# Drought Propagation in Brazilian Biomes Revealed by Remote Sensing
## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & **LST** & **P** & **SM** & **SSM** & **ET** & **TWSA** & **EVI** & **GPP** \\ \hline \multicolumn{8}{c}{Amazon 2010 drought} \\ Onset (month) & \(-1\) & \(0\) & \(1\) & \(1\) & \(4\) & \(5\) & \(3\) & \(4\) \\ Duration (month) & \(3\) & \(4\) & \(7\) & \(7\) & \(4\) & \(5\) & \(4\) & \(9\) \\ Maximum & \(+1.5\) & \(-1.3\) & \(-2.1\) & \(-2.1\) & \(-1.8\) & \(-1.8\) & \(-2.0\) & \(-1.9\) \\ intensity (z-score) & \multicolumn{8}{c}{Amazon 2015 drought} \\ Onset (month) & \(0\) & \(0\) & \(1\) & \(1\) & \(5\) & \(4\) & \(9\) & \(12\) \\ Duration (month) & \(10\) & \(5\) & \(4\) & \(4\) & \(1\) & \(7\) & \(3\) & \(2\) \\ Maximum & \(+1.8\) & \(-2.0\) & \(-2.2\) & \(-2.3\) & \(-0.9\) & \(-1.7\) & \(-1.8\) & \(-1.9\) \\ intensity (z-score) & \multicolumn{8}{c}{Cerrado 2014 drought} \\ Onset (month) & \(0\) & \(0\) & \(0\) & \(0\) & \(1\) & \(2\) & \(1\) & \(3\) \\ Duration (month) & \(3\) & \(3\) & \(6\) & \(7\) & \(11\) & \(15\) & \(2\) & \(10\) \\ Maximum & \(+1.9\) & \(-1.4\) & \(-1.8\) & \(-1.9\) & \(-2.0\) & \(-1.6\) & \(-1.9\) & \(-1.8\) \\ intensity (z-score) & \multicolumn{8}{c}{Pampa 2012 drought} \\ Onset (month) & \(1\) & \(0\) & \(1\) & \(1\) & \(1\) & \(1\) & \(1\) & \(1\) \\ Duration (month) & \(4\) & \(3\) & \(7\) & \(10\) & \(5\) & \(9\) & \(4\) & \(5\) \\ Maximum & \(+2.1\) & \(-1.6\) & \(-1.9\) & \(-1.8\) & \(-2.1\) & \(-1.9\) & \(-2.2\) & \(-1.4\) \\ intensity (z-score) & \multicolumn{8}{c}{Pampa 2012 drought} \\ Onset (month) & \(1\) & \(0\) & \(1\) & \(1\) & \(1\) & \(1\) & \(1\) & \(1\) \\ Duration (month) & \(4\) & \(3\) & \(7\) & \(10\) & \(5\) & \(9\) & \(4\) & \(5\) \\ Maximum intensity (z-score) & \multicolumn{8}{c}{\(+2.1\)} \\ intensity (z-score) & \multicolumn{8}{c}{\(+2.1\)} \\ intensity (z-score) & \multicolumn{8}{c}{\(-1.6\)} \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Characteristics of drought events according to onset, duration, and maximum intensity for the 2010 and 2015 droughts in the Amazon, 2014 drought in the Cerrado, and 2012 drought in the Pampa biome. The onset was characterized relative to the precipitation onset. of drought impacts for four major US drought events. According to [PERSON] [20], a groundwater drought does not always occur, but when it does, it often shows long periods of low groundwater levels. The onset and duration of the droughts showed different behaviors for the analyzed variables, especially considering the duration of _TWSA_ negative anomalies during the Cerrado 2014 drought (over 15 months). The Amazon and Pampa experienced short-duration drought events (less than a year) compared to the 2-year drought event that occurred in the Cerrado from 2014-2016. [PERSON] et al. [45] found that during this drought episode in the Cerrado, there was an association between drought and heatwave (dry and hot extreme condition), as a result of hot periods coupled with long-term \(P\) deficits that induced dry surface conditions. This agreed with our results considering a drought propagation perspective. In this sense, the Cerrado's drought exhibited a longer duration compared with the other study areas, which may have occurred due to a combination of conditions (dry and hot) that amplify the impact of extreme events. The Amazon and Pampa biomes presented a propagation cascade (as defined by [PERSON] et al. [79]) from meteorological to agricultural (soil moisture deficit) to hydrological droughts (_TWSA_), while the Cerrado was more affected by a hydrological drought. [PERSON] et al. [80] also identified a strong response relationship between meteorological and hydrological droughts for a study river basin in China. The intensity of the meteorological drought was significantly amplified in the hydrological drought, which agreed with the results found by [PERSON] et al. [81] in which drought effects were assessed in 130 catchments in southeastern Australia. In addition, hydrological drought recovery is slower than meteorological drought recovery [82].