This study focuses on the Ecological Restoration Zone (ERZ) within the area of influence of the Endhó Dam, encompassing the municipalities of Atitalaquia, Atotonilco de Tula, Tepeji del Río de Ocampo, Tepetitlán, Tezontepec de Aldama, Tlahuelilpan, Tlaxcoapan, and Tula de Allende in the state of Hidalgo, Mexico. This region is of particular concern due to the impacts of climate change and environmental pollution on its vulnerable ecosystems. The Mezquital Valley, where the ERZ is located, faces significant environmental challenges that have been intensified by the historical use of wastewater from the Mexico City Metropolitan Area for agricultural irrigation. This practice has contributed to high levels of water contamination and the presence of a wide range of environmental pollutants.
The primary objective of this research is to analyze climate trends by combining historical and future interannual climate information for the ERZ. Specifically, the study examines trends in mean temperature and precipitation for the period 1958–2024 and their projections for 2025–2100 under different climate change scenarios using two Global Climate Models (GCMs), GFDL-ESM4 and MIROC6. The goal is to generate scientific information that supports environmental management and land-use planning.
During the first phase, the TerraClimate dataset was used to obtain spatiotemporal precipitation and temperature data for the 1958–2024 period. This dataset, generated through the interpolation of observations and reanalysis data, provides a spatial resolution of approximately 4 km × 4 km, enabling a detailed regional assessment of climate trends.
Future climate projections were obtained from two General Circulation Models (GCMs) included in Phase 6 of the Coupled Model Intercomparison Project (CMIP6): GFDL-ESM4 and MIROC6. These models were selected because they provide data for the four Shared Socioeconomic Pathway (SSP) scenarios evaluated in this study: SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5, which represent different radiative forcing trajectories and socioeconomic challenges related to climate change mitigation and adaptation.
Climate trends were evaluated using the nonparametric Mann–Kendall test to identify trend direction and the Theil–Sen slope estimator to quantify the magnitude of change. Statistical significance was assessed using p-values at a 95% confidence level (α = 0.05).
Historical TerraClimate data and future GCM projections were integrated through a downscaling process. Because the original interannual GCM outputs had coarse spatial resolutions (100 km × 100 km for GFDL-ESM4 and approximately 150 km × 150 km for MIROC6), downscaling enabled the construction of a continuous annual time series with a 4 km × 4 km spatial resolution.
Results for the historical period (1958–2024) indicate an increase in annual mean temperature of 1.57°C, rising from 15.13°C in 1958 to 16.70°C in 2024. This warming trend is statistically significant, with an estimated annual increase of 0.022°C according to the Theil–Sen slope estimator. Although precipitation did not exhibit a statistically significant trend (p-value > 0.05), total annual precipitation decreased by 12.65 mm over the study period, with several recent consecutive years experiencing precipitation deficits relative to the historical average.
Spatial analysis reveals substantial heterogeneity in climate conditions across the ERZ. Historical mean annual temperatures range from 12.4–14.0°C in the southwestern portion of the region to 16.5–17.8°C in the northeast. Annual precipitation varies from 329–426 mm in the northern municipalities of Tezontepec de Aldama and Tlahuelilpan to 640–818 mm in the southern municipality of Tepeji del Río. This spatial variability reflects the influence of topography on regional climate patterns.
Future climate projections indicate that both models project declining precipitation through 2100 under all four SSP scenarios. The GFDL-ESM4 model projects the most severe reductions, reaching as much as 20.43% under the SSP5-8.5 scenario, whereas MIROC6 projects more moderate decreases of approximately 13%. For mean temperature, MIROC6 projects greater warming by 2100, ranging from 2.20°C under SSP1-2.6 to 3.95°C under SSP5-8.5. In contrast, GFDL-ESM4 projects more gradual increases, ranging from 1.95°C to 2.86°C across the same scenarios.
These findings have important implications for environmental management. The projected increase in temperature and decrease in precipitation, particularly under the most extreme climate scenarios, could intensify water stress, reduce water availability for agriculture, and alter regional ecosystems.
The integration of historical observations with future climate projections provides a robust basis for understanding the region’s climate trajectory and its potential impacts on ecological restoration and natural resource management. The study highlights the need to implement adaptation and mitigation strategies that account for the vulnerability of both ecosystems and local communities to projected climate change.
Overall, this research contributes to the scientific understanding of climate change in Mexico’s semi-arid and temperate regions by providing valuable information to support environmental policy and sustainable development decision-making in the Mezquital Valley, particularly within the Ecological Restoration Zone.