Underground infrastructure is a critical part of the essential utility services provided to society and the backbone of modern civilization. However, now more than ever before, the disastrous events of a striking underground utilities cost billions of dollars each year in societal damages. Advanced technology and sophisticated visualization techniques such as augmented reality (AR) now play a significant role in mitigating such devastating consequences. Therefore, it is vitally important to coordinate resources, share information, and ensure efficient communication between construction personnel and utility owners. Besides, geographic information systems (GIS) provide a solution for interoperability in the construction industry. Applying such technologies in the field of underground construction requires accurate and up-to-date information. However, there is currently limited research that has integrated AR and GIS and evaluated the effectiveness and usability of the combination in this domain. The main objective of this research was to develop an integrated AR-GIS for mapping and capturing underground utilities using a mobile device. To achieve these objectives, a design research approach utilized to develop and evaluate a mobile extended-reality (XR-GIS) application. This research has produced an efficient solution for data collection and sharing among stakeholders in the underground construction industry. The main challenge in creating a reliable and adaptive outdoor AR system is the accurate registration of virtual objects in the real world. Due to the limited accuracy of smartphones, this study used an external Global Positioning System (GPS) devices to reduce positional error. The primary motivation behind this research is to make the construction industry more aware of the benefits of leveraging AR to prevent utility strikes and enhance public safety.
This dissertation fills the gap in the knowledge regarding applying Augmented Reality (AR) in the underground infrastructure mapping. This study’s three research objectives are:
(1) Identify the challenges and barriers facing the underground construction industry when applying AR.
(2) Develop an integrated AR-GIS for mapping and capturing underground utilities using a mobile device.
(3) Evaluate the horizontal accuracy of the captured data used by the AR phone application XR-GIS that has been developed by the author.
Aboveground nitrogen content showed a maximum in 2011, decreasing until 2015, increasing again until 2017, and dropping in 2018; belowground nitrogen content showed the opposite temporal trend. Because foliar nitrogen content was assumed to be relatively constant over time, my data suggested that belowground nitrogen content increased between 2011 and 2015 and decreased between 2015 and 2017. Aboveground nitrogen content underwent fluctuations due to fluctuations in aboveground biomass. This occurred due to ‘thatching’, or events of widespread toppling of large macrophyte stands. The ratio of aboveground to belowground biomass can vary widely in the same CTW. My findings suggested that managing senesced aboveground plant material in CTWs may optimize the CTW’s ability to sequester nitrogen. Further research is needed to determine the best management strategies, as well as its possible implications.
