Strengthening community resilience to climate change: CRIDA case study on the vital role of endemic Polylepis mountain forests and the link to aquifer recharge

In the context of increasing climate variability and its profound impacts on water resources, robust methodologies for risk analysis and planning are essential to ensure water security and sustainable management. This study applies the Climate Risk Informed Decision Analysis (CRIDA) framework to assess the vulnerability of water resources in the eastern sub-basin of the Chili River in Peru. A participatory approach was used to identify key performance indicators and conduct a hydrological stress test using the WEAP model under scenarios of deforestation and climate change. Results showed that, under a deforestation scenario, average monthly aquifer storage could decrease by approximately 27% compared with the baseline scenario, and 55% under the combined deforestation and climate change scenario. As a consequence, water supply reliability for the residential sector of Characato decreased from 100% to 85% under the combined scenario, while some agricultural sectors reached 0% reliability. In contrast, modelling a reforestation scenario involving 3,000 ha of Polylepis forest improved water supply reliability to nearly 100% for several affected users and increased average aquifer storage by up to 149% relative to the deforestation scenario under climate change. This research examines the hydrological role of Andean Polylepis forests in the eastern sub-basin of the Chili River to enhance groundwater recharge as a strategy for drought adaptation, while also highlighting the dual threat that deforestation has on water availability and rural livelihoods. These findings provide new insights into how forest conservation and local knowledge can contribute to the CRIDA framework to strengthen water security strategies in Andean ecosystems.