wayfriend wrote:Well, you can argue that it takes days for such changes to manifest way out in the Sarangrave (as opposed to the Lifeswaller, which as has been pointed out is more directly affected by the upper Land), or that such risings are only during "abnormal" amounts of rain, whereas the normal cycle of rain every week or so would not affect the equilibrium.
But in the end, it's really a matter of, Donaldson didn't need it.
I completely accept Donaldson's freedom to ignore stuff that is extraneous to the novels. So, he doesn't have to tell us anything about anything that doesn't impinge on the story line directly - the Douglas Adams Fallacy as he describes it in the GI. We don't need to know the name of TC's first novel, for example.
However, I reject the suggestion that he isn't obliged to retain internal consistency within his plot. So, if the three days of the most apocalyptic rain would inevitably have raised water levels in an area of marshland at the foot of a large cliff (ie a place like the Sarangrave), then he can't simply choose to ignore that effect cos it doesn't fit in with his desired plot!!
Your alternative suggestion, that it would just take longer to seep out across the Lower Land to the Sarangrave is the only viable excuse, from my perspective (it was me who pointed out that Lifeswallower is more directly affected to pre-empt that point). However, I just don't find it particularly plausible. At the very least, if you try and put yourself in the position of the quest, heading out into the Sarangrave marshland that sits around 1000m below the Upper Land (or something like that), with three days of torrential rain on that Upper Land all spilling down (and let's face it, the Soulease River wouldn't have been able to cope with all that rain from such a large catchment so there would have been a lot of run off elsewhere) would you not have been thinking to yourself, "Hellfire, we are stuck in the middle of a marshland area with all that water heading off the Upper Land our way... oh bugger!". But they don't give it a thought (yes, I know they are a bit pre-occupied but...).
[There is of course the wider problem of where would all that rain come from? The sunbane only affects the Upper Land. There is nowhere near enough water on the Upper Land to warrant the deluge from the Sun of Rain. So all that water has to come from the Sunbirth Sea. So Foul has to somehow manipulate not only the weather of the Upper Land but also the weather systems a long way out to sea in a complex way to guarantee that sort of deluge. If he is doing that, then it isn't via the sunbane. By contrast, the other suns (pestilence, desert, fertile) do not depend on anything other than the corruption of earthpower on the Upper Land.
I do, however, accept that this is taking the analysis too far. We have to give the author some licence in a Fantasy novel so that not absolutely everything needs to be physically explained. I just found it interesting as a physical explanation would require, it seems to me, a much wider area of significant and regular influence on the part of Foul. (You could perhaps argue that creating extreme low pressure over the Upper Land might draw in moisture rich clouds from the Sunbirth Sea - but weather is complex - and it might just as easily draw in dry winds from the Southron Wastes etc.)
OK, at this point I'll stop! ]