Evaluation of Rainfall Interception by Vegetation Using a Rainfall Simulator

Abstract

Interception by vegetation is one of the main variables controlling hydrological and geo-environmental problems such as erosion, landslides and floods. Interception, along with precipitation and evapotranspiration, is required for the modeling of infiltration, percolation and runoff. Unfortunately, the measurement of interception in the field is time consuming, burdensome and subject to testing parameters with relatively high variability. In this context, experiments using rainfall simulators (RSs) have the potential to provide an alternative approach that addresses most of the limitations of field experiments. This paper presents a new approach to evaluate interception that combines a RS and the monitoring of the wetting front using pore-water pressure instrumentation at specific locations of the specimen. Two specimens are required, one with and another without vegetation. The proposed approach was applied to Paspalum notatum (bahiagrass) and a tropical soil. The results indicated an average interception of 5.1 mm of the simulated rainfall for a slope at 15 degrees, rainfall intensity of 86 mm h−1, and duration of 60 min. Furthermore, the vegetation decreased the surface runoff that contributes to erosion. The proposed method will enable studies on the interception mechanisms and the various involved variables, with benefits to the modeling of soil-vegetation-atmosphere interaction.

Use of Logs Downed by Wildfires as Erosion Barriers to Encourage Forest Auto-Regeneration: A Case Study in Calabria, Italy

“…This finding can be explained by the interception effect of the canopy cover as well as by the wetting processes of the vegetation, which can store significant volumes of rainfall. The decrease in runoff occurs at low rainfall intensities, whereas lower vegetation coverage at higher rainfall intensities decreases the water retention effect [74]. Compared to the F plot-block, the B plot-block shows an average increase in sediment equal to an order of magnitude (about five times higher).…”

Slope Runoff Process and Regulation Threshold under the Dual Effects of Rainfall and Vegetation in Loess Hilly and Gully Region

“…Even if the grassland coverage reaches 80%, the effect of reducing slope runoff was still not significant. This is because when the rainfall intensity is too high, the grass canopy interception and soil water tended to reach saturation quickly [32], the precipitation rate is also far greater than the infiltration rate, and thus most rainfall is converted into runoff. High rainfall intensity has a primal influence on infiltration excess runoff, which was also been confirmed in similar studies in arid areas [33,34].…”

Vegetation patterns affect soil aggregate loss during water erosion

“…Vegetation restoration effectively controls hydrological processes in the slope–gully system, which involves several ways to reduce runoff and sediment (Kervroëdan et al, 2021; Li & Pan, 2018). Plant canopies reduce the surface runoff by intercepting rainfall and reduce splash erosion caused by rainfall (Mendes et al, 2021). Plant roots improve soil stability and infiltration capacity (Chen et al, 2021).…”