A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand

Thesis (M.Eng.) - Asian Institute of Technology, 1978

An experimental investigation regarding sediment transport process in open channel flow was carried out, using more or less uniform coarse sand (D50 = 1.0 mm and a = 1.15). The study was separated into two parts, namely, experiments in uniform and non-uniform flow. The uniform flow experiments were conducted in a straight sediment flume, 20 m long, with different water and sediment discharges to describe the sediment transport over a dune bed configuration. The bed load transport for each run was computed by means of several formulae. Close agreement was obtained when the England-Hansen formula was used to compute the transport rate. The non-uniform flow experiments were conducted in a channel, 16 m long, with a gradual change in width. The purpose being to study sediment transportation under non-uniform flow conditions. The water and sediment discharges were varied for a channel with a contraction ratio of 0.6 and 0.95 respectively. For each test the bed load transport both in the wide and narrow sections was again computed by means of several transport formulae . Moreover the ratio of the depth in the contracted section to that in the uncontracted section was also obtained. The England-Hansen formula gave the best agreement, however, only when the channel is considered as a single channel regardless of the contraction in channel width. The computed depth ratio obtained from equations relating to the channel width ratio are approximately acceptable.