Soil moisture obtained through remote sensing to assess drought events

Abstract

The sequence of drought events in the Northeast of Brazil in recent decades raises attention to the importance of studying this phenomenon. The objective of this study was to evaluate the duration and severity of drought events from 1988 to 2018 in hydrographic basins of the state of Pernambuco, Brazil, using two drought indexes: Standardized Soil Moisture Index and Soil Moisture Condition Index, calculated based on data of the Soil Moisture Project of the European Space Agency’s Climate Change Initiative. The duration of the droughts was determined considering the months between their beginning and end, and their severity was based on the area formed in the graph between the curve of the index and the x-axis. The soil moisture database showed to be a promising tool for the analysis and monitoring of drought events in the Northeast region of Brazil, mainly for analysis and monitoring of drought events. The indexes allowed the evaluation of the drought phenomenon over the 30-year period, showing increases from 2012, which were more pronounced in the Semiarid region. The hydrographic basins responded differently to a same event, depending on the climate characteristics of the region in which they are located. Consecutive years with rainfall below the historical mean increased the magnitude of the droughts, as found for the 2012-2017 period, in which the indexes presented delays to return to more favorable values, showing the effect that one drought year has on the following year.

Identification of desertified and preserved areas in a conservation unit in the state of Paraíba – Brazil

“…Other techniques and methodologies have been used to perform important tasks such as quantifying and situating the influence of moisture on the soil. Some of these allow the surface retention capacity, infiltration, evaporation, influence on vegetation and desertification to be estimated, as in studies conducted by Lopes et al (2011), Francisco et al (2017) and Inocêncio et al (2020), based on the interactions between the different indices and bio-geophysical parameters obtained via remote sensing.…”