1222 followed by heavy rains, there are sudden increases in acidity and dissolved metal concentrations due to the sudden washing away of accumulated acid salts (“first flush”) (Nordstrom & Alpers, 1999; Blowes et al., 2014). Under climate change scenarios, drier summers and more intense but spaced-out rainfall intervals are expected, which could exacerbate these pulses of acid pollution. This reality raises the need to address ARD/ARD not only as a static problem, but as a dynamic one under changing climatic conditions. Although guidelines exist for AMD/AAR, the Andean region, and climate change, the explicit integration of extreme climate indices (droughts, maximum daily precipitation, duration of dry periods) into closure design and monitoring metrics is still limited; recent approaches propose quantifying these indices and mapping their uncertainty for closure decisions. Currently, the prediction and control of DAM in closure planning is often based on static and kinetic geochemical tests, along with assumptions of stationary climate. While advanced reactive transport models exist that simulate DAM generation and attenuation by incorporating variable saturated and unsaturated flow and coupled chemical reactions, the application of long-term climate projections within such models is still in its infancy. Traditional studies (Nordstrom, 2011; IPCC, 2021) have documented seasonal variations in DAM and proposed mitigation strategies based on historical conditions. However, the literature indicates that emerging climate trends (e.g., greater extremes of drought and rainfall) have not been fully integrated into acid risk assessments. For example, Nordstrom (2009) warns that remediation designs must be prepared for conditions more extreme than historical averages. Some international closure guidelines (e.g., GARD Guide) recognize the influence of climate but offer only general guidelines. In practice, scenarios such as Representative Concentration Pathways (RCPs) need to be explicitly incorporated into geochemical modeling tools for mine closure. Only recently have research approaches emerged that link climate models to acid drainage generation, highlighting a gap between climate science and environmental geochemistry applied to mine closure (Nordstrom, 2011; IPCC, 2021). Given this gap, it is critical to develop methods that integrate climate change projections into DAM prediction. The lack of such integration leads to uncertainty in the effectiveness of long-term closure measures, especially in sensitive areas such as the Peruvian Andes where the retreating cryosphere (e.g., glacier loss) and El Niño/La Niña events can drastically alter water recharge. Currently, closure plans often underestimate how extreme precipitation scenarios could reactivate acid generation in seemingly stable deposits, or how prolonged droughts could deepen sulfide oxidation by exposing a larger reactive area to air, thus amplifying the risk of DAM through changes in precipitation patterns, temperature, and water recharge (IPCC, 2021). This points to the need for innovation with predictive tools that dynamically combine hydrology and geochemistry. A model capable of simulating variable infiltration pulses, partially saturated conditions, and oscillating availability of oxidants (O2) would provide a more realistic view of post-closure chemical evolution under different climate futures. Such an advance would allow for the design of adaptive closure strategies, optimizing covers, barriers, and passive treatment systems based on projected risks and not just current conditions. This work contributes to the theme of the conference “Science and Mining Innovation in the Face of Climate Change Impacts” by presenting an integrated geochemical-climatic modeling framework. Specifically, it proposes a conceptual predictive model aimed at assessing sensitivity to hydroclimatic variations, which couples geochemical reactive transport simulations (with PHREEQC) with transient hydrological forcings derived from climate scenarios (e.g., RCP 4.5). Through a sequential approach of monthly infiltration pulses, the model represents the unsaturated behavior of the deposit and the reactions of reactive sulfides (pyrite oxidation, neutralization, precipitation of secondary compounds, etc.) under a variable climate regime. The result is a metric that summarizes the system's propensity to reactivate acidity generation under certain future climate conditions. This proposal is novel in that it directly links climate change projections to acid drainage chemistry, something that has been little explored in conventional planning. This approach makes it possible to identify in advance the most vulnerable areas of the deposit and the critical periods (e.g., the first heavy rain after a prolonged drought) for water quality. In this way, it provides a scientific basis for strengthening closure measures: cover designs that consider future water balance, drainage systems sized for extreme events, and monitoring schemes focused on early indicators of acidification. In short, the interdisciplinary integration achieved by this model (hydrogeology, climate
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