Dynamic puddle delineation and modeling of puddle-to-puddle filling-spilling-merging-splitting overland flow processes

Surface microtopography affects overland flow, infiltration, soil erosion, pollutant transport, and other fundamental hydrologic and environmental processes across scales. Under the influence of surface depressions, overland flow essentially features a series of progressive puddle-to-puddle (P2P) filling, spilling, merging, and splitting processes. The objectives of this study are to characterize puddles and their hierarchical relationships and model the microtopography-controlled P2P processes. We proposed a new modeling framework for simulating the P2P overland flow dynamics through cell-to-cell (C2C) and P2P routing for a set of puddle-based units (PBUs) in a well-delineated, cascaded P2P drainage system. Testing of the P2P model demonstrated its potential to improve overland flow modeling and hydrologic connectivity analysis by explicitly incorporating the hydrologic roles of depressions and quantifying the real microtopography-controlled P2P dynamics.