Endang Purwati
Broad crested weir discharge gauges are simple and easy in construction and building requirements. Elevation threshold (p) erect or so-called threshold slope of 1: 0, with p ≥ 0:20 m. Such requirements in order to discharge formula broad crested weir can be met. Discharge Q = 1.71 Lweir y3/2.y is the height of water in front of the weir. L is the width of the weir to the transverse direction of the channel, with the width of the L weir ≤ L channel. 3/2 is the exponent for the height y in the discharge formula. 1.71 is the weir constant. Heighty measurement at a particular location which is the water inflow comes into the brink, or right on the subcritical flow before the flow decreased due to the flow meets the threshold. On the y measurement location a height bar gauge was mounted as a completion of a measure building.The discharge measurement using a broad crested weir will be impaired when there is a deposit of sediment on the upstream. Deposit sediments would resultsan incorrect bar gauge measurement, the measurement result change because of the sediment height. Deposit sedimentsshould be avoided, because either it would be disrupt the measurement result or it would also be brake the threshold body.Action taken to secure the measurements and the threshold damage is by revising the threshold height by giving a slope of 1: n on the threshold site. The upstream slope is set to 1: 4, while the downstream slope 1: n is sought by a research on the n value which can result a small as possible sediment on the upstream. The research on the n value is done by using a Surface-Water Modeling System software and experimental test models (physical models of buildings) to find a new weir discharge formula. © Research India Publications.
Brawijaya University, Water Resources Engineering Department, Malang, 65145, Indonesia
