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RESEARCH
Publications
Wittich, C. E., & Yáñez González, G. (2023). Leveraging Social Media Data for Emergency Preparedness and Response. National Academies of Sciences, Engineering, and Medicine. Washington, DC: The National Academies Press. https://doi.org/10.17226/27151
Wang, C., Moore, K.J., Yáñez González, G., Wittich, C.E. (2022). Energy isolation in a multi-floor nonlinear structure under harmonic excitation. Nonlinear Dynamics. https://doi.org/10.1007/s11071-022-07744-5
Publications
Conference Proceedings
Conferece Proceedings
Poster Presentations
Poster Presentations
Oral Presentations
Yáñez González, G., Wittich, C.E. (2023). Barriers to Social Media Use for Disasters within Transportation. ASCE INSPIRE 2023, Arlington, VA(September 14, 2022)
Yáñez González, G., Ahmadi, S.Y., Lather, J.I., Wittich, C.E. (2022). Planning for Riverine/Inland Waterway Flood Disaster Resilience: Current and Future Trends. Nebraska Annual Planning Conference, Lincoln, NE (September 14, 2022)
Yáñez González, G., Reyes Cruz, C.A., Villa Zapata, L.M., Rodríguez-Román, D., del Valle González, C.A., Colucci-Ríos, B., & Figueroa-Medina, A.M. (2021). Enhancing Equity and Access in Transportation Services. UPRM Research Fair, Mayagüez, P.R. (March 12, 2021)
Oral Presentations
Wittich Research Group
University of Nebraska - Lincoln
About:
The lab focuses on the analysis and design of structures to improve infrastructure and community resilience to natural hazards and extreme events. In this effort, we employ remote sensing and field testing, full-scale experimental testing, and analytical and predictive modeling.
Graduate Research Assistant
August 2021 - Present
NCHRP Synthesis 20-05/Topic 53-03
August 2022 - November 2023
Principal Investigators:
Christine E. Wittich
cwittich@unl.edu
Overview:
Emergencies are often unpredictable, unique, and hard to track. Timely response to emergencies on highways is a critical issue faced by state departments of transportation (DOTs). State DOTs have been developing emergency response protocols and procedures. The popularity of social media provides an unprecedented opportunity for state DOTs to obtain information. Social media data provides vital spatial and temporal information before, during, and after emergencies and the use of social media is popular in emergency management for its high accessibility and effectiveness. Many DOTs have undergone technology renovations and have started using social media data for rapid emergency situation detection, damage assessment, and evacuation plan propagation. However, there is a lack of documentation of DOT practices of using social media and corresponding data under different emergency scenarios.
The objective of this synthesis is to document current state DOT practices that leverage social media data for emergency preparedness, response, and recovery.
Outcomes:
"NCHRP Synthesis 610: Leveraging Social Media Data for Emergency Preparedness and Response" - (Publication)
Authors:
Christine E. Wittich
cwittich@unl.edu
Gabriela Yáñez González
gyanezgonzalez2@huskers.unl.edu
Abstract:
Most state departments of transportation (DOTs) use social media to broadcast information and monitor emergencies, but few rely heavily on social media data. The most common barriers to using social media for emergencies are personnel availability and training, privacy issues, and data reliability.
NCHRP Synthesis 610: Leveraging Social Media Data for Emergency Preparedness and Response, from TRB's National Cooperative Highway Research Program, documents state DOT practices that leverage social media data for emergency preparedness, response, and recovery.
"Barriers to Social Media use for Disasters within Transportation" - (Conference Proceeding & Presentation)
Authors:
Christine E. Wittich
cwittich@unl.edu
Gabriela Yáñez González
gyanezgonzalez2@huskers.unl.edu
Abstract:
Transportation is a critical sector within emergency and disaster response; and, timely communication is necessary. Social media has gained popularity as both a means to communicate and to gather information during emergencies, however it is rarely leveraged to any significant extent within transportation. Given that some social media platforms have billions of active monthly users, the issue of barriers to leveraging this data source within transportation has been raised and is addressed within this study. The primary objective is to identify the most significant barriers to social media use before, during, and after emergencies within transportation agencies. A state-of-the-art review of social media use within transportation is first presented, in which situational awareness, natural language processing, and image-based machine learning techniques have emerged with transportation applications. This is supplemented by a survey that was conducted of transportation officials to gather insight into current use of social media data and perceived barriers within emergency contexts. Policies, information accessibility, and a lack of specialized tools emerge as common threads that prevent further implementation of social media within transportation. Recommendations are provided for further research to expedite implementation and to positively impact disaster response.
Examining the Vulnerability and Recovery of Small Farms to Natural Hazards
and the Impacts to Rural Community Resilience
November 2021 - Present
Principal Investigators:
Christine E. Wittich
cwittich@unl.edu
Maria K. Watson
maria.watson@ufl.edu
Rebekka Dudensing
rebekka.dudensing@ag.tamu.edu
Overview:
This Disaster Resilience Research Grant (DRRG) project contributes to the advancement of national health, prosperity and welfare by creating new knowledge on disaster recovery for the agricultural industry. Despite the criticality of agriculture to U.S. and global food production, the lack of economic diversity and prevalence of agriculture in many rural areas, particularly in the central US, is theorized to be a major contributor to low disaster resilience. Resilience is a complex function of socio-economic dimensions and the built environment; and the population, economics, and physical infrastructure that comprise agricultural regions are distinct from the urban and suburban areas that are the common focus of most disaster and community resilience studies. This research generates a fundamental understanding of the resilience of farms and agriculture-prevalent rural communities in the face of severe windstorms, which will be of broad benefit to society and to national resilience. The research team will identify, evaluate, and recommend actions to enhance resilience of farms. To maximize the impact of these findings, the team will partner with the Extension Disaster Education Network for outreach and technology transfer. Implementation of these mitigation measures can transform the disaster resilience of rural and agricultural regions, safeguarding the lives of citizens, regional and national economies, and global food production.
The long-term goal of this research is to enhance the resilience of rural communities to natural hazards, which requires state-of-the-art research on the infrastructure that support farm operations, the recovery processes of individual farms, and the interaction of individual farms within the regional agricultural economy. As a first step towards enhancing rural resilience, the interdisciplinary team will conduct a three-year research project carefully tracking resilience from hazards to structures to farms to communities. The project is characterized by two primary goals. The first goal is to generate a fundamental understanding of the vulnerability and recovery of farms following windstorms through longitudinal reconnaissance of impacted agricultural communities, surveys of impacted farmers, correlation of hazard intensity with infrastructure response, and the examination of the linkages between recovery of individual infrastructure with farm-level recovery. The second goal is to develop and validate a risk-informed resilience assessment framework comprised of a farm-level resilience factors and community-level economic analyses to support decisions on business continuity and infrastructure investment for farms and the broader agriculture-prevalent rural communities.
Outcomes:
"Perceptions and Reality: Investigating the Effectiveness of Structural Enhancements in Steel Grain Bins against Wind Loads" - (Conference Proceeding)
Authors:
Christine E. Wittich
cwittich@unl.edu
Gabriela Yáñez González
gyanezgonzalez2@huskers.unl.edu
Andrew Ruder
aruder2@huskers.unl.edu
Maria K. Watson
maria.watson@ufl.edu
Rebekka Dudensing
rebekka.dudensing@ag.tamu.edu
Dean McCorkle
dean.mccorkle@ag.tamu.edu
Steven Klose
steven.klose@ag.tamu.edu
Abstract:
The August 2020 Iowa derecho resulted in significant damage to thousands of steel grain bins, impacting a significant portion of central and eastern Iowan farms. In the years since this storm, storage capacity of most farms has been regained and steel grain bins have been rebuilt. While the majority of bins have been replaced with bins of similar capacity, the structural design and construction varies between the original and replacement bins, which may or may not improve wind performance. This study aims to investigate trends in both perceived and realized structural enhancements of steel grain bins subjected to wind loads. The effect of various structural designs is evaluated using empirical fragility relationships, which yield a probability of damage given wind speed, as derived using damage observations in Iowa following the August 2020 storm and supplemented via finite element analysis. Trends associated with bin replacement are determined by longitudinal reconnaissance, in which follow-up trips to Iowa documented the construction of replaced bins. A structural enhancement factor is then computed for each bin replacement that indicates the increase (or decrease) in expected wind speed to cause damage. Perceptions regarding structural enhancement were gathered through a survey of farmers, in which farmers could indicate whether bins were/will be replaced with an upgraded construction. The perceptions from the survey and actual structural enhancement factor are analyzed and compared to determine if there is a correlation between farmers’ perceptions of structural enhancements with actual wind resistance.
Wittich Research Group
National Institute for Congestion Reduction
University of Puerto Rico - Mayagüez
Mission:
The National Institute for Congestion Reduction (NICR) will emerge as a national leader in providing multimodal congestion reduction strategies through real-world deployments that leverage advances in technology, big data science and innovative transportation options to optimize the efficiency and reliability of the transportation system for all users. Our efficient and effective delivery of an integrated research, education, workforce development and technology transfer program will be a model for the nation.
Enhancing Equity and Access for e-scooters
Research Assistant
March 2020 - May 2021
Principal Investigators:
Benjamín Colucci Ríos
benjamin.colucci1@upr.edu
Project Abstract:
This project will explore the distribution of new micro-mobility services, as well as the factors driving the demand, or lack thereof, of these services in heterogeneous neighborhoods. This project will focus on electric scooter (e-scooter) sharing services. The first e-scooter shared service in Puerto Rico was established by a private operator in the city of Mayaguez in August 2019. E-scooter services were subsequently established by the same company in the cities of San Germán and Río Piedras. The three cities differ in demographics, urban form, and topography. The main common characteristic of the three e-scooter service areas is the presence of a major university campus. E-scooter data will be collected from in-person surveys and from observational studies. Operational data will be requested to the e-scooter service provider to complement the research data collection efforts. Based on these data, statistical and machine learning-based models of the demand for this type of mobility service will be developed. The data and models can be used to: i) examine the equity implications of the e-scooter services implemented in Puerto Rico; ii) analyze the possible congestion reduction impacts of e-scooter shared systems; iii) and develop methods to optimize the spatiotemporal distribution of e-scooters based on equity considerations and congestion reduction potential.
Outcomes:
"User Characteristics, Spatiotemporal Patterns, and Spatial Access in a Dockless E-Scooter Service in Mayagüez, Puerto Rico" - (Conference Proceeding)
Authors:
Andrés G. Camacho Bonet
andres.camacho@upr.edu
Fernando A. Acosta Pérez
fernando.acosta@upr.edu
Lina M. Villa Zapata
lina.zapata@upr.edu
Gabriela Yáñez González
gabriela.yanez@upr.edu
Abstract:
​
A case study is presented of a dockless e-scooter system in Mayagüez, Puerto Rico. In addition to documenting the micromobility experience of a city within the understudied Latin American context, the study proposes methods to quantify spatial access to dockless micromobility systems, as well as to measure the regularity of their spatiotemporal patterns. Spatial access is measured in terms of network-level proximity to the e-scooter fleet, and the regularity of spatiotemporal patterns is assessed using a similarity measure approach. The study also includes an analysis of the attributes and opinions of users and nonusers of the e-scooter service, as collected through an online survey.
The analysis suggests that, like in other cities, users of e-scooters tend to be male and young, and that nonusers tend to not participate in the system because of its cost and perceived safety concerns. Most users are students at the University of Puerto Rico at Mayagüez (UPRM). Trips starting or ending at UPRM accounted for 78% of all e-scooter trips, which are also closely linked to neighborhoods with a high concentration of UPRM students. In terms of temporal patterns, most e-scooter trips occur during weekdays, and the demand for the service drops significantly when UPRM is not in session. The service’s daily peak period occurs between 8:00 AM and 1:00 PM. The application of the proposed methods is illustrated using data from the considered system.
"Travel patterns and spatial access in a dockless e-scooter service in Puerto Rico" - (Publication)
Authors:
Daniel Rodriguez-Roman
daniel.rodriguez6@upr.edu
Alberto M. Figueroa Medina
alberto.figueroa3@upr.edu
Benjamín Colucci Ríos
benjamin.colucci1@upr.edu
Carlos A. Del Valle González
carlosa.delvallegonzalez@upr.edu
Andrés G. Camacho Bonet
andres.camacho@upr.edu
Fernando A. Acosta Pérez
fernando.acosta@upr.edu
Gabriela Yáñez González
gabriela.yanez@upr.edu
Abstract:
A case study is presented of a dockless e-scooter rental service (MDES) in Mayagüez, Puerto Rico, a city within the understudied Latin American region. MDES trip data were used to examine the spatiotemporal patterns of e-scooter trips in the city, while survey data was collected to explore the characteristics of MDES users and nonusers, as well as the factors that influenced their demand for MDES trips. In addition, this study proposes a network-based approach to evaluate the level of spatial access and equity of dockless micromobility vehicles. Three measures are proposed to quantify spatial access at the level of locations (i.e., network nodes) as a function of the distance of each location to each e-scooter. As illustrated in the MDES case, the measures can be used to examine spatial access at the service area-, zonal-, building-, and point-levels, and to compute spatial access inequality indexes.
The survey analysis indicated that female respondents were 1.7 times less likely to use MDES than males and that young populations groups more than two times more likely to be MDES users than the reference population group. The survey analysis also revealed that cost, safety, and built environment concerns were the main barriers to the use of MDES, and that the primary reasons for using the service were parking problems and traffic congestion. Among other things, the spatiotemporal analysis of the MDES trips data shows that 78% of trips started and ended at the city’s main university, that a significant proportion of trips were linked to neighborhoods with a high concentration of university students, and that demand for e-scooter trips dropped drastically when the university was not in session. The analysis of the MDES data revealed marked differences in spatial access within and between zones in the study region. On average, daily Atkinson inequality index values, which were computed using the proposed spatial access indicators, ranged from 0.45 to 0.80, which points to an unequal spatial access to MDES. The paper closes by discussing applications of the proposed methodology for the design of policies aimed at minimizing inequality in spatial access to dockless micromobility services.
"Enhancing Equity and Access in Transportation Services" - (Oral Presentation)
Gallery:
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NICR
2019 Summer Research Program
University of Nebraska - Lincoln
REU: Sustainability of Horizontal Civil Networks in Rural Areas
Research Affiliate
May 2019 - Aug 2019
About Program:
Rural areas, which contain approximately 20% of the US population and over 90% of the land area in the United States, are fundamental to human well-being in both rural and urban areas. Rural areas provide resources such as the infrastructure for U.S. food and bioenergy production as well as the transportation infrastructure from inland urban centers to ports. Rural areas are characterized by agricultural- and natural resource-based economics, stable or declining populations with low population densities, and “farm-to-market” localized transportation patterns, and these characteristics necessitate new technologies and approaches for civil infrastructure. Despite the differences between rural and urban regions, little attention is paid to the unique challenges and opportunities for sustainability in rural areas.
In this ten-week summer research program, students will work with faculty in the Department of Civil and Environmental Engineering to conduct research and will contribute new knowledge to improve our understanding of how best to address the challenges facing rural environments. Through collaboration with industry partners, students will also be given opportunities to learn how infrastructure challenges are currently being addressed by the civil and environmental engineering industry. In addition, this program offers a series of communication development opportunities including preparation of a conference paper, informal presentations to their peers, formal poster presentations, and outreach to high school students.
Resilience of Agricultural Infrastructure and Rural Communities to Natural Hazards
Principal Investigator:
Significance:
Despite the criticality of the agricultural industry to both U.S. and global sustainable food production, the resulting lack of economic diversity in most rural areas is theorized to be a major contributor to the low resilience of rural communities to natural hazards, including earthquakes and windstorms. While resilience is a function of many socioeconomic and organizational factors, the disaster response of the built environment is a critical aspect that cannot be ignored. In many rural areas, critical infrastructure includes vital agricultural support and production systems, such steel grain bins. However, these structures are not typically design to consistent standards and have been observed to perform poorly in recent severe windstorms. This research aims to generate a fundamental understanding of the performance of steel grin bins during extreme windstorms to enhance rural resilience to natural hazards.
Outcomes:
"Resilience of Rural Infrastructure: Shake Table Tests of Scaled Silos" - (Poster Presentation)
Authors:
Christine E. Wittich
cwittich@unl.edu
Gabriela Yáñez González
gyanezgonzalez2@huskers.unl.edu
M. Khalid Saifullah
khalidsaif@huskers.unl.edu
Abstract:
In the United States, communities with a high agricultural economy, depend on unique infrastructures that complies with their needs. Earthquakes can cause great damage to these infrastructures and makes the recovery of the community harder. Some structures that support these communities do not follow typical engineering design and analysis methods. This paper examines the probabilistic response of steel storage silos to past earthquakes. Steel storage silos are thin-walled structures and are subject to buckling when excited by earthquake motions; however, many existing silos are also characterized by weak or no anchorage at the base, which enable the silo to uplift at its base and enter a rocking mode of response. Hence, an experimental campaign of shake table tests has been undertaken in order to probabilistically gauge the impact of material and geometric properties on the rocking response. A total of nine scaled structures, representative of a storage silo, were constructed for testing and were subjected to over 100 individual earthquake motions on the shake table to observe their response. Analysis of these results indicate that certain combinations of geometric and material properties yield systems likely to respond in pure rocking mode, while others result in combination modes and in overturning.
2019 Conference for Undergraduate Women in Physical Sciences (WoPhyS) at the University of Nebraska - Lincoln.
2019 UNL Summer Research Symposium
Gallery:
2019 SRP
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