Type of indicator

Environment

Indicator C42

Soil erosion by water

Definition 

This indicator consists of 2 sub-indicators:

1. Estimated rate of soil loss by water erosion; 

2. Estimated agricultural area affected by a certain rate of soil erosion by water. (The estimated area is also expressed as share of the total agricultural area).

The indicators assess the soil loss by water erosion processes (rain splash, sheetwash and rills) and give indications of the areas affected by a certain rate of soil erosion (moderate to severe, i.e. >11 t/ha/year in the OECD definition).

Estimates of soil loss by water erosion in Europe are expressed in t ha^-1 year^-1 for cells of 100m x 100m for the EU.

The two soil erosion indicators have been produced by the Joint Research Center of the European Commission (JRC-Ispra), on the basis of an empirical computer model. Assessments of soil erosion are based on the output of an enhanced version of the Revised Universal Soil Loss Equation model (named RUSLE2015) (JRC-Ispra) which was developed to evaluate soil erosion by water at a regional scale. The model provides an estimate of possible erosion rates and estimates sediment delivery on the basis of accepted scientific knowledge, peer review published manuscripts, technical judgment and input datasets. In this assessment, the basic RUSLE model has been adapted through the improved quality of the input layers.

RUSLE2015 improves the quality of estimation by introducing updated (2010), high-resolution (100m) and peer-reviewed input layers of rainfall erosivity, soil erodibility, slope steepness and slope length, Land Cover and management and the support practices applied to control erosion. The Rainfall Erosivity was calculated based on high-resolution temporal rainfall data (5, 10, 15, 30 and 60 minutes) collected from 1,541 well-distributed precipitation stations across Europe.  The Soil erodibility is estimated for the 20,000 field sampling points including in the Land Use/Cover Area frame (LUCAS) survey. The Land Cover and management accounts for the influence of land use (mainly vegetation type/cover and crop type) and management practices (mainly in arable lands) in reducing the rate of soil erosion by water. The Slope Steepness and Slope Length have been calculated using the latest Digital Elevation Model (DEM) at 25m. The support practices were estimated for the first time at European level taking into consideration the Good Agricultural and Environmental Conditions (GAEC).

Only soil erosion resulting from rains plash, overland flow (also known as sheetwash) and rill formation are considered. These are some of the most effective processes to detach and remove soil by water. In most situations, erosion by concentrated flow is the main agent of erosion by water.

The results of the soil erosion indicators have been aggregated at NUTS 3 and NUTS 2 level.

The rates of soil loss by water erosion (t ha^-1 year^-1) at Member State level represent national average values and therefore may mask higher erosion rates in many areas even for those countries that have a low mean.

The total area of agricultural land has been defined on the basis of Corine Land Cover (CLC) 2012 classes and includes the area of arable and permanent crops, pastures and permanent grasslands.

Estimated data on soil erosion are published following a qualitative assessment and compared with EIONET country estimates showing that the model output matches general erosion patterns across Europe. However also quantitative validation is foreseen to take place against long-term erosion plots. 

The following indicators also exist:  

- Agro-environmental indicator (AEI) 21 Soil Erosion, http://ec.europa.eu/eurostat/statistics-explained/index.php/Agri-environmental_indicator_-_soil_erosion

1 and 2 above are, respectively, the supporting and main indicator of the AEI 21.

- Soil erosion datasets of 9 European Union Countries have been collected through the EIONET-SOIL network during 2010. 

Unit of measurement

1: t/ha /year 

2: ha and share of total agricultural area

Data source

References/location of the data

- National studies, surveys, reports

Data collection level

National (NUTS 0) and regional (NUTS 2-3) level (based on 1 km cell – model output).

Frequency

A new soil erosion dataset is being published by the JRC in 2015.

To evaluate changes in soil erosion over time it should be noted that an analysis over a time period of at least 15-20 years would be necessary (e.g. comparing the current situation to the 1990s). The time interval of 6 years (e.g. 2000-2006 for which data are available) is limited and differences are primarily due to changes in land cover (as indicated by Corine Land Cover data). Therefore, any conclusion must be drawn with caution. 

Delay

Not defined.

Comments/caveats

The soil erosion indicator has been improved (e.g. taking into consideration the impact of Good Agricultural Environmental Conditions - GAEC) to better measure the link between agriculture and soil erosion. The new updated soil loss map takes into account land management practices such as reduced tillage, the planting of cover crops, keeping plant residues at the soil surface, the maintenance of stone walls,     and the increased use of  grass margins and contour farming.

As it is now, the indicator can only give an indication of the erosion of soil in particular contexts. The estimated erosion rates are linked to agricultural practices and therefore the indicator reflects and captures the effects of policy measures to prevent erosion by agriculture. Moreover, the indicator gives only estimations and it is not directly measurable since it is based on modelling and estimations from different sources and parameters. It will not be updated regularly (depending on availability of resources). The individual layers which have been used to produce the indicator have been peer reviewed and accepted for publication by the scientific community. The individual input layers are also available in the European Soil Data Centre (ESDAC).

In 2010, the European Soil Data Centre (ESDAC) invited the Primary Contact Points (PCPs) of EIONET to contribute to a data collection campaign of EIONET-SOIL in order to develop the European datasets for soil erosion and Soil Organic Carbon (SOC). There was no legal obligation for the EIONET member countries to participate and PCPs and NRCs for soil contributed on a voluntary basis.

18 EIONET countries did not reply or declared that they do not own the requested soil data and/or refused to deliver data due to legal issues or other restrictions

Due to this fact some discrepancies could appear between the data collected at Member State level and those presented by the JRC. The Member States that detect such a discrepancy are strongly recommended to submit their data through EIONET in order to allow the update and improvement of the model. The list of EIONET contact points for SOIL is available at the following URL: http://eusoils.jrc.ec.europa.eu/library/data/eionet/PrimaryPoints.cfm

The indicator only covers soil erosion by water. JRC has developed datasets for the qualitative assessment of wind erosion. http://eusoils.jrc.ec.europa.eu/library/themes/erosion/winderosion/

References

Panagos, P., Meusburger, K., Ballabio, C., Borrelli, P., Alewell, C. (2014) Soil erodibility in Europe: A high-resolution dataset based on LUCAS. Science of Total Environment, 479–480 (2014) pp. 189–200 

Panagos, P., Ballabio, C., Borrelli, P., Meusburger, K., Klik, A., Rousseva, S., Tadic, M.P., Michaelides, S., Hrabalíková, M., Olsen, P., Aalto, J., Lakatos, M., Rymszewicz, A., Dumitrescu, A., Beguería, S., Alewell, C. Rainfall erosivity in Europe. Sci Total Environ. 511 (2015), pp. 801-814.

Panagos, P., Borrelli, P., Meusburger, K., van der Zanden, E.H., Poesen, J., Alewell, C. 2015. Modelling the effect of support practices (P-factor) on the reduction of soil erosion by water at European Scale. Environmental Science & Policy 51: 23-34

Panagos, P., Borrelli, P., Meusburger, K. 2015. A New European Slope Length and Steepness Factor (LS-Factor) for Modelling Soil Erosion by Water. Geosciences, 5: 117-126 

Panagos, P., Borrelli, P., Meusburger, C., Alewell, C., Lugato, E., Montanarella, L., 2015b. Estimating the soil erosion cover management factor at European scale. Land Use Policy Journal (in Revision).

Panagos, P., Meusburger, K., Van Liedekerke, M., Alewell, C., Hiederer, R., Montanarella, L. 2014. Assessing soil erosion in Europe based on data collected through a European Network. Soil Science and Plant Nutrition, 2014, Vol. 60 (1), pp. 15-29