Mitigating the after-effect of climate-induced disaster through energy dissipation using stepped storm waterway in hilly roads

The current research examines the after-effects of climate-induced disasters in India's Himalayan region, as well as the consequences of highway damage. To avoid the damages caused by heavy rain, cloudbursts, and landslides, a design of stepped storm waterway downstream of the underpass rainwater drainage is recommended to overcome such failure in highway design. As a result, an experimental model study was carried out on a stepped channel for a slope of 26.6 degrees with two specific widths. The slope is chosen as it is close to the ideal slope based on the literature. The present research evaluates several characteristics such as the behaviour of flow at different locations (jet length and pool depths), air-water flow properties (air concentration), and energy dissipation efficiency. Different aerated flow depths have been studied to understand their effects on aeration, as well as on energy dissipation. The outcomes showed that the wider channel has a relatively higher energy dissipation efficiency. This outcome could help in modifying the existing storm waterway by widening the channel to facilitate huge runoff during bad climatic conditions. Finally, a multi-nonlinear regression expression is proposed to predict energy dissipation by taking into consideration channel geometry and inflow condition.