Assessing organic water pollution of inland wetlands with remote sensing and field data

Abstract

The purpose of this paper is to assess and monitor water pollution using satellite images, orthophotos, analytical data and field work in a group of Spanish wetlands located in central Spain. The increase in large-scale irrigation schemes, the intensive exploitation of water resources and the water pollution in this area have seriously impacted on these habitats. A multi-temporal analysis carried out from 1989 to 2013 shows the improvement or deterioration in water quality of seven of these wetlands. The water quality was determined using analytical and remote sensing data (vegetation index, spectral profiles and spatial profiles). Two case studies are presented: one wetland shows a remarkable improvement in water quality, with high eutrophication levels reduced as part of a clear decontamination process; the waters of the other wetland remained clean without eutrophication throughout the study period. Remote sensing techniques only detect the presence of algae in wetlands, and chemical analysis of the water is needed to confirm pollution. The integrated use of both methods will enable consultants and wetland managers to manage these areas better and mitigate the pollution problems.