Soil erosion risk

Author: Fabian Becker
Date: February 2015
Document: Soil erosion risk assessment in the Upper Mefou subcatchment, Southern Cameroon Plateau [Master's Thesis]
Database: Institue Géographique National 1956; El-Swaify et al. 1982; Nill et al. 1996; Jarvis et al. 2008; own data (2012–2014)


Risk class (relative) soil loss
low 0–10 t ha-1 yr-1
high 10–100 t ha-1 yr-1
severe 100–1000 t ha-1 yr-1
: values are relative and only qualitative estimates,
as USLE-models might overestimated soil erosion;

Actual soil erosion risk

Actual soil erosion risk (RUSLE3D) is a function of land use and land cover, soil erodibliy, rainfall erosivity and terrain characteristics (slope, flow accumulation).

Potential soil erosion risk

Potential soil erosion risk (RUSLE3D) is a function soil erodibility, rainfall erosivity and terrain characteristics (slope, flow accumulation). In contrast to the acutal soil erosion risk, land use and land cover is not important for the potential risk. Using an RUSLE3D-approach, the C-factor is set to unity to model the potential risk (cf. Grimm 2001).

LULCC scenarios

Change of the soil erosion risk for five land use and land cover change (LULCC) scenarios. The scenarios are descriped in the table below, the assumptions are based on literature research on LULCC in Cameroon ( Kotto-Same et al. 1997, Sunderlin et al. 2000 [cf. Sayer et al. 2012], Imbernon and Branthomme 2001, Lambin et al. 2003, ).


Scenario ID Description
1 In Scenario 1, it is assumed that—possibly driven by a higher demand for food for a growing population in rural or periurban areas— food production in the area is expected to increase by forest clearance (1a) or a cultivation of bush or fallows (1b).
2 Scenario 2 takes account of the intensification of cropping, i. e. mixed-cropping systems will change to cassava or maize mono-cropping.
3 In addition to an intensification of food production, also the production of cash crops might increase. In Scenario 3 it is therefore assumed that forest or dense shrub is converted to plantations—either to coffee, cacao or palm oil plantations for cash food production or to plantains for food production.
4 The last scenario simulates the erosional impact of reforestation measures.

Effect classification


Class Change of relative soil loss
decrease <−15%
slight decrease −15–0%
no change 0%


no effect 0%
slight effect 0–15%
medium effect 15–50%
heavy effect 50–100%
severe effect >100%