INTEGRATED ASSESSMENT AND ANALYSIS OF PHYSICAL LANDSCAPE PROCESSES THAT IMPACT THE QUALITY AND MANAGEMENT OF AGRICULTURAL WATERSHEDS
Location: Watershed Physical Processes Research Unit
Title: Soil erodibility for water erosion: A perspective and Chinese experiences
Submitted to: Geomorphology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 19, 2013
Publication Date: April 1, 2013
Citation: Wang, B., Zheng, F., Romkens, M.J., Darboux, F. 2013. Soil erodibility for water erosion: A perspective and Chinese experiences. Geomorphology. 187: 1-10.
Interpretive Summary: Soil erosion by water is driven by external forces such as rainfall, overland flow, and seepage. The severity of the erosion is controlled by the intrinsic nature of the soil material and soil profile characteristics, and modulated by landscape and surface conditions such as topography, cover and control practices. The soil factor is usually defined in terms of a soil erodibility term, which expresses the relationship between a unit exogenic force and the amount of eroded soil material. With its multitude of constituents, their interactions, differences in particle size, mineralogy, and physico-chemical characteristics, a quantitative assessment of the erodibility of a soil has been an arduous task and has posed enormous challenges. Historically, the evaluation of soil erodibility has been determined from field measurements on natural runoff plots in relation to rainfall characteristics, from field rainfall simulator studies, or from controlled laboratory studies. In these studies, it was often thought there were correlations between the observed measurements and soil properties. This article reviews and summarizes the literature findings in soil erodibility and discusses its fundamental concept. It also discusses the difference in erodibility evaluations between the western world approach and the Chinese experience.
Erodibility is a key indicator to evaluate soil’s susceptibility to erosion and crucial for predicting and evaluating soil loss and its environmental effects. This review aims to synthesize almost a century’s worth of research progress on the concept, indicators, and spatio-temporal variations of soil erodibility, and to discuss their quantifications and related research challenges, especially those related to the Chinese experience. We found that soil erodibility is often a misused term and inappropriately applied when used to describe soil loss by different erosion processes and sub-processes. Soil erodibility indicators have been related to intrinsic soil properties and exogenic erosional forces, measurements, and calculations. The present review revealed major research challenges in soil erodibility studies, including the need for: (1) improved definition of erodibility, (2) modified erodibility determinations in erosion models, especially for specific geographical locations and in the presence of different erosion sub-processes, (3) advanced methodologies for quantifying erodibilities of different soil erosion sub-processes, and (4) a better understanding of the mechanism that causes temporal variations in erodibility. The present paper was conducted to provide a more rational basis for future research on soil erodibility and to support the predictive modeling of soil erosion processes.