Perceptions of scale in hydrology: what do you mean by regional scale?

Abstract

The discipline of hydrology has a long history of research in the practical and theoretical aspects of scaling and scale issues, but little effort has focused on hydrologists' perception of the scale terms. What exactly do hydrologists mean when they use the terms ‘pore scale’ or ‘regional scale’? The application of hydrologic research requires clear communication both within the discipline, and with a broader audience. Quantitative and qualitative data on hydrologists' perceptions of scale were collected using voluntary written surveys and face-to-face interviews. Results suggest that most hydrologists do not consistently define scale terms in the literature and that this is a minor impediment when interacting with other disciplines and stakeholders. Yet surface water and groundwater hydrologists agree, within one to two orders of magnitude, on the length scale for most scale terms. Most respondents suggest the hydrologic community needs to better define the length scale of scale terms. In the short-term hydrologists could more frequently and consistently clarify their own length scales whenever a scale term is used. A common and consistent language of scale for hydrologic researchers could better enable communication, research, pedagogy, and outreach.