dike, dam, slope, bank
坡 centers on a raised or sloped earthwork: a dike, dam, bank, or slope. The meanings all describe a man-made or natural incline of earth.
坡 combines 土 (earth) with 皮, which likely contributes the sound and may suggest a covering or surface, giving the idea of an earthen slope or bank.
The left side is earth 土, and the right side 皮 looks like a covering. Picture a layer of earth piled up to form a sloping dike or bank.
For ハ, imagine a laughing 'ha!' as you slide down the slope: ha -> ハ, and the earth bank makes a fun slope.
Dongpo pork; Chinese pan-fried red-cooked pork squares