Storage and the Unit Hydrograph

During the period since 1930, study of the flow records of many and various types of streams by the engineers of the United States has resulted in an improved concept and understanding of the physical factors which influence runoff and the flood-producing capacity of streams. Two fundamental tools have emerged from these studies, the unit hydrograph and methods of flood routing (means of modifying a hydrograph by the effects of valley storage), both of which have been the subject of many papers.