Study of vegetal cover influence on experimental erosion plots by a runoff-erosion modeling

Abstract

The present paper describes the observed data concerning water erosion for different experimental plots of São João do Cariri experimental basin located in a typical semiarid region of Brazil. The semiarid area of Paraíba state presents long drought periods, different types of vegetal cover and great spatial variability of intense rainfall events. All those factors are condicionantes to the erosion process, since they directly influence the sediment yield, agricultural soil loss and, consequently, the degradation of rural areas.This study presents the application of KINEROS2 model (kinematic runoff and erosion model), to the erosion plots of 100 m 2 in São João do Cariri experimental basin located in the semiarid area of Paraíba state. The main objective of this work is to model the erosion process and to try to quantify the influence of the vegetal cover and slope degree for several events observed into two erosion experimental plots. The application of the model enclosed the selection of the precipitation data and calibration of the physical basin parameters. The observed data showed that these bare plots presented, larger sediment yield than when they are with vegetal cover. The simulation results showed that the initial degree of soil saturation (S i ) and the rain splash coefficient (c f ) were the most sensitive parameters during the calibration process, presenting small values of S i for the bare plots and small values of c f for the plots with vegetal cover. Finally, the results showed that the KINEROS2 model can be also considered a promising tool for the simulation of the runoff and erosion processes in the semiarid area of northeastern Brazil.