Coupling of Dynamic TOPMODEL and HEC-RAS to Evaluate Catchment-scale Natural Flood Management in the Upper Calder

In recent years, catchment-scale Natural Flood Management (NFM) interventions have become an increasingly common approach for mitigating flood risk in the UK. Local stakeholder groups now play a strong role in implementing NFM. The significant challenges they face in implementing NFM (tight budgets, limited time frames, an uncertain evidence base etc.) have impacted the role of modelling within catchment-scale design. After reviewing these challenges, this study presents a novel, coupled model methodology (using Dynamic TOPMODEL and HEC-RAS) for evaluating catchment-scale NFM. The benefits of this methodology are demonstrated through a case-study investigation into the impact of hypothetical tree planting on tributary desynchronisation within a Yorkshire catchment. This is shown to enhance the impact of such interventions at a catchment scale.