Agri-environmental indicator - soil erosion

From Statistics Explained

Data from March 2013. Most recent data: Further information, Main tables and Database.

This article provides a fact sheet of the European Union (EU) agri-environmental indicator soil erosion. It consists of an overview of recent data, complemented by all information on definitions, measurement methods and context needed to interpret them correctly. The soil erosion article is part of a set of similar fact sheets providing a complete picture of the state of the agri-environmental indicators in the EU.

Example of soil water erosion on arable land
© Joint Research Centre, European Commission
Map 1: Soil erosion by water (tonnes per ha per year), 2006, EU-27, NUTS 3
Source: Joint Research Centre, European Commission
Map 2: Soil erosion by water (tonnes per ha per year), 2006, EU-27, 1km cell size
Source: Joint Research Centre, European Commission
Figure 1: Percentage of the EU territory affected by soil water erosion (%) according to soil erosion rate (tonnes per ha per year), 2006, EU-27
Source: Joint Research Centre, European Commission
Figure 2: Mean rates of soil erosion by water (tonnes per ha per year), 2006, EU-27
Source: Joint Research Centre, European Commission
Figure 3: Soil water erosion rate by country (tonnes per ha per year), 2006, EU-27, EFTA, Candidate and Potential Candidate Countries
Source: Joint Research Centre, European Commission
Map 3: Soil water erosion trends, 2000-2006, EU-27, NUTS 3
Source: Joint Research Centre, European Commission
Map 4: Soil erodibility factor (K) in Europe
Source: Joint Research Centre, European Commission
Map 5: Cover management factor (C) in Europe
Source: Joint Research Centre, European Commission

The indicator soil erosion estimates the areas affected by a certain rate of soil erosion by water.

Main indicator:

  • Areas with a certain level of erosion (aggregated to NUTS 3 regions).

Supporting indicator:

  • Estimated soil loss by water erosion (tonnes per ha per year).

Main statistical findings

Key messages

  • According to recent studies, approximately 15 % of the European Union (EU) territory (data not available for Cyprus, Greece and Malta) is estimated to be affected by a significant soil erosion rate (moderate to high level). Mean rates of soil erosion by water in EU-27 amounted to 2.76 tonnes per hectare per year and was higher in the EU-15 (3.1 tonnes per hectare per year) (data not available for Greece) than in the 12 Member States which joined the EU in 2004 and 2007 (1.7 tonnes per hectare per year) (data not available for Cyprus and Malta). 
  • Just over 7 % of cultivated land (arable and permanent cropland) in EU (excluding Cyprus, Greece and Malta) is estimated to suffer from moderately-high to high erosion. This equates to 115 410 km2 or approximately the entire surface area of Bulgaria. 1 % of the EU land surface suffers from extreme erosion (over 50 tonnes per hectare per year).
  • Only 2 % of permanent grasslands and pasture in EU (excluding Cyprus, Greece and Malta) is estimated to suffer from moderate to severe erosion. This equates to around 9 000 km2. This demonstrates the importance of maintaining permanent vegetation cover as a mechanism to combat soil erosion.

Assessment

This fact sheet describes the susceptibility of soil to erosion by water across Europe, including current estimated levels and historical trends. The trend information identifies those countries or areas for which an improvement and/or deterioration in soil erosion rate can be observed. It is important to note that both indicators are outputs of a modelling exercise and are estimates rather than measured values.
Erosion can be defined as the wearing away of the land surface by physical forces such as rainfall, flowing water, wind, ice, temperature change, gravity or other natural or anthropogenic agents that abrade, detach and remove soil or geological material from one point on the earth's surface to be deposited elsewhere. When used in the context of pressures on soil, erosion refers to accelerated loss of soil as a result of anthropogenic activity, in excess of accepted rates of natural soil formation[1]. The loss of soil leads to a decline in organic matter and nutrient content, the breakdown of soil structure, a reduction of the available soil water stored, which can lead to an enhanced risk of flooding and landslides in adjacent areas. Nutrient and carbon cycling can be significantly altered by mobilization and deposition of soil[2], as eroded soil may lose 75 - 80 % of its carbon content, with consequent release of carbon to the atmosphere[3]. Soil erosion impacts strongly on the environment and has high economic costs; to mitigate these effects, soil and water conservation strategies are required.

Soil erosion by water is one of the most widespread forms of soil degradation in the European Union. Map 1 shows the soil water erosion across all land surfaces in EU. No results are reported for Cyprus, Greece and Malta due to a lack of harmonised landcover data. This map presents the mean level of soil water erosion in administrative areas by NUTS 3 level with a range starting from a very low level (less than 0.5 tonnes per hectare per year) to a level which is considered as high (more than 20 tonnes per hectare per year). Map 2 represents the water erosion in tonnes per hectare per year (cell size: 1 km) across all land surfaces in EU. No results are reported for Cyprus, Greece and Malta due to a lack of harmonised landcover data. Note that patterns and maximum values may differ slightly from Map 1 due to the smoothing effect that results in the calculation of mean values for administrative regions (i.e. in Map 1 low and high values are not visible in individual NUTS 3 polygons).

According to recent studies, approximately 15 % of the EU territory is estimated to be affected by a significant soil erosion rate (moderate – high level or more than 5 tonnes per ha per year) (Figure 1). This is in line with previous estimations that 16 % of European Union's land area is affected by soil erosion[4]. Mean rates of soil erosion by water in the EU amounted to 2.76 tonnes per hectare per year and was higher in the EU-15 (3.1 tonnes per hectare per year) than in the 12 Member States which joined the EU in 2004 and 2007 (1.7 tonnes per hectare per year) (Figure 2).

Just over 7 % of cultivated land (arable and permanent cropland) in EU is estimated to suffer from moderate to high erosion (more than 5 tonnes per hectare per year). This equates to an area of 115 410 km2 (close to the entire surface area of Bulgaria). Using conservative estimates of wheat yields of 1 tonne per hectare and a market price of EUR 300 per tonne of wheat, in an area of cultivated land affected by moderate to severe soil erosion, agricultural production in the region of EUR 3.5 billion could be under threat. If the economic value is placed on the loss of soil carbon (currently CO2 credits are around EUR 20 per tonne), the figure would be even higher.

Several countries in the southern part of Europe show mean erosion rates that are significantly higher than the mean value for EU (Figure 3). However, countries with low mean erosion rates may contain areas where erosion rates are significantly higher (and of course, vice versa). No harmonized measure of soil erosion rates exists for the European continent. To date, the only harmonized pan-European estimates of soil erosion by water have been provided by the PESERA project[5]. This fact sheet is based on a methodology to improve on the limitations of the PESERA model.  

Increasing awareness amongst scientists and policy-makers about the problem of soil degradation through erosion in Europe has made the quantification of its extent and impact an urgent requirement. The identification of areas that are vulnerable to soil erosion can be helpful for improving our knowledge about the extent of the areas affected and, ultimately, for developing measures to keep the problem under control.
Considering the average of soil water erosion rate by country (Figure 3), several European countries appear not to be significantly affected by notable soil erosion susceptibility when compared to a ‘continental mean’ of around 2 tonnes per hectare per year. However, such values can be misleading as they mask the fact that erosion rates in many areas can be much higher, even for those countries that have a low mean rate of erosion. The converse is also true for countries with high values. On the other hand, some countries, mainly in the southern part of Europe, are clearly characterised as being particularly susceptible to erosion.
There are some exceptions (e.g. northern Scotland). There is a high probability that the erosion rate is over-estimated in some areas due to the low value of explained variance for the calculation of the rainfall erosivity factor and the presence of many areas having an actual stoniness value that is much higher than the value indicated by the underlying soil database.
Soil stoniness is known to have a strong influence on erosion rates[6]. Rock fragments in the soil top layers affect soil water erosion processes in various ways, both direct and indirect. Direct effects on soil erosion comprise the shielding of the soil surface from detachment by raindrop splash and runoff or the interception of splashed sediment. Indirect effects are numerous but the most important ones are the effects of rock fragments on physical properties of the fine earth (e.g. porosity, organic matter content) affecting soil erosion sub-processes, physical degradation (i.e. surface sealing, compaction) of the soil top layer, hydrological processes affecting runoff generation and discharge (e.g. infiltration, percolation) and hydraulics of runoff.
There has been much discussion in the literature about thresholds above which soil erosion should be regarded as a serious problem. This has given rise to the concept of ‘tolerable’ rates of soil erosion that should be based on reliable estimates of natural rates of soil formation. However, soil formation processes and rates differ substantially throughout Europe. In some cases, rates of soil erosion larger than 1 tonne per hectare per year are regarded as tolerable from the wider perspective of society as a whole, for example for economic considerations or the preservation of soil functions. In Switzerland, the threshold tolerated for soil erosion is generally 1 tonne per hectare per year, though this rate can be increased to 2 tonnes per hectare per year for some soil types[7]. In Norway, 2 tonnes per hectare per year is adopted as the threshold for tolerable soil loss. In general, losses above 1 tonne per hectare per year are generally considered as irreversible. Nevertheless, there may be a need to propose different thresholds of rates of soil erosion that are tolerable in different parts of Europe. However, this aspect needs further elaboration.

Soil erosion trends resulting from changes in land cover and rainfall erosivity have also been analyzed. A time interval of six years was evaluated (2000 - 2006) (Map 3). The results do not show any particular trend in the erosion of soil by water. This finding is contrary to the results of some simulations using Intergovernmental Panel on Climate Change (IPCC) scenarios (2070 - 2100)[8] but due to the time interval analysed, any conclusions must be made with caution. To understand better the real trend, an analysis over a time period of at least 15 - 20 years would be necessary (e.g. comparing the current situation to the 1990s). 

Data sources and availability

Indicator definition

The indicator soil erosion estimates the areas affected by a certain rate of soil erosion by water.

Measurements

Main indicator:

  • Areas with a certain level of erosion (aggregated to NUTS 3)

Supporting indicator:

  • Estimated soil loss by water erosion (tonnes per hectare per year)

Links with other indicators 

Soil erosion does not serve as an input to other AEI, but has indirect links to the following indicators:

AEI 09 - Land use change AEI 11.2 - Tillage practices
AEI 10.1 - Cropping patterns AEI 12 - Intensification/Extensification
AEI 11.1 - Soil cover AEI 14 - Risk of land abandonment

Data used and methodology

Two soil erosion indicators have been produced on the basis of empirical computer model.

  • The main indicator represents estimated soil erosion levels for NUTS Level 3 administrative areas that range from very low values (less than 0.5 tonnes per hectare per year) to high values (more than 20 tonnes per hectare per year) for the EU.
  • The second indicator is a cell-based map that estimates the rate of soil erosion by water in Europe in tonnes per hectare per year for cells of 1 km x 1 km for the EU.

The indicators are predicted estimates and not actual values. They are derived from an enhanced version of the Revised Universal Soil Loss Equation (RUSLE) model [9] which was developed to evaluate soil erosion by water at a regional scale. The model was developed primarily to guide conservation planning, inventory erosion rates and estimate sediment delivery on the basis of accepted scientific knowledge and technical judgment. In this assessment, the basic RUSLE model has been adapted through the addition of a new factor that improves the estimation of the effect of stoniness on soil erosion. The RUSLE model has been used due to its flexibility in relation to input data requirements. In addition, a novel approach was used to develop input data on the erosivity of precipitation.

Only soil erosion resulting from rainsplash, 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 (rills and gullies) is the main agent of erosion by water. Readers should be aware that due to the scale of the input data, the results provide an overview of the soil erosion susceptibility in the landscape rather than a real estimation for a specific location.

A major consideration in any modelling exercise is the quality of the input datasets. Many pan-European datasets are small-scale (e.g. 1:1 000 000) or coarse in their resolution (e.g. 1 - 10 km cells). Data limitations stimulated an innovative approach to estimate the erosivity of rainfall through the development of a climatic-based ensemble model which merged multiple empirical equations of rainfall erosivity. These equations were collected from specific case studies published in the literature covering a range of climatic areas throughout Europe. The merging was done by extending the original geographical domain of validity of each equation to similar climatic areas.

Due to limited measurement data across Europe, the validation of modelled data is problematic.

The RUSLE model benefits from an array programming paradigm[10][11] which allows the final assessment to be calculated on the basis of a series of scale-independent modules. This allows users to process large volumes of data. The revised version of the RUSLE is an empirical model that calculates soil loss due to sheet and rill erosion. The model considers seven main factors controlling soil erosion: the erosivity of the eroding agents (water), the erodibility of the soil, the slope steepness and the slope length of the land, the land cover, the stoniness and the human practices designed to control erosion.
The model estimates erosion by means of an empirical equation: Er = R K L S C St P
Where:
Er = (annual) soil loss (tonnes per hectare per year).
R = rainfall erosivity factor 
K = soil erodibility factor 
L = slope length factor (dimensionless).
S = slope steepness factor (dimensionless).
C = cover management factor (dimensionless).
St = stoniness correction factor (dimensionless)
P = human practices aimed at erosion control (dimensionless).

  • Rainfall erosivity factor (R). The intensity of precipitations is one of the main factors affecting soil water erosion processes. R is a measure of the precipitation’s erosivity and indicates the climatic influence on the erosion phenomenon through the mixed effect of rainfall action and superficial runoff, both laminar and rill. Wischmeier[12] identified a composite parameter EI, as the best indicator of rain erosivity. It is determined, for the ki-th rain event of the i-th year, by multiplying the kinetic energy of rain by the maximum rainfall intensity occurred within a temporal interval of 30 minutes. Due to the difficulty in obtaining precipitation data with adequate temporal resolution over large areas, the R factor has been calculated using a series of simplified equations available in scientific literature. In the present application, an innovative climatic-based ensemble model to estimate erosivity from multiple available empirical equations has been created for the pan-European maps[13]. The R factor has been computed using the E-OBS database as data source[14]. E-OBS is based on the largest available pan-European precipitation data set, and its interpolation methods were chosen after careful evaluation of a number of alternatives.
  • Soil erodibility factor (K) (Map 4). The soil erodibility factor represents the effects of soil properties and soil profile characteristics on soil loss[15]. The K factor is affected by many different soil properties and therefore quantifying the natural susceptibility of soils is difficult. For this reason, K is usually estimated using the soil-erodibility nomograph[16]. The European Soil Database (SGDBE) at 1:1.000.000 scale has been used for the calculation (see also[17]).  
  • Topographic factors - slope length (L) and slope steepness (S). The effect of topography within the RUSLE model is accounted for by the slope length factor and the slope steepness factor. For the calculation of the L and S factors, the Shuttle Radar Topography Mission (SRTM) [18] digital terrain model was used as it is one of the most complete high-resolution digital topographic databases of the Earth.
  • Cover-Management factor (C) (Map 5). The cover-management factor represents the influence of land cover, cropping and management practices on erosion rate. The calculation of the C factor is very difficult due to the lack of detailed information in Europe. In this study, the C-factor has been calculated using average values from literature[19][20][21] and the Corine Land Cover database for 2006 and [22]  The impact of natural vegetation suggests further analysis with detailed forest types and tree species distribution maps[23][24][25] to increase the corresponding C factors accuracy.
  • Stoniness Correction factor (St). The stoniness correction factor has been introduced to correct the negative relation between rock fragment cover and relative inter-rill sediment yield. The RUSLE model considers stoniness indirectly within the K and the C factor. Regarding the K factor, as already mentioned, only the effects of rock fragment within the soil profile are considered. For the C factor stoniness is taken into account in calculating the Surface Cover subfactor. For the calculation of the St factor, the equations of Poesen and Lavee[26] have been applied to the European Soil Database (SGDBE) where IR = e -b(Rc) with IR being the inter-rill sediment yield, b being a coefficient indicating the effectiveness of the rock cover (Rc,%) in reducing inter-rill soil loss. Poesen and Ingelmo-Sanchez[27] found a b-value of 0.02 for partly embedded rock fragments and a b-value of 0.04 for fragments placed on the soil surface. Unfortunately detailed information on soil stoniness does not exist for Europe. However, the ESGDB database contains information about the stoniness volume of soils with an important rock fragment content. Stony soils cover about 30 % of the surface soils of Western Europe, and 60 % in Mediterranean areas. They consist of rock fragments whose diameters are larger than 2 mm (the rock fragment). These fragments may alter the physical, chemical and agricultural properties of soils[28]. Various studies indicate that these stony soils are at least partly a result of their often long and intense history of deforestation and cultivation, during which erosion rates were larger than the long-term soil formation rate[29][30][31][32][33]. Although stony soils do not necessarily generate less runoff, they are considerably less susceptible to water erosion[34].
  • Human Practices factor (P). This factor includes land management practices (such as terracing, strip cropping or ploughing direction) that affect erosion phenomena. For areas where there are no support practices or without any data, the P factor is set to 1.0.

A number of issues should be noted:

  • The model estimates soil loss caused by raindrop impact, overland flow (or sheetwash) and rill erosion. It does not estimate gully or stream-channel erosion. As a consequence, the risk of soil degradation in areas affected by different erosion phenomena (gully erosion, wind erosion, etc.) are probably underestimated.
  • As mentioned previously, the lack of high-resolution pan-Europe environmental datasets, the non linearity present within the climatic-based ensemble model and the underlying principles of the RUSLE model that considers only some categories of soil erosion lead to a level of uncertainty in the output predictions. As a consequence, quantitative assessments using the model should not be undertaken without the right awareness.
  • There are also great difficulties in gathering enough information to drive an adequate validation of the model results, but this aspect applies to the output from any large area erosion-prediction model. The validation of erosion estimates at continental scale is not technically and financially feasible. One validation option is through the upscaling of local monitoring studies of large-scale modelling assessments.
  • The selection of input datasets in the development of this indicator is a crucial process as they have to offer the most homogeneous and complete spatial coverage of the target area.
  • The model must also allow the produced information to be harmonized and easily validated.
  • In the case of this indicator, an alternative qualitative validation method, based on expert judgement was applied. Modelled results were compared with the soil erosion maps provided by different countries through the European Environment Information and Observation Network (EIONET) (EIONETSOIL). Most of the maps in this exercise were also calculated using the RUSLE model, using higher resolution datasets or containing less uncertainty. Overall, the results show a high correlation in the pattern of the erosion. Furthermore, a qualitative evaluation is being carried out based on the analysis of soil erosion evidence on satellite images and pictures published in Google Earth.

Context

Soil is a valuable, non-renewable resource that offers a multitude of ecosystems goods and services. Soil erosion is the wearing away of the land surface through the action of water and wind, and is exacerbated by tillage and other disturbances (e.g. removal by crop harvesting, dissolution and river bank erosion). At geological time-scales there is a balance between erosion and soil formation[35]. However, in many areas of the world there is an imbalance with respect to soil loss and its subsequent creation, caused principally by anthropogenic activities (mainly as a result of land use change) and climate change.
The Thematic Strategy for Soil Protection and the proposed Soil Framework Directive recognise soil erosion as a major threat to the soil resources of Europe and is one of three priority areas for policy recommendations. Soil erosion requires immediate attention and irreversible degradation is to be avoided in certain landscapes of Europe. Climate, vegetation cover, land use, topography and soil characteristics as well as conservation practice have a strong impact on soil erosion rates. Soil erosion reduces the ecological functions of soil over time. The main on-site consequences regard biomass production and crop yields (due to removal of nutrients and reduction in soil filtering capacity).
The Mediterranean area is particularly prone to soil water erosion because of long dry periods followed by heavy bursts of intense precipitations on steep slopes with fragile soils. In some areas, erosion has reached a state of irreversibility with the complete removal of all soil material.
Soil erosion in northern Europe is generally less pronounced because of the lower erosivity of the rain and the higher vegetation cover. However, arable lands in this part of Europe are also susceptible to erosion, especially loamy soils after ploughing[36], as are some areas under natural vegetation.
Given the increasing threat of erosion by the detachment of soil particles by water in Europe, and the implications this has on future food security and water quality, it is important that land managers are provided with accurate and appropriate information on the amount of soil that is actually being lost. It is impractical and technically difficult to measure soil loss across whole landscapes and thus research is urgently needed to improve methods of estimating soil erosion using modelling, upon which mitigation can be implemented.
A wide variety of models are available for soil water erosion estimation. The selection of a model depends mainly on the purpose for which it is intended and the available dataset. Some models are designed to predict soil erosion from single storms while others predict long-term effects. Models such as the Universal Soil Loss Equation and derived versions[37]  are developed to predict only sheet and rill soil erosion and do not take into account other processes like gully erosion. Most models have been designed for local scale applications. Therefore, several problematic issues occur when applying quantitative soil erosion models at regional-level or for smaller scale mapping. At these levels, the spatial resolution of the dataset is too coarse to ascertain accurately a single specific erosion process (i.e. it is impossible to differentiate between rill erosion and gully development). In addition, the poor resolution of the spatial data used as model inputs can limit their use in some applications. Uncertainties in the model inputs propagate throughout the model so that the quality of the model input is strictly linked with the quality of model results. Consequently, care should be taken not to use an ‘over-parameterised’ model when the quality of the input data is poor. At the regional scales, outputs need to be interpreted carefully and a reliable estimation of absolute soil erosion rates is almost impossible to obtain. Because of all these issues the relative values obtained when applying soil erosion models at regional levels are generally more reliable than the absolute values. Readers should be aware that the model gives a broad overview of the soil water erosion phenomena in the landscape rather than providing an accurate value for a specific point.
The soil erosion indicators presented here have been obtained by applying a soil water erosion model. Two indicators are proposed to locate the areas with an estimated level of erosion.
Only soil erosion resulting from rainsplash, overland flow (also known as sheetwash) and rill formation are considered. In most situations, erosion by concentrated flow (rills and gullies) is the main agent of erosion by water. These are some of the most effective processes to detach and remove soil by water: 

  • Rainfall has the ability to move soil particles directly. This is known as rainsplash erosion. This action is only effective if the rain falls with sufficient intensity. When raindrops hit bare soil, their kinetic energy is able to detach and move soil particles a short distance. Because soil particles can only be moved short distances (few millimetres at the most), its effects are solely on-site. Although considerable quantities of soil may be moved by rainsplash, it is generally all redistributed back over the surface of the soil. On steep slopes, there can be a modest net downslope movement of splashed soil due to the effect of gravity and the gradient of the land. Rainsplash erosion requires high rainfall intensities such as those that accompany convective rainstorms. Rainsplash erosion also weakens the soil surface structure, making it more vulnerable for transport by overland flow.
  • Overland flow occurs either when the soil is infiltrated to full capacity and excess water from rain, meltwater or other sources, flows over the land as a sheet. Alternatively, the rainfall rate may be higher than the infiltration rate of the soil. Sheetwash erosion occurs without any well defined channel and can manifest itself across entire slopes. As a consequence, the erosion can affect large areas and move significant amounts of soil.
  • Rills occur when overland flow begins to develop preferential flow paths. In turn, these flow paths are eroded further which results in small, well-defined linear concentrations of overland water. In many cases, small rills may disappear over time due to sedimentation. However, persistent micro-rills can develop further to become rills, with a subset eventually becoming gullies.
  • Gullies are deeper channels, often resulting from unchecked rill erosion. Due to their size, gullies are capable of moving large amounts of soil, into larger channels such as streams and rivers and thus out of the original site. Gully erosion is not considered in the RUSLE model.

Other forms of erosion (for example, gully erosion and wind erosion) are important and should be considered in the future.

Policy relevance and context

The European Union’s Sixth Environment Action Programme (Environment 2000-2010: our future, our choice. Decision 1600/2002 of the European Council and Parliament) declared a necessity to protect soil against degradation, due to the influence of human actions. This resulted in the publication of a Thematic strategy for soil protection (Communication from the Commission to the Council, the European Parliament, the European Economic and Social Committee and the Committee of the Regions - Thematic Strategy for Soil Protection COM final 0231/2006). Through this Strategy, the European Union has defined an action plan for soil conservation in Europe. With the EU Soil Thematic Strategy, the objective to define a common and comprehensive approach to soil protection, focusing on the preservation of soil functions, has been introduced. It is based on the principles of:

  •  preventing further soil degradation and preserving its functions, and
  •  restoring degraded soils to a level of functionality consistent at least with current and intended use.

The Soil Thematic Strategy considers a number of soil degradation processes, including erosion, that should be identified and for which appropriate measures should be put in place to preserve soil functions.
Soil has not been subject to a dedicated protection policy at EU level. Provisions for soil protection are spread across many different areas, either under environmental protection or other policy areas such as agriculture and rural development. These provisions are considered to not offer a sufficient level of soil protection. A coordinated action at European level would therefore appear necessary, hence the adoption of the Soil Thematic Strategy and of the proposed Soil Framework Directive. The state of soil influences other environmental and food safety aspects governed at EU level giving an international dimension of the problem. The common agricultural policy (CAP) contributes to preventing and mitigating soil degradation processes. In particular, agri-environment measures (which offer opportunities for favouring the build-up of soil organic matter, the enhancement of soil biodiversity, the reduction of soil erosion, contamination and compaction) and cross-compliance (which can play an important role for soil protection).

Agri-environmental context

Soil erosion costs the economy a large amount of money. Research on the quantification of external effects of soil erosion is more advanced in the United States of America and Australia than in Europe. Only a few examples can be shown for Europe but sufficient cases exist to establish a reliable impression of the real situation. J.N.Pretty calculated that the annual external costs for agricultural production in the UK from soil erosion were almost EUR 3.5 billion and at least EUR 1.8 billion in Germany[38].
On-site effects of water soil erosion (loss of organic matter and nutrients, soil structure degradation, plant uprooting, reduction of available soil moisture, etc.) are particularly important on agricultural areas resulting in a reduction of cultivable soil depth and a decline in soil fertility. The loss of soil productivity following erosion may be significant. Topsoil, which is the most fertile layer of the soil, is the most exposed to erosion; also the mechanisms of soil erosion preferentially remove soil organic matter, clay, and fine silt material. Soil erosion also reduces the volume of soil available for plants roots and degrades soil physical properties (such as water holding capacity). In most cases extra fertilizer can compensate the impacts of soil erosion on soil fertility, but it represents an extra cost for farmers, and does little to offset the physical impacts of erosion on soil productivity.
Off-site effects of soil water erosion arise from sedimentation, which causes infrastructure burial, changes in watercourses shape and obstruction of drainage networks enhancing the risk of flooding and shortening the life of reservoirs. Many irrigation or hydroelectricity projects have been damaged by soil water erosion.
Generally, high intensity agricultural land use leads to higher soil loss by water and wind erosion, especially in potentially high erosion risk areas. However, the reverse could equally be true. For example, an intensive farming system employing soil conservation measures such as terracing and cover crops may result in less soil erosion than a more extensive system that does not involve conservation techniques. Intensive land use can be combined with efficient soil conservation measures.

See also

Further Eurostat information

Publications 

Dedicated section

Source data for tables, figures and maps (MS Excel)

Other information

External links

  • Database:
  • Other external links:

Notes

  1. Huber S., Prokop G., Arrouays D., Banko G., Bispo A., Jones R.J.A., Kibblewhite M.G., Lexer W., Möller A., Rickson R.J., Shishkov T., Stephens M., Toth G., Van den Akker J.J.H., Varallyay G., Verheijen F.G.A., Jones A.R. (eds.): Environmental Assessment of Soil for Monitoring: Volume I Indicators and Criteria. Office for the Official Publication of the European Communities, Luxembourg, 339 pp. EUR 23490 EN/1. (2008)
  2. Quinton J.N., Govers G., Van Oost K., Bardgett R.D.: The impact of agricultural soil erosion on biogeochemical cycling. Nature Geoscience, April 2010, 311-314. DOI 10.1038 (2010)
  3. Morgan R.P.C.: Soil Erosion and Conservation, 3rd edn. Blackwell Publ., Oxford. (2005)
  4. EEA: Assessment and Reporting on Soil Erosion. EEA Technical Report 94. European Environment Agency. (2003)
  5. Gobin A. and Govers G. (Eds.): Pan-European Soil Erosion Risk Assessment Project. Third Annual Report to the European Commission. EC Contract No. QLK5-CT-1999-01323. (2003)
  6. Poesen J., Torri D., Bunte K.: Effects of rock fragments on soil erosion by water at different spatial scales: a review. Catena 23:141–166. (1994)
  7. Schaub, D. and Prasuhn V.: A Map of Soil Erosion on Arable Land as a Planning Tool for Sustainable Land Use in Switzerland. Advances in GeoEcology 31. (1998)
  8. Bosco C., Rusco E., Montanarella L., Panagos P.: Soil erosion in the alpine area: risk assessment and climate change. Studi Trent. Sci. Nat., 85, pp 119 – 125. Museo Tridentino di Scienze Naturali, Trento. (2009)
  9. Renard K.G., Foster G.R., Weesies G.A., McCool D.K., Yoder D.C.: Predicting Soil Erosion by Water: A Guide to Conservation Planning with the Revised Universal Soil Loss Equation (RUSLE). US Dept Agric., Agr. Research Service. Agr. Handbook No. 703 (1997)
  10. Iverson K.E.: Notation as a tool of thought. Comm. of the ACM 23, 444–465. (1980)
  11. Quarteroni, A. and Saleri F.: Scientific Computing with MATLAB and Octave. Texts in Computational Science and Engineering. Springer, Milan. (2006)
  12. Wischmeier W.H.: A rainfall erosion index for a universal Soil-Loss Equation. Soil Sci. Soc. Amer. Proc. 23, 246–249. (1959)
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