Estudio de procesos hidrológicos a diferentes escalas (marco teórico y propuesta metodológica)

Norba. Revista de geografía, ISSN 0213-3709, Nº 10, 1998, pags. 81-94 01/1998;
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    ABSTRACT: A framework is provided for scaling and scale issues in hydrology. The first section gives some basic definitions. This is important as researchers do not seem to have agreed on the meaning of concepts such as scale or upscaling. ‘Process scale’, ‘observation scale’ and ‘modelling (working) scale’ require different definitions. The second section discusses heterogeneity and variability in catchments and touches on the implications of randomness and organization for scaling. The third section addresses the linkages across scales from a modelling point of view. It is argued that upscaling typically consists of two steps: distributing and aggregating. Conversely, downscaling involves disaggregation and singling out. Different approaches are discussed for linking state variables, parameters, inputs and conceptualizations across scales. This section also deals with distributed parameter models, which are one way of linking conceptualizations across scales. The fourth section addresses the linkages across scales from a more holistic perspective dealing with dimensional analysis and similarity concepts. The main difference to the modelling point of view is that dimensional analysis and similarity concepts deal with complex processes in a much simpler fashion. Examples of dimensional analysis, similarity analysis and functional normalization in catchment hydrology are given. This section also briefly discusses fractals, which are a popular tool for quantifying variability across scales. The fifth section focuses on one particular aspect of this holistic view, discussing stream network analysis. The paper concludes with identifying key issues and gives some directions for future research.
    Hydrological Processes 03/1995; 9(3‐4):251 - 290. · 2.50 Impact Factor
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    ABSTRACT: 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.
    Science of The Total Environment 04/1996; 183(1):89-97. · 3.16 Impact Factor

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