Dr. Jessica Meyer, Assistant Professor, Earth & Environmental Sciences - University of Iowa: "Characterizing water and solute exchanges between groundwater and human impacted lakes and streams"

Although groundwater and surface water are often conceptualized and managed as separate resources, they are typically very closely linked via the exchange of water, solutes, and energy. Although these linkages are well known they are not always well understood. This is particularly true in complex hydrogeologic settings and/or with respect to new and emerging contaminants. This presentation will describe two separate studies focused on characterizing water and solute exchange between groundwater and surface water. The overall objective of the first study is to describe the spatial and temporal variability in water and iron exchange between a ferruginous, meromictic kettle lake and the underlying groundwater system in Minneapolis, Minnesota. Improving our understanding of the scale and variability of these exchanges is critical to constraining the coupled biogeochemical cycling of iron and carbon in ferruginous, meromictic lakes in previously glaciated terrains. The overall objective of the second study is to determine if and how groundwater participates in the attenuation of complex mixtures of wastewater effluent derived contaminants in Muddy Creek, a small effluent dominated stream in Coralville, Iowa. The contaminants of interest include pharmaceuticals, neonicotinoids, and per- and polyfluoroalkyl substances (PFAS). Advancing our understanding of attenuation mechanisms for these complex mixtures in streams like Muddy Creek will contribute to our overall understanding of wastewater impacts on receiving streams in temperate environments, which are increasing due to urbanization and climate change. The results of both studies highlight the importance of opening up the ‘black box’ of the groundwater system with a diverse set of field measurements (e.g., geologic, hydraulic, biogeochemical) made at multiple scales to advance our understanding of water and solute exchange in these systems.

Dr. Caglar Koylu, Associate Professor, Geographical & Sustainability Studies - University of Iowa: "Analysis of U.S. internal migration using population-scale family tree data, 1789-1930"

Analysis of long-term migration data is crucial for understanding the changing nature of the drivers of migration, regional disparities, demographic changes, and climate variability. Specifically, in the context of the U.S., the study of long-term migration is distinct because the European settlement was significantly influenced by land resources and economic prospects, highlighting the unique role of geographic and demographic expansion in shaping the nation's complex history, mindful of the profound effects on Indigenous populations. The increasing availability of digitized historical sources on genealogy websites have enabled numerous individuals to assemble and share their family trees. Only a handful of research teams have leveraged extensive datasets of user-contributed family trees, and cleaned, connected and deduplicated them to generate population-scale family trees to investigate social processes, particularly migration. In this presentation, Dr. Koylu will shed light on his team’s efforts to construct the largest connected family tree to date, connecting 40 million relatives spanning across several centuries and continents. He will delve into the innovative techniques that harness the power of geographic information science to analyze and visualize big family tree data. These efforts enable the assessment of how representative the tree data is of the overall population in the U.S., the exploration of migration patterns and kinship networks across geographic space and time and provide valuable insights and historical context crucial for understanding the ongoing socio-economic and demographic transformations.