Pete Chirico will be presenting “Temporal Geomorphic Change Mapping using SfM DEMs from Historical Aerial Photography as a Complement to 3DEP Lidar Data” at the next GeoBytes webinar on Friday, March 12th at 12:00 pm EST. The webinar is FREE for all CaGIS members.
Please see the CaGIS GeoBytes page for more information on registering.
Abstract
Increasing urbanization and suburban growth in cities globally has highlighted the importance of land planning using detailed geomorphologic maps that depict anthropogenic landform changes. Such mapping provides information crucial for land management and the challenges arising from urbanization. The development and use of quantitative and repeatable methods to map anthropogenic and natural processes are required to advance the science of urban geomorphological mapping. This study created digital terrain models (DTMs) from historical aerial images using Structure from Motion (SfM) for a variety of image dates, resolutions, and photo scales. Accuracy assessments were performed on the SfM DTMs, and they were compared to the USGS’s three-dimensional digital elevation program (3DEP) light detection and ranging (lidar) DTMs to evaluate geomorphic change thresholds based on vertical accuracy assessments and elevation change methodologies. The results of this study document a relationship between historical aerial photo scales and predicted vertical accuracy of the resultant DTMs. The results may be used to assess geomorphic change thresholds over multi-decadal timescales depending on spatial scale, resolution, and accuracy requirements. Further, the work presented contributes to a discussion about the growing importance of sequential elevation change detection to complement land-cover/land-use change mapping in urban and natural environments.
Pete Chirico is the Associate Center Director of the USGS Bascom Geoscience Center in Reston, VA. In over 24 years at USGS, he has focused his research on various aspects of remote sensing and geomorphology including anthropogenic landform change and mapping and monitoring illicit small-scale mining in conflict zones. Pete develops tools and techniques to map elevation change from sequential digital elevation models from a variety of remote sensing sources including aerial photography, satellite imagery, lidar and structure-from-motion photogrammetry. He has worked extensively with the U.S. Government, the United Nations, and the Kimberley Process to understand how natural resource exploitation contribute to conflict financing. While his regional expertise is Sub-Saharan Africa, he has led or been a member of more than 30 field expeditions throughout Central America and the Caribbean, the Middle East, and Africa. He is author/coauthor of over 50 peer reviewed scientific reports and journal articles in the fields of geography, geomorphology, remote sensing, and natural resources. Since 2017, Pete has served as scientific
and technical advisor to the Office of Threat Finance Countermeasures in the Department of State’s Bureau of Economic and Business Affairs. In February 2021, Pete was awarded a US Embassy Science Fellowship to the US Embassy in Georgetown, Guyana to focus on mapping forest and land-cover changes due to small-scale gold mining using radar remote sensing and geospatial modelling techniques. Degrees: PhD Candidate (expected 2022) in Geography and Environmental Systems, University of Maryland Baltimore County (UMBC); MA in Geography, University of South Carolina; and BA in Geography, University of Mary Washington.