Humans are Earth too: Hydrology, stream restoration, and the human side of Earth science

Abstract

Human beings (Homo sapiens) influence the Earth in profound and multifaceted ways. Humans directly alter geologic processes, including sediment transport, altered hydrologic pathways, and more. Humans also benefit and suffer from geologic processes – access to water, greenspace, and hazards. And human processes, including discrimination and power dynamics affect where and how science is done. My dissertation addresses each of these dimensions of human/Earth interaction. I begin with a human → Earth interaction by analyzing the influence of climate change and land-use change on streamflow in Minnesota and Wisconsin. We find that precipitation change has been consistent across the region, but streamflow response has been variable. Watersheds in (geologically) recently glaciated central and western Minnesota had greater streamflow increases than watersheds in eastern Minnesota and the western Wisconsin Driftless Area. This streamflow response also maps onto land-use change, as watersheds with glacial till have more agriculture drainage. Information-theory metrics reveal inconsistent patterns in the relationship between precipitation and streamflow, underscoring the hydrologic complexity of the upper Midwest. I then explore an interrelated human ↔ Earth system by developing a new stream restoration database for the state of Minnesota and exploring the environmental justice implications of restoration siting. We find that restoration projects are systematically located in whiter and more affluent locations compared to the overall population of the state. Restoration projects are also responsive to environmental degradation, as restored streams are more likely to be impaired than average streams in the state. Finally, I explore human aspects of the geosciences through three chapters: I present reflections and recommendations from my time balancing life as a geoscientist and a black resident of South Minneapolis following the murder of George Floyd in summer 2020, with a focus on how greater institutional risk is needed to truly advance visions of diversity equity and justice. I describe the pedagogical underpinnings of field learning via a literature review in geoscience, environmental science, and ecology. We find that active learning, co-creation of knowledge, rapid feedback, and place-based learning are key reasons that students learn during field trips. Finally, I offer reflections from a community science event hosted between local organizations and the Department of Earth & Environmental Sciences. Attendees considered the event a success and there were many positive and negative lessons to implement in future attempts to bridge the divide between university and non-university partners. These diverse projects illustrate a multitude of ways that humans influence and interact with the Earth, and underscore the need to consider human processes as a key element of the Earth system.