Uncertainty in modelling the detachment of soil by rainfall

• Published in: Earth surface processes and landforms Vol. 25; no. 7; pp. 723 - 728
• Main Authors: Parsons, Anthony J., Gadian, Alan M.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.07.2000
• Subjects: modelling soil erosion; raindrop-size distribution; rainfall kinetic energy; soil detachment
• ISSN: 0197-9337; 1096-9837
• DOI: 10.1002/1096-9837(200007)25:7<723::AID-ESP127>3.0.CO;2-X

In process‐based models of soil erosion, soil detachment by rainfall is commonly modelled as a simple function of rainfall intensity, based on the assumption of a relationship between drop‐size distribution and intensity. Here we show that rainfall kinetic energy (and hence soil detachment) does not bear a simple relationship to intensity. For low‐intensity rainfall, observed variations in drop‐size distributions indicate that soil detachment, at a given rainfall intensity, may vary by about a factor of two. Comparable estimates of variation in soil detachment at high rainfall intensity are not possible because of a dearth of observational data on variation in drop‐size distributions in high‐intensity rainfall. Variation in drop‐size distributions in natural rainfall may, therefore, account for a significant component of differences between observed soil detachment and that predicted by models of soil erosion. Copyright © 2000 John Wiley & Sons, Ltd.