Balanço hídrico climatológico como ferramenta de análise hidroclimática de núcleos de susceptibilidade a desertificação

Abstract

Desertification is a phenomenon of global proportions that has been causing economic, political and social damage to an increasing number of countries around the world. The nuclei of susceptibility to desertification are areas that constitute degradation conditions that actively impact on the reduction of their productive capacity, thus being maximum expressions of the desertification process. The nucleus of susceptibility to desertification of Irauçuba / Centro-Norte has a total area of 12,202.41km² and is formed by the municipalities of: Irauçuba, Santa Quitéria, Sobral, Itapajé, Miraíma and Canindé (FUNCEME, 2015). This nucleus is one of the most susceptible to the worsening of the desertification process due to its history of caused land use, which together with its rainfall irregularity, potentiate the degradation effects of desertification. The objective of this research is to understand through the variables of the climatological water balance of Thornthwaite & Mather (1955), the variation of the water storage of the soil of the ASD Irauçuba / Center-North, and in this way to understand how this variation influences the desertification process and the productive activities of the nucleus. It is concluded that the residual massifs of Uruburetama (located between Itapajé and Irauçuba), the Meruoca / Rosário massif (Located in Sobral) and the Baturité massif (Located in Canindé), act as moisture condensing nuclei in the nucleus. It was noted the decrease in protection volumes according to the rainfall retention based on the massifs. The arrangement of historical surpluses followed the general pattern of rainfall distribution, with values included in the south-central portion of the ASD, with an increase in its volume with the approximation of the residual massifs of Baturité and Meruoca. The largest volumes of water deficiency were located in the south-central ASD, with a reduction in their volume with the approach of the residual massifs of Baturité and Meruoca. In general, the production of temporary and permanent crops, as well as livestock production, irregular dissipation in dry years, does not represent a predominance of growth or reduction in production. In the wet years, there was a predominance of productive growth in permanent, temporary crops and in livestock production.