Urban and rural flood forecasting

Abstract

iii ACKNOWLEDGEMENTS Thanks to Witold Krajewski for giving me the opportunity to work with him and others at the Iowa Flood Center. Thank you for advising me in my research and for showing me the value (and necessity) of clear communication whether to scientists or the public. I appreciate your patience and sincerity. What a privilege to work with such a leading scientist in the field of hydrology who was approachable and generous in his guidance of my work.I would like to acknowledge Felipe Quintero who was a great mentor and friend constantly giving research guidance, a practical outlook to solving problems, and most importantly a good sense of humor. To all my colleagues and friends at IIHR, thanks to everyone who shared their passions with me and enlightened me on the many exciting areas within hydrology. The community at IIHR made my graduate experience formative and enriching, and I am honored to have had the chance to work with the students, staff, and faculty. This project was possible thanks to Ryan Wicks and others at Fehr and Graham for making data available and hosting me at Manchester. The project's momentum was continually fueled by the participation of Shirley Johnson (USACE) and members of other local agencies. Thank you to all other local agencies who provided data and models for this project. iv ABSTRACT Floods are the most common natural disaster in the U.S. as reported by the Federal Emergency Management Administration (FEMA), and there is a need to provide advance warning to vulnerable communities on the potential risks of flooding after intense storms. The key drivers of urban hydrological research include climate change impacts and adaption, city resilience to hydrological extremes, and integration with emergency management and city planning disciplines. Significant advances in modeling techniques and computational resources have made real-time flood forecasting tools in urban and rural areas an achievable goal, but there is no universal method for flood modeling. Urban landscapes pose a challenge because of fine-scale features and heterogeneities in the landscape including streets, buildings, pipes, and impervious land cover.A nested regional-local modeling approach was used to evaluate its capabilities to provide useful and accurate flood related information to a small community in Iowa. The advantage of a nested approach is the ability to harness the computational efficiency of the regional model while providing reasonably accurate streamflow boundary conditions to the local model. The nested model incorporates the tools and products maintained at the Iowa Flood Center (IFC) including the streamflow bridge sensors, rain gauges, radar rainfall product, and statewide model. A one-way connection was made between the regional model of the upper Maquoketa Watershed (275 mi 2 ) and the local model of the City of Manchester (5 mi 2 ). The uncalibrated, nested model was validated using photos and streamflow records for flood events that occurred in July 2010 and September 2016.Multiple radar rai...