Modelling the Hydrological Effects of Woodland Planting on Infiltration and Peak Discharge Using HEC-HMS

Abstract

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.

The Impact of Tree Planting on Infiltration Dependent on Tree Proximity and Maturity at a Clay Site in Warwickshire, England

“…Metrologically, December, January, and February are defined as winter, and June, July, and August are defined as summer by the UK met office [61,62]. However, as this collected data is the precursor to the development of a hydrological model (see Revell et al, (2021)); winter is defined as October to March, and summer is defined as April to September. These timeframes are based on UK average annual temperature and rainfall data, provided by the Met Office [63].…”

“…However, regardless of funding allocations and the increased investment in tree planting, few studies have assessed the impacts of tree planting on infiltration, and contextualised this with regard to flood risk mitigation and the use of tree planting as a method of NFM [3,[27][28][29][30][31]. Therefore, the aim of this study is to investigate the impacts of tree planting on infiltration dependent on tree maturity and tree proximity.…”

“…This work is the precursor to another study previously conducted by the same authors [31], which focused on the hydrological modelling of the collected infiltration data (used for this work and listed in Section 3) and the analysis and variations in peak flow and total discharge from the study site as a result of changing land cover. Therefore, the same sample site and infiltration data collection methods (presented in Section 2) are used in both studies.…”

Modelling the effectiveness of land‐based natural flood management in a large, permeable catchment

“…Whereas modelling studies tend to support the hypothesis that increasing tree cover reduces flood peaks, results from observation‐based studies are more mixed (Stratford et al, 2017). It is likely that the effect of woodland planting is dependent on a range of local factors including soils and geology (Peskett et al, 2021), catchment size (Ewen et al, 2015), the land use being replaced (Revell et al, 2021), and forest age, type and management (Archer et al, 2013, 2015; Chandler et al, 2018; Lunka & Patil, 2016; Xiao et al, 2022). The effect of regenerative agriculture (RA) on flooding is even less clear than that of afforestation.…”

Applied methodology based on HEC-HMS for reservoir filling estimation due to soil erosion

“…There is an urgent need to adopt methodologies that allow defining sedimentation yield (Đukić and Erić, 2021). For this purpose, current tools available for hydrological modeling, such as HEC-HMS are used (Chiang et al, 2022;Revell et al, 2021;Şengül and İspirli, 2022). The current availability of environmental information of different types (thematic cartography, diverse climatic data and others) requires a method to obtain the dates and degrees.…”