Moving Ahead from Assessments to Actions by Using Harmonized Risk Assessment Methodologies for Soil Degradation

Abstract

Almost all developed countries use risk assessment methodologies (RAMs) for the evaluation of risks related to soil degradation, viz. soil organic matter decline, erosion, landslides, salinization and/or compaction. However and for various reasons, seldom the use of such RAMs seldom results in actual measures to combat soil degradation in practice. In this study the current status of RAMs in EU-27 was evaluated and factors hampering the implementation of action plans were explored. To do so we used a so-called risk assessment chain, which describes the five successive steps of any risk assessment for soil threats viz., (1) notion of the threat, (2) data collection, (3) data processing, (4) risk interpretation and (5) risk perception. Based on this assessment we identified three factors that hampered the execution of measures to combat soil degradation following the application of soil RAMs:

• Many RAMs are incomplete and focus on the first steps of the risk assessment chain, and ignore the decision for action to combat land degradation;

• Member states preferably monitor soil threats that are clearly present (e.g. landslides) and may overlook “slow killers” like compaction and soil organic matter decline.

• Different RAMs for the same threat provide different results for the same exposure. This undermines the scientific credibility of the RAMs and the plausibility of the severity of the threat and may result in loss of commitment to take remedial actions.

These factors may be overcome by harmonizing RAMs, i.e. by making results comparable and/or compatible. Therefore, complete RAMs, i.e. covering all aspects of the risk assessment chain, should be developed for each threat and different RAMs for the same threat should be made intercomparable, i.e. yield similar risk perceptions for a certain exposure to a threat. We recommend implementing a Tiered methodology, where the Tier 1 method is a standardized and uniformly applicable method across EU-27, at a relatively low spatial resolution and is used to identify areas at risk. The Tier 2 method is a regional-specific and more detailed assessment of the risk in the areas identified by the Tier 1 method, where the Tier 2 method is harmonized to the Tier 1 method. We urge to initiate this process timely considering that as long as different unharmonized soil RAMs are used simultaneously, the implementation of remedial measures will be frustrated by ambiguous results.