Climatic and Anthropic Influence on the Geodiversity of the Maranhão Amazon Floodplain

Abstract

The Maranhense Amazon floodplain shelters a Ramsar site established by the United Nations for the protection of wetland biodiversity. Despite its protected ecological status, the impacts from deforestation, burning, the agricultural and livestock industries, are on the rise. Knowledge of the spatial distribution and temporal dynamics of these impacts are important to improve the understanding of how this region is affected. Data on increasing deforestation and hot pixels were used to evaluate the anthropogenic pressure under the geodiversity of the region, relating them to the environmental variables (rainfall, Normalized Difference Vegetation Index and Deforestation annual deforestation rate) measured through the rainfall data and the Normalized Difference Vegetation Index (NDVI). In this study, the potential of remote sensing and geographic information system. The time series were used from 2001 to 2016 for all variables. We observed a strong negative and significant correlation between hot pixels and NDVI, while hot pixels increase, the vegetation indexes tend to decrease. In 2006 an abrupt fall in the NDVI occurred due to the marked increase in the deforested area. In 2010, the NDVI reached its highest levels, because the vegetation responded to the highest rainfall observed in the period in 2009. Unit 4 presented the highest pixels number in the period evaluated (2,978 pixels; 55% of the total). There is a significant correlation between NDVI and rainfall.