Katherine Anarde

This project will provide new empirical insight regarding if and how coastal flooding influences migration decisions and community composition. We adopt an interdisciplinary approach to understanding the causes and consequences of chronic coastal flooding. Our research addresses two key knowledge gaps. First, we will deploy a novel, low-cost sensor system that will enable us to detect flooding where people live (rather than at tide gauges), at high temporal resolution. This approach ensures that we capture both ????????????????flash??????????????? and prolonged flood events, and the numerous drivers that contribute to them including rain, wind, groundwater, and local drainage infrastructure. Second, we will go beyond studying infrastructure impairment to investigate how people and communities experience and respond to chronic flooding through household surveys and large-scale administrative data.

In August 2012, a new terminal groin permit associated with the new Basnight Bridge was signed. As with the original (1989) Oregon Inlet Terminal Groin permit, the new permit requires NC DOT to monitor the adjacent beach in order to determine whether or not there is adverse impact of the presence of the terminal groin, including a determination of whether sediment loss is greater than that predicted by the historical rates. In addition, NC DOT has proposed coastal and biological monitoring in support of the NC 12 Transportation Management Plan (NC 12 TMP) alternative (as discussed in the B-2500 ROD) and a review of the historical rate used for a basis comparison. The monitoring associated with the NC 12 TMP is needed in order to determine the location and extent of future phases of the B-2500 project. This study will gather and analyze the data that is needed to satisfy the requirements of both 1) the new terminal groin permit and 2) the coastal monitoring program component of the NC 12 TMP. The present proposal includes the following program elements: 1) data collection by NC DOT, 2) monitoring of the existing Oregon Inlet terminal groin, 3) mapping and modeling of coastal habitat changes, 4) TMP coastal monitoring, including development of vulnerability indicators related to the island morphology, and 5) integration of physical and biological monitoring data from NC DOT with the morphological indicators. An annual report will be developed detailing the program tasks and annual results, including a comparison with baseline conditions.

The goal of the Early Career Research Fellowship ??? Environmental Protection and Stewardship track is to advance scientific knowledge and its application to predict and prepare for ecosystem changes in the Gulf of Mexico and its coastal zones as the region navigates a changing climate and energy transition.

This project will address the problem of recurrent, shallow flooding in low-lying coastal communities. As local sea-level rise (SLR), land subsidence, and heavy rainfall events increase, so does the frequency of flooding in low-lying coastal areas. The tidal cycle now takes place on higher average sea levels, resulting in ????????????????sunny-day??????????????? flooding of roadways during high tides. Sea water also infiltrates stormwater drainage systems at low tidal levels, such that ordinary rainstorms lead to flooding. While these minor floods draw less attention than catastrophic storms, their high frequency imposes a chronic stress on coastal communities and economies by disrupting critical infrastructure services. The proposed work integrates outreach and research activities over the two-year project period to improve our prediction and communication of chronic flood hazards. First, we will couple an existing high-resolution hydrodynamic model used for prediction of estuarine flooding in the region (SWAN+ADCIRC) with a stormwater management model (SWMM5) to hindcast and identify the drivers of unexpected flood events in Carolina Beach, a community plagued by chronic flooding. In parallel, we will co-develop potential flood-mitigation actions with Carolina Beach??????????????????s Flood Working Group to inform future work using the coupled model framework. Second, we will deploy a real-time flood sensor network (in development by PIs Anarde, Hino, and Gold) in Carolina Beach to fill data gaps on the incidence and causes of chronic flooding. These data will inform an early-warning system, designed with local officials and community members, for real-time communication of flood hazard.

The integrity and reliability of flood-control earthen dams and levees are essential components to homeland safety. The failure of such systems due to natural or man-made hazards may have monumental repercussions, sometimes with dramatic and unanticipated consequences on human life and the country??????????????????s economy. The levees network in the Sacramento-San Joaquin Delta support exceptionally rich agricultural area (over a $500 million annual crop value). Currently, the risk of levee failure in this area from potential flooding or draught threatens the lives of individuals living behind the levees, but also, the water quality in this water-transfer system. Preliminary risk assessment demonstrated a 40% chance that at least 30 islands within the Delta area would be flooded by simultaneous levee failures in a major earthquake in the next 25 years. The teamwork proposed herein will extend the remote sensing monitoring by InSAR and Joint Scatterer interferometry (JSInSAR) to monitor levees deformation with a resolution on the order of a few millimeters. The research team ay NCSU will participate by integrating the use of measurement data and modeling techniques, using the concept of performance limit states, to effectively achieve a performance based health assessment of the delta levees network.

Roadway vulnerability assessments are often used to predict which routes are currently, or may in the future, be subject to natural hazards. However, these assessments are often conducted for individual roadways and therefore do not assess to what degree road closures affect the connectivity of road networks ??? i.e., the ability for a user to access other roads in the network. A consequence of this is that future roadway retrofits, such as raising the elevation of roadways, could alter network connectivity in a way that has cascading impacts on community accessibility during extreme events. The principal goal of this project is to improve predictions of roadway vulnerability by using network science and network analysis to understand the connectivity of road networks during extreme events. By treating road intersections as ???nodes??? and road segments as ???edges???, we can successively remove nodes based on some criteria (such as increasing elevations, akin to flooding or another extreme event) to identify the threshold where the entire network starts to break apart. The network analysis proposed in this project is focused on coastal settings, and specifically flood hazards, but the methodology is broadly applicable to other regions of North Carolina and additional natural hazards (e.g., landslides).

Microbiological contaminants will be screened in floodwaters during high tide floods in Beaufort and Carolina Beach, NC.

Hurricanes, with their strong wind, large waves, and storm surge, can profoundly reshape coastal landforms and damage near-coast structures. Mutual resilience of coastal communities, ecosystems, and landscapes to future storm impacts requires a clear understanding of the hydrodynamic forces impacting coastal systems during storms and accurate representation of these processes in numerical models. Previous efforts to collect coastal data during storm impact have relied on the ????????????????deploy and retrieve??????????????? model wherein successful data acquisition hinges on post-storm retrieval of data loggers. Inevitably under this paradigm, instrument damage and loss has resulted in sparse data sets with limited spatial and temporal resolution. Recent technological advancements in wireless monitoring and distributed sensor networks have the potential to catalyze a shift away from the ????????????????deploy and retrieve??????????????? framework toward ????????????????real-time monitoring??????????????? of storm impacts. Leveraging this potential, we propose to design and test a new low-cost wireless pressure sensor network for real-time measurement of waves and water levels during hurricane impact. The distributed wireless network will consist of multiple pressure sensor ????????????????nodes??????????????? that transmit data via short-range radio to a central ????????????????gateway???????????????, and thereafter to the cloud via a cellular modem. While the sensor in the proposed project records pressure, distributed wireless networks are inherently modular and future work will add utility to the instrument array by incorporating additional sensors (e.g., accelerometers). The proposed project will utilize existing infrastructure and expertise for laboratory (flume) and field-based testing of the prototype sensor network at the University of North Carolina ?????????????????? Wilmington (Dr. Mieras) and North Carolina State University (Dr. Anarde), as well cultivate new research collaborations among institutions and with a North Carolina-based startup, Agrinik Technologies, LLC. Once optimized, the new distributed wireless network will be used to address a myriad of data and knowledge gaps related to storm processes, including infrastructure fragility, feedbacks between structures and flow routing, and wave transformation during island overwash.