• 浅海せんかい — shallow sea
• 浅草あさくさ — Asakusa (place name)
• 浅瀬あさせ — shallow water, shoal
• 浅薄せんぱく — superficiality
• 浅知恵あさぢえ — shallow wisdom
• 浅緑あさみどり — light green

The left side 氵(sanzui) means water, and the right side 戋 (often used phonetically) contributes sound. Together, they describe something related to water that is not deep — hence “shallow.”

It also figuratively implies “not deep” in thinking or feeling, and even colors can be described as shallow or pale.

この川かわは 浅あさいので 子供こどもも 遊あそべます。
This river is shallow, so children can play in it safely.

彼かれの 考かんがえは 少すこし 浅あさいと感かんじました。
I felt his thinking was a bit superficial.

The kun-yomi “あさい” is used for physical and figurative shallowness. The on-yomi “セン” appears in compounds like 浅海せんかい and 浅薄せんぱく.