## 5 Results and Discussion
### TMPA and IMERG

Table 2: Results of the statistical metrics for comparing TMPA and IMERG data over the highland and lowland regions at successive times of 0 h, 3 h, 6 h, 9 h, 12 h, and 24 h from the start of the rainfall event: (a) the Wilcoxon signed-rank tests (\(p_{w}\), values \(p_{w}\) < 0.05 are denoted as D, indicating a significant difference between the two sets, otherwise they are denoted as ND (No Difference), (b) the Spearman correlation coefficient (\(R_{s}\), negative values indicate a negative correlation), (c) the Spearman \(p\)-value range (\(p_{s}\), where VS (Very Strong) denotes very strong evidence for rejecting the null hypothesis [\(p_{s}\) < 0.01], S strong evidence [\(0.01\leq p_{s}\) < 0.05], W weak evidence [\(0.05\leq p_{s}\) < 0.1], and VW (Very Weak) very weak evidence [\(p_{s}\geq 0.1\)]. Secondly, the calculations for the Spearman's rank correlation coefficient (\(R_{s}\)) and its associated \(p\)-value (\(p_{s}\)) revealed a very strong evidence for a positive correlation between the two 2018 satellite-based datasets at all times and for both the lowland and highland regions. However, for the other events, the situation is not straightforward. At the onset of the 2015 event, very weak evidence that the data are correlated was observed over the lowland region. However, strong or very strong evidence of correlation was found for the subsequent time thresholds. Over the highland region, the 2015 satellite-based datasets exhibit a negative \(R_{s}\) at all times, with a very weak evidence for correlation at onset and at 3 h, but with very strong evidence afterward. For the 2016 event, there is very strong evidence that the two data sets are correlated except for limited times after the onset of the events. Additionally, the correlation was found to be negative for all time thresholds from 9 h onwards, for both the lowland and highland regions. For the 2017 event, the lowland region exhibits evidence for a very strong correlation during the first 6 h of the event, which subsequently changes into a weak or very weak event. The correlation is positive at almost all time points. Regarding the highland region, the situation is generally reversed with very weak evidence during the first 6 h, subsequently changing into very strong events. The correlation coefficient is positive initially, but it turns negative in the later stages of the event. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Event**} & \multirow{2}{*}{**Region**} & \multirow{2}{*}{**Time** (**Hours**)} & **Wilcoxon** & **Spearman** & **Spearman** \\  & & & \(p\)**-Value** & **Correlation** & \(p\)**-Value** \\ \cline{3-5}  & & & \(p_{w}\) & \(R_{s}\) & \(p_{s}\) \\ \hline \multirow{4}{*}{**Event**} & 0 & D [\(2.2\times 10^{-16}\)] & 0.42 & VS [\(1.776\times 10^{-6}\)] \\  & 3 & ND [\(0.7851\)] & 0.71 & VS [\(2.2\times 10^{-16}\)] \\ \cline{1-1}  & 6 & ND [\(0.3289\)] & 0.70 & VS [\(2.2\times 10^{-16}\)] \\ \cline{1-1}  & 9 & D [\(0.0329\)] & 0.64 & VS [\(2.2\times 10^{-16}\)] \\ \cline{1-1}  & 12 & D [\(0.0329\)] & 0.64 & VS [\(2.2\times 10^{-16}\)] \\ \cline{1-1}  & 24 & D [\(0.03293\)] & 0.64 & VS [\(2.2\times 10^{-16}\)] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
Figure 3: _Cont._