Effects of Hydrological and Catchment Biophysical Factors on Baseflow Dynamics in Two Neighbouring Micro-Catchments of the Andean Ecosystems

Abstract

Baseflow is crucial for designing minimum flows to support ecosystems in headwater catchments. Yet, understanding of its dynamics and determinants remains limited. We employed an experimental paired catchment approach to investigate baseflow dynamics and its determinants in two neighbouring wet puna micro-catchments, Anduy and Shigual, located in the Andean wet puna ecosystems. We found significant seasonal variation in baseflow dynamics between the Anduy and Shigual catchments. Although mean baseflow indices were similar, Anduy exhibited sharper baseflow recession. With a strong predictive power (R² = 0.99), the multiple linear regression models identified that precipitation, streamflow, soil water depletion, baseflow, and deep percolation predicted baseflow dynamics in Anduy, with only streamflow, soil water depletion, and baseflow significantly affecting these dynamics in Shigual. These findings indicate that even neighbouring catchments with similar biophysical and hydrological characteristics may have different dominant hydrological processes. Our findings emphasise the need for catchment-specific minimum flow designs and highlight the importance of strategically managing land cover to balance baseflow magnitude and stability for dry-season water management.