Stow Research Group

The research group of Dr. Doug Stow, Distinguished Professor of Geography at San Diego State University, emphasizes multi-temporal remote sensing for a wide range of applications and techniques. Multi-temporal remote sensing pertains to the processing and analysis of images captured by sensors on aerial and satellite platforms for the same locations over time. Access to multi-temporal data provides users with the ability to monitor and study land surface dynamics associated with human activities and natural processes; update maps; and track changes in infrastructure, as well as movements of people, plants and animals. More specifically, Dr. Stow and his team of students, post-docs and staff currently conduct research within the following realms: (1) wildfire processes and postfire vegetation recovery; (2) mapping and monitoring of vegetation, habitat and wildlife; (3) land use and land cover change associated with urbanization; and (4) repeat station imaging for detailed change detection and inspection. Current projects and participants are summarized below.

Projects

Wildfire processes and postfire vegetation recovery

Southern California is particularly prone to large, catastrophic fires, making it worthwhile to better understand how wildfires spread and how vegetation recovers after burning. With support from the National Science Foundation (NSF), Stow, his SDSU team, and collaborators with the U.S. Forest Service and National Center for Atmospheric Research are developing and testing new approaches for: (1) measuring rates of wildfire spread through repetitive airborne thermal infrared imaging and (2) understanding how fuels, topography and weather control spread rates. Gavin Schag is completing his MS thesis research on how fuel and topography influence the rate of wildfire spread.

Others in the research group study how well chaparral shrub communities have recovered from multiple fires and drought over the past 35 years, based on the archived record of Landsat satellite imagery. Dr. Emanuel (Manny) Storey defended his doctoral dissertation on this topic, which was supported by a NASA Earth Science Fellowship. He will continue on this research path as a post-doctoral researcher supported by a grant from the California Strategic Growth Council. Manny, a new doctoral student, Krista West, and SDSU-UCSB joint doctoral program (JDP) alumna, Alexandra Syphard, and Stow are collaborating with a large team of primarily SDSU investigators to develop data, tools and knowledge pertaining to the interaction of climate change, fire, hydrology, habitat connectivity and at-risk human communities in southern California. Krista’s research emphasizes the changing wildfire risk to communities in and near the wildland-urban interface, associated with climate and vegetation change.

Mapping and monitoring vegetation, habitat and wildlife

Dr. Kellie Uyeda, a post-doctoral researcher and alumna of the JDP, is leading efforts to map vegetation communities and monitor important shrub habitat for San Clemente Island. These research and development activities are funded by the U.S. Navy, which uses the island for military training and also is responsible for managing its natural resources. Kellie collaborates with Professors John O’Leary and Stow, a current MS student, Kelsey Warkentin, and SDSU Soil Ecology Research Group staff. Kelsey is testing various aerial imagery and image processing techniques for reliable shrub cover monitoring through her MS thesis research. Dr. Uyeda is also supported by the U.S. Forest Service to generate maps of drought effects on vegetation throughout the western U.S.

As part of an NSF Complex Human-Environment Systems (CNH) funded project for which Geography Professor Li An is P.I., MS student Blair Mirka and Stow are developing and testing techniques for using thermal infrared (TIR) sensors on drones to detect and locate monkeys. The study area for the CNH project is the Fanjingshan National Nature Reserve (FNNR) in the Guizhou Province of China, and snubbed nose monkeys are the rare and shy “targets” of interest. This (2019) summer, Blair is in Austria as a Marshall Plan Foundation Visiting Scholar, and is working with researchers at Carinthia University on the drone TIR monkey detection research at a nearby zoo. Blair’s MS thesis results will inform drone TIR imaging studies at the FNNR. Blair is also building upon the research of Dr. Yu-Hsin Tsai, a recent JDP graduate, to map locations of afforested plots associated with rural residents near the FNNR who participate in payment for ecosystem programs implemented by the national government of China.

Land use and land cover change associated with urbanization

Distinguished Emeritus Professor John Weeks and Stow were funded for over the past decade by NASA and NIH to conduct research on rural-to-urban migration and associated land use change in Ghana. Building on his MS thesis research pertaining to land use change analysis in southern Ghana, doctoral student Hsiao-Chien (Ace) Shih is studying the relationship between migration and population change with land use change associated with urbanization in Taiwan, his home country. This research exploits unique data sets for annual population change and land use change based on dense Landsat satellite image time series.

Repeat station imaging for detailed change detection and inspection

For over 20 years, research and campus GIS database staff member Pete Coulter and Stow have conducted research on detecting very detailed changes of land surfaces and built features. This is based on relatively low-cost aerial imaging systems and a new approach to capturing and co-aligning images captured over time called repeat station imaging (RSI). RSI supports applications such as law enforcement, post-hazard damage assessment, and even detection of monkeys, as mentioned above. This research was funded by federal agencies such as DHS, NASA and NSF. Coulter and Stow have four issued U.S. patents related to this technology and are collaborating with a local company to commercialize this intellectual property. Doctoral student Andy Loerch’s dissertation research builds on RSI image capture with drones and co-alignment techniques, and integrates advanced machine learning object classifiers to automatically detect damage to built structures and infrastructure following earthquakes and other hazards. Drone image capture, using survey-grade GPS and image co-alignment software tools that Andy is developing and testing, are providing prototypes for commercial applications with Coulter and Stow.

Current grants, contracts and cooperative agreements

  • NSF Geography and Spatial Sciences, Landscape-level Measurements of and Controls on Wildfire Spread Rates, $295,000, 2016-2019.
  • NASA, Earth Science Fellowship, Emanuel Storey, $82,000, 2017-2019.
  • US Forest Service, Effects of Drought Stress and Forest Management on Fire Behavior and Post-Fire Forest Structure in a Western Coniferous Forest, $92,000, 2018 – 2024.
  • US Navy, Shrub Cover Monitoring and Sensitivity Analyses of Vegetation Community Maps for San Clemente Island, CA, $226,861, 2018-2019.
  • California Strategic Growth Council, Climate Smart Connectivity Planning for Southern California Communities, (Megan Jennings and Rebecca Lewison, Co-P.I.s), $1,800,000, 2019-2023.
  • Co-Investigator, National Science Foundation Award “CNH-L: People, Place, and Payments in Complex Human-Environment Systems, Impacts of Ecosystem Service Payments in Coupled Natural and Human Systems (Li An, P.I.), $1,450,000, 2018-2022.