Document Type : Original Article
Authors
Abstract
Vegetation cover is a major environmental issue in rivers, streams, and irrigation channels. It constrains water discharge, increases sediment accumulation, and traps river loads. The present research experimentally determined the effects of vegetation coverage in an irrigation channel on its hydrological characteristics. The rate of sediment trapping, sediment load from the exit point of the flume, Froude number, and bed slope were assumed as the experimental boundaries to test different types of vegetation coverage. A flume was constructed at the Soil Conservation and Watershed Management Institute that was 7 m in length and 25 cm in width. Testing was conducted at three vegetation densities (12%, 25%, and 50%) at water discharge rates of 4, 6, and 8 l.s-1. These conditions were repeated at bed slopes of 0.002, 0.004, and 0.006. A sediment load of 4000 g/min was added for each test. The highest sediment trap efficiency was reported at 50% vegetation coverage density and a Froude number of 0.015 with water discharge of 4 (l.s-1) and a bed slope of 0.002%. The results revealed an increase in sediment discharge as the Froude number decreased. The rate of sediment trapping increased as the vegetation density increased. An increase in load and a decrease in rate trap efficiency of vegetation were recorded for the steeper flume bed.
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