Theses_Highlights

Student Highlights

Measuring and Modeling Potable Water Demand in the U.S. Virgin Islands

ENS Andrew Borgdorff, USN (June 2020) [Read]

In September 2017, Category-5 Hurricanes Irma and Maria struck the U.S. Virgin Islands (USVI) within a two-week period and collectively devastated homes, businesses, and infrastructure throughout the Territory. In particular, damage to water pipes, cisterns, and reverse osmosis (RO) facilities made it difficult or impossible for residents of the USVI to get access to clean water. In order to be better prepared to supply fresh water, in the event of a natural disaster, we first have to understand water demands in the USVI.

This thesis focuses on modeling demand for water on the island considering multiple different demand sources. The USVI Water and Power Authority (WAPA) is the primary producer of RO water on the islands and services primary water pipelines and water truck delivery companies. However, there also private parties and businesses that produce their own water like hotels that sometimes compete with WAPA for water sales to water trucks. In addition, there are households with a WAPA pipe connection, a cistern, or both. These customers may have access to WAPA, rainwater catchment, and purchases from water trucks to fill the cisterns. A model for the combination of customers in the USVI does not exist. The lack of a demand model means there is no way to estimate who will have fresh water when parts of the system (e.g., WAPA pipelines) are in degraded service conditions. Moreover, without a demand model there is no means to coordinate water distribution across the multiple Territorial stakeholders when future disaster strikes. This model will offer realistic estimates of water demands, including how much each customer is using and where they are accessing their water from (e.g., cistern-rain, cistern-truck, cistern-WAPA, WAPA, or otherwise). Moreover, this model will provide a snapshot of water supplies, including tank levels within the WAPA system, cistern levels at customer residences, water truck purchases from WAPA and other sources, and current water production across the islands.

This work is in support of Federal Emergency Management Agency (FEMA) response and recovery activities and part of a broader FEMA-funded effort by the Naval Postgraduate School (NPS) and Department of Energy (DOE) to assess and improve the resilience of interdependent USVI lifeline infrastructure systems. This thesis additionally supports several other complementary efforts with the University of the Virgin Islands (UVI) to develop a next-generation Hazard Mitigation and Resilience Plan for the Territory.

 

Analyzing Cell Phone Network Resilience in the U.S. Virgin Islands

Capt William Wine, USMC (June 2020) [Read]

In September 2017, two Category-5 hurricanes struck the U.S. Virgin Islands (USVI) within a two-week period and collectively devastated homes, businesses, and infrastructure throughout the Territory. The AT&T and Sprint towers and antennas received significant damage which exposed many vulnerabilities in the communications capabilities of the Territory. The hurricanes showed that towers, antennas, and fiber lines are vulnerable to high winds, copper wire is susceptible to flooding, all cellular network structures are dependent on the power grid, and backup generators depend on unpredictable fuel deliveries to operate. Cellular service is also dependent on the local internet service provider (ISP) for backhaul services that are not always owned by the cellular service provider and are also dependent on the power grid. In addition to loss of communications, the lack of cell phone service in many areas of the islands resulted in additional heavy traffic conditions because of the number of people who weretrying to get to a location where service was stable enough for phone calls to family and friends.

This thesis will assess cell phone service coverage in the USVI during normal and disaster situations. This work will map the current wireless infrastructure on the island of St. Croix (STX), develop models for cell phone coverage and reception, and use those models to test coverage and access during “what if?” situations that simulate realistic worst-case situations like hurricane disasters. Together, the data curation, model development, and analysis will support the design and operation of resilient communications networks in the USVI.

Our model will utilize previous thesis work on wireless network resilience and use a defender-attacker- defender model to analyze the impacts of threats on network coverage. The model will also leverage current thesis work on the power grid and ISP networks because the cellular network is dependent on both of these systems and the status of those systems will sometimes dictate the status of the cellular network. The final output of this thesis will be recommendations on how to maintain cell phone service with those losses or build in redundancies to minimize losses.

Synthetic Network Generation and Vulnerability Analysis of Internet Infrastructure Systems in the U.S. Virgin Islands

Major Brian Moeller, USMC (2020) [Read Executive Summary]

In September 2017, Category-5 Hurricanes Irma and Maria struck the U.S. Virgin Islands (USVI) within a two-week period and collectively devastated homes, businesses, and infrastructure throughout the Territory. In particular, the loss of hardline telecommunications infrastructure during the storms significantly impacted emergency response and recovery operations. The operation and management of the Territory’s telecommunication network is, unfortunately, spread out over a mixture of public and private entities who have considerable economic incentive to hide or obscure information about their systems. As a result, there is no organization or community with operational view of the USVI telecommunication system which makes vulnerability analyses of the system challenging.

This thesis focuses on overcoming these challenges by creating a synthetic model of the USVI hardline internet backbone that facilitates operational resiliency analysis. Synthetic networks embed the characteristics and function of the actual system for analysis by incorporating generic or functionalized information to avoid issues with proprietary information. The goal of this thesis is to:

  • Produce a curated geospatial data set that aggregates public and private telecommunications systems data into a single repository for modeling and analysis.

  • Develop a synthetic network model that produces realistic internet network maps.

  • Conduct network and vulnerability analysis on those models.

    This work is in support of Federal Emergency Management Agency (FEMA) response and recovery activities and part of a broader FEMA-funded effort by the Naval Postgraduate School (NPS) to assess and improve the resilience of interdependent USVI lifeline infrastructure systems [1]. This thesis additionally supports several other complementary efforts with the University of the Virgin Islands (UVI) to develop a next-generation Hazard Mitigation and Resilience Plan for the Territory.

 

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