“One Out–All Out” Principle in the Water Framework Directive 2000—A New Approach with Fuzzy Method on an Example of Greek Lakes

Abstract

The “One Out–All Out” (OOAO) principle imposed by the WFD selects the worst ecological status assessed by different biological quality elements (BQEs). Since it is a precautionary rule that can lead to problems of underestimation of the overall status, its amendment has been a matter of debate for WFD 20+. The use of fuzzy methods that express the functional relationships between variables in ecology and management has been gaining more ground recently. Here is attempted the inclusion of a fuzzy regression among the frequently monitored BQE (phytoplankton) and the outcome of OOAO application in six Greek lakes. The latter was determined by the comparison of four BQE indices in order to assess the extent to which BQEs might underpin the optimal/actual qualitative classification of a waterbody. This approach encompasses the uncertainty and the possibility to broaden the acceptable final EQR based on the character and status of each lake. We concluded that the fuzzy OOAO is an approach that seems to allow a better understanding of the WFD implementation and case-specific evaluation, including the uncertainty in classification as an asset. Moreover, it offers a deeper understanding through self-learning processes based on the existing datasets.

Impact of hydrotechnical construction on aquatic ecosystems of the Kiliia branch of the Danube Delta

“…One of the ways of implementing the purposes of this document is assessment of ecological condition and risks that could hinder its improvement (Solimini et al, 2008;Allan, 2012). Measures of the Water Framework Directive of the EU have already been introduced for many aquatic objects of Europe: rivers (Spänhoff et al, 2012;Bilous et al, 2021;Skoulikidis et al, 2021), lakes (Søndergaard et al, 2005;Latinopoulos et al, 2021;Ntislidou et al, 2021), transitional (Pérez-Ruzafa et al, 2007;Cacciatore et al, 2019;Facca, 2020) and coastal (Giovanardi et al, 2018;Gerakaris et al, 2022) water, including river deltas (Newton et al, 2014;Stoica et al, 2014;Goulding et al, 2021).…”

Natuurrapport 2023 - uitdaging 1: schade door droogte en overstromingen beperken. Achtergrondrapport: de uitdaging doorgelicht op basisvan interviews en documentanalyse.

“…Het one-out all-out principe strookt dus niet altijd met systeemfunctioneren en brengt reële verbeteringen niet of vertraagd in beeld. Een andere methode voor de combinatie van de verschillende maatlatten kan soelaas bieden (Langhans et al, 2014;Latinopoulos et al, 2021).…”

Performance analysis of the water quality index model for predicting water state using machine learning techniques

“…Consequently, the traditional classification techniques can provide inconsistent results in the final assessment of water quality for similar groups of water quality indicators (Uddin et al, 2022a(Uddin et al, , 2021. In addition, recently a number of studies have reported that the widely used classification scheme "One Out-All Out" of the water framework directive also received much more criticism for the same problem (Latinopoulos et al, 2021;Prato et al, 2014). Therefore, in order to avoid this inaccurate assessment and optimize the metaphoring problems of existing classification systems, the authors have proposed a universal classification scheme (see Table 3) for assessing coastal and transitional water quality in an earlier study (Uddin et al, 2022a).…”