Análise da variabilidade climática na nova fronteira agrícola do Brasil: região do Matopiba.

Abstract

During the 1980s, a new agricultural frontier in Brazil emerged occupying part of the states of Maranhão, Tocantins, Piauí and Bahia. Currently, this new frontier has been called the MATOPIBA, an acronym formed by the junction of the symbols of the four states that comprise the region. The region underwent sweeping changes in their social and environmental characteristics, with the emergence of large areas of intensive agriculture and large herds. The objective of this research is to study climate variability of rainfall and temperature on the MATOPIBA region. Data from 11 meteorological stations over the period 1965-2012 for precipitation and 1970-2012 for temperature were analyzed. Methods of linear regression analysis and Kendall-tau test to check the tendency of precipitation and temperature series were used. The sequential Mann-Kendall test was applied to check the approximate year when trends began. Indices of extreme rainfall and temperature were also analyzed. Finally, the correlations between teleconnections during the wet period and oceanic-atmospheric indices were verified. Trend analysis of precipitation, temperature extremes indices and correlations between precipitation and oceanic-atmospheric indices series were made with application developed in this project, the CLIMAP. The results indicate that MATOPIBA Region showed no trend in most series of monthly and quarterly totals and precipitation extremes index, predominantly high annual variability of the variable rainfall. In contrast, the analysis of monthly maximum and minimum temperature series and temperature extremes index showed strong positive trend in almost all series. These results indicate that the region undergoes a significant warming process the last four decades. The correlations between precipitation and ocean-atmospheric indices indicated that the teleconnections are most evident in the months of March, April and May, especially when dealing the aggregate indices EGAP and EGA, and the cities with the highest correlations are in the northern region. The CLIMAP application proved to be very practical and efficient to achieve the results of the research.