Ecological status of rivers in preserved areas: Effects of meteorological parameters

The assessment of aquatic ecosystem health has been totally revised in European countries, driven mainly by the European water framework directive (WFD), which requires member states to assess the quality of rivers. Watercourses quality is strongly influenced by both meteorological conditions and human activities; aim of the present work is to investigate potential links between meteorological parameters and ecological quality of a river. In order to reduce surrounding interferences due to the human presence, the study has been focused into a preserved area. The work deals with the case study of the Calore Irpino river, in the Regional Park of "Monti Picentini" (Southern Italy), where ecological quality of the watercourse has been monitored for 5 years, together with meteorological parameters. Ecological quality has been evaluated through the introduction of a set of macroindicators that have been monthly screened for 5 years, according to European and Italian legislation. Based on the hydrological and weighted usable area (WUA) method, the minimum environmental flow was then evaluated considering the most dominant fish species (Brown Trout) as target organisms, and the related habitat suitability models (HSMs) for water depth, current velocity and substrate. These elements are connected with meteorological parameters such as rainfall, therefore the WUA method may better explain causative links between meteorological and water quality parameters, biological and hydrological ones, which have been investigated and discussed in this work. Results confirm the presence of a mutual bond between meteorological and water quality that should raise awareness of both academics and professionals. This knowledge contributes to both the definition of water quality protection plans, supported by a specific chemical and biological monitoring plan, and environmental restoration activities, to foster the river hydrological-hydraulic states variability and to support the living communities. (C) 2012 Elsevier B.V. All rights reserved.