Assessing Impact of Nature Based Solutions on Peak Flow Using HEC-HMS

The objective of the study is to explore and assess the potential of Nature based Solutions (NbS) to mitigate the peak discharge rate in Banas River catchment, India. Dynamic modelling using the HEC-HMS modelling system to simulate the peak discharge rate of runoff was conducted. A systematic literature review was conducted to assess how NbS could be introduced in HEC-HMS and then be applied to a case study located in northern India to assess the potential impacts on peak flow. It was found that the overall peak discharge rate of runoff at the sink reduced from 1069.9 m³/s to 1033 m³/s on application of Nature based Solutions. Next, scenarios were built for four pilot sub-catchments where the effect of Nature based Solution was represented as surface roughness modulators. A reduction in the peak discharge by 24.9%, 34.16%, 81.02% and 27.73% was observed. The findings suggest that the application of NbS has the potential to reduce surface runoff, peak flows, and flood volumes in the Banas River catchment area and in other catchments with similar conditions.