I sometimes come across expressions like this:
土地、宅地の利用区分の"一形態"で、受託の用途に供せられる土地のことを言うことが一般的である。 (definition of 住宅地)
特に、国家・団体などが立てる、"一会計年度"の収支の見積もり。(definition of 予算)
Basically you have a noun which is preceded by 一. I interpret this as a way to say "a specific ...", like "特定の". Do you even pronounce it いち? Is it natural to do it with any kind of noun, or only with sinojapanese nouns?
This is the use of 「一{いち}」 as a prefix and yes, it is read 「いち」. It can be used with all types of nouns -- Yamato, Sino-loanwords and katakana words.
When used with inanimate objects as in your examples, 「一」 means "a certain ~~", "a certain type/kind of ~~", etc.
「特定{とくてい}の」 would be too strong a word choice for the translation in most cases. It would be more natural to use 「ひとつの」、「一種{いっしゅ}の」、「ある」, etc.
When used with animate nouns, 「一」 becomes more nuanced and the "一 + noun" is usually, if not always, followed immediately by 「として」 ("as a ~~").
We say things like 「一人間{いちにんげん}として」、「一{いち}アスリートとして」、「一市民{いちしみん}として」, etc. When we use these phrases, we are being a little more humble about who/what we are than when we just say 「アスリートとして」 without the 「一」 prefix.
「一」 in this usage means practically the same thing as 「一介{いっかい}の」 ("a mere ~~").
