JRC MissionAs the science and knowledge serviceof the European Commission, the Joint Research Centre’s mission is to support EU policies with independentevidence throughout the whole policy cycle.

Soil Erosion Modelling

20-22 March 2017

JRC Ispra

EFFECT OF LAND COVER CHANGESON SOIL EROSION IN A TYPICAL

MEDITERRANEAN AREA(PORTOFINO NATURAL PARK, ITALY)

Ivano Rellini - University of Genova rellini.ivano@dipteris.unige.it

Scopesi C., Maerker M., Olivari S., Firpo M.

2nd day: 21 March 2017 (Block C)

PORTOFINO PROMONTORYRepresents a territory of great environmental value, which has been under the protection of Portofino Park since 1935 (Law 1251/1935).

SOIL MAPPING (1:10,000)

Cambisol: 40 %Regosol: 37 %Leptosol: 8 %Acrisol: 5%Luvisol: 3 %

Umbrisol: 0.5 %

Rellini I , Scopesi C , Firpo M , Olivari S (2017) - The soils of Portofino promontory (NW Italy): distribution, genesis and palaeoenvironmental implications. Geografia Fisica Dinamica Quaternaria: in print

SOIL LOSS MODEL

For the prediction, the Revised Universal Soil Loss Equation (RUSLE) has been adopted in a Geographical Information System framework:

R x K x LS x C x P(Renard, 1997)

In the application of RUSLE soil loss is estimated within the raster/grid GIS (Saga and Arcgis). All factors values were computed at a 5 m spatial resolution

The R-factor was calculated from monthly and annual precipitation data of 10 years for 8 rain guage stations. Spatial distribution with Universal Kriging for grid interpolation

R = rainfall-runoff erosivity factor

R = 4,17 * ∑(p2 /P) – 152Wischmeier and Smith (1978)

The K-factor was calculated using GIS dataset of the soil map.

K = [2.1 x 10-4(12-OM) x M1.14+ 3.25 (s-2) + 2.5 x (p-3)] / 100 x 0,137

K = soil erodibility factor

(Renard, 1997)

The LS-factor was calculated from a 5-m digital elevation model.

LS = slope length/steepness factor

(Moore et al., 1991)

C = Cover Management factor

The C factor was estimated on the basis of the land use map, obtained from the legend of soil map at 1:10,000

Landuse/landcover C_factor

Olive groves 0,3Garigue 0,01Maquis 0,005Chestnut wood 0,003Mixed forest 0,003Mixed oak forest 0,003Transitional woodland-shrub 0,002Ilex wood 0,001

P = support practice

For the study area, the P-factor for terracing and step systems were the only used since the other practices were absent.

Support practices P_factor

No practices 1

Step system “ciglionamento” 0,8

Abandoned tarraced land 0,6

Terraced land 0,2

Munro et al., Catena 75 (2008)

Soil erosion rate “Current scenario” The results show that the cultivated area on terraced slope are undergoing severe erosion. The

mean annual soil loss is predicted up to ∼4 (t/ha year−1)

European Soil Data Centre (Panagos et al. 2015) : ∼7 (t/ha year−1)

SCENARIO “ABANDONMENT”

The mean annual soil loss is predicted up to ∼ 1 (t/ha year−1)

C

K

P

CONCLUSION The analysis shows that the abandonment of terraced

slopes (rural activities) in future does not necessary mean higher erosion rates

This study thus provides useful preliminary information for landscape planning authorities and can be used as a decision support tool in quantifying the implications of management actions

It also contributes to validate the existing national data set on the soil mapping and the soil erosion map of Europe.