The limits of splitting: Hydrology

Hydrology and the other environmental sciences need to re-evaluate their approach to the scientific study of the problems with which they deal; there is a fundamental conflict between the scale of experiments and the scale of problems of significance. This conflict will not be resolved in hydrology with the range of measurement techniques that are currently available and, for good reasons, cannot be solved by theoretical reasoning alone. An interim approach is advocated, in which hypotheses to be tested and predictive models are formulated from a disaggregation point of view, rather than the futile attempts at aggregation represented by most of today's 'physically-based' theorising. Such an approach must recognise explicitly the equifinality and uncertainty that will accompany the limitations of disaggregation from a larger scale, but can, in fact, use uncertainty as a tool in working towards more realistic theory, as and when new data and measurement techniques become available.