Quantifying the hydrological effect of woodland creation in the Camowen and Drumragh catchments, Omagh, Northern Ireland
Lead Author: Huw Thomas
We use some essential cookies to make this website work.
We’d like to set additional cookies to understand how you use forestresearch.gov.uk, remember your settings and improve our services.
We also use cookies set by other sites to help us deliver content from their services.
Lead Author: Huw Thomas
A rainfall-runoff model based on the Soil Conservation Service (SCS) Runoff Curve Number method has been applied to the catchments draining to Omagh, Northern Ireland, to assess the potential effect of woodland creation on flood flows. Realistic woodland creation targets that would extend woodland cover to 13.8% of the catchment was predicted to reduce more frequent flood events (1 in 5 year) at Omagh by 13%, reducing to 8% for more extreme storms (1 in 100 year). The existing 6% woodland cover was predicted to be making a relatively small contribution to flood alleviation, decreasing peak flows by between 1% and 3% (for the 100 year and 5 year flood, respectively).
Modelled runoff maps were created for the different land use scenarios to allow identification of areas which generate the largest amounts of runoff. Unfortunately, the scope for woodland planting in these target areas was often constrained, requiring investigation of opportunities for improved management or suitability for other natural flood management measures. Where woodland creation is not possible, management of the existing land cover should be considered in order to help reduce runoff. This is particularly relevant on upland heather and heather-grassland for example, since woodland creation opportunities are very small on both land areas. Heather cover itself is effective at reducing runoff, having a high surface area, thus increasing evapotranspiration rates, and its root systems allows increased infiltration, compared to other land uses.
As with all modelling, the results need to be treated with caution since the SCS method remains to be validated for UK conditions. However the potential reductions in flood peak predicted 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 may have a significant role to play in flood risk management. The SCS method provides a potentially powerful tool for evaluating the impact of land use change and management on runoff, as well as for identifying areas where such measures could be most effective.
This 2018 report describes modelling and quantifying the hydrological effect of woodland planting opportunities identified in the Camowen and Drumragh catchments in Omagh, Northern Ireland using rainfall-runoff modelling techniques.
Cookies are files saved on your phone, tablet or computer when you visit a website.
We use cookies to store information about how you use the dwi.gov.uk website, such as the pages you visit.
Find out more about cookies on forestresearch.gov.uk
We use 3 types of cookie. You can choose which cookies you're happy for us to use.
These essential cookies do things like remember your progress through a form. They always need to be on.
We use Google Analytics to measure how you use the website so we can improve it based on user needs. Google Analytics sets cookies that store anonymised information about: how you got to the site the pages you visit on forestresearch.gov.uk and how long you spend on each page what you click on while you're visiting the site
Some forestresearch.gov.uk pages may contain content from other sites, like YouTube or Flickr, which may set their own cookies. These sites are sometimes called ‘third party’ services. This tells us how many people are seeing the content and whether it’s useful.