The sensitivity of hydrological models to spatial rainfall patterns: an evaluation using observed data

摘要: Spatial variability of rainfall is often considered as a major source temporal in the resulting basin hydrograph. Since direct experimental evidence not available, this must be verified through modelling approach, provided adequate data are available. A semidistributed version TOPMODEL has therefore been applied to Real Collobrier (71 km2 southeast France with 21 recording raingauges) using an hourly time step and series independent events. First, set reference results built under assumption spatial uniformity for rainfall. Two different densities network have tested (including 5 or gauges), showing significant advantage dense estimate. Next, field confirmed, commonly factor 3 between simultaneous average over subcatchment areas 6–8 km2. However, model response reflects only secondary peaks which usually order magnitude smaller than bulk hydrograph always present observed discharges. An extended discussion considers if these may dependent on setting up numerical experiments. In fact, it seems that rainfall, although important, sufficiently organized space overcome effects smoothing dampening when running off rural medium-sized catchment. Such hold urbanized larger basins.