EVI2 index trend applied to the vegetation of the state of Rio de Janeiro based on non-parametric tests and Markov chain

Abstract

The study aimed to assess the growth and decrease in vegetation trend by Enhanced Vegetation Index (EVI2) through the application of statistical tests and Markov's chain in the state of Rio de Janeiro (SRJ). Monthly data from EVI2 were calculated for the vegetations of the State of Rio de Janeiro (SRJ) from 2001 to 2012. Mann-Kendall (MK), Pettitt (P) and Estimator of Curvature Slope Sen (Se) tests assessed EVI2 trend, while the future scenarios were evaluated by Markov chain. Overall, there is an insignificant trend in vegetation growth in 75%, followed by a significant trend of decreasing in 25% of the regions. Pettitt's test showed that there is not significant (NS) abrupt changes, both growth and decreasing vegetation, and significant (S) abrupt changes of decreasing vegetation in the others Government regions. Spatial analysis from EVI2 in the regions Médio Paraíba amd Serrana showed the occurrence of NS abrupt change in the vegetation in November 2007 and 2003. Norte Fluminense and Metropolitana showed a NS vegetation increase in October 2003 and 2005. Noroeste Fluminense and Centro Sul Fluminense revealed an NS and S abrupt change of decreasing vegetation in April 2006. In Costa Verde and Baixadas Litorâneas NS and S abrupt changes in decreasing vegetation were observed in May 2004. Future scenarios showed changes in vegetation trend in SRJ with indication of decreasing. Predictions of changes in future scenarios ranging from 1 to 2 years in constant intervals (3 to 10 years) were observed in all future scenarios analyzed in the SRJ.