Woodland planting is gaining momentum as a potential method of natural flood management (NFM), due to its ability to break up soil and increase infiltration and water storage. In this study, a 2.2 km2 area in Warwickshire, England, planted with woodland every year from 2006 to 2012, was sampled using a Mini Disk infiltrometer (MDI). Infiltration measurements were taken from 10 and 200 cm away from the trees, from November 2019 to August 2021. Two individual hydrological models were built using the US Hydraulic Engineering Center Hydrological Modelling System (HEC-HMS), to model the effects of infiltration change on peak flows from the site throughout the summer and winter. The models were calibrated and validated using empirical data; the Nash and Sutcliffe Efficiency (NSE) was used as an indicator of accuracy. Results from this study show that woodland planting reduced peak flow intensity compared to impermeable land cover by an average of 6%, 2%, and 1% for 6-h, 24-h, and 96-h winter storms, respectively, and 48%, 18%, and 3% for 6-h, 24-h, and 96-h summer storms, respectively. However, grassland simulations show the greatest reduction in peak flows, being 32%, 21%, and 10%, lower than woodland for 6-, 24-, and 96-h winter storms, respectively, and 6%, 3%, and 0.5% lower than woodland for 6-, 24-, and 96-h summer storms, respectively.

Urbanisation and the replacement of previously vegetated areas with impermeable surfaces reduces the lag times of overland flow and increases peak flows to receiving watercourses; the magnitude of this will increase as a result of climate change. Tree planting is gaining momentum as a potential method of natural flood management (NFM) due to its ability to break up soil and increase infiltration and water storage. In this study, a 2.2 km2 clay-textured area in Warwickshire, England, planted with trees every year from 2006 to 2012 was sampled to investigate how infiltration varies dependent on season and tree proximity and maturity. Infiltration data was collected from 10 and 200 cm away from selected sample trees from November 2019 to August 2021 using a Mini Disk infiltrometer (MDI). The results show that mean infiltration is higher at the 10 cm proximity compared with the 200 cm proximity by 75.87% in winter and 25.19% in summer. Further to this, mean 10 cm infiltration is 192% higher in summer compared with winter, and mean 200 cm infiltration is 310% higher in summer compared with winter. There is little evidence to suggest a relationship between infiltration and tree maturity at the study site.

Defining the infiltration characteristics of an area is beneficial for understanding soil compaction, determining soil health, and measuring the rate of surface water infiltration, which is needed for hydrological modelling. Single and double ring infiltrometers (SRI, DRI) are commonly used to determine infiltration characteristics in the field, however these are frequently impractical due to the required water volume, the weight and the intrusiveness of measurement, hindering the ease of replication. The Mini Disk Infiltrometer (MDI) offers a lightweight, portable and non-intrusive method of measuring infiltration, however no previous research has explained the influence of changing the tension settings on the collected infiltration data. To address this gap, this novel study tested the relationship between infiltration data collected using all tension settings of the Mini Disk Infiltrometer (MDI), against infiltration data collected using a 100mm Single Ring Infiltrometer (SRI). Three soil textures (sand, silt and clay) were collected from different geographical areas of the UK and deposited within the experimental facility designed for this study. Controlled infiltration measurements were taken with both the MDI and the SRI for each soil type, to further define the impact of MDI tension settings on derived infiltration, in comparison to the SRI. For the first time, the results show that the MDI tension setting of 0cm most closely replicated the findings of the SRI across all soils, which was supported through applying the Nash and Sutcliffe Efficiency (NSE) analysis. The accuracy with which the MDI replicated the infiltration of the SRI reduced as tension increased. Consequently, the previously assumed ideal tension setting of 2 cm, as defined by the MDI handbook and used in previous research, does not offer an accurate representation of derived infiltration.