Influência da precipitação sobre a lâmina escoada e produção de sedimentos em parcelas de 100 M2.

Abstract

Studies carried out in small scale and small-scale experimental areas indicate that there is an influence of vegetation cover on runoff generation and sediment production, but there are few studies that attempt to associate the effects and relationship of daily rainfall height and of vegetation cover on runoff generation and sediment production. This work has as main research problem, to evaluate the influence of the precipitation height on the runoff and sediment production in two experimental plots of 100 m2, considering the effect of the previous precipitation and the vegetation cover. The values ​​obtained from precipitation, runoff and sediment production used in this work are part of the data collection of the São João do Cariri Experimental Basin of the Center for Technology and Natural Resources of the Federal University of Campina Grande. Two hundred and seventy-five precipitation events with consequent runoff were used where it was possible to identify thirteen groups of the same precipitation height, which resulted in forty-six events, with different values ​​of runoff and sediment production from 1999 to 2015. In an attempt to explain the differences in runoff and sediment production, we conducted an assessment of the existence of antecedent rainfall. The results indicate a reduction of up to 100% of runoff and sediment production in plot 2 in relation to plot 1 in the first period of fallow regime. Evaluating the thirteen groups of the same precipitation height it was concluded that the rainfall prior to the precipitation events with consequent runoff influence the runoff generation and sediment production and that there is no function that represents well the existence of a relationship between the precipitation. daily and the slide drained as well as with sediment production. The best functional relationships obtained were the second degree polynomials with coefficients of determination R² ranging from 0.6 to 0.71.