The Force of Water teaches the reader about Earth's most valuable resource--water. The book explains how water changes our planet's surface, how it changes form as it moves through the water cycle, and how and why it is important to living things. Photos and other visual aids support the text.The Force of Water teaches the reader about Earth's most valuable resource--water. The book explains how water changes our planet's surface, how it changes form as it moves through the water cycle, and how and why it is important to living things. Photos and other visual aids support the text.