Mountain water resources are of particular importance for downstream populations but are threatened by decreasing water storage in snowpack and glaciers. Groundwater contribution to mountain streamflow, once assumed to be relatively small, is now understood to represent an important water source to mountain streams and rivers. This presentation will focus on recent hydrogeological research in the Peruvian Andes which examines the role of groundwater in sustaining streamflow as glacier meltwater supply diminishes. Our tracer experiments have revealed that groundwater discharge in the Peruvian Andes is an important source of stream flow, and that certain landforms, like moraines, are characterized by significant groundwater-surface water exchange. Next, we integrated groundwater, surface water and glacier melt numerical models and applied climate projections to assess the impact of climate change on the mountain hydrological system over the 21stcentury. Relatively consistent groundwater discharge feeds dry-season streamflow as glacier meltwater decreases. However, as temperature and evapotranspiration increase through time, groundwater recharge decreases, resulting in an overall reduction in streamflow. In response to changing hydrologic conditions, several climate change adaptation strategies have been proposed to increase groundwater recharge. We collected field data and applied numerical modelling to assess the efficacy of hillslope trenching as an adaptation strategy in the Peruvian Andes. Overall, this work demonstrates the importance of groundwater in Andean hydrological systems and highlights the need for improved observation and management of mountain groundwater resources.
Lauren Somers is an Assistant Professor at Dalhousie University, Canada, in the Civil and Resource Engineering Department and Centre for Water Resources Studies. Her research centers on groundwater and surface water systems, how they are affected by and contribute to climate change and other perturbations. Her recent work focuses on wetland and mountain settings and engineering strategies to enhance water supply and carbon storage of natural environments.