The yí reading is the everyday one, bound in 逶迤 — a road, river, or mountain range stretching on in long, winding curves. It is a literary, descriptive word.
The walking radical, written last and wrapping the lower left. It marks the character as something about a path or extending along — here a road winding on and on. It groups 迤 with 迂, 道, and 远.
The right-side element, supplying the sound (yě shifting to yí). It works purely as a pronunciation marker; the same element gives 他 and 池 their reading.