Searching for the ideal river? New directions in geographical geomorphology

Abstract

Geomorphology’s development as a scientific subject has produced increasingly sophisticated insight into the physical processes shaping the earth’s surface. It is increasingly apparent, however, that understanding contemporary environments requires equal attention to the processes through which people’s aspirations for landscape are constructed and enacted. Building on and extending traditions of geographical geomorphology as the study of relations between people and landscape, this thesis draws attention to the politics of knowledge production in fluvial geomorphology and river management. Drawing on case studies from western China and Aotearoa New Zealand, the thesis demonstrates how the contemporary practice of geomorphology and river management are entangled with normative understandings of an ideal river. It advances this argument through three interventions focusing on geomorphic diversity, measurement, and the concept of river health. Beginning on the Qinghai-Tibetan Plateau, the first intervention proposes a broad understanding of geodiversity as a fundamental basis for understanding relationships between fluvial geomorphology and ecology. It highlights the role of historically-determined valley setting in the headwaters of the Yellow River as a key cross-scalar control on the contemporary river, sketching the outlines of a place-based approach to understanding relationships between form and process in the region. Inspired by conversations with colleagues during fieldwork on the Qinghai-Tibetan Plateau, the second intervention takes a step back to investigate the assumptions and ethical implications of geomorphology’s practice as an objective science. Drawing on contemporary developments in critical environmental geographies, and building on geomorphology’s rich but often-maligned history of methodological debate, it explores possibilities for more reflexive river science and management. Recognising the mutually constitutive relationship between geomorphic enquiry and landscape, this intervention presents an open-minded, constructive engagement towards a socially situated, reflexive physical geography. Returning specifically to freshwater, the third intervention investigates meanings of ‘good condition’ as a basis for river research and intervention. It follows the transition of river health from a holistic but hazy ethic of environmental care to specific sets of diagnostic indicators for guiding intervention. Tracing this transition from metaphor to metric, this third intervention examines how common-sense understandings of river condition were first challenged by, and then incorporated within, the scholarly and political project of river health. Arguing that a search for objectivity entrenched assumptions that naturalness was both desirable and attainable, it proposes a revitalised approach to river health as a platform for constructively renegotiating ‘what matters’ for freshwater. Finally, I consider the contemporary meaning of place as a basis for understanding and intervening in the landscape. Looking beyond binary notions of ‘place-based’ versus ‘placeless’ approaches to knowledge, I critically examine the implications and limitations of essentialist assertions of uncertainty. I conclude by out-lining potential new directions for a progressive geographical geomorphology that is grounded in scientific approaches to understanding landscapes, but which takes seriously the social and political contexts in which geomorphic knowledge is produced and used.