A new modeling approach for simulating microtopography-dominated, discontinuous overland flow on infiltrating surfaces. (April 2015)

• Record Type: Journal Article
• Authors: Yang, Jun; Chu, Xuefeng
• Is Part Of: Advances in water resources. Volume 78(2015)
• Page Start: 80
• Page End: 93
• Publication Date: 2015-04
• Subjects: Overland flow -- Microtopography -- Puddle dynamics -- Depression -- Infiltration -- Digital elevation model; Hydrology -- Periodicals; Hydrodynamics -- Periodicals; Hydraulic engineering -- Periodicals; 551.48
• DOI: 10.1016/j.advwatres.2015.02.004
• Languages: English
• ISSNs: 0309-1708

Abstract

Highlights: Improved understanding of overland flow generation mechanism. New method for modeling microtopography-dominated, discontinuous overland flow. Unique cell-to-cell (C2C) and puddle-to-puddle (P2P) two-domain modeling. Hierarchical modeling of P2P filling–spilling–merging–splitting dynamics. Abstract: Realistic modeling of discontinuous overland flow on irregular topographic surfaces has been proven to be a challenge. This study is aimed to develop a new modeling framework to simulate the discontinuous puddle-to-puddle (P2P) overland flow dynamics for infiltrating surfaces with various microtopographic characteristics. In the P2P model, puddles were integrated in a well-delineated, cascaded drainage system to facilitate explicit simulation of their dynamic behaviors and interactions. Overland flow and infiltration were respectively simulated by using the diffusion wave model and a modified Green–Ampt model for the DEM-derived flow drainage network that consisted of a series of puddle-based units (PBUs). The P2P model was tested by using a series of data from laboratory overland flow experiments for various microtopography, soil, and rainfall conditions. The modeling results indicated that the hierarchical relationships and microtopographic properties of puddles significantly affected their connectivity, filling–spilling dynamics, and the associated threshold flow. Surface microtopography and rainfall characteristics also exhibited strong influences on the spatio-temporal distributions of infiltration rates, runoff fluxes, and unsaturated flow. The model tests demonstrated its applicability in simulating microtopography-dominated overland flow on infiltrating surfaces.