Geomorphometry is the science of quantitative land surface analysis. It gathers various mathematical, statistical and image processing techniques to quantify morphological, hydrological, ecological and other aspects of a land surface. Common synonyms for geomorphometry are geomorphological analysis, terrain morphometry or terrain analysis and land surface analysis. The typical input to geomorphometric analysis is a square-grid representation of the land surface: a digital elevation (or land surface) model.
The first Geomorphometry conference dates back to 2009 and it took place in Zürich, Switzerland. Subsequent events were in Redlands (California), Nánjīng (China), Poznan (Poland) and Boulder (Colorado), at about two years intervals. The International Society for Geomorphometry (ISG) and the Organizing Committee scheduled the sixth Geomorphometry conference in Perugia, Italy, June 2020. Worldwide safety measures dictated the event could not be held in presence, and we excluded the possibility to hold the conference remotely. Thus, we postponed the event by one year – it will be organized in June 2021, in Perugia, hosted by the Research Institute for Geo-Hydrological Protection of the Italian National Research Council (CNR IRPI) and the Department of Physics and Geology of the University of Perugia.
One of the reasons why we postponed the conference, instead of canceling, was the encouraging number of submitted abstracts. Abstracts are actually short papers consisting of four pages, including figures and references, and they were peer-reviewed by the Scientific Committee of the conference. This book is a collection of the contributions revised by the authors after peer review. We grouped them in seven classes, as follows:

• Data and methods (12 abstracts)
• Geoheritage (6 abstracts)
• Glacial processes (9 abstracts)
• LIDAR and high resolution data (6 abstracts)
• Morphotectonics (8 abstracts)
• Natural hazards (11 abstracts)
• Soil erosion and fluvial processes (17 abstracts)

The 69 abstracts represent 80% of the initial contributions. The remaining ones were either not accepted after peer review or withdrawn by their Authors. Most of the contributions contain original material, and an extended version of a subset of them will be included in a special issue of a regular journal publication.

Three keynote speakers were scheduled for the conference: Marco Cavalli, Igor V. Florinsky and Michael Hutchinson. Prof. Hutchinson is the recipient of the ISG’s Lifetime Achievement Award.

Marco Cavalli is researcher at CNR IRPI Padova since 2009. His research interests mainly focus on the development and application of geomorphometric approaches to LiDAR data and high-resolution Digital Terrain Models with specific attention to geomorphic processes and sediment dynamics in mountain catchments. His main works concerned the development of indices of surface roughness and sediment connectivity along with the use of DEM differencing techniques to assess geomorphic changes.

Igor V. Florinsky is a Principal Research Scientist at the Institute of Mathematical Problems of Biology, Keldysh Institute of Applied Mathematics at the Russian Academy of Sciences. He is the author or editor of over 150 publications including 4 books and 60 papers in peer-reviewed journals. His research interests include theory, methods, and applications of digital terrain modeling and geomorphometry, as well as the influence of geological environment on humans, society, and civilization.

Michael Hutchinson is recognized internationally for his contributions to the theory and practice of spatial and temporal analysis of environmental data. His methods for modelling of climate and terrain, as implemented in the ANUDEM, ANUSPLIN and ANUCLIM computer packages, are widely used to support hydrological and ecological modelling and the assessment of the impacts of climate change. His Australia-wide terrain and climate models have underpinned much of the natural resource and environmental analysis carried out by Australian Universities and Natural Resource Agencies over the last 30 years.

T4E Technology four Elements

– Massimiliano Alvioli (CNR IRPI)
– Ivan Marchesini (CNR IRPI)
– Laura Melelli (Università di Perugia)
– Peter Guth (US Naval Academy)
– Scott Peckham (University of Colorado)

Alexander Brenning Friedrich Schiller University
A-Xing Zhu University of Wisconsin
Carlos Grohman University of Sao Paolo
Hannes I. Reuter ISRIC – World Soil Information
Helena Mitasova North Carolina State University
Ian Evans Durham University
Jaroslav Hofierka University of Presov
John Gallant CSIRO
John Lindsay University of Guelph
Lucian Dragut West University of Timisoara
Massimiliano Alvioli CNR IRPI Perugia
Mihai Niculita University Al. I. Cuza
Peter L. Guth US Naval Academy
Qiming Zhou Hong Kong Baptist University
Qin Cheng-Zhi Chinese Academy of Sciences
Robert A. MacMillan LandMapper Environmental Solutions Inc.
Samantha Arundel USGS
Steve Kopp ESRI
Tomislav Hengl OpenGeoHub Foundation