title: River pollution remediation monitored by optical and infrared high-resolution satellite images.
abstract: The Bormida River Basin, located in the northwestern region of Italy, has been strongly contaminated by the ACNA chemical factory. This factory was in operation from 1892 to 1998, and contamination from the factory has had deleterious consequences on the water quality, agriculture, natural ecosystems and human health. Attempts have been made to remediate the site. The aims of this study were to use high-resolution satellite images combined with a classical remote sensing methodology to monitor vegetation conditions along the Bormida River, both upstream and downstream of the ACNA chemical factory site, and to compare the results obtained at different times before and after the remediation process. The trends of the Normalised Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) along the riverbanks are used to assess the effect of water pollution on vegetation. NDVI and EVI values show that the contamination produced by the ACNA factory had less severe effects in the year 2007, when most of the remediation activities were concluded, than in 2006 and 2003. In 2007, the contamination effects were noticeable up to 6 km downstream of the factory, whereas in 2003 and 2006 the influence range was up to about 12 km downstream of the factory. The results of this study show the effectiveness of remediation activities that have been taking place in this area. In addition, the comparison between NDVI and EVI shows that the EVI is more suitable to characterise the vegetation health and can be considered an additional tool to assess vegetation health and to monitor restoration activities.
authors: Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale Amedeo Avogadro, Viale Teresa Michel 11, 15121 Alessandria, Italy. paolo.trivero@mfn.unipmn.it
authors: Paolo
authors: P
authors: Trivero
authors: Maria
authors: M
authors: Borasi
authors: Walter
authors: W
authors: Biamino
authors: Marco
authors: M
authors: Cavagnero
authors: Caterina
authors: C
authors: Rinaudo
authors: Matias
authors: M
authors: Bonansea
authors: Sofia
authors: S
authors: Lanfri
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring / Q000379:methods*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007558:Italy; D045483:Rivers / Q000737:chemistry*; D063809:Satellite Imagery; D014876:Water Pollution / Q000032:analysis* / Q000706:statistics & numerical data