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.

Expert Insight into the Assessment of Competence in Cognitive–behavioural Therapy: a Qualitative Exploration of Experts' Experiences, Opinions and Recommendations

To offer insight into how cognitive–behavioural therapy (CBT) competence is defined, measured and evaluated and to highlight ways in which the assessment of CBT competence could be further improved, the current study utilizes a qualitative methodology to examine CBT experts’ (N = 19) experiences of conceptualizing and assessing the competence of CBT therapists. Semi-structured interviews were used to explore participants’ experiences of assessing the competence of CBT therapists. Interview transcripts were then analysed using interpretative phenomenological analysis in order to identify commonalities and differences in the way CBT competence is evaluated. Four superordinate themes were identified: (i) what to assess, the complex and fuzzy concept of CBT competence; (ii) how to assess CBT competence, selecting from the toolbox of assessment methods; (iii) who is best placed to assess CBT competence, expertise and independence; and (iv) pitfalls, identifying and overcoming assessment biases. Priorities for future research and ways in which the assessment of CBT competence could be further improved are discussed in light of these findings.