## 5 Discussion  
First, to determine the existence of significant differences in water depth by control point for the years 2009, 2013, and 2020, as shown in Table 1, a one-way ANOVA was conducted (Table 2). The results indicate that there were no significant differences (\(p>0.05\)) between the years. For this reason, we analyzed the annual clogging rate (marsh sediment deposition) in each of the years specified in Table 1 (see Table 3). As inferred from Table 4, the ACR varied between 0.75 and 2.86 mm/year, with higher values observed when the ratio between the mean monthly rainfall (MMR) and the mean temperature (MT) of the last year of the analyzed period was lower (see Table 4). The ongoing dry period trend led to the growth of shrub and bush vegetation, which, over time, retained the soil in the non-flooded marshland [53], increasing the clogging rate. It is also noteworthy that, annually, as specified by the Guadalquivir River Basin Authority [53] data on the Donana aquifer, 105 hm\({}^{3}\) of water is extracted for irrigation maintenance, exacerbating human-induced climate change as if this extraction trend were to continue alongside global warming in the study area (Figure 22a,b), the marshland completely clogs up (Figure 23). Applying the model in Figure 23 allowed us to infer the water depth equivalent to the 105 hm\({}^{3}\) extracted from the aquifer. For 2009, this volume corresponded to 0.226 m, while for 2013 and 2020 it amounted to 0.223 m and 0.205 m. To determine the proportion of these depths per control point (17 in total), we simply divided them by 17, resulting in 0.0133 m, 0.0131 m, and 0.012 m for 2009, 2013, and 2020, respectively. Next, we were able to obtain the net average inundated depth by subtracting these proportional depths per control point from the average water depths in the Donana marshes, \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Year** & **Rainfall (mm)** & **MMR (mm)** & **MT (\({}^{\circ}\)C)** & **MMR/MT** \\ \hline
2009 & 609 & 51 & 18.7 & 2.72 \\
2013 & 558 & 46 & 18.3 & 2.51 \\
2020 & 420 & 33 & 18.8 & 1.86 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Mean temperatures, precipitations, MMR, MT, and MMR/MT for 2009, 2013, and 2020. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **SS** & **df** & **MS** & **F** & \(p\) \\ \hline Treatment (between groups) & 0.005434 & 2 & 0.002717 & 0.26 & \textgreater{}0.05 \\ \hline Error & 0.510406 & & & & \\ Total & 0.515840 & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of the analysis of variance (ANOVA) for the estimated depth variable (SS = sum of squares; df = degrees of freedom; MS = mean squared; F = value of the test statistic; and \(p\) = significance). \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Year** & **Year** & **Year** \\  & **2009** & **2013** & **2020** \\ \hline Mean depth (m) & 0.155 & 0.152 & 0.132 \\ Time period & 2009–2013 & 2009–2020 & 2013–2020 \\ Length (years) & 4 & 11 & 7 \\ Average depth decrease (m) & 0.003 & 0.023 & 0.020 \\ ACR (mm/year) & 0.75 & 2.10 & 2.86 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Annual clogging rate (ACR) based on the mean water depth for 2009, 2013, and 2020.  
as shown in Table 4 (see Table 5). This depth reflects the impact of induced climate change, primarily because the 105 \(\text{hm}^{3}\) obtained does not recharge the Dofana marsh itself. Similarly, considering each of the ACR values from Table 4 as different scenarios (favorable = ACR value from 2009 to 2013; neutral = ACR value from 2009 to 2020; and unfavorable = ACR value from 2013 to 2020), we could determine the number of years remaining until the complete drying of the Donana marshes (Table 6 and Figure 23). Additionally, by applying a patented procedure [30], it was possible to annually predict the soil deposited over the Donana marshes (Figure 24).