# The Hydroological Balance in Micro-Watersheds Is Affected by Climate Change and Land Use Changes
## 3 Results and Discussion
### Hydrological Balance
#### 3.4.1 Projections of Future Hydrological Conditions  
The simulations of the hydrological balance under the conditions of the positive scenario of land use change mainly implied an increase in the cover of the temperate forest (85.9%). The increase assumes that there will be no forest fires for the next 60 years, a situation that would allow for significant ecosystem restoration through both reforestation and natural regeneration. Similarly, a reduction in agricultural rain-fed use (\(-\)38.7%) near or within the preferred forest area was considered. The results show that under the climatic conditions, mainly due to the influence of the precipitation regimes proposed by the GCMs, and despite the recovery of the ecosystem according to the positive scenario, an increase in surface runoff in the three microbasins  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & **Scenario** & **Current** & \multicolumn{4}{c}{**Negative**} & \multicolumn{4}{c}{**Positive**} \\ \cline{2-9}  & **Units** & **(mm/Year)** & \multicolumn{4}{c}{**ENRM**} & **HADGEM** & **MPI** & **CNRM** & **HADGEM** & **MPI** \\ \hline \multicolumn{9}{c}{**Evolution (\%)**} \\ \hline \hline  & Precipitation & 652.5 & 42.7 & 32.0 & 20.0 & 42.7 & 32.0 & 20.0 \\ \cline{2-9}  & Water stored \({}^{\star}\) & 130.7 & 23.8 & 9.5 & 3.9 & 43.1 & 23.8 & 17.5 \\ \cline{2-9}  & Evapotranspiration & 533.7 & 32.7 & 30.7 & 19.1 & 41.7 & 37.3 & 24.9 \\ \cline{2-9}  & Water storage in the soil & 199.8 & 29.6 & 13.4 & 7.1 & 46.7 & 24.8 & 17.7 \\ \cline{2-9}  & Base flow & 4.1 & \(-\)70.1 & \(-\)74.3 & \(-\)75.8 & \(-\)67.1 & \(-\)72.8 & \(-\)74.6 \\ \cline{2-9}  & Inter flow & 2.7 & 146.4 & 115.8 & 100.0 & 116.3 & 89.0 & 75.1 \\ \cline{2-9}  & Surface runoff & 25.9 & 355.6 & 184.2 & 142.4 & 137.7 & 32.6 & 12.0 \\ \hline  & & \multicolumn{4}{c}{Chapingo River} \\ \hline \hline  & Precipitation & 652.5 & 42.7 & 32.0 & 20.0 & 42.7 & 32.0 & 20.0 \\ \cline{2-9}  & Water stored \({}^{\star}\) & 108.5 & \(-\)22.5 & \(-\)25.5 & \(-\)34.9 & 33.4 & 19.7 & 8.8 \\ \cline{2-9}  & Evapotranspiration & 534.7 & 23.9 & 23.7 & 13.5 & 37.7 & 34.3 & 22.6 \\ \cline{2-9}  & Water storage in the soil & 153.3 & 1.8 & 6.1 & \(-\)15.0 & 46.5 & 27.9 & 17.3 \\ \cline{2-9}  & Base flow & 4.2 & \(-\)80.9 & \(-\)81.5 & \(-\)81.7 & \(-\)80.3 & \(-\)81.2 & \(-\)81.5 \\ \cline{2-9}  & Inter flow & 12.3 & 86.8 & 68.2 & 59.8 & 97.7 & 74.6 & 65.1 \\ \cline{2-9}  & Surface runoff & 40.0 & 332.1 & 187.8 & 140.6 & 125.1 & 36.9 & 12.6 \\ \hline  & & \multicolumn{4}{c}{San Bernardino River} \\ \hline \hline  & Precipitation & 652.5 & 42.7 & 32.0 & 20.0 & 42.7 & 32.0 & 20.0 \\ \cline{2-9}  & Water stored \({}^{\star}\) & 108.5 & \(-\)6.4 & \(-\)8.7 & \(-\)20.6 & 106.3 & 82.3 & 67.5 \\ \cline{2-9}  & Evapotranspiration & 534.7 & 17.7 & 18.3 & 8.6 & 34.3 & 30.9 & 19.5 \\ \cline{2-9}  & Water storage in the soil & 153.3 & 21.1 & 13.0 & 2.5 & 103.7 & 76.2 & 62.7 \\ \cline{2-9}  & Base flow & 4.2 & \(-\)35.5 & \(-\)41.2 & \(-\)43.5 & \(-\)29.8 & \(-\)39.6 & \(-\)42.6 \\ \cline{2-9}  & Inter flow & 12.3 & 77.5 & 59.2 & 51.2 & 84.5 & 57.9 &is expected as follows: CNRM-CM6-1 model: Chapingo River (125.1%), Texcoco River (137.7%) and San Bernardino River (110.1%); HadGEM3-GC3-LL: Chapingo River (36.9%), Texcoco River (32.6) and San Bernardino River (35.2%); and MPI-ESM1-2-LR, Chapingo River (12%), Texcoco River (12.6%), and San Bernardino River (13.2%). These increases are indicators that despite the implementation of actions (reforestation, stimulation of natural regeneration, commercial plantations, control of fires, pests, and diseases) that mitigate the effects of climate change, it will be impossible to completely reverse the changes in the balance of the hydrological conditions, mainly due to the increase in precipitation and temperature values. However, a considerable decrease in surface runoff was observed: \(-\)46.2% (CNRM), \(-\)68.6% (HadGEM3), and \(-\)83.8% (MPI) in the entire study area compared to the scenario with negative land use change.