Photogeomorphological studies of Oxford stone : a review

This paper surveys work in geomorphology that incorporates photography to study landforms and landscape change. Since this is already a large area of study, the city centre of Oxford, UK is adopted as a case study for focus. The paper reviews broader literature pertaining to ‘photogeomorphology’ since the 1960s and delves into contemporary publications for Oxford geomorphology. Developments in the general field do not embrace close-range ground-based photography, favouring aerial photography and remote sensing. The author postulates that, as evident in the Oxford studies, that the subdiscipline should be less fixated on landscape-scale approaches and also employ close-up ground-based photography and rephotography in the assessment of landforms and landscape change. This broader scale of application could benefit the study of stone soiling and decay (weathering) studies as smaller forms may be overlooked

AN IMAGING APPROACH FOR A CONTACTLESS MONITORING OF THE CONSERVATION STATE OF METALLIC WORKS OF ART

An easy-to-use and cheap diagnostic tool based on digital photography and 2D-FFT imaging processing is described that can be used to monitor the corrosion process occurring over time on the surface of metallic works of art in indoor and outdoor environments and to assess the stability of the materials employed for restoration. The proposed solution has the advantage of not requiring standard lighting and artifacts manipulation, that are not easily achievable in real applications. The imaging algorithm is capable of highlighting the changes in the surface uniformity due to the corrosion process and can be used to put in evidence the beginning of dangerous localized corrosion phenomena onto the metallic surface. Although this technique does not allow a quantitative measurement of the corrosion rate, it has proved to be an effective approach to assess the stability of protective coatings. The proposed processing has been tested in laboratory to asses the stability of SiO2-like protective coatings deposited by PECVD on a set of silver reference alloys submitted to a tarnishing test in the presence of H2S vapors

A nested hierarchical perspective to enhance interpretations and communication in fluvial geomorphology for use in water resources management: Lessons from the Okavango Delta, Botswana

A key skill that geomorphologists possess is the ability to use multi‐scale perspectives in their interpretations of landscapes. One way to gain these perspectives is with the use of nested hierarchical frameworks. In fluvial geomorphology, such frameworks help with assessment of large‐scale controls (e.g., tectonic activity, climate change) on the pattern and dynamics of smaller‐scale physical features (e.g., channels, floodplains, bars), and conversely illustrate how these smaller‐scale features provide the building blocks from which to make interpretations of fluvial processes and dynamics over larger spatial and temporal scales. Given the rapid pace of technological developments, the range of relatively inexpensive tools available for visualising and mapping landscapes at different spatial scales is expanding exponentially. In this paper, which focuses on the World Heritage‐listed Okavango Delta in Botswana, we demonstrate how various visualisations generated by different technologies at different spatial scales (catchment, landscape unit, reach, site and geomorphic unit) are providing critical baseline information to enhance interpretation and communication of fluvial geomorphology, with potential application in water resources management. In particular, our nested hierarchical approach could be used as an interactive communication tool for non‐specialists and embedded within existing and future management plans for the Delta. The construction of nested hierarchies that synthesise information and analyses can be a valuable addition to the environmental manager's toolki