns later, I noticed that rest of the river downstream from the borehole had disappeared . I found this to be rather unpleasant, since the downstream part of the river was highly developed, with 2 bases and half a dozen other tiles being worked, each of which would lose 1 energy, not to mention the 'multiplier' effect (I was Morgan, so I was into economics). At least I got the mins, but I'm sure I lost a bundle on the energy; building a mine would have been much better, both in time and in energy. And as if that wasn't bad enough, I was partly dependent on the river for movement - it could have been worse, but I had built a few shortcuts across bends in the river and to other places.

I am assuming that it was the construction of the borehole that caused this effect since the river stopped right at the borehole, and it happened about the same time the borehole was finished (I don't know when for sure because I didn't notice the river was gone until a unit stopped there unexpectedly). I suppose that the designers reasoned that the river would pour down into the center of Planet or some such (do they think that there isn't enough room in a tile for both a borehole and a river? are the rivers and boreholes each hundreds of miles wide? ).

In another MP game, I was the Hive, and had my HQ on a river to help with the Hive's chronic energy shortage. Again, I was using the river as a part of my transportation network as well as availing myself of the much needed extra energy production. Out of the blue, the river changed course, leaving my HQ high and dry and disconnected from the "road", as was another base which had previously been downstream. In this case, there was no apparent connection with my own terraforming, as it was too early in the game for any fancy work. Later, as I saw more of the map (still POed about this enough to remember), I could see no traces of an earthquake, rogue terraforming or any other cause I could imagine.

Does anyone know what gives with these moving rivers? On Earth, they tend to stick around for thousands, not just tens of years. If I removed the borehole, would the river come back? If so, would it be in the same place? What if I started a new river near (probably can't do it right next to) the BH; would it flow down the old valley or might it flow "backwards" also into the BH (the whole valley is in the 10-1000 range)? How much more terraforming effort can I waste in this pursuit?

[TresXF]

well, i think these 'river movements' are the symptoms of land consolidation by the settlers. myself is living at a medium large river, and when i look at my grandparents' photo collections it comes clear: many arms of the river are dry or diversed today. to handle the increased ship traffic the river was 'terraformed' over decades... (bad for the environment of course - extinction of animals and plants, pollution, floods...).

that's my theory about your observation.

[Lefty Scaevola]

Diffing a borehole on a river will suck it up. Delete the borehole and it comes back. One of the borehole in the borehole cluster on the map of planet (I forget if regular or huge or both) has a start of a river in it. Destroy the borehole and the river flows. Strangely, if you bore to an aquifer and the river flows through an existing borehole, it pass thru without going down the borehole.

[vitamin j]

I've suffered the borehole/river effect too... Once. I still don't know what to expect with some terraforming... In my last SP game, I made a land energy park. Following some Apolytoners' suggestion, I started four different drill to aquifer operations at once, in a line of four tiles, all at 3500m, envisioning massive rivers flowing everywhere... When the formers were finished, I had a river connecting those four squares and - nothing else! I thought a river would run down at least ONE of the adjacent lower squares, but no such luck. So much for that strat! I don't like to alter the terrain very much, since usually by the time it's practical, all the big decisions are made and I don't want to risk f***ing something up...

[Hydro]

Boreholes have the effect of raising the temperature in that specific area, effectively creating local global warming. That is what is probably drying up your river. Rivers do change location over time, by the way. Many US states along the Mississippi have long-running disputes over their boundaries, which were established as the middle of the river, since the river has moved so much in the last hundred-plus years. There are also instances of catastrophic changes related to changes in landforms (typically mountain building over eons), or river piracy where one river effectively takes over the water flow of another when their river valleys merge. Rivers can disappear, too, due to climatic changes. For instance, the Mississippi is much smaller than what its valley indicates it should be, since the amount of water flowing down it is much smaller than when the glaciers were melting!!

Hydro