One of the common sound (euphonic) changes in 関西弁（かんさいべん） is that of
い-Adjectives. Usually, a euphonic change is something that changes the pronunciation of a specific word, without changing the meaning/using a different word. The sound change that occurs with
い-Adjectives in the Kansai dialect is that of the く form, otherwise known as the
indeterminate form.
In the Kansai dialect, く will be replaced by う, while the previous kana will ke replaced by an お sound kana from the same row. This means that
い-Adjectives in 関西弁（かんさいべん） actually behave in exactly the same was as the
auxiliary verb う, when paired with う - Verbs. Let's take a look at a few examples.
早（はや）く Will become 早（はよ） (with or without う)
小（ちい）さく Will become 小（ちい）そ (with or without う)
高（たか）く Will become 高（たこ） (with or without う)
大（おお）きく Will become 大（おお）きゅ (with or without う)
Note with the last example that きゅう is used instead of きう in order to prevent an unnatural (two syllable) pronunciation change.
はよう起（お）き。Hurry up and wake up.
全然（ぜんぜん）会（あ）わないうちに太（ふと）うなったな。
You got fat while we haven't seen each other. (You got fatter since the last time I saw you)
最近（さいきん）は米（こめ）も高（たこ）うなったな。
Recently, even rice has been rising in price, don't you think?
In almost all cases, う may be omitted, meaning that the お sound change will appear by itself.
For
い-Adjectives that have an お sound kana before く, they will retain their previous form, rather than being changed. This can be seen with 広（ひろ）く 'wide', which already has a ろ before く, and therefore will remain the same when paired with う.
この辺（へん）も昔（むかし）と比（くら）べて道路（どうろ）がひろうなったな。
The roads around here have gotten wider, compared to how it was back in the days.
い-Adjectives actually have two forms that use く. The indeterminate form, and the conjunctive form. The reason that we are able to determine that indeterminate form is being used in this case is primarily due to う itself behaving in the same way as it would with う - verbs, making this う a pseudo auxiliary verb.