Conceptualization and scale in hydrology

Abstract

It is argued that the levels of scale at which a meaningful conceptualization of physical processes is possible are not arbitrary and their range is not continuous. Formulations appropriate at a given level usually are not applicable at the immediately adjoining levels. This is seen as one of the important reasons for the slow progress of hydrological science on basin scale since it is dominated by different effects than those observed at the immediately lower level of channel reaches and hillslopes which represent the focus of current hydrological research. The search for an appropriate level of conceptualization can proceed either upward or downward along the hierarchy of scales. Both possibilities are discussed and an example of the downward route is given. © 1983.