difference in elevation (between two points in a body of water); head; drop (e.g. of a waterfall); fall distance
difference; gap
努力と結果の落差にがっかりした。
I was disappointed by the gap between my effort and the results.
この区間の急な落差が治水工事で緩和される。
The steep drop in this section will be alleviated by flood control work.
経済政策は貧富の落差を生み出し社会問題となった。
The economic policies created a wealth disparity, becoming a social problem.