Detection and Classification of Anomalous Events in Water Quality Datasets Within a

Abstract—Continual measurement is key to understanding sud-den and gradual changes in chemical and biological quality of water, and for taking reactive remedial action in the case of contamination. Monitoring of water bodies will increase in future within Europe to comply with legislative requirements such as the Water Framework Directive and globally owing to pressure from climate change. Establishing high quality long-term monitoring programs is regarded as essential if the implementation of perti-nent legislation is to be successful. However, conventional discrete sampling programs and laboratory-based analysis techniques can be costly, and are unlikely to provide timely and reliable estimates of true ranges of deterministic physicochemical variability in a water body with marked temporal or spatial variability. Only continual or near continual measurements have the capacity to detect ephemeral or sporadic events, thus providing the potentia