The authors begin by outlining fundamental hydrologic theories and the current general knowledge then expand into a formal discussion specific to Hawai'i and the distinctive elements and their interrelations under natural and human-influenced conditions. They include chapters on rainfall and climate, evaporation, groundwater, and surface run-off. Details on the quantification of hydrologic processes are available to those with more technical knowledge, but interested general readers will find much in this volume that is timely and accessible.