Natural Resources, School of


First Advisor

Brian Wardlow

Date of this Version

Summer 8-1-2019


Mariano, D. (2019) Drought impacts assessment in Brazil - a remote sensing approach.


A DISSERTATION Presented to the Faculty of The School of Natural Resources at the University of Nebraska In Partial Fulfillment of Requirements For the Doctor of Philosophy, Major: Natural Resources Sciences (Climate Impacts & Assessment), Under the Supervision of Professor Brian D. Wardlow. Lincoln, Nebraska: August, 2019

Copyright 2019 Denis Araujo Mariano


Climate extremes are becoming more frequent in Brazil; studies project an increase in drought occurrences in many regions of the country. In the south, drought events lead to crop yield losses affecting the value chain and, therefore, the local economy. In the northeast, extended periods of drought lead to potential land degradation, affecting the livelihood and hindering local development. In the southern Amazon, an area that experienced intense land use change (LUC) in the last, the impacts are even more complex, ranging from crop yield loss and forest resilience loss, affecting ecosystem health and putting a threat on the native population traditional way of living. In the studies here we analyzed the drought impacts in these regions during the 2000s, which vary in nature and outcomes. We addressed some of the key problems in each of the three regions: i) for the southern agriculture, we tackled the problem of predicting soybean yield based on within-season remote sensing (RS) data, ii) in the northeast we mapped areas presenting trends of land degradation in the wake of an extended drought and, iii) in southern Amazon, we characterized a complex degradation cycle encompassing LUC, fire occurrence, forest resilience loss, carbon balance, and the interconnectedness of these factors impacting the local climate.

Advisor: Brian D. Wardlow