The Río Claro Mountain Observatory ‘Poleka Kasue’: improving our understanding of the complexity of tropical high-altitude watershed hydrology

Abstract:

A faster tropical upper-tropospheric warming and its concomitant changes in the snowline, Equilibrium Line of Altitude and Level of Free Convection are having numerous negative impacts on the altitudinal distribution of solid and liquid precipitation in tropical high-altitude Andean watersheds, and consequently on the overall integrity of páramo environments. The goal of our long-term, multi-tiered, integrated approach is to deepen our understanding of the role of moist convection in the response of and potential changes in eco-hydrological regimes of high-altitude watersheds. Activities are focused on the Río Claro, a key high-altitude basin located in Los Nevados Natural Park, on the El Ruiz-Tolima volcanic massif, in the Colombian Central Andean region. Research activities are supported on the analysis of primary data collected by weather and gauging stations, sets of U23-001 HOBO® near-surface temperature, relative humidity and dew point data loggers, and various biological parameters from vegetation experimental plots. Hourly data gathered at the HOBO digital sensors, which are distributed along a 4,000 m altitudinal gradient, are used to characterize ground-based environmental lapse rates, time of occurrence of vertical motions, and moist and dry Brunt-Väisälä frequencies. Spatially-distributed hydrological modeling is implemented to assess changes in water balance and hydrological regimes, and is complemented with on-the-ground activities aimed at measuring changes in snowpack melting, peatland and lagoon water storage, horizontal precipitation, and water retention in páramo vegetation. Research activities also integrate different ecological scales (from general ecosystem approach to specific species level) and multiple methodological approaches (from geographical modelling to in-situ observations and long-term monitoring). The proposed Poleka Kasue mountain observatory is already providing multiple insights into the complexity of tropical high-altitude watershed hydrology.