title: Assessing remotely sensed chlorophyll-a for the implementation of the Water Framework Directive in European perialpine lakes.
abstract: The lakes of the European perialpine region constitute a large water reservoir, which is threatened by the anthropogenic pressure altering water quality. The Water Framework Directive of the European Commission aims to protect water resources and monitoring is seen as an essential step for achieving this goal. Remote sensing can provide frequent data for large scale studies of water quality parameters such as chlorophyll-a (chl-a). In this work we use a dataset of maps of chl-a derived from over 200 MERIS (MEdium Resolution Imaging Spectrometer) satellite images for comparing water quality of 12 perialpine lakes in the period 2003-2009. Besides the different trophic levels of the lakes, results confirm that the seasonal variability of chl-a concentration is particularly pronounced during spring and autumn especially for the more eutrophic lakes. We show that relying on only one sample for the assessment of lake water quality during the season might lead to misleading results and erroneous assignments to quality classes. Time series MERIS data represents a suitable and cost-effective technology to fill this gap, depicting the dynamics of the surface waters of lakes in agreement with the evolution of natural phenomena.
authors.affiliation: Optical Sensing Group, Institute for Electromagnetic Sensing of the Environment, National Research Council of Italy, via Bassini 15, I-20133 Milano, Italy.
authors.forename: Mariano
authors.initials: M
authors.lastname: Bresciani
authors.forename: Daniela
authors.initials: D
authors.lastname: Stroppiana
authors.forename: Daniel
authors.initials: D
authors.lastname: Odermatt
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Morabito
authors.forename: Claudia
authors.initials: C
authors.lastname: Giardino
mesh_terms: D002734:Chlorophyll / Q000032:analysis*; D000077194:Chlorophyll A; D003247:Conservation of Natural Resources / Q000331:legislation & jurisprudence; D004784:Environmental Monitoring / Q000379:methods*; D058735:Environmental Policy; D005062:European Union; D005618:Fresh Water / Q000737:chemistry*; D011050:Policy Making; D058998:Remote Sensing Technology; D012621:Seasons; D014876:Water Pollution / Q000331:legislation & jurisprudence* / Q000706:statistics & numerical data
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A