The 'Runoff Curve Number' rainfall-runoff model, developed by the USDA Soil Conservation Service, was applied to the catchments draining to Omagh, to assess the potential effect of woodland creation on flood flows.
The 'Runoff Curve Number' method provides a potentially powerful tool for evaluating the impact of land use change and management on surface runoff, as well as for identifying areas where the the catchment such measures could be most effective.
Modelled runoff maps were created for the different land use scenarios (including increasing woodland cover to 13.8% of the catchment) to indentify priority areas for woodland creation in the catchment. The need for better management of existing priority habitats to reduce runoff was also identified.
The predicted potential reductions in flood peak lie within the range of values generated by other modelling studies and therefore add to the growing body of evidence that woodland creation and management can have a significant role in flood risk management.