How do I parse this sentence? （年中行事について）


The sentence in question:

> 年中行事の生ずるのは季節のうつりゆきが農業などの上にすぐ影響するし、それが国民生活の上に現れて種々の行事が生ずるのである。

My attempt at a semi-literal translation:

> As for the arising of annual observances, changes in the seasons not only
> directly influence agricultural matters; they also spring up in various
> observances which appear in peoples' lives.

I made a lot of guesses in that translation, and I'd appreciate it if you
could help me turn those guesses into right or wrong answers.

  1. I think that the antecedent of それが in the second half of the sentence is 季節の移りゆき, which means that it's the subject of the entire sentence (with the predicate being である). Is that correct?

  2. The structure of 国民生活の上に現れて種々の行事 really baffles me. My best guess is that the whole thing is a relative clause describing 行事. Or, more accurately, one relative clause 「国民生活の上に現れて」and one simple modifier 「種々」. Is that in the ballpark, or is the answer something else entirely? 

  3. I'm confused about the two uses of 上に in the sentence. At first glance I thought they meant "On top of that...." or "Not only..." but that interpretation doesn't seem to work for the second 上に, which I kind of thought of as functioning as "...appearing on top of people's lives." And if the second 上に can be interpreted that way, then I figure, why can't the first? (I.e., "Changes in the seasons directly influence-on-top-of agricultural matters.") But as far as I know I totally invented this interpretation of 上に, cause it didn't really show up in the dictionaries I looked in. Please let me know.

I think I got the gist of the sentence down, but I'm asking for a really
detailed breakdown of all the grammatical things happening inside it, to make
sure I really understand it (and also so that I don't come away from this with
completely wrong assumptions).

I'd really appreciate it if you could break it down entirely and not just give
me your own translation!




1

I think No1. is an interaction between human activities and a change of
seasons. So in this case, it would be more natural to take “影響” than
“季節の移り変わり”.

2 and 3

I think 上に現れて could be intepreted like being covered with a blanket. I mean
it’s a bit metaphorical and you could interpret it as “affect”.

> 国民生活の上に現れて種々の行事が生ずる

それが国民の生活の上に現れて、種々の行事が生ずる。implies 国民の生活の is affected by them and it arises ...

