Arequipa’s Water in the Short Future: a Hydrologic Outlook in an Arid Peruvian Andes Region Utilizing Hyperresolution RCM and CREST-VEC Model Simulations Under SSP5-8.5

Under the high-emission SSP5-8.5 scenario, Arequipa's Rio Chili is projected to experience complete 'no water' events by 2078-2079, with a significant reduction in wet season duration and streamflow, while flood risks are expected to rise. This study utilizes hyperresolution Regional Climate Model (RCM) outputs and the CREST-VEC hydrological model to simulate future hydrological conditions in Arequipa, Peru, comparing 2075-2079 projections with baseline data from 2015-2019. Findings indicate a 19.8% reduction in runoff, an 83%-86% average decrease in streamflow, and a 37.8-day shorter wet season, with first-order streams drying more than 50% of the time by 2075-2079—up from less than 40% in the baseline period. Despite reduced water availability, flood risks are projected to increase, with at least one severe flood event expected to surpass those seen in 2017 and 2019, while Rio Colca faces more frequent flooding.

Chen, M., Huang, Y., Hu, X.-M., Xue, M., Hong, Y., Mayol Novoa, H., R. Martin, E., A. McPherson, R., Zhu, S., Vitaliano Peraz, A., Luis Ticona Jara, J., & Yanqui Morales, I. (2025). Arequipa’s Water in the Short Future: a Hydrologic Outlook in an Arid Peruvian Andes Region Utilizing Hyperresolution RCM and CREST-VEC Model Simulations Under SSP5-8.5. American Journal of Water Resources, 13(2), 51–62. https://doi.org/10.12691/ajwr-13-2-3