The politics of data in the history of the Earth sciences: The case of fluvial geomorphology
with Dr Etienne Bensen

 In this talk I focus on the history of fluvial geomorphology, in particular developments in the quantitative study of rivers and landscapes in the United States in the mid-20th century. The story is a clear example of the phrase of Auguste Comte (1798–1857) that is the motto of HOGG: "To understand a science it is necessary to understand its history".

I show how, in the 1950s, the emergence of modelling in geomorphology and new ways of thinking about rivers – as advocated by Arthur Strahler, John Hack, Luna Leopold, and others – depended not only on the adoption of systems theory but also on new ways of acquiring, organizing, and valuing geoscientific knowledge.  A vast collection of stream-gauge data held by the U.S. Geological Survey, for example, which had once been used mainly for practical local purposes (flood prediction, irrigation management, etc.) was transformed during this period into scientific evidence for universal models of river behaviour.

Luna Leopold in the field on the bank of the East Fork River near Boulder, Wyoming USA

This transformation had political and economic aims, as well as for geoscientific knowledge . 

The geomorphologists who developed these universal models argued that they were better positioned understand and predict rivers than the hydrologists, water managers, and stream-gaugers who could only draw on their observation of a few specific rivers. They sought to use new models of rivers to establish a new form of expertise, and thereby to displace an older form of expertise. And they hoped that this new expertise would allow them to shape the development of water resources in the United States. They were not entirely successful, but their efforts nonetheless had consequences and shed some light on the development of the Earth sciences in the second half of the 20th century.

One of Strahler's models - the relation between drainage density and a related index, the texture ratio. Strahler applied and tested his models on different geology across the USA.

One of the lessons we can draw from this history is the importance of the material and social context for determining whether and how quantification and precision in the Earth sciences are seen as adding to or subtracting from the authority of the expert geoscientist - whether in the past or today. As such, this history has strong resonance with contemporary geoscientific issues and the generation of geo-scientific knowledge and its application in policy-making and public acceptance.

Dr Etienne Bensen is Director of Department II, Knowledge Systems and Collective Life at the Max Planck Institute for the History of Science, Berlin.
His current work examines the political and scientific implications of the development of a quantitative science of landscapes in the mid-twentieth century.