# The Hydroological Balance in Micro-Watersheds Is Affected by Climate Change and Land Use Changes
## 3 Results and Discussion
### Calibration  
Calibration is a step to improve a model for a given set of local circumstances [53]. Calibration reduces the uncertainty of the prediction and can be considered parameter estimation or parameter optimization [73]. Figure 4a shows the comparison of observed and model-simulated monthly streamflow data in the Texcoco River. The model prediction of the hydrological response of the watershed was very good according to estimators (NSE = 0.98, R2 = 0.93, RSR = 0.15, and PBIAS = 5.3). It was also observed that the model was not able to simulate the peak flow rates and that the simulation was closer to the base flow rates. This performance of the model was different from the results of other studies [74], which described that WEAP better simulated the peak runoff of the base flows with data for the Conchos River basin in Mexico. \begin{table}
\begin{tabular}{l c c c c c} \hline \hline \multirow{2}{*}{**Land Use Class**} & \multicolumn{5}{c}{**Area (\%)**} \\ \cline{2-7}  & **1995** & **2008** & **Current** & **Positive** & **Negative** \\  & & & & **Scenario** & **Scenario** \\ \hline Temperate forest & 31.0 & 30.3 & 26.0 & 48.5 & 13.6 \\ Reforestation & 12.5 & 14.3 & 14.9 & 9.6 & 2.4 \\ Secondary vegetation & 1.8 & 3.9 & 5.7 & 0.3 & 4.9 \\ Pasture & 1.0 & 1.3 & 0.7 & 0 & 2.8 \\ Mine & 1.9 & 1.6 & 2.7 & 2.8 & 3.6 \\ Agriculture (rainfed) & 32.6 & 31.0 & 29.6 & 18.2 & 48.7 \\ Agriculture (irrigated) & 8.6 & 6.3 & 6.9 & 3.6 & 5.6 \\ Agriculture (protected) & 0.3 & 0.4 & 1.1 & 2.6 & 2.1 \\ Urban & 10.2 & 10.9 & 12.2 & 14.3 & 16.3 \\ Water & 0.1 & 0.0 & 0.1 & 0.1 & 0.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Area (%) of reference years and current and future scenarios. \begin{table}
\begin{tabular}{l l c c c c c c c c c} \hline \hline  & **Land Use Classes** & **TF 1** & **R 2** & **SV 3** & **G 4** & **M 5** & **RA *** & **LA 7** & **PA 8** & **U *** & **W 10** \\ \hline \multirow{6}{*}{**Daily**} & Secondary vegetation & 34.7 & 4.3 & - & 0.9 & - & - & 2.7 & - & - & - \\  & Reforestation & 18.2 & - & 100.2 & 0.1 & 5.4 & 49.3 & 8.9 & 0.4 & 35.0 & - \\  & Pasture & 3.5 & - & 1.2 & 0.0 & - & - & - & - & - \\  & Temperate forest & - & 32.6 & 49.3 & 31.7 & - & 2.7 & - & 0.8 & 0.4 & - \\ \hline \multirow{6}{*}{**Daily**} & Pasture & 68.9 & 0.1 & 0.5 & - & - & 0.2 & - & - & - & - \\  & Secondary vegetation & 26.6 & 106.2 & - & 0.9 & - & 42.2 & 0.2 & 0.6 & 0.6 & 0.1 \\  & Reforestation & 14.4 & - & 31.9 & 0.1 & 8.2 & 197.1 & 53.8 & 3.4 & 42.6 & 0.2 \\  & Temperate forest & - & 131.5 & 280.9 & 18.3 & - & 4.1 & - & - & - & - \\ \hline \hline \end{tabular}  
* \({}^{1}\) temperate forest, 2 reforestation, 3 secondary vegetation, 4 grassland, 5 mine, 6 rainfed agriculture, 7 irrigated agriculture, 8 protected agriculture, 9 urban, 10 water bodies.  
\end{table} 
Table 5: Land use changes (has) matrix between 1995–2008 and in the period 2008–2021. In the San Bernardino micro-watershed, the goodness-of-fit indicated that it was very good (NSE = 0.84, R2 = 0.76, and RSR = 0.38) and good (PBIAS = \(-\)13.5). The simulated flow showed repetitive behavior because the software accepts the results to be performed even if there are no rainfall records in the period. This was possible because the software allows the model to run with a full degree of accuracy when the data are available, or it can calculate it when the data are not available [75]. It was observed that when precipitation data were inputted with values estimated using isohyets, the model failed to reproduce the variation in peak flows, and the simulation was closer to the variation in base flows. In Chapingo River, the goodness-of-fit indicated that the ability of the model to predict the hydrological response was very good (NSE = 0.93, R2 = 0.81, and RSR = 0.26). The simulation has overestimated the flow rate according to the PBIAS = \(-\)13.1 since, in most years, the peak flows were above the observed values. However, this percentage is considered good, and it was observed that the modeled curves (Figure 4b) of the base flows were closer to the records.