Integrating subgrid connectivity properties of the micro-topography in distributed runoff models, at the interrill scale

Effect of Slope, Rainfall Intensity and Mulch on Erosion and Infiltration under Simulated Rain on Purple Soil of South-Western Sichuan Province, China

“…The runoff losses significantly (α = 0.05) increased with an increase in the rainfall intensities from 33 to 120 mm·h −1 at all slope levels, however, there was a non-significant change in runoff between rainfall intensity of 33 mm·h −1 and 54 mm·h −1 at 5 • and 15 • slopes. When rainfall begins, surface depressions progressively overflow and are connected to nearby depressions resulting in overland flow [30,33,34]. This process starts when the infiltration capacity during a rainfall event is lower than the rainfall intensity [35].…”

A new modeling approach for simulating microtopography-dominated, discontinuous overland flow on infiltrating surfaces

“…5) were applied to surfaces S4-S6 to discuss the influences of temporal variability in rainfall on the P2P dynamics. Note that the three unsteady rainfall events (Rain [2][3][4] had the same cumulative rainfall as that of the steady rainfall event (Rain 1). Clay loam soil with an initial moisture content of 0.32 was used in these simulations ( Table 2).…”

“…topographic surface was commonly assumed in such conceptual models (e.g., [15,14,4,5,38], which may not be valid for a larger scale hydrologic system. To consider the runoff water transferring time and depression storage, Antoine et al [3] integrated the connectivity information of subgrids (relative surface connectivity function) into the hydrograph by implementing two corrective procedures (weighted-source and weighted-surface). A uniform slope and 1D sheet flow were assumed in their modeling.…”

“…In addition, such numerical models are computationally intensive and time consuming. For instance, Antoine et al [3] found that the computation time of a numerical diffusion wave model for a small plot (1 Â 1 m 2 and 2-mm DEM resolution) was three orders of magnitude slower (100 days) than that of their simplified conceptual model (10 min). Importantly, those numerical models may not be able to account for the important hydrologic roles of surface depressions and realistically simulate the P2P dynamics and the resulting discontinuous overland flow (e.g., [18,19,40]).…”

How do slope and surface roughness affect plot-scale overland flow connectivity?

“…Overland flow is a spatially distributed process whereby depressions progressively overflow and connect to either nearby depressions or to the outflow boundary (Onstad, 1984;Darboux et al, 2002b;Antoine et al, 2011;Chu et al, 2013). During a rainfall event this process starts when the infiltration capacity becomes lower than the rainfall intensity.…”