Combined-book

Jun Yang; Xuefeng Chu North Dakota State University Department of Civil Engineering Ph.D. Candidate; Assistant Professor jun.yang.2@ndsu.edu Poster Title: Modeling of Microtopography-Controlled Hydrologic Connectivity and Overland Flow Dynamics Abstract: Land surfaces are characterized by depressions, which break spatial continuity of various hydrologic features/properties. The varying connectivity of topographic surfaces and the threshold characteristics of a series of hydrologic and geomorphologic processes result in localized and independent hydrologic mass balance. This study centers on modeling the formation and evolution of the puddle-to-puddle (P2P) dynamic overland flow processes and further examining the effects of surface microtopography on hydrologic connectivity. An instantaneous-profile laser scanner is utilized to acquire high-resolution DEMs of various surfaces. A conceptual P2P overland flow model is developed to simulate the P2P processes and characterize hydrologic connectivity for microtopography-controlled overland flow systems. It is found that the number and normalized average of connected areas follow a similar nonlinear decreasing trend for small scale surfaces. Connectivity properties vary with different stages of the P2P overland flow dynamics, depending on the spatial patterns of puddles.