Sistemas de dessalinização como medida de adaptação às mudanças climáticas no semiárido Pernambucano

Abstract

The semi-arid region naturally presents conditions of environmental vulnerability in terms of irregular rainfall in space and time, accompanied by high temperatures and high rates of potential evapotranspiration. For a better structuring and applicability of policies aimed at climate adaptation and coexistence with water scarcity, it is necessary to map and evaluate critical points in the State of Pernambuco. In view of this, this study sought to analyze the use of desalination systems as a measure of adaptation to climate change in the semi-arid region of Pernambuco, in the municipalities that are in the scope of service provided by the Água Doce Program (PAD). An analysis of the climate trend of the Agreste and Sertão of the state was carried out, as a subsidy for the evaluation of the climatological behavior of these two regions over the course of 36 years. Being approached a study of the quality of the underground reserves of these locations more critical in terms of access to water, having as subsidy of evaluation, parameters of concentration of total dissolved solids, that directly reflect in the quality and potability of the water for human consumption, for the indication of priority use of desalination systems in the semi-arid region of Pernambuco. The research used data from a bibliographic, cartographic and documentary survey referring to the physical and climatological characterizations of the semi-arid region of Pernambuco. The results obtained show a great diversity of climatic variables (Precipitation, Tmax, Tminimum, Tmean and ETo) between the years 1980 and 2016, with characteristics that contribute to a greater water limitation in the Sertão region, in which a wider range is observed between precipitation and evapotranspiration, combined with a greater temperature difference. When the trends in climate change are evaluated, based on the comparative scenario of Agreste and Sertão, it appears that the indices of temperature extremes tend to decrease cold periods, and increase hot periods in both regions, with greater disparity in the Sertão. With regard to rainfall extremes, it was observed in the 36 years studied that in the Agreste there was an increase in the total accumulated rainfall, combined with a decrease in the rate of evapotranspiration, resulting in a higher index of aridity and less susceptibility to desertification. In the Sertão, however, there was a decrease in rainfall, with an increase in average temperature, and consequent expansion of evapotranspiration, so that there is a lower rate of aridity and greater susceptibility to desertification. Allied to this, there is the compromise of the quality of groundwater, due to the high levels of salinity, which make it impossible to use one of the main sources of human supply in diffuse communities, mainly for human consumption. The results obtained suggest the need to use desalinators as a tool to mitigate adverse conditions related to water resources in the region and to meet the demand of the population. The technical product resulting from this study will be an action plan for the PAD on the adoption of this social technology for the most critical areas of the State