A comparison of measured catchment sediment yields with measured and predicted hillslope erosion rates in Europe

Abstract

Purpose: This study aims to understand better the relationship between measured soil loss rates due to sheet and rill erosion (SL), predicted SL rates and measured catchment sediment yields (SY) in Europe.2 Materials and methods: Analyses were based on a recently established database of measured annual SY for 1794 catchments, a database of 777 annual SL rates measured on runoff plots, and two recent maps of predicted sheet and rill erosion rates in Europe (i.e. one based on empirical extrapolations of measured SL data, and one based on the PESERA model). To identify regional trends, all data were grouped into eight climatic zones.Results and discussion: Measured SL rates are generally a factor of five to 10 times larger than predicted SL rates and are strongly biased towards erosion-prone situations in terms of land use. Also measured SY are generally higher than predicted SL rates, especially in the Mediterranean and Alpine regions where SY is generally 10 times higher than predicted SL rates. This illustrates the importance of other erosion processes contributing to SY. Regional differences in the importance of these processes and their implications are discussed. Conclusions:This study confirms previous findings indicating the relatively low sheet and rill erosion rates compared to SY in the Mediterranean region, and illustrates the importance of other erosion processes contributing to SY in most regions of Europe. This indicates that hillslope erosion rates cannot be used directly to estimate SY, and consequently soil conservation programmes should focus more on the dominant erosion processes in each catchment.

Suspended solids in freshwater systems: characterisation model describing potential impacts on aquatic biota

“…The PESERA model estimates mean annual gross soil erosion rates by running water, particularly due to sheet and rill erosion (Vanmaercke et al 2012), taking into account the effect of topography, climate and land use.…”

Taking advantage of a new hydraulic infrastructure to study the sediment yield in a small basin of central Spain

“…According to de Vente et al (2005), an elongated shape with one main river channel draining to the limno-reservoir and a dense vegetation cover may result in low connectivity between the stream network and the limno-reservoir and, consequently, in low sediment yield. Besides, higher sediment delivery is expected in those areas where other erosion processes than rill and interrill erosion are also present, especially gully erosion (de Vente et al, 2008;Vanmaercke et al, 2012). Gullies, landslides or riverbank erosion processes are rare in our study area.…”

“…Eroded sediments may be deposited at field boundaries, footslopes as colluvium, floodplains, valley bottoms, depressions or perched flat areas before reaching the limno-reservoir (de Vente et al, 2005;Alatorre et al, 2010;Vanmaercke et al, 2012).…”

Por qué la geomorfología es una ciencia global

“…Nevertheless, there is agreement in that small catchments (tens to hundreds of hectares) are excellent for study of the natural functioning of landscapes (e.g. García-Ruiz et al, 2010;Vanmaercke et al, 2012). This is logical: the study area is sufficiently large to enable analysis of the development of natural hydrological and erosion processes in hillslopes (including landslides and gullying), and the study of a fluvial network is crucial to assess: (i) the complex relationships between hillslopes and channels; (ii) the temporal variability of sediment transport in relation to the occurrence of rainfall events and the soil humidity characteristics; (iii) the location of runoff, and sediment sources and sediment sinks and their seasonal variability; (iv) the connectivity between hillslopes and channels, and the factors that enhance or interfere with it (Quiñonero-Rubio et al, 2013); and (v) the role of fluvial channels as sediment sources or sinks.…”