Introduction

Overland flow and surface runoff are critical to watershed hydrologic modeling and environmental management. Overland flow generation and surface runoff involve a series of complex, dynamic processes at various scales that are associated with both surface and subsurface systems. Hortonian infiltration-excess and saturation-excess overland flow theories have been widely used for representing the overland flow generation mechanism. However, recent studies reveal that neither overland flow theories are able to explain some field observations, which can be closely related to small-scale processes controlled by microtopography. This NSF-funded project is aimed to develop improved methods to quantify the puddle-to-puddle (P2P) filling, spilling, merging, and splitting overland flow processes under control of surface microtopography, with focus on characterizing discontinuity, variability, and hierarchy of threshold overland flow. A comprehensive modeling system and interactive teaching-learning software are developed to integrate the new modeling methods, enhanced 3-D visualization techniques, and education-oriented tools in a user-friendly Windows interface.

Publications

Habtezion, N., M. Tahmasebi Nasab, and Xuefeng Chu. 2016. How does DEM resolution affect microtopographic characteristics, hydrologic connectivity, and modelling of hydrologic processes? Hydrological Processes. doi:10.1002/hyp.10967.

Yang, J. and Xuefeng Chu. 2015. A new modeling approach for simulating microtopography-dominated, discontinuous overland flow on infiltrating surfaces. Advances in Water Resources, 78:80-93.

Chu, Xuefeng, G. Padmanabhan, and D. Bogart. 2015. Microrelief-controlled overland flow generation: Laboratory and field experiments. Applied and Environmental Soil Science. Volume 2015, Article ID 642952, 11 pages, doi:10.1155/2015/642952.

Zhang, J. and Xuefeng Chu. 2015. Impact of DEM Resolution on Puddle Characterization: Comparison of Different Surfaces and Methods. Water, 7:2293-2313, doi:10.3390/w7052293.

Chu, Xuefeng. 2015. Delineation of pothole-dominated wetlands and modeling of their threshold behaviors. Journal of Hydrologic Engineering, D5015003-p1-11, doi:10.1061/(ASCE)HE.1943-5584.0001224.

Chu, Xuefeng, J. Yang, Y. Chi, and J. Zhang. 2013. Dynamic puddle delineation and modeling of puddle-to-puddle filling-spilling-merging-splitting overland flow processes. Water Resources Research. 49(6):3825-3829.

Yang, J. and Xuefeng Chu. 2013. Quantification of the spatio-temporal variations in hydrologic connectivity of small-scale topographic surfaces under various rainfall conditions. Journal of Hydrology. 505:65-77.

Chu, Xuefeng, J. Nelis, and R. Rediske. 2013. Preliminary study on the effects of surface microtopography on tracer transport in a coupled overland and unsaturated flow system. Journal of Hydrologic Engineering. 18(10):1241-1249.

Yang, J. and Xuefeng Chu. 2013. Effects of DEM resolution on surface depression properties and hydrologic connectivity. Journal of Hydrologic Engineering. 18(9):1157-1169.

Chu, Xuefeng, J. Yang, and Y. Chi. 2012. Quantification of soil random roughness and surface depression storage: Methods, applicability, and limitations. Transactions of the ASABE. 55(5):1699-1710.

Chi, Y., J. Yang, D. Bogart, and Xuefeng Chu. 2012. Fractal analysis of surface microtopography and its application in understanding hydrologic processes. Transactions of the ASABE. 55(5):1781-1792.

Sande, L. and Xuefeng Chu. 2012. Laboratory experiments on the effect of microtopography on soil-water movement: Spatial variability in wetting front movement. Applied and Environmental Soil Science. Volume 2012, Article ID 679210, 8 pages, doi:10.1155/2012/679210.

Sande, L., Xuefeng Chu, and T. DeSutter. 2011. A new method for replicating complex microtopographic surfaces in laboratory soil box experiments. Applied Engineering in Agriculture, ASABE. 27(4):615-620.

Chu, Xuefeng. 2011. Characterization of Microtopography and its Hydrologic Significance (Chapter 1), p1-14. In: Modeling Hydrologic Effects of Microtopographic Features (ISBN 978-1-61668-628-4), edited by X. Wang. Nova Science Publishers, Inc.

Chu, Xuefeng and N. Habtezion. 2014. Applications of the Green-Ampt Method across Scales, p282-291. In: Water without Borders, Proceedings of the 2014 ASCE World Environmental and Water Resources Congress, edited by Wayne C. Huber. American Society of Civil Engineers.

Liu, Y., J. Yang, and Xuefeng Chu. 2013. Infiltration and unsaturated flow under the influence of surface microtopography - model simulations and experimental observations, p468-475. In: Showcasing the Future, Proceedings of the 2013 ASCE World Environmental and Water Resources Congress, edited by C. L. Patterson, S. D. Struck, and D. J. Murray. American Society of Civil Engineers.

Yang, J. and Xuefeng Chu. 2012. Effects of surface microtopography on hydrologic connectivity. p339-348. In: Crossing Boundaries, Proceedings of the 2012 ASCE World Environmental and Water Resources Congress, Edited by E. D. Loucks. American Society of Civil Engineers.

Chu, Xuefeng, J. Zhang, Y. Chi, and J. Yang. 2010. An improved method for watershed delineation and computation of surface depression storage, p1113-1122. In: Watershed Management 2010: Innovations in Watershed Management Under Land Use and Climate Change, Proceedings of the 2010 Watershed Management Conference, edited by K. W. Potter and D. K. Frevert. American Society of Civil Engineers.

Chu, Xuefeng, J. Zhang, J. Yang, and Y. Chi. 2010. Quantitative evaluation of the relationship between grid spacing of DEMs and surface depression storage, p4447-4457. In: Challenges of Change, Proceedings of the 2010 World Environmental and Water Resources Congress, edited by R. N. Palmer. American Society of Civil Engineers.

Chi, Y., J. Yang, and Xuefeng Chu. 2010. Characterization of surface roughness and computation of depression storage, p4437-4446. In: Challenges of Change, Proceedings of the 2010 World Environmental and Water Resources Congress, edited by R. N. Palmer. American Society of Civil Engineers.

Yang, J., Xuefeng Chu, Y. Chi, and L. Sande. 2010. Effects of rough surface slopes on surface depression storage, p4427-4436. In: Challenges of Change, Proceedings of the 2010 World Environmental and Water Resources Congress, edited by R. N. Palmer. American Society of Civil Engineers.

Software Manuals

Chu, Xuefeng. 2013. HYDROL-INF Modeling System - Hydrologic Research and Teaching Software, Version 6.10, User's Manual, North Dakota State University, 80 pages.

Chu, Xuefeng, J. Zhang, J. Yang, N. Habtezion, Y. Chi, and Y. Yang. 2013. P2P Modeling System, User's Manual, Version 1.50, North Dakota State University, 45 pages.

Chu, Xuefeng, J. Zhang, J. Yang, N. Habtezion, Y. Chi, and Y. Yang. 2013. P2P Tools, User's Manuals, Version 1.50, North Dakota State University, 64 pages.

Chu, Xuefeng, J. Zhang, J. Yang, N. Habtezion, Y. Chi, and Y. Yang. 2013. P2P Education, User's Manual, Version 1.50, North Dakota State University, 10 pages.

M.S. Theses and Ph.D. Dissertations

Yang, Jun. 2014. Microtopography-Dominated Discontinuous Overland Flow Modeling and Hydrologic Connectivity Analysis, Ph.D. Dissertation. North Dakota State University, Fargo, North Dakota.

Habtezion, Noah. 2014. Modeling of Surface Microtopography and Its Impacts on Hydrologic Processes, M.S. Thesis. North Dakota State University, Fargo, North Dakota.

Bogart, Daniel. 2014. Hydrologic Experiments and Analysis - The Effect of Microtopography on Runoff Generation, M.S. Thesis. North Dakota State University, Fargo, North Dakota.

Liu, Yang. 2014. Infiltration and Unsaturated Flow under the influence of Surface Microtopography - Model Simulations and Experimental Observations, M.S. Thesis. North Dakota State University, Fargo, North Dakota.

Chi, Yaping. 2012. Characterization of Surface Microtopography and Determination of Hydrotopographic Properties, M.S. Thesis. North Dakota State University, Fargo, North Dakota.

Sande, Leaf. 2011. Experimental Studies on Infiltration/Soil-Water Movement Processes and Green-Ampt Modeling, M.S. Thesis. North Dakota State University, Fargo, North Dakota.

Avadhuta Shravan. 2011. Topography Analysis: Evaluating DEM Data Sources for TWI Calculation, M.S. Thesis. North Dakota State University, Fargo, North Dakota.

Higgins, Jessica. 2009. An Experimental Study on Overland Flow and Tracer Transport: Investigating Influences of Soil Surface and Texture under Steady Rainfall, M.S. Thesis. Grand Valley State University, Allendale, Michigan.

Conference Presentations

Chu, Xuefeng. 2015. DEM-based Wetland Delineation and Application in the Prairie Pothole Region. ASCE 2015 World Environmental and Water Resources Congress, May 17-21, 2015, Austin, TX.

Habtezion, N. and Xuefeng Chu. 2015. Effects of Multiple Rainfall Events on Soil Water Dynamics and Surface Hydrologic Response. ASCE 2015 World Environmental and Water Resources Congress, May 17-21, 2015, Austin, TX.

Chu, Xuefeng, G. Padmanabhan, D. Bogart, and N. Leelaruban. 2015. Overland Flow Generation under the Influence of Microrelief, Soil, and Rainfall. ASCE 2015 World Environmental and Water Resources Congress, May 17-21, 2015, Austin, TX.

Chu, Xuefeng and N. Habtezion. 2014. Applications of the Green-Ampt Method across Scales. ASCE 2014 World Environmental and Water Resources Congress, June 1-5, 2014, Portland, OR.

Habtezion, N. and Xuefeng Chu. 2014. Surface Microtopography and Its Significance on Spatial Distribution of Hydrologic Processes. ND EPSCoR/IDeA 2014 State Conference, April 29, 2014, Grand Forks, ND.

Chu, Xuefeng, J. Yang, and D. Bogart. 2013. Modeling of Infiltration and Discontinuous Overland Flow Dynamics under Various Topography, Soil, and Rainfall Conditions. ASCE 2013 World Environmental and Water Resources Congress, May 19-23, 2013, Cincinnati, OH.

Liu, Y., J. Yang, and Xuefeng Chu. 2013. Infiltration and Unsaturated Flow under the Influence of Surface Microtopography - Model Simulations and Experimental Observations. ASCE 2013 World Environmental and Water Resources Congress, May 19-23, 2013, Cincinnati, OH.

Habtezion, N. and Xuefeng Chu. 2013. Segmentation of Land Surface Image Using Object-based Method. North Dakota/South Dakota Engineering Research Summit, NDSU, UND, and SDSU, April 23, 2013, Brookings, SD.

Liu, Y. and Xuefeng Chu. 2013. Wetting Front Movement Affected by Surface Microtopography. North Dakota/South Dakota Engineering Research Summit, NDSU, UND, and SDSU, April 23, 2013, Brookings, SD.

Chu, Xuefeng, J. Yang, and N. Habtezion. 2012. Dynamic puddle delineation and threshold-driven hydrotopographic processes. AGU Fall Meeting, December 3-7, 2012, San Francisco, CA.

Yang, J., D. Bogart, and Xuefeng Chu. 2012. Quantification of the spatio-temporal variability in threshold-controlled overland flow generation processes - A combined experimental and modeling study. AGU Fall Meeting, December 3-7, 2012, San Francisco, CA.

Chu, Xuefeng and J Yang. 2012. A New Surface Delineation Approach for Characterizing Threshold-Driven Watershed Processes - Introduction to the Puddle-to-puddle (P2P) Modeling System. Fifty Years of Watershed Modeling - Past, Present and Future, Engineering Conferences International, September 24-26, 2012, Boulder, CO.

Chu, Xuefeng. 2012. Surface Ponding and Its Influence on Infiltration and Unsaturated Flow - Introduction to a New Version of HYDROL-INF Software. ASCE 2012 World Environmental and Water Resources Congress, May 20-24, 2012, Albuquerque, NM.

Yang, J. and Xuefeng Chu. 2012. Effects of Surface Microtopography on Hydrologic Connectivity. ASCE 2012 World Environmental and Water Resources Congress, May 20-24, 2012, Albuquerque, NM.

Yang, J. and Xuefeng Chu. 2012. Modeling of Microtopography-Controlled Hydrologic Connectivity and Overland Flow Dynamics. North Dakota/South Dakota Engineering Research Summit, NDSU, UND, and SDSU, April 23, 2012, Grand Forks, ND.

Bogart, D., J. Yang, and Xuefeng Chu. 2012. Runoff Generation of Rough and Smooth Plots under Natural Rainfall Events. North Dakota/South Dakota Engineering Research Summit, NDSU, UND, and SDSU, April 23, 2012, Grand Forks, ND.

Chi, Y., J. Yang, and Xuefeng Chu. 2012. Application of Fractal Analysis for Surface Characterization and Hydrologic Analyses. North Dakota/South Dakota Engineering Research Summit, NDSU, UND, and SDSU, April 23, 2012, Grand Forks, ND.

Chu, Xuefeng. 2011. State-of-the-art Hydrology Education: Development of Windows-based and Web-based Interactive Teaching-Learning Software. NSF Special Session ED30: Impacts of Over a Decade of CAREER Awards, AGU Fall Meeting 2011, December 5 - 9, San Francisco, California.

Chu, Xuefeng, J. Yang, Y. Chi, Y. Yang, and J. Zhang. 2011. Development of a Windows-based Modeling System for Simulating Microtopography-Controlled Overland Flow. AGU Fall Meeting 2011, December 5 - 9, San Francisco, California.

Yang, J. and Xuefeng Chu. 2011. Surface Microtopography and Hydrologic Connectivity Analysis. AGU Fall Meeting 2011, December 5 - 9, San Francisco, California.

Yang, J. and Xuefeng Chu. 2011. Surface Delineation and Hydrologic Connectivity Analysis. ND-SD 2011 Joint EPSCoR Conference, October 4, 2011, Fargo, ND.

Chu, Xuefeng, Y. Chi, J. Yang, L. Sande, and D. Bogart. 2011. Microtopographic Characteristics of Soil Surfaces and Overland Flow Generation. ASCE 2011 World Environmental and Water Resources Congress, May 22-26, 2011, Palm Springs, California.

Sande L., D. Bogart, and Xuefeng Chu. 2011. Infiltration and Surface Runoff: Laboratory Experiments vs. Physically-based Modeling. ASCE 2011 World Environmental and Water Resources Congress, May 22-26, 2011, Palm Springs, California.

Chu, Xuefeng. 2011. Characterization of Surface Microtopography and Modeling of Overland Flow. North Dakota/South Dakota Engineering Research Summit, NDSU, UND, and SDSU, April 29, 2011, Fargo, ND.

Chi, Y., J. Yang, L. Sande, D. Bogart, and Xuefeng Chu. 2010. An improved surface delineation method - Puddle delineation program and applications. North Dakota EPSCoR 2010 State Conference, September 29, 2010, Grand Forks, ND.

Chu, Xuefeng, J. Zhang, Y. Chi, and J. Yang. 2010. An improved method for watershed delineation and computation of surface depression storage. ASCE 2010 Watershed Management Conference: Innovations in Watershed Management under Land Use and Climate Change, August 23-27, 2010, Madison, Wisconsin.

Chu, Xuefeng, J. Zhang, J. Yang, and Y. Chi. 2010. Quantitative evaluation of the relationship between grid spacing of DEMs and surface depression storage. ASCE 2010 World Environmental and Water Resources Congress, May 16-20, 2010, Providence, Rhode Island.

Yang, J., Xuefeng Chu, Y. Chi, and L. Sande. 2010. Effects of rough surface slopes on surface depression storage. ASCE 2010 World Environmental and Water Resources Congress, May 16-20, 2010, Providence, Rhode Island.

Chi, Y., J. Yang, and Xuefeng Chu. 2010. Characterization of surface roughness and computation of depression storage. ASCE 2010 World Environmental and Water Resources Congress, May 16-20, 2010, Providence, Rhode Island.

Chu, Xuefeng and Jianli Zhang. 2009. An automated algorithm for quantifying depression filling and storage. ASCE 2009 World Environmental and Water Resources Congress, May 17-21, 2009, Kansas City, MO.

Yang, J., Y. Chi, Xuefeng Chu. 2009. Experimental study on microtopography-controlled overland flow. 3th Annual Joint Student Environmental Conference, July 29-30, 2009, South Dakota State University, Brookings, SD.

Chi, Y., J. Yang, Xuefeng Chu, J. Zhang. 2009. Characterization of surface roughness and computation of depression storage. 3th Annual Joint Student Environmental Conference, July 29-30, 2009, South Dakota State University, Brookings, SD.

Chu, Xuefeng, Jessica Higgins, and Jianli Zhang. 2008. Multi-scale DEM-based delineation and quantification of overland flow processes. AGU 2008 Fall Meeting, December 15-19, 2008, San Francisco.

Funded by National Science Foundation This material is based upon work supported by the National Science Foundation under Grant No. EAR-0907588. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.