Modelling non-linear deforestation trends for an ecological tension zone in Brazil

Abstract

Tropical deforestation is a recent phenomenon that started in the second part of the twentieth century. One may argue that the Brazilian state of Maranhão is an excellent case study for ex-amining deforestation trends and the effects of environmental policies. A man-made line sepa-rates Maranhão into two sections. Due to the administrative divide between the Legal Amazon Maranhão (LM) and the Cerrado Maranhão (CM), one may hypothesize about differences in deforestation between the two regions. This research employs a nonlinear modelling approach based on Generalized Additive Models (GAMs) with a quasi-Poisson distribution and a logarith-mic function to detect deforestation patterns in these areas. Deforestation is linked to the year and a variety of climatic variables. These covariates differ substantially across seasons (rainy and dry) and regions. During times of above-average precipitation, including in the dry and wet seasons, deforestation occurred in the LM area. However, in the non-enforced region, this regime was not followed. According to the statistics, deforestation decreased in the LM region when precipitation levels were below average.