THE ROLE OF SCALE IN RESEARCH ON THE HIMALAYA-GANGES-BRAHMAPUTRA INTERACTION

This paper investigates the role of scale in research on the link betw een the Himalaya-Ganges-Brahmaputra. fluvial system and floods in Bang ladesh. Fifty-two studies, ranging from one hectare to near continenta l scales, were reviewed for variables selected in analysis and researc h designs. Three overall patterns of scale dependence were identified. The first is dominated by the precision with which scales and study a rea are defined. Local studies tend to have temporal and spatial scale s which are explicitly defined while continental scale studies are dom inated by general and abstract or implicitly defined scales. The secon d pattern indicates that local scale studies tend to focus upon physic al variables such as rainfall, runoff, and mass wasting, while researc h at the regional and continental scales focuses on natural resource t opics such as land-use change and flood mitigation policy. The third p attern identifies the degree to which studies attempt to scale up to l arger regions from local scale studies. Specifically, this final patte rn identifies a scale independent model which upscales stream discharg e/sediment load across all three scales. The topics examined and resea rch results presented are clearly scale dependent. It is proposed that scale perspectives are partially responsible for shaping opposing the ories in the debate over the causes of flooding in Bangladesh. In conc lusion, three strategies are outlined that may assist future research to incorporate multi-scale analysis of flooding in Bangladesh.