ABSTRACT
Linear proportional weirs refer to as sharp crested weir in which the discharge is linearly proportional to the head over the weir crest and tend to have high accuracy when compared with the non linear ones. The main objective of the study was to investigate the flow characteristics of a Sutro weir in an open channel.In this research work the flow characteristics of a Sutro Weir were studied. The assumption of the linearity of the flow through the weir was investigated. In addition, the effects of the rectangular base height (s) and the radius (R) of the curved section on the head measured above the weir sill were monitored. The experiments were conducted in a flume having a working length of 6m with a cross section 0.3m wide and 0.3m deep. A total of 45 laboratory experiments were carried out on nine different models for five different discharges. The models made of wood were grouped in to two sets of which set one(1) consists of five models of constant radius of 9cm and varying base heights. The set 2 consists of four models of constant weir base height of 4cm and varying curve radius.The results showed that the radius (R) of the curved section has more effect on the head measured above the weir sill compared with the rectangular base height(s). The set 2 models showed a better linear relationship between the actual discharge and the head measured above the weir sill compared to the set 1 model.