A precipitação pluvial nos meses de junho e julho nos sertões da Paraíba e seus impactos ambientais

Abstract

The Rainfall is a determining factor in the study of the climate of a tropical region, and can affect all forms of terrestrial survival, especially in semi-arid areas, such as the Northeast region of Brazil. In this context, this research aimed to analyze the effects of rainfall in the post-rainy season period (June - July) (P-EC) for the homogeneous Sertão and Alto Sertão regions of the State of Paraíba, taking into account the dynamics of local vegetation . To this end, annual precipitation series from a total of 73 rainfall stations in this State were used, comprising 29 years (1994 – 2022) of regional climatology data. The annual distribution of precipitation in the western region of Paraiba showed high spatio-temporal variability, reaffirming the dependence on atmospheric systems. From the analysis of the Pearson correlation coefficients for the annual totals of the rainy season (February - May) (EC), and the P-EC, it is possible to affirm that the post-season precipitation is independent of the rainy season precipitation, triggering the study of possible contributions of precipitation from this period to the plant environment. Therefore, the capacity of June-July precipitation to modify the vegetation landscape of the entire Sertão was investigated. To this end, monthly compositions of the IVDN were used, referring to the months of July, August and September, obtained from the MODIS/Terra sensor for the period from 2000 to 2022. This study between precipitation patterns and IVDN was carried out through the analysis of Person's correlation coefficient (r) and the graphical monitoring of the interannual variability curves of the standardized devivo indices. It was found that the vegetation vigor is extremely dependent on the precipitation that occurs in the EC, and that the P-EC rains do not have the capacity to increase a more intense vegetative vigor, except in years in which both the EC and the EC rains P-EC are above average. In this case, the vegetation remains green, but less vigorous depending on the type of coverage.