Precipitação pluvial na bacia hidrográfica da Lagoa dos Patos, no período de 1964 a 2007 e suas associações com as safras de camarão-rosa

Abstract

A abundância de pós-larvas no estuário depende, diretamente da salinidade, que é afetada pelo vento de quadrante sul que facilita a entrada de águas marinhas no estuário, e pela vazão provocada pela precipitação pluvial, que limita a entrada de água salina. A precipitação pluvial na região da bacia hidrográfica da Lagoa dos Patos é influenciada por sistemas atmosféricos de diferentes escalas espaciais e temporais. Nesse trabalho foram analisados dados de pluviosidade da bacia hidrográfica da Lagoa dos Patos para o período de 1964 a 2007. Os 43 anos estudados foram classificados, através da Técnica dos Quantis, em: muito secos, secos, normais, chuvosos e muito chuvosos. Através da mesma técnica, as safras de camarão-rosa também foram classificadas em: muito pequenas, pequenas, normais, altas e muito altas

The abundance of pink shrimp post-larvae at Patos Lagoon estuary is directly dependent on salinity and influenced by the wind from the south quadrant and the flow caused by rainfall. The rainfall of hydrographic basin of Patos Lagoon is influenced by weather systems from different spatial and temporal scales. In this work, was analyzed data from rainfall of hydrographic basin of Patos Lagoon for the period 1964 to 2007. The 43 years studied were classified by Technical quantiles in: very dry, dry, normal, rainy and wet. Using the same technique, the pink shrimp harvests were also classified as very small, small, normal, high and very high. Rainfall fluctuates around the average in most periods, with no indication of increase or decrease in total volumes. The semesters with precipitation equal to or less than 6093.5 mm were classified as very dry, between 6093.5 and 6516.4 mm were classified as dry, between 6516.4 and 7684.8 mm were considered normal, between 7684.8 and 8593.3 mm rainfall and were considered equal to or greater than 8593.4 mm were considered very rainy. The harvests equal or less than 721 t were classified as very small, between 721 and 1544 t were classified as small, between 1544 and 3607 t were considered normal, between 3607 and 4897 t were considered high and equal or greater than 4897 t were considered very high