Environmental dynamics of the Juruá watershed in the Amazon

Abstract

The Jurua Watershed region, an important tributary of the Amazon River, lacks scientific information related to climate and environmental variables. In this sense, this study intends to analyze the environmental dynamics of the Jurua Watershed in the Amazon. We used monthly weather data derived from Reanalysis 2. The products fire foci, vegetation index and surface water index derived from the MODIS sensor for a monthly time series from 2001 to 2018. The ARIMA model was used to simulate future changes from NDFI. The lowest rainfall years of the series were 2005, 2010 and 2016 also observed for soil moisture in 2005 and 2016; the most rainfall years were 2009 and 2014, with the highest values of flooded areas in January, 23,772 km2. The highest concentration of fire foci occurred in August and September, coinciding with the lowest NDFI values found (1421 km2 and 890 km2), with the years 2005 and 2010 with highest fire foci. The EVI showed higher values from October to December with values close to 0.57, the lowest values in June and July (0.50). The years 2009 and 2015 showed largest flooded area records, 2005 and 2010 the lowest records. The PCA pointed out the rain as the variable of greatest influence in the basin with 0.98, followed by hot flashes with − 0.90. NDFI was highly correlated with rainfall and ARIMA modeling allowed the generation of a reliable future scenario and a significant downward trend in flooded areas by 2030.