2. Methods
Study area
The primary area of interest for this study, Cumbria, Northwest England (Figure 1) where the Q-NFM project (http://www.lancaster.ac.uk/lec/sites/qnfm) is tasked with simulating the effects of broad-scale tree planting scenarios on flood hydrographs using a catchment hydrological model. The study catchments are within a mountainous area where there have been 4 major flood events in the last 15 years. Cumbria, as for many mountainous regions of the UK, is situated towards the west coast and hence strongly influenced by temperate maritime airflows from the Atlantic Ocean. Mountainous regions of the UK are areas of extremely complex topography which, in combination with the predominant airflow, gives rise to orographically-influenced and spatially heterogeneous meteorological patterns (Blackie and Simpson, 1993; Ferranti, Whyatt, & Timmis, 2009, Mayes, 2013). Annual rainfall is generally high; for example, across Cumbria the long-term annual average rainfall ranges from below 1000 mm yr-1 on the coast and in areas of rain shadow to greater than 3500 mm yr-1 across the highest mountains. Given there are no CWB Ewc data for this study area we consider other mountainous sites in the UK (Figure 1) and other temperate locations around the world.