Information on sediment and nutrient export from catchments and about related erosive processes is required by catchment managers and decision-makers. Many models exist for the consideration of these processes. However, these models differ greatly in terms of their complexity, their inputs and requirements, the processes they represent and the manner in which these processes are represented, the scale of their intended use and the types of output information they provide. This paper reviews several different erosion and sediment and sediment-associated nutrient transport models with regard to these factors. The review of models is limited to those models with explicit considerations of either the sediment generation or transport process.

A review of erosion and sediment transport models

Vegetation controls soil erosion rates significantly. The decrease of water erosion rates with increasing vegetation cover is exponential. This review reveals that the decrease in water erosion rates with increasing root mass is also exponential, according to the equation SEP e b RP where SEP is a soil erosion parameter (e.g., interrill or rill erosion rates relative to erosion rates of bare topsoils without roots), RP is a root parameter (e.g., root density or root length density) and b is a constant that indicates the effectiveness of the plant roots in reducing soil erosion rates. Whatever rooting parameter is used, for splash erosion b equals zero. For interrill erosion the average b-value is 0.1195 when root density (kg m 3) is used as root parameter, and 0.0022 when root length density (km m 3) is used. For rill erosion these average b-values are 0.5930 and 0.0460, respectively. The similarity of this equation for root effects with the equation for vegetation cover effects is striking, but it is yet...

Impact of plant roots on the resistance of soils to erosion by water: a review

Predicting soil erosion and sediment yield at the basin scale: Scale issues and semi-quantitative models

of crop-productivity loss. Conservationists refer to this process as soil loss, referring to the net loss of soil over only the portion of the field that experiences net loss over the long-term. Areas of soil loss end where net deposition begins. Off-site concerns, on the other hand, are associated with the sediment that leaves the field, which we term here sediment yield. In this case, we are not necessarily concerned with the soil loss, or for that matter the amount of sediment deposited prior to leaving the field, although estimation of both of these may be used to estimate sediment yields. Ideally, a model will compute soil loss, deposition and sediment yield, and thus have the capability to address both on-site and off-site issues. Data variability and model uncertainty are two related and important issues associated with the application of erosion models. Data from soil-erosion plots contain a large amount of unexplained variability, which is an important consideration for using erosion data to evaluate soil-erosion models, as well as for interpreting erosion data. This variability is due both to natural causes and measurement errors. When comparing measured rates of erosion to predicted values, a portion of the difference between the two will be due to model error, but a portion will also be due to unexplained variance of the measured sample value from the representative, mean value for a particular treatment. Knowledge of variability in soil-erosion data, however, is somewhat limited, although recent studies have enlightened us to some degree. Only one experimental erosion study to date has been conducted with a sufficient number of replicated erosion plots to allow an in-depth analysis of variability. Wendt et al. (1986) measured soil erosion rates on 40 cultivated, fallow, experimental plots located

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=2295&context=usdaarsfacpub

Soil Erosion and Conservation

http://wpg.forestry.oregonstate.edu/sites/wpg/files/seminars/2000_Bryan_Geom.pdf

Soil erodibility and processes of water erosion on hillslope

The European Soil Erosion Model (EUROSEM) is a dynamic distributed model, able to simulate sediment transport, erosion and deposition over the land surface by rill and interill processes in single storms for both individual fields and small catchments. Model output includes total runoff, total soil loss, the storm hydrograph and storm sediment graph. Compared with other erosion models, EUROSEM has explicit simulation of interill and rill flow; plant cover effects on interception and rainfall energy; rock fragment (stoniness) effects on infiltration, flow velocity and splash erosion; and changes in the shape and size of rill channels as a result of erosion and deposition. The transport capacity of runoff is modelled using relationships based on over 500 experimental observations of shallow surface flows. EUROSEM can be applied to smooth slope planes without rills, rilled surfaces and surfaces with furrows. Examples are given of model output and of the unique capabilities of dynamic erosion modelling in general. © 1998 John Wiley & Sons, Ltd.

https://gruenland.wzw.tum.de/fileadmin/auerswald/1998_Morgan-ESPL.pdf

Rpc Morgan

Papers

The European Soil Erosion Model (EUROSEM): A dynamic approach for predicting sediment transport from fields and small catchments.