SANTA FILOMENA – PIAUÍ, BRAZIL AND ITS EROSIVE VARIABILITY BY DIFFERENTIATED METHODS

Abstract

The objective is to analyze the variability of aridity indices and their climatic classifications with level of susceptibility; estimation of annual soil losses through the universal equation and erosivity factors and evaluating the impacts of the studied elements and their possible climate and erosive changes.  To compute the erosivity factor, the equations proposed by Wischmeier et al. (1971) and Wischmeier and Smith (1958, 1978). In addition to carrying out the classification regarding the level of susceptibility to desertification with the help of the use of the Aridity Index. Areas identified as vulnerable to desertification, due to the lower aridity index, may not be located in the degraded area, and areas that present a higher aridity index and are not warned as vulnerability processes may be degraded to the point of being considered desertified areas. This variability can occur due to inadequate use of the soil and the environment. The period from 1960 to 2017 was studied in order to determine with greater certainty the data on the levels of susceptibility and climate classifications with greater precision to determine the existence or not of areas with desertification. In this sense, the greater the precipitation, the greater the aridity index, and in the face of desertification, the lesser the susceptibility. The aridity index calculated in the water balance shows wide interannual and intermunicipal spatial oscillation, however the aridity indices are above the values ​​established for desertification.