Definizione dello stato ecologico secondo il D.M. 260/2010 in due fiumi di pianura (Adda e Ticino) interessati dal Deflusso Minimo Vitale

The Water Framework Directive has introduced a new ecosystem approach for the evaluation and classification of watercourses quality, based on the taxonomic structure analysis of main lotic communities. This approach has forced the Member States to urgently develop analytical methods and biological indices suitable for evaluating the status of each bioindicator. Referring to Italy, the new monitoring system, reported in D.M. 260/2010, still shows some criticisms, both of operational and interpretative character. Nevertheless, today it represents the most important national technical-normative reference also for the experimental evaluation of minimum flows defined at regional scale. In this context this paper shows and discusses the results of a three years survey carried out in two large lowland rivers, Adda and Ticino, within two projects dealing with the minimum flow experimentation. This study allowed a critical analysis of the national watercourses monitoring methods and of the consequent problems concerning the results interpretation. Comments about minimum flow experimentations also aim to scientifically report one step of the implementation process of the European Directives about waterbodies management, that, in the near future, will be involved in further developments following the introduction of the environmental flow concept.