Risk Assessment Methodologies of Soil Threats in Europe

Data interpretation phase
Classification systems for erosion risk are tailored to the hazard, vulnerability and value properties of a
country’s territory, and therefore differ between countries. Especially the delimitation of the tolerable
erosion risk class expresses different perceptions of erosion risk between countries.In several countries
(Austria, Czech Republic, Hungary, Norway) water erosion is no longer tolerable at smaller rates than
those proposed by generally accepted standards like the expert-based rate of 2 t/ha/yr (ESBN, 2005) and
the classification system of the OECD (2008). This illustrates the difficulty of harmonizing frameworks
for the translation of erosion hazard into risk assessment.
In the literature on soil erosion, soil erosion is commonly considered ‘tolerable’ (i.e. at low or zero risk) if
it does not impact on long-term productivity by changing properties like depth, nutrient status and texture
(e.g. Gobin et al., 2004; Jones et al., 2004; OECD, 2008). This concept considers only the direct soil value
for agricultural production. Morgan (2005) suggests that the severity (or risk) of soil erosion is better
judged in relation to the damage caused and the costs of its amelioration. This would fit better into
generally accepted definitions of environmental risks in terms of the consequences of the environmental
process occurring, in this case soil erosion (damage caused relates to vulnerability ; costs of its
amelioration relates to value).
The variety in outputs of RAMs for soil erosion indicates that there is no clearly defined target variable for
soil erosion risk assessments performed in European countries. This is a requirement for harmonization of
RAMs.
Risk perception phase
The inventory of RAMs for soil erosion show that the risk perception phase is not formalized or
documented in the risk assessment methods. This may be explained by the fact that this phase essentially
deals with the understanding of the significance of soil erosion risk to individual and societal values
(Pollard et al., 2008), and therefore require the intricate involvement of stakeholders who benefit from the
reduction of soil erosion risk. They also require a distinction between actual soil erosion risk, and potential
(future) risk due to driving forces like climate change, land use and management, agro-ecosystem
management and human population dynamics (EEA, 2002; Gobin et al., 2004). This distinction is not
always provided in the preceding data processing phase. Due to the patchy nature of soil erosion impacts
in time and space values and stakeholders are difficult to identify. The large number of farmers and other
owners involved complicate the involvement of stakeholders compared to risk assessment processes for
other environmental media (air, water). Also, there is a sense that private land owners are or should be
sufficiently self interested and farsighted to manage their land (IEEP, 2008; Pesonen, 2008). Finally, soil
erosion risk, like many other soil threats, is not readily noticed by the media and the general public, and
there have not been dramatic triggers to initiate risk assessment compared to other threats like catastrophic
flood and landslide events (IEEP, 2008; Van Beek et al., submitted).
These observations explain why current risk assessment methods for soil erosion in European countries, if
existent at all, are not or marginally used in processes with stakeholders to judge erosion risk against
acceptable levels of residual risk (because soil erosion will always occur), and to establish a ‘common
operational picture’ of the sense of urgency to act against the gamut of soil erosion risks.
Ultimately, the weak incorporation of the data interpretation and risk perception phases in the risk
assessment chain for soil erosion may be one of the reasons why European or national policy measures to
directly or indirectly protect soil against erosion have only been adopted or implemented in a few member
states, despite the huge amount of available knowledge on the principles and technologies of soil
conservation developed in the US and Europe since the 1930s (Kwaad, 2008).
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