Main water characteristics and climatic types of environments undergoing degradation and/or desertification in northeastern Brazil

Desertification is one of the biggest socio-environmental concerns on the planet, given the reduction in the land's productive capacity, especially in areas with a semi-arid climate. Most areas in the process of environmental degradation are said to be desertification, although there is conceptual controversy and causes: climatic, anthropogenic and/or an interaction between them. In view of this, we sought to compare the conceptual differences and the rainfall and water conditions of the desertification centers in the State of Paraiba, in relation to the centers of other northeastern states, with these determinations being the main objectives. To carry out this study, the aridity indexes (Ai) of the UNEP, adopted by the FAO, and the Ai, derived from the climatologically water balance (BHC), were used, in addition to establishing the pluvial climatology. The degradation processes require detailed studies of the rainfall and water regimes and not just the aridity index. The rainfall anomaly criterion proved to be an excellent environmental indicator, as it contemplates the value of expected rainfall. The Ai, from the BHC, differs from the Ia from the UNEP, in addition to enabling a broader analysis of water availability and aridity categories. Desertification is a dynamic and complex environmental degradation process and, therefore, requires the inclusion of other water indicators and not just the aridity index.