Mapping of Submerged Aquatic Vegetation in Rivers From Very High Resolution Image Data, Using Object Based Image Analysis Combined with Expert Knowledge

The use of remote sensing for monitoring of submerged aquatic vegetation (SAV) in fluvial environments has been limited by the spatial and spectral resolution of available image data. The absorption of light in water also complicates the use of common image analysis methods. This paper presents the results of a study that uses very high resolution (VHR) image data, collected with a Near Infrared sensitive DSLR camera, to map the distribution of SAV species for three sites along the Desselse Nete, a lowland river in Flanders, Belgium. Plant species, including Ranunculus aquatilis L., Callitriche obtusangula Le Gall, Potamogeton natans L., Sparganium emersum L. and Potamogeton crispus L., were classified from the data using Object-Based Image Analysis (OBIA) and expert knowledge. A classification rule set based on a combination of both spectral and structural image variation (e.g. texture and shape) was developed for images from two sites. A comparison of the classifications with manually delineated ground truth maps resulted for both sites in 61% overall accuracy. Application of the rule set to a third validation image, resulted in 53% overall accuracy. These consistent results show promise for species level mapping in such biodiverse environments, but also prompt a discussion on assessment of classification accuracy.

Evolution of an Interactive Online Magazine for Students, Academics and Expert Practitioners to Engage Students in ESD

Urgency to embed awareness of sustainability principles and practice across society, and need for digital literacy and advocacy for sustainability are reshaping ESD. These, together with developments in learning and teaching, demand new tools to support implementation of project-based learning and more interactive approaches. This investigation explores the evolution of susthingsout.com, an online magazine for students, academics and expert practitioners, developed by the University of Worcester. This comprises two parts; the first, a private site specifically for students involved in sustainability learning on-campus; the second, an open-access site developed to deliver sustainability information and good practice across campus, community and not-for-profit and commercial organisations. This paper involves only the private site i.e. the equivalent of an in-house VLE specifically designed to support the teaching of sustainability to multi-disciplinary first and second year undergraduate students. It reports on the progress of the VLE, following three years of use and initial improvements, in terms of the student support and engagement, as well as considering the practical issues affecting these. The results fall into four categories of pedagogical, operational, cultural and external factors, which are synthesised to capture and share emerging knowledge of good practice offering insights to other developers of online sustainability materials.