Optimizing Crown and Trunk Heights in Rigid Vegetation Model for Effective mitigation of Flood Damages

The effectiveness of flow energy reduction and flow characteristics through emergent vegetation have been studied assuming only a trunk portion of the vegetated corridor to the flow direction. However, in real scenarios, riparian areas, whether natural or restored, typically feature trees positioned in both the upper canopy (crown) and lower trunk regions, relative to the direction of flood flow. Therefore, the present study involves an experimental investigation into the impact of a tree’s vegetative structure, encompassing both its canopy and trunk, on the flow direction considering the open channel flow. A sequence of experimental trials was conducted, involving the variation of Froude numbers ([Formula: see text], variations in crown height ratio above the ground surface ([Formula: see text], and a case with no crown (NC), which was included for the purpose of comparison. The results showed that the backwater rise was increased with the increase in Froude number and decrease in crown height ratio. A steep slope was generated within the vegetation region when the crown height was minimum ([Formula: see text] as compared to NC case due to the high blockage ratio generated by the crown portion the trees. Maximum energy loss ([Formula: see text] was generated when the crown part of the trees ([Formula: see text] were close to the ground surface as compared to NC ([Formula: see text]. Similarly, energy loss was maximum with the increase in Froude number. Therefore, the optimum outcome produced in terms of energy loss was when the tree consisted of both trunk and crown portions considerably close to the ground surface in order to reduce the impacts of floods. The findings of this study enhance flood mitigation by strategically optimizing crown and trunk heights in rigid vegetation to improve flow resistance and energy dissipation.