Where does “阿拉爾” come from?

阿拉爾 (Chinese) comes from Uyghur ئارال, from Proto-Mongolic aral — river, island; shaft of a cart.

Ancestry of “阿拉爾”, step by step

Step	Language	Word	Meaning
1	Uyghur	ئارال	island
2	Proto-Mongolic	aral	river, island; shaft of a cart