Topographic data are widely used across the geosciences, as fundamental to landscape characterization, supporting numerical modelling and for monitoring topographic changes. Emerging technologies are now providing new opportunities (e.g. rapid data acquisition) and challenges (e.g. post-processing large data sets). Over the last decade laser-based instruments have dominated data provision for research, while recent advances in digital photogrammetry and computer vision, particularly in ‘structure from motion’ (SfM) algorithms, offer a new paradigm to geoscientists. Reduction in the difficulties of generating point clouds from 2D-image information has seen a rapid increase in topographic modelling.

These new techniques have the advantage of being a non-contact survey method, either ground-based (e.g. handheld cameras or Terrestrial Laser Scanning) or with aerial platforms (e.g. UAVs), avoiding unnecessary disturbance to extremely fragile surfaces. High resolution topographic (HiRT) data can be obtained and digital elevation models (DEMs) can be created in a fast and flexible manner. Multiple spatial-scale coverage is possible, from millimetres to kilometres. Moreover, temporal scales can be investigated from single events to lasting time series, or from sub-second to decades (cf. time-lapse), allowing evaluation of the dependencies between event magnitudes and frequencies. These capabilities of 4D-reconstruction are enabling new insights in diverse fields such as soil erosion, micro-topography reconstruction, volcanology, glaciology, landslide monitoring, and coastal and fluvial geomorphology. In addition, multi-scale HiRT can support the development, calibration and validation of landscape and erosion models. Broad data integration from multiple sensors is offering further exciting opportunities.

This session will evaluate the capability of new techniques to model topography and study patterns of topographic changes at multiple temporal and spatial scales. We invite contributions covering all aspects of HiRT reconstruction in the geosciences. Contributions that transfer traditional expertise or demonstrate a significant advance enabled by novel datasets are particularly welcome. We encourage contributions describing workflows that optimize data acquisition and post-processing to guarantee acceptable accuracies and to automate data application (e.g. geomorphic feature detection and tracking), and field-based experimental studies using novel multi-instrument and multi-scale methodologies. A major goal is the exchange of experiences with modern technologies as well as data processing tools, to highlight their potentials, limitations and challenges in different environments.

Confirmed keynote speaker: Dr. Nick Rosser (Durham University, UK) - 4D monitoring of actively failing rockslopes