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Effects of Deforestation on the Onset of the Rainy Season and the Duration of Dry Spells in Southern Amazonia
Author(s) -
LeiteFilho Argemiro Teixeira,
Sousa Pontes Verônica Yameê,
Costa Marcos Heil
Publication year - 2019
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2018jd029537
Subject(s) - deforestation (computer science) , wet season , dry season , amazon rainforest , precipitation , geography , environmental science , amazonian , climatology , physical geography , forestry , ecology , meteorology , biology , geology , cartography , computer science , programming language
Amazonian deforestation is causing notable changes in the hydrological cycle by altering important precipitation characteristics. This study uses daily rainfall time series data from 112 rain gauges and a recent yearly 1‐km land use data set covering the period from 1974 to 2012 to evaluate the effects of the extent of deforestation at different spatial scales on the onset of the rainy season and on the duration of dry spells in southern Amazonia. Correlation analyses indicate a delay in the onset of 0.12–0.17 days per percent increase in deforestation. Analysis of cumulative probability density functions emphasizes that the likelihood of rainy season onset occurring earlier than normal decreases as the local deforestation fraction increases. In addition, the probability of occurrence of dry spells in the early and late rainy season is higher in areas with greater deforestation. The delayed onset and longer dry spell events in highly deforested areas increase the climate risk to agriculture in the region.