Natural flood management (NFM) is the use of natural processes and environments to mitigate flood risk by reducing and delaying peak flood. This review introduces the concept and history of NFM and looks at the current state of research into the potential for using different types of woodland to fulfill the
aims of NFM. Four woodland types (catchment, cross-slope, floodplain, and
riparian) are discussed with reference to studies carried out, mainly in the
United Kingdom, to determine the relative merits of each type and their effectiveness in mitigating flood risk. We then discuss how trees interact with the
hydrological cycle, along with a discussion of modeling methods which seek to
determine the amount of water intercepted by different types of forest cover.
We find that while there is some evidence that carefully planned and managed
woodland can mitigate flood risk, the published data for this evidence base is
somewhat sparse. This may be either due to the long timescales needed for
comprehensive studies or the relative infancy of the research on NFM. More
research needs to be carried out in each of the four woodland types, especially
in the UK, as policy makers are increasingly looking towards nature based
solutions to mitigate the potential impacts of climate change. The concept of a
combined canopy/hydrological model which can be scaled from stand to
watershed level and incorporate different types of woodland is suggested as it
would be beneficial in guiding woodland creation policy in the future, both at
the local and regional scales.