Quantification of runoff generation from a combined glacier and páramo catchment within an Ecological Reserve in the Ecuadorian highlands

Abstract. Hydrological processes in combined glacier and páramo catchments are vitally important to serve the water needs of communities in the surrounding areas. Previous studies have shown that the melting of glaciers contributes to runoff generation and that the páramo ecosystem acts as a natural sponge, which plays an important role in regulating the runoff during the dry-season. However, not all runoff processes are well-understood in the Andean region due to the high spatial variability of precipitation, young volcanic ash soil properties, soil moisture dynamics and other local factors such as vegetation interception and high radiation that might influence the hydrological behaviour. In addition, there is a lack of evidence of the origin and quantification of the contribution of runoff components in the páramo ecosystem. This study focuses on data collection and experimental investigations in a small catchment (15.2 km²) within an ecological reserve in the Ecuadorian Andean region. The approach consists of the identification of suitable environmental tracers and hydrochemical features to identify the various runoff sources in order to determine their respective contribution during dry and wet conditions. The results show the great importance of the páramo on the contribution to total runoff during baseflow and rainfall conditions.