Résumé
The Alto Mayo calcareous mountains (San Martin, Perú) present a developed and active karstic system, nowadays poorly studied. The aim of this study is to determine the discharge of the main resurgences of this region and their catchment area. We used hydrologic and pluviometric data used from the local observatory (ANA and SENAMHI) and from the KarstAm project. We measured some resurgences” discharges at 24 m3/s on average, ranking them among the most important of South America. The seasonable variability of the discharges shows an atypical behavior, closer to a porous than a karstic aquifer. As the specific discharges are higher than the regional tendency, we reevaluated catchment areas, by assuming the presence of major karstic captures upstream. We also corrected the precipitation values using the regional vector method. These recalculatedspecific discharges are then closer to the regional tendency, but the run-off coefficient remains too high. We attribute the errors to the precipitations values in the global Alto Mayo basin that seem underestimated.