Publications by Year: 2021

The formation of urban coastal flooding is mainly ruled by the interaction between rainfall-runoff and storm surge. This study aims to advance the understanding of coastal urban flood mechanism by developing an integrated modeling and multivariate analysis framework, which involves a hydrologic model (Storm Water Management Model (SWMM)), as the core model, coupled with a coastal hydrodynamic model (Delft3D). The uncertainty associated with the flood depth prediction by integrated models is analyzed using the multivariate Gaussian Copula. The performance of the integrated modeling framework is evaluated for the Chittagong City of Bangladesh, which has experienced extreme and frequent coastal urban floods. Results from modeling indicate that changes in the tidal phase of coastal urban flooding alter the flood’s duration and depth. The intensity of compound flooding is higher for the co-occurrence of rainfall and surge peaks than the occurrence of both events in succession. The average flood duration and depth can be increased by about 2.5 h and 0.24 m, respectively, during compound events. When the storm surge occurs during the transition phase, between high/low tides (2–4 h before peak low/high tide), the duration of flood extends due to longer surge duration (4–4.5 h). Finally, the multivariate Gaussian Copula model adjusts the integrated modeling outputs and enhances the skill to predict the inundation depth by 4.6–24.3%. The findings of this study are critical for a better understanding of coastal urban flood processes and enhancing the informed decision-making for emergency management and planning in low-lying coastal regions.

The South Carolina Department of Transportation (SCDOT) identified three areas that have significant effect on its ability to deliver projects on time and on budget: 1) inconsistent permit application submittals among consultants that led to delay in approval by the U.S. Army Corp of Engineers (USACE), 2) inability to consistently identify red flags early in the project development process, and 3) lack of mitigation credit coverage. The objective of this project is to decrease the risks in these three areas. A review of the literature and other state highway agencies practices indicated that some agencies have used Geographic Information Systems (GIS) to develop in-house mitigation and project screening tools and some agencies have transitioned from paper-based permit applications to web-based permit applications. None of the off-the-shelf products or other agencies in-house applications can be easily tailored to the SCDOT s practice. For this reason, this project focused on development and technology transfer of applications to enable the SCDOT s Environmental Services Office (ESO) to accelerate project delivery by improving the consistency of ESO s deliverables, avoiding and minimizing impact of projects through proper screening, and increasing available mitigation credits through transparency with the banking community. Five applications were developed which involved input from the Project Steering and Implementation Committee throughout the design and implementation process: 1) Project Screening Tool ArcGIS webapp, 2) Mitigation Forecasting Tool ArcGIS webapp, 3) Jurisdictional Determination (JD) ArcGIS webapp, 4) JD web-based smart form, and 5) General Permit web-based smart form. After several rounds of beta testing involving SCDOT staff, consultants, and USACE, these five apps have been adopted by the SCDOT and have been incorporated into the agency s existing workflows.