Comportamento dos elementos climáticos selecionados no período de 1971 a 2003 na cidade de Cáceres-MT/Brasil

Abstract

Queries related to environmental degradation, climate changes, quality of life, sustainable development and thermic comfort have brought great interest and worries not only among scientists but within the most diverse social sectors. The objective of this study is to analyze the climate behavior in the city of Cáceres-MT, which is located on the left bank of the Paraguay river, in southwest of State Mato Grosso, central Brazil.To verify the behavior of the climatic elements ( temperature, atmospheric pressure, evaporation,moisture and precipitation) in the city of Cáceres-MT during the 1971-2003 period, there were fulfilled the following steps: (a) data collection; the meteorological data was analyzed infour periods: 1971-1980; 1981-1990; 1991-2000; and 2000-2003; (b) construction of climategraphics and their comparative interpretation which ended in this paper. Annual precipitation mean is of 1200 mm, with a well defined rainy period (from Octoberto April, with major incidence from December to March), and another considered dry from April to September. Temperature analysis in three decades show variations: in the first decade (1971-1980) there was a mean of 24,7 °C; this rose to 25,1 °C in the decade of 1980 (1981-1990), continued rising in the decade of 1990 (1991-2000) to reach 25,4 °C and to26 °C in the last three years of the period studied (2001-2003). Air pressure varies in general from 997 to 998,5 milibars. This variation keeps relation with the mean temperature changes in the region. Contrary to the evaporation that showed high and low fluctuations, moisture was almost stable and the variation was les than 3,5% in 33 years. As for precipitations, it was found that in the decade of 1970, the pluviometric mean was 1.402,2 mm; it was 1.259,5 in the following decade, rising to 1.358,2 mm in the decade of 1990, and went down to 1.172,1mm in the last three years analyzed. In correlating the climate variations to the urban expansion of the city of Cáceres we may say that the temperature increase is due to the disappearance of the forest cover and its replacementby constructions and pavement.