Healthy soils are one of the key priorities of the EU Soil Strategy, and soil erosion can present a threat to soils around the world. Rainfall erosivity is the main driver of soil erosion by water. Rainfall interception by vegetation can reduce the erosive power of raindrops, and consequently measures involving vegetation can mitigate soil erosion losses. In this study, the effect of rainfall interception on the erosive power of raindrops under the birch tree in an urban park in the city of Ljubljana is investigated. More than one year of measurements of drop-size distribution using two optical disdrometers placed above and below the birch tree canopy were used to investigate the impact of rainfall interception on the erosive power of raindrops. The number of drops, fall velocity, and drop diameter were, on average smaller below the canopy in comparison to the measurements above the canopy for 20%, 7% and 27%, respectively. This also resulted in a reduction in the rainfall kinetic energy (3% and 30% in the leafless and leafed periods, respectively) and rainfall erosivity (21% and 50% for the leafless and leafed periods, respectively). The results demonstrate that rainfall interception has a significant seasonal influence on the erosive power of raindrops. Therefore, vegetation characteristics should be considered as time-varying rather than constant parameters in soil erosion modelling studies.

健康的土壤是欧盟土壤战略的重点之一，土壤侵蚀可能对世界各地的土壤构成威胁。降雨侵蚀力是水对土壤侵蚀的主要驱动力。植被拦截降雨可以降低雨滴的侵蚀力，因此涉及植被的措施可以减轻土壤侵蚀损失。本研究在卢布尔雅那市的一个城市公园中，研究了降雨拦截对白桦树下雨滴侵蚀力的影响。使用放置在白桦树冠层上方和下方的两个光学量度计对雨滴尺寸分布进行了一年多的测量，以研究降雨拦截对雨滴侵蚀力的影响。滴数、下落速度和滴直径分别为，与树冠之上的测量值相比，树冠之下平均小 20%、7% 和 27%，分别。这也导致降雨动能（在无叶期和有叶期分别为 3% 和 30%）和降雨侵蚀力（在无叶期和有叶期分别为 21% 和 50%）降低。结果表明，降雨截留对雨滴的侵蚀能力具有显着的季节性影响。因此，在土壤侵蚀建模研究中，植被特征应被视为随时间变化的参数，而不是恒定参数。分别）和降雨侵蚀力（无叶期和有叶期分别为 21% 和 50%）。结果表明，降雨截留对雨滴的侵蚀能力具有显着的季节性影响。因此，在土壤侵蚀建模研究中，植被特征应被视为随时间变化的参数，而不是恒定参数。分别）和降雨侵蚀力（无叶期和有叶期分别为 21% 和 50%）。结果表明，降雨截留对雨滴的侵蚀能力具有显着的季节性影响。因此，在土壤侵蚀建模研究中，植被特征应被视为随时间变化的参数，而不是恒定参数。