Hydrologic Connectivity and Patch‐To‐Hillslope Scale Relations in Dryland Ecosystems

In drylands, runoff during storms redistributes water and nutrients from bare soil areas to vegetated patches, subsidizing vegetation with additional resources. The extent of this redistribution depends on the interplay between surface roughness permeability; greater permeability in patches promotes run-on vegetation, but diverts runoff, producing tortuous flow paths that bypass vegetation. Here, is examined virtual experiments using 2D Saint Venant Equations measure connectivity. Flowpaths are delineated tracers advected by flow. Distances tracer sources sinks along flowpaths hydrologic connectivity at two lengthscales: hillslope outlet within-slope source-sink Differences these lengthscales indicate how may “by-pass” within hillslopes. At scale, a derived power-law relation coefficient describes losses, providing foundation for identifying landscapes likely shed water.