Presentation short abstract

This paper explores how photography can render groundwater governance visible by tracing the surface signs of subsurface extraction. Through the concept of "mosaic evidence", I consider how photographic images index the invisible politics of California’s depleting aquifers.

Presentation long abstract

"Indexing the Invisible" examines the visual and epistemic challenges of photographing climate change and aquifer depletion in California’s Central Valley, where decades of agricultural extraction have caused the earth to subside by more than twenty feet. Drawing on fieldwork from the small farming town of Corcoran, I develop the concept of "mosaic evidence" to describe how multiple, fragmentary visual traces can collectively index seemingly-invisible hydrosocial processes. While aquifers are materially real, they resist direct representation, and must be constructed semiotically through surface signs of cracks, landscapes, labor, and infrastructure. The camera becomes a tool for tracing the causal residues of extraction, where photography’s indexicality allows the invisible to be known through its effects rather than its presence. Situating this inquiry at the intersection of political ecology, media studies, and visual anthropology, I argue that the act of photographing subsidence mirrors the very problem of representation it seeks to solve, by making the invisible visible through signs of loss. Yet by assembling diverse images and temporalities, "mosaic evidence" offers a counter-practice that rearticulates the relation between visibility and proof. This paper thus proposes a visual anthropology of groundwater that interrogates the separations of above and below, showing how environmental images both reflect and reconfigure the governance regimes through which waters—and their absences—are made legible.