Analysis and quantification of erosion by splash effect speckling on a quartzarenic neosol of the state university of Feira De Santana (BA)

Abstract

Erosion is a natural process of the Earth, which has been occurring over time, preceding even the first forms of life on the planet. Before these first forms of life existed, erosion was quite intense, because the rocks and soils were exposed to atmospheric weather, but with the appearance of plant life, this intensity of erosion was drastically reduced, thus causing the formation of thick soils. However, with the appearance of man and his modifications in nature, this process considered natural began to accelerate again, thus breaking the balance between erosion and soil formation, since to have the formation of 1 cm of the same, it is estimated approximately four centuries, while in a few years with anthropography, tons of soils can be lost through accelerated erosion. The "splash effect" also known as splash erosion, is the first stage of the erosive process, in which the particles that make up the soil are prepared to be transported by surface runoff, and this Preparation can occur in two ways: By breaking the aggregates, which consequently tends to reduce the size of the particles, or by their transport at the beginning of splashing, causing them to occupy the pores of the soil, covering it and preventing water from infiltrating, and so the tendency is for surface runoff to occur in the soil. But it is necessary to emphasize that the action of the splash effect under the soil is conditioned not only by the resistance that each soil presents to this phenomenon but also by the kinetic energy of the raindrops (GUERRA et al., 2007, p. 18). Bertoni & Lombardi Neto (1993) when studying the behavior of soil with an exposed surface found that the greater the intensity of rainfall (mm/h), the greater the amount of breakage and detachment of aggregates from the soil mass. These authors highlight that generally aggregates between 0.063 and 0.250 millimeters are the most vulnerable to detachment, coarser aggregates are resistant to detachment due to the weight of the particles being Larger. In addition, during a high-intensity rain the ruptured particles can be released up to 0.6 m high and 1.5 m lateral, contributing to the erosion of three main shapes: a) detaching and breaking the soil particles in the place that suffers the impact of the drop of water with the surface; b) transporting by splash the detached and ruptured particles; (c) printing energy, in the form of turbulence in shallow surface runoff. Studies related to splash have improved significantly over the last two decades, however, most of these studies are developed through laboratory experiments, and there are few studies developed from an interpretative perspective of the processes of individual form. Unfortunately, the results of laboratory studies are not easily converted to field situations, as work with simulated rainfall has kinetic energy, drop sizes, and rainfall intensities most often different from natural rainfall. In natural rains, there are times when the size of the drops can increase with the variation of intensity, and even in low-intensity rains there are drops with high erosive capacity. Being the yes, the present work has as its main objective to present some data referring to the production of sediments by the action of a splash in a flat area, thus with a unidirectional splash, the characteristics of this material and the relationship between the quantities and intensity of rainfall with the quantity of material produced during the events.