Discharge Characteristics of Broad-Crested Weirs (GSC-397)
U.S. Geological Survey, 1967
Frequently, so-called indirect methods of discharge measurement are the only practicable means of obtaining the magnitude of a peak flood flow past a given site. These determinations are based on the water surface profile, usually defined from high watermarks, and upon the geometry and hydraulic characteristics of the channel. If a transition structure, such as a dam or abrupt channel constriction, is used as the measuring device, the geometry of the structure also affects the water surface profile for a given discharge. For this reason, a knowledge of the head discharge relation for a given weir or spillway may prove invaluable for the determination of an important flood peak which could not be otherwise measured.
This report deals only with the broad-crested weir form. This study is based on existing data on flow over broad-crested weirs, and no new experimental work is involved. It has not been possible to answer many questions which arise. For example, sufficient data have not been published to define the effect of angularity of crest to direction of flow, of gates and piers, of end abutments, and so on. The question of submergence has also been considered in only a very general manner.
Revision ID: 6738
Revision Date: 04/06/2023