Effects of different forest cover configurations on reducing the solitary wave-induced total sediment transport in coastal areas: An experimental study

Abstract

The sediment transport phenomenon is considered to be an important factor in improving coastline hydraulic performance. This research studied the effects of long waves as simulated solitary waves on the sediment transport to estimate the sediment transport rate in different coastal forest cover (CFC) densities. To examine how trees altered the wave characteristics, artificial trees were used experimentally to simulate the aligned and staggered configurations in totally 32 cover densities and 3 different wave heights. Results revealed that the CFC could averagely reduce the total sediment transport rate by up to 41.18% (in the densest case by 54% and 45% in staggered and aligned configurations, respectively, compared with the no-CFC case). The optimum density limit with maximum reduction effect was determined as 40–50% for the staggered and 70–80% for the aligned pattern. The configuration effects on the CFC efficiency were also investigated and showed the superiority of the zigzag configuration over the aligned arrangement. This study also used the laboratory data to develop two equations for calculating the sediment transport rate in the presence of coastal cover.