Predicting the impact of changing climate and anthropogenic influences
on stream discharge dynamics and baseflow conditions requires insight
into the main factors that regulate storage and transfer of water from
hillslope aquifers to surface streams. Classically, it is assumed that
above a certain scale, hydrological laws involved at small-scale can be
simplified, allowing the representation of the landscape and its
subsurface in models as a homogeneous hillslope with effective slope,
length and hydraulic properties. From a comprehensive analysis of
hydrological, geological and geomorphological databases available in the
Swiss Alps we provide evidence that such simplification might lead to
inaccurate estimates of streamflow dynamics at baseflow. We reveal that
recession behavior strongly deviates from that predicted by idealized
homogeneous theories. A correlation analysis allows us to identify which
key features of the landscape might control this deviation, with
particular attention to slope, drainage density, depth to bedrock, and
lithology as the main drivers. We summarize the current knowledge of
physical mechanisms that could lead to complex hydrological behavior in
Alpine contexts, and we finally discuss implications in defining
modeling strategies for the Critical Zone community.