Impacto das mudanças climáticas no cultivo do algodão herbáceo em sistema de sequeiro no Nordeste do Brasil.

Abstract

This study assesses the impacts of climate change on the agricultural zoning of climatic risk in cotton (Gossypium hirsutum L. latifolium Hutch) grown in northeastern region of Brazil, based on the IPCC reports. The water balance model, combined with geospatial technologies (GIS), was used to identify areas of the study area where the crop will suffer yield restrictions due to climate change. The data used were the time series in rainfall at least 30 years of daily data, crop coefficients, potential evapotranspiration and duration of the crop cycle. The scenarios referred here as A, B and C are corresponding to the increases in air temperature of 1.5, 3 and 5 oC, respectively. These scenarios of increase in air temperature were associated with changes in precipitation ± 10, ± 25 and ± 40%, which are associated to the El Niño events (negative deviations) and La Niña (positive deviations) in the simulation of sowing crop. It was adopted as baseline for the Water Requirements Satisfaction Index for culture (WRSI), defined as the ratio between actual evapotranspiration and maximum evapotranspiration (ETr/ETm), the value 0.55. The results suggest that climate change leads to the reduction in agricultural areas of cotton crop growth in northeastern region of Brazil, and thus resulting in significant losses in crop production.