Paul Zukowskyj

Estimation of error in bankfull width comparisons from temporally sequenced raw and corrected aerial photographs

This study investigates the propagation of error through image-to-image comparison of 285 river bankfull width measurements of the Afon Trannon, mid-Wales. Bankfull width is quantified from both aerial photographs analysed as rectified images in ERDAS Imagine OrthoMax and raw images in Paintshop Pro. A method for the robust estimation of bankfull width measurement error through temporal sequences of scanned aerial photographs is presented and the improvement in accuracy achieved using rectified imagery is quantified. Results from this study are placed in the context of previously published rates of bankfull width change, from a wide range of river scales, and the bankfull change rates for robust medium-term analysis using approximately 1:10,000 historical aerial photography are identified.

Moderating accurate topographic EDM survey with expert-derived planimetric geomorphological information: a case study mapping soil pipes, Mocatán, SE Spain

Abstract Please click here to download the map associated with this article. This paper describes the mix of methods involved in the development of a detailed geomorphology map designed to facilitate the analysis and interpretation of an area of rapidly eroding soil pipe badlands in the Mocatán basin near Sorbas in SE Spain. Accurate EDM survey data was moderated by inclusion of expert-derived planimetric geomorphological information to produced as accurate as possible a map of the complicated pipe and channel landscape. It is argued here that although the spacing of the topographic data was close, the spline algorithm that generates the topographic contours between pipes can be improved by hand-mapping topography whilst in the field. Whilst the primary aim of the expert was to add in the vegetation cover distribution, fan pipe exits and the 175 entrances, pipe roof-collapse features, and the position of roads, quarry and breaks of slope, the process also adds value to topographic information. Combining the old and new geomorphological tools resulted in a useful and detailed expertly-adjusted map tailored to the needs of the project.

Quantitative accuracy assessment of contextually filtered classified images

Original article can be found at: http://www.informaworld.com/smpp/title~content=t713722504~db=all Copyright Informa / Taylor and Francis [The full text of this article is not available in the UHRA]