Author(s): Vajapeyam S. Srinivasan; Walszon T. A. Lopes; Eduardo E. Figueiredo
Linked Author(s): Vajapeyam S. Srinivasan
Keywords: Runoff-Erosion Modelling; Scale Effect; Semiarid Region Of Brazil
Abstract: In this study, two runoff-erosion models, distributed and event oriented, Kineros2 (Kinematic Runoff and Erosion Model) and WESP (Watershed Erosion Simulation Program), have been used to investigate the scale effects on their parameters, when they applied to hydrologic basins varying in size from 100 m2 of experimental erosion plots to a major sub-basin of 140 km2. The Kineros2 model was applied to nine 100 m2 plots and four microbasins (0,5 ha-1.0 ha) of the Experimental Basin of Sume (EBS) and to three sub-basins 10 km2 to 140 km2 area of the Representative Basin of Sume (RBS), located in the semiarid region of the State of Paraiba, in the northeastern region of Brazil. The model WESP was applied only to the three sub-basins, since it had already been applied to the experimental units of the EBS in earlier studies. The results show that the main parameters of the Kineros2 model, the effective net capillary drive (G) of the Smith and Parlange infiltration equation and the parameter relative to the splash erosion, cf, suffer scale effect. It was also found out that the parameter Ns of the Green and Ampt infiltration equation, used in the WESP model, also varies with the watershed size and hence subject to the effect of scale.
Year: 2004