The first catchment water balance: New insights into Pierre Perrault, his perceptual model and his peculiar catchment

Abstract

ABSTRACT Pierre Perrault and his 1674 book De l’Origine des Fontaines are widely acknowledged in hydrology as the first formal articulation of the catchment water balance based on field data. Many summaries of his work have now been written, but few of these summaries have examined Perrault’s perceptual model in detail and none that we are aware of have gone back to his study catchment to collect new data in which to frame these historic findings in a modern context. Here we report new insights (with re-calculations of some of his analyses) into Perrault’s work, his perceptual model of streamflow generation and his rather peculiar 119 km2 headwater catchment of the Seine River basin. We show the uncertainty of his flow and catchment area estimates, some errors in perception about hydrological flowpaths and new age estimates for the spring-fed site where he worked. Despite these modern criticisms and updates, Perrault’s place in hydrological history is secure: he was the first to bring quantitative analysis to fundamental questions of the terrestrial water cycle.