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Our planet’s surface is constantly being reshaped by natural processes and occurring on a range of timescales. Today, however, human activities are accelerating these changes faster than ever before. To better understand these rapid shifts, EUC Professors Adeyemi Olusola and Joshua Thienpont from 91��ɫ’s Faculty of Environmental and Urban Change are carrying out cutting-edge research across Canada, supported by infrastructure funded through the . Using the latest technological advancements in field-based surveying, laboratory sample analysis, and computing, the project aims to understand how and why environmental geohazards are impacting ecosystem sensitivity across Canada. The research activities, collectively brought together under the theme of “Landscapes in Transition” investigate how climate change modifies temperate, Arctic, and subtropical terrains. With a combined expertise, Thienpont and Olusola intend to turn complex environmental data into practical solutions for communities and decision-makers.

A central concept driving their work is environmental memory, the idea that modern landscapes carry the imprints of their past changes, which can influence future response. This memory can manifest in varying ways, such as climatic memory, where past weather patterns dictate current landscape shapes, or anthropogenic memory, where historical human land use continues to disrupt modern water flows and sediment movement. Due to our terrain carrying these legacies of past environmental change, predicting the future requires us to examine how past and present drivers interact. Ultimately, the research seeks to answer a core question: what are the cumulative consequences of these combined pressures, and how sensitive will these environments be in a rapidly warming world?

Olusola is leading research on these environmental pressures within the river and lake systems of the Lake Ontario Basin. Although it’s the smallest of the Great Lakes, Lake Ontario features the highest ratio of watershed area to lake surface area, making its river catchments highly sensitive to climate-driven hazards. His research tracks the past, present, and future trajectories of extreme events such as severe droughts, flooding, and soil erosion, each of which reshapes the basin’s water systems in different ways. When water moves eroded soil into lake systems, it can damage aquatic habitats, lower water quality, and transport toxic chemicals. To track and anticipate these changes, his team combines several advanced monitoring approaches, including laser-equipped drones, river velocitimeters, and machine learning algorithms.

As Olusola explains, “compared to traditional methods, these techniques allow us to cover larger areas, improve large-scale mapping and upscaling, and rapidly evaluate and monitor the emergence of flooding and drought within the Great Lakes basin.” Supported by high-end computing infrastructure acquired through a CFI-JELF grant, this advanced toolkit enables the team at the to conduct large-scale analyses across the Great Lakes Basin to study these events.

Shifting focus to Canada’s north, Thienpont, who is part of the brings twenty years of field experience to investigate the rapidly warming permafrost landscapes of the western Arctic. Permafrost underlies roughly half of Canada’s land surface, and as temperatures rise, this frozen ground is thawing rapidly. In ice-rich, hilly terrain, this triggers large-scale landslides called retrogressive thaw slumps, which dump massive volumes of sediment into downstream rivers and lakes. Thienpont’s work examines how the sediment legacy of past thaw slumping impacts how these disturbances alter water chemistry and biological life and how new thaw slumps occurring because of ongoing climate change differ from those that occurred in the past. By extracting deep lake sediment cores to study past environmental conditions, his team can look back thousands of years to see how prior warming periods triggered similar ecosystem responses.

As Thienpont notes, “One newly acquired tool, the vibracorer, allows us to collect sediment records from locations and over timescales that we were previously unable to do so. This includes thick sediment records from areas impacted by inputs from terrestrial landslides or rivers or contiguous cores stretching 3+ metres that span the entire Holocene in some northern environments. For lakes in permafrost regions, it will allow comparisons between lakes with different histories of past thaw in order to understand how past thaw episodes modify future risk of further permafrost degradation.”

While their field sites sit thousands of kilometres apart, Olusola and Thienpont share a complementary vision rooted in physical geography. Their combined supported equipment package allows them to address a broad range of research questions about landscape vulnerability and resilience. Their research collaborates directly with partners that include Indigenous rightsholders, local conservation authorities, government researchers, and industrial partners. The infrastructure enabled not only by  CFI-JELF, NSERC, Government of Northwest Territories, Canada Water Agency, among others, provide researchers and student trainees in EUC as well as other 91��ɫ Faculties with critical environmental data that will be used to ensure that communities are better equipped to adapt to future landscape changes.