THE LIMITS OF SPLITTING - HYDROLOGY

Hydrology and the other environmental sciences need to re-evaluate the ir approach to the scientific study of the problems with which they de al; there is a fundamental conflict between the scale of experiments a nd the scale of problems of significance. This conflict will not be re solved in hydrology with the range of measurement techniques that are currently available and, for good reasons, cannot be solved by theoret ical reasoning alone. An interim approach is advocated, in which hypot heses to be tested and predictive models are formulated from a disaggr egation 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 th at will accompany the limitations of disaggregation from a larger scal e, but can, in fact, use uncertainty as a tool in working towards more realistic theory, as and when new data and measurement techniques bec ome available.